I don´t collect them with a certain strategy. The radios find their place here by coincidence because I can´t help taking care of the worn, non-working sets and give them new life and a good home. The fun part is troubleshooting and tuning-up as well as finding the parts needed in my junkbox. The restored radios which have no given place in my rooms are presently piled in the wardrobe or the garage.
Antique radios don't appeal to me as much as those from the 1950´s. People who fancy old things often have an emotional relation to them, perhaps as memories of their childhood. Magic eye, gold-gleaming speaker cloth, lots of geographical names on the well-lit dial glass, brass edgings, white pushbuttons, everything enclosed with polished hardwood, it was that kind of radio that I had a yearning for when I was a boy. The manufacturers´ brochures boasted with the number of tubes, the more the better of course. As I had started with dx-ing I preferred radios with more than one shortwave band and on the 80 m band were AM-transmissions from Swedish radio amateurs. In spite of all this my first radio turned out to be an old set.
A Marconiphone 853 alias H.M.V. 657 from 1938 was bought at an auction for 5 kr (my weekly pocket money) in the late fifties. It has LW-, MW- and two SW-bands (13-30 and 30-90 m), tuned RF-stage, magic eye and motor-driven tuning capacitor with buttons for eight preset favourite stations on LW and MW. A circular logging scale facilitates tuning and it is driven together with the dial rod by a thin wire so there is no need to change a cord. The band indicator is driven by a chain from the switch. The dial.
The tubes are Marconi´s equivalents to American octal tubes: KTW63 (6K7G), X65 (6K8G), KTW63 (6K7G), DH63 (6Q7G), KT63 (6F6G), Y63 (6E5), U50 (5Y3G). The properly sized loudspeaker gives a rich sound and this was a great receiver for its time, the price in England was 39 guineas and in Sweden 460 kr. I have replaced electrolytic and paper capacitors but the tubes are the original ones except the magic eye which is now EM34. Because I don't care for museum condition but want to use my sets, I have put a PCIM177 frequency readout behind the glass, zener-stabilized the voltage to the oscillator and replaced the tone control with an antenna switch. I can select either the original high-impedance antenna connector or a 50-ohm connector coupled to a grounded-gate FET as impedance transformer. The sensitivity using the FET is high, 3 uV for 50 mW output with 30 % modulation. An S-meter has been placed behind the glass to the left of the magic eye (not visible on the the photo).
In the beginning of the 1960´s I mostly listened to the pirate station Radio Nord with it, but later in the 1980´s I used the radio for renewed dx-ing during a couple of years. It was then I added the digital display. The latest improvement is a change of the IF-tube KTW63 to 10E/278, it is the same age and looks exactly the same but has more than double gain. A disadvantage is that the mixer noise is rather loud but the improved sensitivity on SW makes the change worth while. The Internet is a remarkable source of odd information, I found service information to this old radio at www.radiomanuals.infoOne year later I bought a Marconiphone 563 radiogram, from the same year as the radio above. The price paid at the flea market was 10 kr (two weeks´ pocket money), it was a heavy piece of furniture on wheels that I rolled in the street and it just fitted inside the lift. After changing the rectifier tube I could finally enjoy listening to my father´s 78-records with a proper pickup and electrical amplification. The favourite record was "Lazy River" with The Mills Brothers. With a 10 W push-pull amplifier and two big loudspeakers the sound was as good as it could be when the radio was made and it contained a tuned RF-stage, two IF-stages with variable bandwidth and three SW-bands between 5-107 m. I sometimes heard the police radio on 40 MHz. The radiogram contained an EMI record changer for eight records and it originally cost 67 guineas in England. How sad that I scrapped it when I moved to a flat of my own. It was a premium model but it is complicated to be fond of radiograms.
When I started with amateur radio it was with telegraphy and I needed a beat oscillator. As such I borrowed the family radio which besides LW, MW and UKV also had two SW-bands, 16-55 and 55-180 m, and whose tuning could be chosen so that the local oscillator interfered with the Marconi set to give the necessary beat note. This Swedish Kungsradio 755 UKV from Göteborg, of 1955 vintage, became my gateway to the dx-hobby. It was in daily use until the year of 2002 and still works reliably after changing of tubes, capacitors and dial lamps.
The tubes are ECC85, ECH81, EF85, EABC80, EL84, EM34. Sensitivity is 4-8 uV on frequencies below 5 MHz, on the highest frequency SW-band varying between 6-20 uV. There is no ferrite antenna and the tone control is a simple treble suppressor. The sound is mediocre, lacks deep bass and the loudspeaker is half-hidden behind the dial glass. The rotary band switch was out of fashion when this set was made in 1957, most radios had pushbuttons. The price on sale was 300 kr, reduced because the radio was old stock.
A Swedish Luxor Tenor 4192W from 1962 was found at a flea market for 75 kr, the original price was 335 kr. Three tubes, two capacitors a dial lamp and a fuse had to be replaced and the selenium rectifier had so high voltage drop that I put silicon diodes in parallel with it. The SW-band covers 6-18 MHz and the FM-band 87-101 MHz. The single tone control affects both bass and treble. There is a ferrite antenna for MW and LW.
The tubes are ECC85, ECH81, EBF89, ECC82, EL84, EM84. Notice the symbol for LUFOR (air defence warning) on LW, characteristic of the time, where the Swedes were supposed to listen for important messages in times of stress and calamity. The dial has channel numbers on MW and LW, which I have seen only on Swedish Luxor and Radiola radios.
Another Tenor-chassis is installed in a home-made cabinet measuring 37x17 cm because the original cabinet was found broken in the 1960´s and the rear cover was missing. I use a separate speaker with it, giving better sound quality than the built-in oval loudspeaker can produce.
This Swedish Luxor Populär 3095W was made in 1956 in Motala with original price 427 kr and recently found at a flea market for 75 kr. It has LW, MW, SW and the FM-band extends to 108 MHz, laudable forethought or just a cut-price on Telefunken´s converters for the USA market. The tubes are ECC85, ECH81, EF85, EABC80, EL84, EM80, EZ80. The tone control is a four-position switch and the radio comprises two loudspeakers, a 6-inch full range and an electrostatic tweeter. The ferrite rod which works on MW only is adjustable from the rear. A short piece of wire inside the cabinet works on LW and SW. The SW-band 19-52 m has fine adjustment by means of the UKV-knob with the cursor initially placed on 97 MHz. White letter and numbers had fallen like autumn leaves for the indicating rod so I sprayed clear lacquer on the glass to keep the remaining ones fixed. Three tubes and a number of paper capacitors have been replaced, otherwise the radio was in good shape. Although it hasn´t got remarkable sound it occupies a position in the bookcase above the Luxor Tenor.
Luxor Luxorita from 1954 belongs to the smallest mains-operated radios, something for one who needed a set in the kitchen or the summer cottage. Yet it has two SW-bands, 17-51 m and 75-200 m, so it received both amateurs and fishing boats. It is a variant of a model which had been available since the late 1940´s. On the back there is a sliding switch for treble cut which is not necessary, the 6-inch speaker gives a balanced sound although without deep bass and the output power is just over one watt. There is no switch position for record player, one has to disconnect the antenna.
The tubes are 6BE6, 6BA6, 6AV6, 6AQ5, 6X4, all Swedish-made SER-tubes. The rectifier is a halfwave circuit, unusual in an AC set but it probably saved some money on the transformer. I changed to a bridge rectifier by adding two silicon diodes and got higher voltage with less hum. The radio seems to be little used, I replaced a tube, a resistor, an electrolytic capacitor and I added a mains fuse. The transformer has seen some damage so I must use the 250 V winding. Therefore I have added a small 18 V-transformer inside to give the radio correct voltage. I also added rubber strips between cabinet and chassis to get rid of microphonics. The radio was a gift.
