Restoring A 1949 Golden Throat Radio

[Mr. Carlson] has a really beautiful old 1949-era radio to restore and you can watch him do it in a comprehensive video, below. We aren’t sure what we were more amused by: the odd speaker that looks like a ceiling air vent or the sticker on the back certifying that the radio produces the tone of the “golden throat” signed by RCA’s chief engineer.

Electrically, the radio didn’t look that remarkable. Of course, the capacitors were presumed bad and replaced. The video made us remember how much we hated restringing dial radios!

The best part about any [Mr. Carlson] video, though, is the view of his workshop. It looks like some 1955 concept of an orbital space station for one astronaut. We aren’t sure where he gets the bench space to work on things like this beautiful old radio though.

Despite the unusual speaker covering, the speaker itself looked pretty conventional. [Carlson] notes that all speakers are inherently screwdriver magnets. At the end, though, you can hear the sound coming from that speaker and it sounds great. If it’s whetted your appetite for more, this is hardly the first tube radio restoration we’ve shown you.

14 thoughts on “Restoring A 1949 Golden Throat Radio

      1. An audiophile will tell you this curses your children unto the 7th generation and makes Jimi Hendrix sound too much like Marc Knoppfler, but if you DO poke a hole in a paper cone you can fix it with one of those rubber cement type general purpose glues, sparingly applied, like Uhu or bostick orrrr…. damn I never really latched onto the North American brand name, generic stuff I’ve got here is “Fix-all cement” .. just kinda get it filming between the edges of the tear and leave to dry.

    1. There is a very strong magnet in a large speaker like that and in the older devices there’s rarely any magnetic shielding. When you lay it on your workbench, with a