Philips B2X63U "Philetta" made in the Netherlands in 1956 became very popular as supplementary radio after the introduction of a second radio channel on the UKV-band because it was cheap and needed little space and there was often a bigger radio in the household. With improved housing conditions it also found its way into the teenage room. It is an AC/DC-set, both because there were many places with DC-mains even in the 1960´s and a transformer would make the radio bigger and more expensive. In spite of its compact size 19x17 cm the reception capability is as good as that of bigger radios, there are just as many tubes and circuits and the audio power (1.5 W at the onset of clipping) is enough, but everything is compressed and the components are placed in layers below the chassis. The few capacitors that need to be replaced are easily reached, however. The cabinet is made of bakelite and on the front there is a plastic piece with dial and vertical ribbons in front of the loudspeaker net. It is lighted from beneath by two lamps and it gives the radio a pleasant appearance in a dark room. For MW and LW there is a built-in ferrite rod but for UKV an external antenna is required. Even a SW-band is included but limited to 23-51 m and it has no other markings than the four broadcast segments. There are separate knobs for UKV- and AM-bands and behind the loudness type of volume control there is a treble-cutting tone control.
The tubes are UCC85, UCH81, UF89, UABC80, UL84, UY85. I replaced the mixer tube and four capacitors, put in a new temperature fuse and increased the value of the run down filter capacitor with 33 uF in parallel. The SW-band needed a change of two capacitors in the antenna circuit for full sensitivity and after that it measures 4 uV for 50 mW output power at 10 MHz. With regard to input power to the UL84 the AF output should be twice as high, the low efficiency probably depends on too low inductance in the tiny output transformer, but with connection to external loudspeaker the sound is rich enough. I did not expect this sort of radio to end up in my collection but it is better than I had anticipated and it was free in the scrap container.
Found at a scrap-yard was this Swedish Centrum 261 from 1958, it was made by Gylling & Co in Stockholm and the original price was 495 kr. Beside LW, MW and UKV it has two SW-bands, 18-50 and 55-185 m. The UKV-knob gives bandspread on the high frequency SW-band. The radio has "3D-sound" using three loudspeakers, two of them for midrange and treble on the sides which can be switched off with one button and the red button turns off all three. The tone control affects treble while four small buttons select fixed registers, Orchestra-Opera-Solo-Jazz. I have replaced electrolytic and some paper capacitors, dial lamps and three of the tubes.
The tubes are ECC85, ECH81, EF89, EABC80, EL84, EM84. The radio lacks a ferrite antenna for LW and MW but uses the built-in UKV-dipole for them. It is surprisingly sensitive having no RF-stage, 5-10 uV on SW. It is unusual to find names of Swedish stations on the FM-band dial but here they are.
I couldn´t help buying this Blaupunkt Granada 2626 from 1959 at the flea market for 200 kr. It worked from the beginning and even the EM84 has its colour left. The tubes are ECC85, ECH81, EF89, EABC80, EL84, EM84. There are two SW-bands, 17-50 and 60-180 m, and the UKV-knob gives bandspread on the high frequency SW-band. The sensitivity on the AM-bands is 10 uV. The register buttons HiFi, Solo and Sonor work beside the separate controls for bass and treble. The main speaker is on the front and two smaller ones are on the sides. It is similar to the Centrum above but has better sound, built-in ferrite antenna for LW and MW adjustable from the rear, and the built-in UKV-dipole works on SW. The original price was 565 kr, typical for a German medium-priced radio of good quality.
Grundig 3097S from 1958 is similar to the Blaupunkt above. The tubes are ECC85, ECH81, EF89, EABC80, EL84, EM34. The original price was 565 kr but my winning auction bid was 2 kr. The radio has three loudspeakers with two on the sides. The tone control comprises four knobs, the outer ones are conventional bass and treble controls while those in the middle activate traps on 750 and 3000 Hz. In addition to them are pushbuttons for Speech and Music both of which deactivate the traps, Speech lowers the bass response and Music lifts the bass but keeps the high tones at an intermediate level. The volume control has a loudness curve. A fixed ferrite rod, switchable from the front, works mainly on MW since on LW it is just a fraction of the total inductance. I replaced four tubes including the magic eye, one bad capacitor and two burnt resistors. On SW there were no trimming capacitors in the tuned circuits so I installed two instead of the fixed ones and that improved both calibration and sensitivity (8 uV). This well-sounding radio in mint condition is an ornament on the chest of drawers and another set which is a gift sits on the spare shelf.
Grundig 97S from 1959, original price 335 kr, I couldn't resist such a cute little radio in mint condition for the bedside table so I paid 150 kr for it. The brown plastic case forms a nice contrast to the bright front with its white knobs and pushbuttons. There are separate knobs for AM-FM, six tubes and a selenium rectifier, ferrite antenna, tone control and buttons for Music or Speech. The tubes are ECC85, ECH81, EF89, EABC80, EL84, EM84.
I had to replace the "the magic band" EM84, a resistor and lubricate the UKV tuning capacitor which was stuck, but there was no need for contact spray to make it play. The sound is good enough in spite of the small size and with a short antenna wire along the cornice the radio receives SW stations well with careful treatment of the tuning knob..
Grundig 5080S from 1956-57 is a premium model of tabletop radio which I found in a second-hand shop for 200 kr, a big-sized cabinet 68 cm wide and 43 cm high. The original price was 795 kr. It has a five-stage tone control, "Wunschklang-Register", a push-pull amplifier with 8 W power at the onset of clipping and five loudspeakers of which two are electrostatic tweeters. Two knobs are conventional bass and treble controls while those in the middle activate traps on 750, 1800 and 4000 Hz. With the controls adjusted for a flat response the -3 dB limits are 50 Hz and 7 kHz but they are extended to 35 Hz and 13 kHz respectively if one reduces the intermediate frequencies. The 4000 Hz control also affects two IF-transformers for variable bandwidth 4-12 kHz in the two IF-stages.
The tubes are ECC85, ECH81, EF89, EF80, EAA91, ECC81, EBC41, EL84, EL84, EM34. A ferrite antenna for MW can be rotated from the front with a position indicator and external antenna is switched in with a push-button. The ferrite rod only works partly on LW where it is in series with the main inductance. The sensitivity on SW is 6 uV for 50 mW output measured with a 200 ohm signal source.
All tubes except EAA91 and EM34 are replaced as well as the dial lamps, the magic eye has got better brightness with its plate voltage raised with 65 V, a temporary solution due to lack of a new tube. All moving parts were lubricated to make the radio work and the UKV-tuning mechanism needed some metal washers inserted for increased spring tension. The electrostatic tweeters were out of order, they consist of a plastic sheet with its outer side copper-plated and its inner side pressed against an earthed metal grid. The copper side has 230 V DC on it together with the AC voltage. I made one tweeter work after cleaning oxide from the connecting piece of metal pressed against the copper sheet. The other tweeter is replaced with a conventional one wired through a 4.7 uF capacitor.
The sound is impressive with deep bass which makes playing of gramophone records with a crystal pickup enjoyable. There is also a connection for tape recorder and a separate pushbutton for it.
An unusual piece of furniture from 1961 comes from the German furniture factory Ilse which also included radio chassis from German plants in what looks like 19th century style. This model Gracia 2338 holds a Telefunken chassis 2180 and behind the upper door a Telefunken TW504 record changer. The tubes are ECC85, ECH81, EBF89, ECC83, EBC91, EL84, ECL86, EM84. The radio has a ferrite antenna, separate controls for bass and treble and pushbuttons for Bass-Solo-Intim-Jazz which reduce or enhance low and high frequencies. There is a big full-range loudspeaker on the front and two smaller ones on the sides for midrange and treble. The UKV tuning knob gives bandspread on the SW-band which covers 5.9-18 MHz.
The word "Stereo" only applies to the record player if it has a stereo pickup, not the radio. Strangely enough the left channel goes only to an amplifier for medium and high frequencies to one loudspeaker on the side while the right channel goes to the full range speaker and amplifier. The radio needed a new coupling capacitor and slight tuning-up but I increased the audio power because I felt that the tube currents left some margin. The tone arm of the record changer was broken so I replaced the changer deck with a tape cassette deck. With both doors closed nothing reveals the technique behind them and the sound is great.
A friend who knows better than throwing radios in the trash bin left this Swedish Dux V373 from 1956-57 to me. Its original price was 499 kr, it was made at the Philips plant in Norrköping and exists in the Philips-version as BS461A. It has had rough usage but after I changed the tubes and many capacitors it works well. The radio has separate bass and treble controls as well as variable AM-bandwidth. There is no ferrite antenna but a built-in frame antenna for MW-LW. The two SW-bands cover 1.6-4.8 MHz and 5.9-16 MHz and offer the high sensitivity of 4 uV. The UKV-band covers 87.5-100 MHz with good sensitivity due to two IF-stages. The tubes are ECC85, ECH81, EBF80, EF89, EABC80, EL84, EM80, EZ80. This worn set with two loudspeakers on the front is my garage radio.
This Swedish Philips BS371A from 1957-58 is a cheaper sibling to the Dux above from the same plant, the original price was 430 kr. They have much in common. The differences are a single IF-tube, just one SW-band and one knob for tone control and fixed AM-bandwidth. Common features are two loudspeakers, 7-inch and 5-inch and a frame antenna. The tubes are ECC85, ECH81, EF89, EABC80, EL84, EM80. I changed tubes, made the set play with contact spray and and put silicon diodes across the selenium rectifier to raise the plate voltage. The magic eye is replaced with an UM80 whose heater is fed with 18 V from a voltage tripler. This radio was a gift for spare parts but since it was easy to restore it will stay in working order on my bookshelf.
Dux V1370 from 1956-57 is a Swedish tabletop radiogram which also came from the Norrköping plant and cost 645 kr. It has two IF-stages but the second one only for FM. The AF-amplifier consists of a transformerless single-ended push-pull stage which feeds two 5-inch 400-ohm speakers in series, one with a double-cone. An output transformer is switched in when an external low-impedance loudspeaker is connected. There are separate tone controls for bass and treble and a ferrite antenna with separate rods for LW and MW can be turned with a knob. In one end position an outer antenna is switched in. The tubes are ECC85, ECH81. EF89, EF85, EABC80, EL84, UL41, EM80, EZ80. The chassis is the same as Philips B5X61A and H5X63.
Most of the tubes seem to have been changed recently, only the magic eye was worn and I replaced it with a UM80 with 19 V heater transformer. Two electrolytic capacitors were replaced. The tuning capacitor drive was sluggish but I managed to make it work. The simple 3-speed record player Dux 5156 has a crystal pickup for normal- and micro-groove records. The player needs to be replaced because the rubber rim of a transfer wheel is dried up and the pickup is faulty so I have put a portable CD-player under the lid. The cabinet looks nice, FM-sensitivity is adequate and the sound is fairly good although lacking deep bass, the resonance frequency of the speakers is 130 Hz. I couldn´t say no to the price 25 kr in the second-hand shop.
This Swedish tabletop radiogram Philips H4S03A, made in 1960 in Norrköping under the name "Anita" with original price 722 kr, was a bargain for 25 kr at the summer sales in the second-hand shop. The record player and the amplifier are equipped for stereo but not the radio. Although the two side-mounted 5-inch speakers AD3500AM have 800-ohm impedance the amplifiers have output transformers, a solution which seems puzzling but the radio was meant to be used with separate high-impedance speakers. The stereo effect will not be good with the built-in ones, the bass response is limited and the user's manual recommends Philips HZ 6. The output transformers are spare-coupled with plate voltage on the loudspeaker coils so the three-pole connectors are protected and luckily enough I had two suitable male connectors, probably bought in the 1980's. I have added a switch for the built-in loudspeakers to disconnect them when separate ones are used. The output power is 3 W each channel.
The tubes are ECC85, ECH81, EBF89, ECC83, EL86, EL86, EM84. The FM-discriminator has germanium diodes. Two tubes had to be replaced, among them the EM84, and as usual a number of leaky paper capacitors. The selenium rectifier had a short-circuit which had made a temperature fuse open, so I used silicon diodes and a glass fuse instead. An extra electrolytic capacitor is required to keep hum low. The FM tuning capacitor was stuck but released when I heated the shaft bushing with my soldering iron to soften the grease.
The record player started after lubricating the motor shaft but the stereo crystal pickup didn´t give any output, a common fault with those made by Philips which can´t be repaired. I will have to stay with a mono pickup until I find a better one.
For just 50 kr I brought this Löwe-Opta Truxa 2731W from the flea market. It was made in 1958, the price then was 485 kr and it represents German middle-class with loudness-type of volume control, separate controls for bass and treble as well as fixed registers so typical of its time: Bass-Jazz-Sprache-Solo-Orch. Besides the UKV-band it covers LW, MW and SW 6-19 MHz. The dial is not adapted to Scandinavian customers, Motala is missing on LW and the UKV-band holds a number of German FM-transmitters. A big oval loudspeaker on the front is combined with electrostatic tweeters on the sides but the sound is not as good as I had expected. The front speaker is attached to the chassis (picture) and while its cone is 14 cm high the opening in the cabinet is not more than 9 cm.
The tubes are ECC85, ECH81, EF89, EABC80, EL84, EM80. The ferrite antenna is built-in but in fixed position. The dial. I had to replace two tubes, one heater fuse and a number of leaking paper capacitors. Just as in my Grundig 3097 there are no trimming capacitors for the SW-band, I had to add one in the antenna circuit for the best result and after that the sensitivity on SW is 7 uV. This radio is named after a well-known Danish entertainer and magician who was popular in Germany at the time.
Siemens Kammermusik-Schatulle M 57 from 1956 isn´t a radio for people who are short of space being 89 cm wide with the doors open. This model was aimed at those who find no pleasure in seeing the lit dial and magic eye but prefer a non-technical look. The combined mains switch and volume control is in front of the doors and when they are closed the dial lamps and magic eye are shut off. In this particular set the switch for the magic eye was missing but I solved the problem by using a relay activated by the lamp voltage. The dial
This model belongs to the luxury class since it is equipped with a tuned RF-stage, two IF-stages with variable AM-bandwidth in two transformers linked to the treble control and a push-pull amplifier with 7 W output measured at the onset of clipping. On FM the sensitivity is excellent due to four IF-stages. A single SW-band, 5.9-18.5 MHz, is a bit scanty though. On SW and MW the sensitivity for 50 mW output is 5-8 uV measured with a 200 ohm signal source, but on LW it is only 18 uV depending on intentional damping to achieve acceptable AF-bandwidth. The ferrite antenna only works on MW, it can be rotated from the front and switched out with a pushbutton. Another button chooses a local station on MW and then the coupling between the RF-stage and mixer is untuned. The power amplifier has separate controls for bass and treble, loudness volume control and a button to switch between Speech/Music. There are separate output transformers for low and high frequencies and two 8-inch full range loudspeakers together with two 4-inch ones, all at the front.
The tubes are EC92, EC92, EF89, ECH81, EF89, EF80, EABC80, ECC83, EL84, EL84, EM80. All of them needed replacement but the fixed capacitors and dial lamps were in good condition. The FM-tuning capacitor was stuck, the tuned circuits needed adjustment and the selenium rectifier delivered too low voltage so I wired a silicon diode bridge in parallel with it. Otherwise the radio is well preserved, a bargain at the flea market for 250 kr. The original price was 848 kr.
An strange detail is that the smaller speakers are not mounted directly on the front board but on bent plastic tubes ending up on the front. This causes the high tones to travel a longer distance and a creates a phase shift compared to the sound from the bigger speakers. Nowadays we place the elements at the same distance from the listener to avoid this problem but in the mid 1950´s the manufacturers boasted with "space sound" and "3D-sound" in the adverts and this was Siemens´ contribution to acoustical hocus-pocus. In any case the sound is marvellous with deep bass, just as good as that of Philips BX998 below, and the frequency span is 35 Hz to 12 kHz measured at the -3 dB limit.
Luxor Diplomat 399L from 1951 was the top model of that Swedish manufacturer with a price tag of 775 kr. It is an AC/DC-set for which I paid 100 kr, the AC-version is 399W and it is based on a model from 1945. Because it has five SW-bands, 11-230 m with some bandspread on the 16-, 25- and 41-meter bands and a good logging dial, it was sought after among dx-ers but in other aspects the radio is in no way remarkable. It would benefit from a separate preselector to appear to advantage since its sensitivity on SW is 9-18 uV for 50 mW output measured with a 200 ohm signal source. On the LW- and MW-bands the bandwidth is increased in the first IF-transformer and on the three high frequency SW-bands the oscillator is below the signal frequency.
The tuning mechanism "mikrosving" has two speeds, fine and coarse, with a knob on the right-hand side and it uses a huge flying-wheel. A metal dial string strengthens the impression of quality. The AF section with two 8-inch loudspeakers is indeed unconventional with separate power tubes for low and high frequencies, each of which feeds its speaker. On the front are knobs for loudness volume and tone control and there is a 9 kHz-trap across the output transformer. Output power is 3 W (bass) and 1-1.5 W (treble). The tone control is passive, at one end position the left speaker gives an unintelligible growl and at the other end the right speaker howls with the same result, so I have chosen a position in between.
One of the pushbuttons is meant for a local station and a set of coils is plugged into a tube socket. Mine is designed for the middle part of MW (900-1200 kHz). When broadcasts started on UKV in 1955-56 many people bought a separate tuner to connect to the gramophone input. In this particular radio some handy person included the tuner so that its controls are in an aperture on the left side, a unique solution making the radio useful for today´s programmes.
The tubes are UCH21, UF21, UF21, UBL21, UBL21, UM4, UY1N. I replaced three tubes and the restoration included replacement of electrolytic capacitors and some flaked resistors. Contact spray was needed in potentiometers and contacts. The plate voltage is increased by means of a silicon diode across the rectifier tube. The unusual dial lighting uses four 110 V 4 W lamps and to my delight and surprise the missing three ones were found in my drawer. One shall not unnecessarily throw things away!
Advert 1, advert 2, advert 3.
Luxor Ambassadör 3098W from 1956-57 is one of the big tabletop radios, 62 cm wide and weighs 17 kg, and it is the successor to the previous 399. The chassis is the same as in the radiogram Aristokrat and by judging from the model names we understand that these sets represented Luxor´s upper class. This one cost 850 kr but I got away with 50 kr at an auction. The sound part is well developed with loudness volume control, separate controls for bass and treble, 7 W push-pull amplifier and four speakers with two on the sides. The receiver part is average with two exceptions, a generous coverage of SW 11.5-210 m in three bands and that the UKV-FM band covers 86-108 MHz. The dial. On the AM-bands a 9 kHz-trap is placed across the output transformer and on SW2 the bandwidth is narrowed in the second IF-transformer. Sensitivity on SW and MW is 5-9 uV for 50 mW output measured with a 200 ohm signal source, good figures for a set without an RF-stage. The ferrite antenna for MW can be turned from the front, with an external antenna switched in at one end position. There is also a speaker switch to use the built-in ones when Luxor´s tape recorder is connected.
The tubes are ECC85, ECH81, EF85, EF80, EABC80, ECC83, EL84, EL84, EM80. The second IF-stage is used for FM only. Six tubes out of the nine needed replacement as well as the electrolytic capacitor and almost all paper capacitors and the selenium rectifier is replaced with silicon diodes. The common stinginess of not using trimming capacitors in the antenna circuits on SW was found here so I added two for best sensitivity. The cords to the tuning capacitor and ferrite antenna were broken, the work to change them was tedious and the bakelite wheel on the capacitor shaft broke during the process. The treble sound was sharp and unpleasant so I modified the negative feedback circuit by removing a capacitor and that made an improvement.
Philips 796A was made in The Netherlands in 1936, only a few years after the breakthrough of the superheterodyne principle. The model was called Sonata, the most expensive one of the three sets in the Symfoni-series, and the price in Sweden was 410 kr. It is a big cabinet which holds a 10-inch speaker with permanent magnet. The bakelite part housing the dial can be folded inwards to make the upper surface flat, an unusual detail, but the most remarkable item is the joystick which controls tuning (rotate), volume (up/down) and tone (right/left). The big knob outside the joystick is the mains switch and band selector with a position indicator in the upper-right round window. The movement of the joystick is transferred via bowden wires and the tone control also affects the bandwidth by changing the spacing of the coils in one IF-transformer. The tuning control has coarse and fine characteristic, the latter covering a broadcast band on SW. On the rear are three switches, one turns off the loudspeaker, one reduces bass in the Speech-position and one lets you use the power cord as an antenna via a protection capacitor. The joystick is not well suited for shortwave listening, it is easy to lose the station while adjusting the volume, and it is impractical to have to select a band at turn-on not to mention the need to stretch to the rear to reach the speech-control. This Art déco-design was decided on at the expense of function. On the back there is a switch to turn off the loudspeaker but the connector for external speaker has a protective cover because it is wired in parallel with the primary of the output transformer and carries plate voltage, something that is easily changed.
The tubes are AK2, AF3, ABC1, AL4, AM1, AZ1, although a later version used the E-series of tubes. Two tubes are replaced, EK2 and EM1 are fed with 6 V from a separate small transformer, and ABC1 has an intermittent fault and must be changed. A problem with oscillation in the IF-stage was due to the metal paint coating of the tube not making contact with the earthed pin, but I solved it with thin bare wire and careful soldering. I treated the mixer and AF-tubes in the same way. Beside LW and MW there is an SW-band, a progress compared to earlier TRF (tuned radio frequency) sets, but an octode mixer tube as oscillator causes a frequency change with variation in signal strength, a problem on the high-frequency part of the shortwave band. The IF frequency is only 128 kHz meaning inadequate attenuation of the image frequency on SW so there are twice as many stations received there and a lot of beat notes, but on MW there is a gadget for image suppression and there are double-tuned circuits on both LW and MW. It took a couple of years before the engineers raised the IF to around 450 kHz.
This model is difficult for the serviceman because the components are placed above each other, the rubber wire insulation flakes off when touched and it is unusually laborious to get the chassis out of the cabinet: 12 screws to loosen, 11 wires to unsolder and a special tool must be made to remove the outer knob for bandswitching. I have replaced the capacitors and added black colour on the dial glass where the original colour was flaked off. The wire to the band indicator is broken and remains to be replaced. The mains transformer which has its primary winding outermost had developed a short to the chassis and when I by mistake connected an earth wire to the antenna terminal the antenna coupling coil on MW was damaged. It resulted in difficult repair of both transformer and coil, it was not successful as the sensitivity on MW is poor so something must be done. On SW the sensitivity varies between 10 and 100 uV for 50 mW output due to capacitive coupling to the mixer grid. On LW where coupling is both capacitive and inductive the figures are 25-40 uV. The sound is good considering the age of the radio with deep bass, the speaker resonance is 45 Hz, but there is a lack of high frequencies. The switch on the back should be in Speech position, the low IF reduces the sidebands and I had to change a resistor in the negative feedback circuit to stretch the -6 dB limit to 2700 Hz. In the gramophone position the limit is 9 kHz however. Maximum output is 2.2 W at the onset of clipping.
Centrum GU60 was also made in 1936 but it looks older than the previous radio. It is an AC/DC-set, the AC version is GW60. It has LW, MW and SW (18-50 m) and a tuned RF-stage. The high profile cabinet holds an electromagnetic 10-inch loudspeaker mounted on a slanting board. The circular dial is controlled by a two-speed planetary drive. The tone control is a simple attenuator for high tones. The tubes are 6D6, 6A7, 6D6, 75, 12A5E, U30. The mixer tube has no AGC-control on SW so the frequency won´t change with varying signal strength.
Since all tube heaters are in series it is enough that one of the four dial lamps burns out to make the radio stop working. I replaced two bulbs and a fuse, all electrolytic and most of the paper capacitors and I put a silicon diode across the faulty half of the rectifier tube. With a tuned RF-stage the sensitivity is of course good on LW and MW (6 uV) but for some reason worse on SW (16-30 uV). The figures are valid for 50 mW output at 200 ohm signal source impedance. Because the IF-frequency is only 140 kHz there is inadequate attenuation of the image frequency on SW in spite of the RF-stage, so beat notes are heard when the image falls within the same broadcast band. A peculiarity in the circuit diagram is that the RF- and IF-pentodes have their suppressor grids connected to the screen grids. I changed this and the radio works well, it is also easier to repair and nicer to use than the Philips above. However, the sound lacks bass despite the big loudspeaker, the response has fallen 3 dB at 700 Hz and 6 dB at 350 Hz perhaps explained by the absence of negative feedback and that the inductance (5 H) of the output transformer is too small. The upper 3 dB-limit is 7 kHz and output power is 1 W at the onset of clipping.
The original price was 345 kr, one and a half month´s wages for a factory worker. It was the good condition of the cabinet that made me pay 300 kr at an auction, previous owners have treated it carefully and I am pleased that five out of the six tubes measure like new ones.
Centrum W51 is a few years younger than the Centrum above, probably from 1942, also made in Stockholm and with the same chassis as the model KW5 from 1939-40. It ranks as lower middle class, certainly without gadgets as wavelength indicator and magic eye, but with two SW-bands 13,5-85 m and five-position tone control for reduction of low or high tones and with variable bandwidth in two IF-transformers. The 7-inch loudspeaker has field excitation coil instead of permanent magnet. The dial. This radio has very good sensitivity on LW and MW, 4-5 uV for 50 mW output with 200 ohm signal source impedance. The SW antenna circuit was probably designed for a high impedance antenna, sensitivity with my signal generator is not better than 20-40 uV, but stations are well received even with a short piece of wire. The output power is no higher than 1 W at the limit of clipping but with an impressive frequency response, -3 dB at 70 Hz and 17 kHz respectively.
The tubes are 6J8EG, 6K7G, 6Q7G, 6F6EG, 5Y3G. In my set the mixer tube is replaced with ECH35, only tubes 3 and 4 are original ones. I changed electrolytic and paper capacitors and some resistors that had increased too much. A mica capacitor and two ceramic trimmer capacitors had developed an open circuit, the switches required cleaning and I added a mains fuse. This radio was a gift (described as "stone-dead") by a friend who believed me capable of giving it new life.
AGA Europa 51 of 1939 vintage is an elegant Swedish radio with good sound bought at an auction for 100 kr, the original price was 330 kr. Perhaps the name was chosen because the dial on LW and MW holds 160 stations and some 60 are listed on SW. There is bandspread on the 19- and 31-meter bands which facilitates listening to foreign stations but the entire SW-band, 16.4-53 m, is also represented. The dial. The sensitivity is 20 uV for 50 mW output with a 200 ohm signal source. Because the front is dominated by the large dial the 8-inch loudspeaker with field excitation coil is mounted on a slanting board. The tuning knob has so great reduction drive that the radio has a handle for fast movement of the dial rod, the clutch is released by pinching the two parts of the handle. The tone control has five positions, two of them increase treble response and the bandwidth in one IF-transformer. The bass response is increased by pulling the knob, hardly necessary because low tones are lifted 5 dB around the resonance frequency (70 Hz) of the speaker. Treble response has fallen 3 dB at 8 kHz but there are two positions for even stronger reduction: -3 dB at 1400 Hz and -3 dB at 550 Hz. The last two are effected by capacitors between plate and control grid of the power tube and these should have a smaller value. Output power is 3.4 W at the onset of clipping.
The tubes are 6J8G, 6K7G, 6B8G, 6V6G, 5Y4G, EM1. Three of the six tubes have been changed, probably in the beginning of the 1950´s. I raised the plate voltage to the magic eye with 100 V for better brightness. Furthermore I added a filter capacitor to reduce hum, changed a resistor and put in a mains fuse. This and tuning up were all electronic steps needed, a blessing compared to the previous two sets that required extensive replacement of components. The slow-motion drive for the tuning capacitor proved a failure, however. The knob shaft drives a wheel with a rubber rim and the rubber was worn and hard. I glued a narrow piece of bicycle rubber tube onto the rim, not a perfect solution because I must pull the knob before using the quick-tuning handle but it works passably well. The fact that the cord is a steel wire means that I won´t need to replace it, I wish that all manufacturers were so provident.
It is easy to tune stations, among other things helped by the logging scale, but the low IF (133 kHz) causes quite a lot of beat notes on SW. In that respect this radio was not up-to-date when it was introduced. On LW and MW there is a double-tuned antenna circuit to avoid such problems.
AGA 1771-1 from 1948 is a younger version of the original one from 1946, often called "The long sofa" because of its width 69 cm, and it was dx-ers´ favourite for its sensitivity and bandspread on the SW-bands. It is still a real good radio for shortwave listening with the bands 19, 25 and 31 m marked with both frequency and wavelength. The two major SW-bands cover 13.3-84 m. The dial. There is a separate pushbutton for local station on LW or MW. A tuned RF-stage and variable bandwidth in one IF-transformer give useful sensitivity and selectivity, the former being 2-5 uV for 50 mW output from a 200 ohm signal source. The AF-section was paid attention to with a 10-inch permanent magnet loudspeaker, 5 W push-pull amplifier, loudness volume control and separate switches for bass and treble so the sound is excellent.
The tubes are EF22, ECH21, EF22, ECH21, EBL21, EBL21, AZ1, EM4. I replaced four tubes, all electrolytic capacitors, some paper capacitors and some resistors. An oscillation on the most high frequency SW-band gave me much work, I improved earth connections and bypassing but since it was not enough I had to put a resistor across the coupling loop of the coil in the plate circuit of the RF-stage. This problem turned up also with my second set of this model and it is obvious that the engineer fought with problems of stability because such resistors are used on the LW- and MW-bands. At first I couldn´t make the dial on the bandspread bands show correct frequency but after adding 10 pF to the padding capacitor the 31- and 25-m bands agreed and the 19-m band required addition of another 18 pF padding capacitor. The rectifier tube was insufficient so I changed to AZ4 and it reduced voltage drop by 45 V. Certainly AZ4 draws twice as much filament current but the winding is outermost and has good cooling. The radio received stations without an antenna connected (not always desirable) so I covered the perforated bottom with earthed metal foil.
The original price was 641 kr and I paid 400 kr at an auction. This was my dream radio in 1958 having borrowed it from the used stock of the local dealer, but my parents were not so delighted, it didn´t receive the second program on UKV FM, so there was no deal as it cost 200 kr then. This is my best radio from the 1940´s, when I have set the frequency the station will be heard if propagation allows, and I am going to equip it with an SSB-detector.
Philips 933A was made in 1943 in Norrköping, Sweden and the price then was 495 kr, eight weeks´ wages for a factory worker. It is a standard model with LW, MW and SW but with gadgets like switch position for local station and variable bandwidth in two IF-transformers. For LW and MW there are double-tuned antenna circuits, but not on SW. Sensitivity is 15-25 uV for 50 mW output with a 200 ohm signal source impedance. The fold-up dial glass is an impracticable detail, hard to read without a suitable background and with insufficient lighting from the sides. This radio is difficult to pile in the radio closet and before taking out the chassis one must make and mount supports for the rail that holds the pulleys for the dial cord, but these can remain in place afterwards. The advantage is that the length of dial gives good tuning resetability, the logging scale consists of no less than 375 small dots. Notice all Swedish relay stations to the left on the MW band.
The tubes are ECH4, EBF2, EF9, EL3N, EM4, AZ1. Five tubes had to be replaced. I changed the connection for the grid of the eye to the AGC-line to a point with higher control voltage.
The AF-circuit has a tone switch with three positions Speech, Music narrow and Music broad and a knob for treble reduction. The first two positions connect a 9 kHz trap across the output transformer and the Speech-position reduces frequencies below 100 Hz. The 8-inch loudspeaker has a field excitation coil. Its sound was surprisingly dull but removal of a capacitor between the plate and control grid of the power tube raised the treble response from 3.7 kHz to 5.5 kHz while the lower limit is 60 Hz, all measured at 3 dB down related to 1 kHz. Output power is 2.5 W at the onset of clipping. I spent much work on this radio, the volume control and almost all capacitors are replaced and the IF-stage oscillated until I had soldered a thin wire between the chassis and the metal paint of the tube. At first it was housed in the garage but I gradually changed my mind due to its good sound so I let it in and it works satisfactory. Brochure for 933.
Concerton V488 from 1947 was also built at the Philips plant in Norrköping. It has the typical Swedish design from the late 40´s with a slanting dial, so easy to read without having to crouch down when the radio is on a low table. Light elmwood in the neat cabinet was popular in home furnishing at that time. The three shortwave bands comprise 16.7-20.7 m, 20.7-33.3 m and 33.7-51.8 m, both wavelength and frequency are marked so it is easy to tune in a station. Fixed coils (beside those in the IF-transformers) provide very low frequency drift. Some lettering on the dial has unfortunately been lost due to moisture. The tone switch has five positions and it also changes bandwidth in the first IF-transformer. My Philips BX760X has the same tone circuit and I will do the same modification of the feedback circuit to reduce the augmented and unpleasant treble. With that exception the sound quality from the 8-inch speaker is really good.
The tubes are ECH21, ECH21, EBL21, EM4, AZ1. Two of them are original ones, the IF-tube and the magic eye had been replaced in the late 50´s together with the electrolytic capacitor but nevertheless I had to put in new ones as well as the power tube. The IF-coils were far off resonance but after trimming them the radio worked on shortwave. With fixed coils there are plenty of trimming capacitors and the lack of a service manual and circuit diagram made the adjustments time-consuming. Neither the MW- or LW-band worked, the series-connected antenna coils seemed to be burnt due to thunderstorm. I managed to repair them although with difficulty because the wires are not much thicker than a piece of hair. A remaining job will be to check and probably replace the "tar" capacitors. I had better not take out the chassis to avoid problems with the thin wire to the dial mechanism. The original price was 390 kr but I got off with 50 kr at an auction.
This Radiola 475V from Svenska Radioaktiebolaget (SRA) was made in 1947 and with its slightly slanting dial it follows the Swedish design of its time. The radio has five SW-bands covering 16-51 m, only one of those bands has trimming capacitors, on the four other bands there are just coils to adjust. One of the drawbars switch in a local station whose tuning control on the back moves ferrite cores so that no switching between MW and LW is needed. The second drawbar is a tone control for bass response. By pulling the volume control knob one can change bandwidth in the first IF-transformer by controlling the distance between coils and at the same time treble is attenuated in four steps with a capacitor from the plate of the final tube to ground. There is a 9-inch loudspeaker which can be switched off when an external speaker is used. Strangely enough there is no wavelength indication on LW and MW, just station names.
The tubes are 7S7, 7H7, 7B6, 7C5, EM4, AZ1. The radio had its latest service in 1954 when two tubes were replaced but the others were original ones. I have replaced all tubes but one. Moreover I replaced the dial lamps and a paper capacitor. The original electrolytic capacitor took a whole day to reform. I had to reduce the value of the padding capacitors in the oscillator circuit to make the dial markings correspond, the idea with bandspreading is to know where one is tuned so it is worth the effort. Now I set the dial rod to the wanted wavelength and the station is there if it is on the air, such a radio would have been an asset when I was a young dx-er. The cabinet and dial look excellent, that was what made me pay 130 kr at an auction.
Philips 915X originates from 1940 but this set was made in 1942, it belongs to the well-equipped category and was aimed at customers interested in shortwave reception. A tuned RF-stage, variable bandwidth and bandspread of the broadcast bands 13-, 16-, 19-, 25- and 31-meter was certainly a temptation for those who could afford 579 kr. After the first year the price had decreased to 525 kr. During 1939 Philips had launched pushbuttons for pre-set stations, "Linodyne-system", which controls a variable three-gang capacitor consisting of cylinders with moving outer caps. On MW a fraction of the oscillator inductance is also variable, "padding correction". The position of pre-set stations is adjusted with a screw somewhat awkward to reach through the lower side of the pushbutton. Three keys choose stations on LW and three on MW and the remaining three are used for manual tuning on LW, MW and SW (13.8-50.5 m) by means of the upper dial rod. All six pre-sets can be used on MW if that is preferable. On SW there is a knob for fine tuning with a lower dial rod which normally should be placed at a centre position to guarantee the calibration of the main dial.
For manual tuning the main tuning knob must be pushed to become active and the bandspread switch set in "zero" position. One selects a bandspread SW-band by pushing the fine tuning knob and turning it and that deactivates the main tuning knob. In order to make the bandspread dial show the correct wavelength the main tuning must be placed in a certain position, this is made automatically and the position is adjusted with a screw accessible through a hole on the front. Only the coils are variable then. There is complicated mechanics to make everything work and it does so fairly well but anyone who wants to trust the bandspread dial must have a screwdriver ready to adjust the main dial with the help of a known station and that tool is supplied, it is stored on the back of the radio. There is insufficient precision of the main dial pre-set and the bandspread dials do not completely agree even after that. Perhaps the permeability of the coil cores have changed.
Instead of ordinary metal dial rods there are glass rods giving a narrow white line on the dial glass by means of a lamp bulb far behind them, unusual and free of parallactic errors. Station names on the SW dial show what the owner was expected to listen to in the beginning of the 1940´s. The dial.
The tubes are EF8, ECH3, EF9, EAB1, EF6, EL3, EM4, AZ1. The EF8 tube was introduced in 1939 to give low noise in the RF-stage, it is a hexode where an extra grid is placed in front of the screengrid to reduce the screen current and hence the thermal noise. The triple diode EAB1 offers separate plates for detection, AGC-voltage and AGC-delay to the RF-tube and mixer tube, this lowers distortion and improves weak signal reception. A tone switch with three positions also chooses IF-bandwidth of 10, 13 or 17 kHz and moreover there is a treble-cutting knob below the pushbuttons. The volume control has a loudness characteristic, the 8-inch speaker with permanent magnet gives good bass response and can be switched off by the listener who prefers headphones.
It took a lot of work to restore this radio to working condition: lubricating, new capacitors, some new resistors, repair of the volume control, changing wires whose insulation had disintegrated and three new tubes. I reduced hum in the narrow bandwidth position by feeding the heater of the AF-tube with DC. My set lacks vertical ribs in front of the loudspeaker and the Philips badge is missing as well. Advertisement 1, advertisement 2.
The big brother of 915X above and from the same year is Philips 990X, the biggest and most expensive tabletop radio from that manufacturer in the Netherlands. With a weight of 30 kg it is a heavy piece of furniture and its price 985 kr certainly deterred most customers because in 1941 the price had been reduced to 750 kr. The radio is principally identical with the one in 915X but it has two SW-bands (13.6-170 m). The tubes are EF8, ECH3, EF9, EAB1, EF6, EL6, EM4, 1561. The variable padding inductance is abandoned and the RF-stage has an untuned plate circuit on LW and MW, but instead there are double-tuned antenna circuits on those bands. Band switching and station presets are carried out by a motor and five preset stations can be programmed on any of the wavelengths. The choice of band is made by pulling out the pushbutton and turning it so that its white mark comes in the correct position. After that the station is tuned in with a screw accessible through a hole behind the tuning knob which must be pulled out. A long screwdriver is required and that tool is supplied, it is stored on the back of the radio. Separate knobs are used for main and bandspread tuning. The dial indicators are thin light lines of which one is used on the bandspread bands, illuminated only in SW2 position. The dial.
The cabinet holds two 8-inch speakers delivering 6 W output. Besides the three-position tone control with switching of IF-bandwidth there are controls for attenuation of bass and treble. The sound quality is good considering the 1940 vintage when the broadcasters did not pass frequencies above 8 kHz. It does not measure itself against the FM-radios of the 1950´s, but it was an advantage not to receive beat notes from MW stations on neighbouring channels or noise from shellac records. The frequency response falls at 6 kHz and at 9 kHz there is nothing left. The 915X has the same characteristics.Both motor and mechanics caused me trouble and required both lubricating and cleaning of contacts and without the service manual I wouldn´t have managed to make it work. Four tubes and most of the capacitors are replaced. Instead of the 1561 rectifier tube I use a GZ34 on a socket adapter. Originally the panel cloth was light grey but some previous owner has unfortunately dyed it and the Philips badge on the bright metal plate is gone. The motorization results in an unnecessarily complicated radio, it provided nothing but impression but it was fashion of that time. The smaller brother 915X is an equally good receiver with the exception of lower AF power, but one has greater tuning precision with a conventional variable capacitor than their quick tuning technique. The axial shifting of the capacitor is a mere 1 cm to cover the whole band, something that gives poor stability on shortwave. Advertisement.
At an auction I found this premium model Philips BX760X, made in the Netherlands in 1947. The original price was 725 kr, the most expensive one of the tabletop radios. In this Swedish brochure it was called Stratocruiser and it was described as "the greatest radio ever built by Philips" with "a sound reproduction of extraordinary quality". It has all controls on the sides while the front is occupied by a 10-inch full range loudspeaker. The dial glass, which can be folded down during transport, is on top of the cabinet, but unfortunately it lacks a contrasting background. This radio has three SW-bands 13-51 m, MW and LW. A 6-gang variable capacitor has a set of specially cut plates to give unique bandspread of the broadcast bands on SW. The dial. A tuned RF-stage and variable IF-bandwidth 10-16 kHz give the impression of a radio intended for long distance reception, but even the AF-circuit is well developed with a 7 W push-pull amplifier, loudness volume control and a 5-position tone control which also switches IF-bandwidth. Compared with the AGA 1771 from the same year and with the same tubes the sensitivity of BX760X is lower, 4-14 uV for 50 mW output with 200 ohm source impedance.
The tubes are EF22, ECH21, EF22, ECH21, EBL21, EBL21, EM4, AZ4. The magic eye is behind the left window and the wavelength indicator behind the right one. The circuit diagram is more than usual complicated since the engineer was given a free rein. The AGC-circuits are separate for the IF-tube and the RF- + mixer-tubes to give the best possible signal-to-noise ratio. In the second ECH21 the heptode forms an AF-amplifier as well as a phase inverter with a 3 dB dynamic expander. The latter is achieved by rectified AF-voltage from the output transformer giving the heptode lower control grid bias which means higher gain. The triode is used for AF-AGC which prevents the output power to exceed the limit for 10 % distortion. The audio section passes 40-8300 Hz, a lowpass filter attenuates 9 kHz beat notes from the neighbouring channel on MW and LW and of course noise from shellac records. Another unusual detail is that the IF-tube is used as an preamplifier for the gramophone, the output is taken from the unbypassed screengrid.
I reduced hum from the AF-tube heater by feeding it with DC but some of it remains, probably due to long unshielded wires. The tone control lifts the range 3-5 kHz far too much in the broad position, giving an unpleasant sound, but I flattened the response by changing the value of a resistor in the feedback circuit. Five tubes required replacement as well as the dial lamps and all electrolytic and almost all paper capacitors. It means fiddling with components that are placed above each other in the deep chassis and as a whole this radio is cumbersome to work with because many components are hidden in sealed cans. I had to use spirits and a small file to clean the sockets of the RF- and mixer tubes and the bandswitch contacts. The radio is fairly good for dx-ing, sensitive, with good stability and excellent bandspreading, but how inconvenient it is to stretch ones arms to handle the volume on one side and the tuning on the other. The width of the cabinet is 63 cm.
As an experiment I replaced the RF-tube with EF85 on a socket adapter and that doubled the sensitivity.For radios after WW2 Philips used model numbers that gave information about the set. The first letter stated if it was B tabletop radio or F console radiogram with record changer, the second letter indicated country of manufacture: S for Sweden and X for the Benelux-countries. The first figure indicated price level 1-9: 1 for the simplest little radio, 4 for a middle-class set and 7 for an expensive and well equipped tabletop radio. The radiograms were between 6-8 but in the luxury class 9 I have found only two sets, those which are mentioned below. The second figure stood for model year, 6 meant either 1946 or 1956, and the third figure meant model variant. The suffix A meant AC, U AC/DC and X that the radio was made for AC but prepared to be used with an outboard DC-converter, then the radio contained some extra capacitors to cut voltage transients and a multi-pin mains connector.
After 1957 the second and third signs changed places, a radio was marked B4S81A if it was a Swedish-made middle-class radio from the model year 1958.
My most complicated and competent domestic radio is Philips BX998A, with the same chassis as in the radiogram FX995A. This top model from 1956 shows off with no less than 16 tubes, it was meant for customers with much money, interested in good sound and shortwave listening. The 1956 year price was just under one thousand kr, twice as much as for an average good radio, and the buyer got a 30 cm dial glass with three SW-bands covering 11-180 m, MW, LW, local station on MW and two UKV-choices, with or without squelch. The AM-section starts with a tuned RF-stage EBF80, followed by mixer/oscillator ECH81 and two IF-tubes with detector, EF89 and EBF80. The FM-section has an RF-stage EF80, oscillating mixer EC92, the two IF-tubes shared with AM, a third IF-stage EF85 and discriminator EAA91. The AF-section comprises ECC83, EBC41 and two power amplifiers. The low frequencies are handled by two PL81 in series-ended push-pull delivering 10 W to an 8.5-inch speaker with 700 ohm impedance. The intermediate and high tones are amplified by EL84 giving 3 W to a 7-inch dual cone speaker. Both amplifiers deliver power to an output transformer which is switched in circuit if an external loudspeaker is connected. Finally there are the magic eye EM34 and two rectifiers EZ80. I replaced seven of the tubes and the dial lamps, as to the rest it was enough with lubricating and tuning up because the radio is in mint condition. It is the radio that I paid the most for, 500 kr for 26 kg, and it occupies the place of honour in my house and is in almost daily use.
The wavelength selector is driven by a motor, at the push of a button the switch is parked in the wanted position and an indicator lamp is lit. While the motor is running the AF-amplifier is silenced by a blocking voltage. The knob around the magic eye turns the ferrite antenna (separate rods for MW and LW) which is screened for best directivity, and in one end position an external antenna is connected. There are separate controls for bass and treble, the latter being linked to two IF-transformers where the distance between the coils is variable in order to change the AM-bandwidth between 7 kHz and 17 kHz. There is fine tuning on the two highest SW-bands and for local MW-reception there is a separate knob and dial. Because the amplification on the FM-band is higher than usual, noise and weak stations can be a nuisance when one wants to change between local stations. With the choice FM-squelch the oscillating triode in ECH81 delivers a voltage which is rectified in the RF-tube EBF80. The negative voltage is brought to the suppressor grid of EF85 where the amplification and noise is reduced but when a local station is tuned in, a voltage is created which blocks the oscillator and sensitivity is restored to normal. Since this model has two more amplification tubes than an ordinary radio, it is the most sensitive broadcast receiver that I have came across, with a sensitivity of 3 uV on SW. The sound is also the best of all tabletop radios, certainly the radiogram FX995A has deeper bass response due to its bigger size but lack of space forced me to sell it.
What is missing is a more detailed shortwave dial with close marks. Because I can´t see what exact wavelength I have tuned in I have connected an external digital frequency display with compensation for the IF-frequency. Moreover I wish I could switch off the magic eye when I don´t need it, so I will put a toggle switch on the back. There is also a need for temperature compensation of the SW-oscillator.
This is the radio panel of the Swedish radiogram Stern & Stern Concerton U584 from 1953. The S&S company was bought by Concerton which was later bought by Philips, so the technical contents were made in Norrköping. The corresponding Philips model is FS741U. It is an AC/DC-set, a beautiful piece of furniture with two lids for radio and record changer Philips 2975 which was launched in 1950 and has separate electromagnetic pickups for 78-turn and microgroove records. The UKV-band is missing of course but the radio has five SW-bands covering 15.4-185 m, variable bandwidth in one IF-transformer, switch position for local station, 3-stage bass- and continuos treble control, loudness volume control and 5 W push-pull amplifier. The loudspeaker measures 28 cm and can be turned off when an external speaker is connected. The big screw heads on the front are used for band selection and tuning of the local station, the wavelength of which is visible in a small window behind the dial.
The tubes are UCH42, UAF42, UAF42, UAF42, UL41, UL41, UM4, UY1N. I replaces six tubes, the electrolytic capacitors, some paper capacitors and the 19 V dial lamps, lubricated moving parts and repaired the the dial drive. Mains wiring with dried insulation had to be changed. The SW-bands 1-4 do not have trimming capacitors in the antenna circuit so I added 4-8 pF on bands 1-3 for best sensitivity and image frequency suppression. I have increased the filter capacitance to 150 uF and put a silicon diode across the rectifier tube. This, together with a bit more idle current in the final tubes, raised the output power to 7 W at the point of clipping. The frequency span was 30 Hz-6 kHz at -3 dB, but I increased the upper limit to 7.5 kHz by using half the value of the shunt capacitors from the plates of the UL41s. With reduced position of the volume control the compensation makes the response flat to 12 kHz.
The record changer did not work well enough so I put in a Garrard RC121D, a flea market bargain for 50 kr. The original magnetic pickup was connected to the radio through an insulating transformer, an unsuitable method for a crystal pickup which needs at least 1 Mohm impedance for good bass reproduction. Therefore I use a field effect transistor as impedance converter. A compact stereo fits in one of the compartments behind the doors and provides output from FM-radio, CD-player and cassette player to the gramophone connector. I bought the radiogram in a second-hand shop for 125 kr although I haven´t got room for it, but it looked so good. Advertisement. The original price was 1420 kr.
Grundig K41 S from 1958-59 is a medium-priced radiogram with an original price tag of 1350 kr. Its chassis is similar to that of Grundig 3097S but has a push-pull amplifier with two EL95 for 7 W output to four loudspeakers, two oval ones on the front and two electrostatic tweeters on the sides. Side view. The tone register buttons are labelled Jazz-Tal-Ork-Sordin around the broad Klangväljare where only the four variable controls are active. The record changer is the four-speed Perpetuum Ebner Rex S Deluxe with crystal pickup for normal- or microgroove. A jalousie shutter hides the radio from curious young fingers.
As usual I had to change tubes, capacitors and tune it up. The rubber lips of the changer´s centre rod must be replaced, they are so worn that they don´t handle a pile of records but a single record can be played. The output of the pickup has deteriorated and I added a preamplifier with a bit of RIAA-compensation but the tone controls have so great range that it is not really necessary. With increased amplification of low tones follows the risk of acoustic feedback because there is no wall between loudspeakers and record player.
Telefunken Opus 6 from 1955 was at that time their finest tabletop radio with six loudspeakers, two 8-inch ones on the front and in each rounded front corner a 4-inch one with permanent magnet and a 2.5-inch electrostatic tweeter. The AF-stage is push-pull with separate controls for bass and treble and loudness volume control. The output power is 6 W when clipping starts, so the final tubes are run conservatively. The 3 dB-limits of the frequency response are 30 Hz and 11 kHz. The AM-bandwidth can be narrowed in two IF-transformers with a button and the recommended procedure is to start with the narrow choice to get right on spot. The second IF-tube is not connected to the AGC-line and draws only little current. The sensitivity for 50 mW output is 9-14 uV on SW and MW but 21 uV on LW, all measured with a 200 ohm source. There are separate pushbuttons for gramophone and tape recorder inputs. The ferrite antenna for LW and MW can be rotated with a knob and an external antenna is connected in one end position. The UKV-knob offers gives bandspread on SW (KW-Lupe) and the dial rod shall then be placed in a centre position for correct calibration.
The tubes are ECC85, ECH81, EF89, EF89, EABC80, EC92, EL84, EL84, EM80. I replaced dial lamps and almost all tubes, the magic eye being replaced with an EM85 which required wiring change at the tube socket. Some leaky coupling capacitors and an electrolytic capacitor were changed and the keyboard contacts needed cleaning spray. With silicon diodes across the selenium rectifier the plate voltage rose with 20 V to 250 V. The cabinet has some scratches in the veneer on the top that ought to be treated, that is why I only paid 50 kr for the set but its sound is excellent and worth many times as much.
Telefunken Opus 9 from 1958, within easy reach from my armchair, is a broad-shouldered German in the upper price range. It cannot fully stand comparison with the sound quality of my best radios however, in spite of two oval speakers on the front and on each side one conventional speaker plus one electrostatic tweeter. Five pushbuttons affect the sound reproduction: Intim softens high tones while Jazz enhances them, Solo increases the medium range and Bass the low tones. Orchest. gives a flat response and activates the controls for bass and treble but the treble response is not hi-fi: -6 dB at 6 kHz, -12 dB at 8.5 kHz and -18 dB at 11 kHz. Therefore the best sound comes with the addition of the Bass and Jazz buttons. The output power of the push-pull stage is 6 W at the onset of clipping, the final tubes are run far from their limit. A separate button selects a tape recorder input. The dial. The chassis is almost identical to that in Opus 6 with the exception of the fixed tone registers.
The tubes are ECC85, ECH81, EF89, EF89, EABC80, EC92, EL84, EL84, EM84. The AM-bandwidth can be switched to smal (narrow) with a button that changes the amount of coupling between the coils in two IF-transformers. On the SW-band there is bandspread by means of the UKV-knob (KW-Lupe). The ferrite antenna for LW and MW can be rotated with a knob and in one end position an external antenna is connected. A nice feature is AFC on the FM-band which I haven´t seen on any other tube radio. The tuning knob has three white buttons and when any of them is pressed down the frequency lock is released.
I replaced three weak tubes, four leaky capacitors and two fuses and I put silicon diodes in parallel with the selenium rectifier to eliminate its voltage drop. My price was 400 kr, half of the original one 798 kr in 1958.
Beside the radio is a three-speed Philips gramophone 22GA214 from 1974, a flea market bargain for 50 kr with a ceramic stereo pickup. Both 78-turn records and modern LP´s give a pleasant sound in Opus.
A Real Radio has a lighted dial glass with station names, a magic eye and shortwave band, and it is used not only for local reception but with an external antenna for listening to foreign stations. It uses tubes and should not be missing in any well-furnished home. What charm does a Far-Eastern made plastic box provide?
E-mail: lenradio (a) passagen.se
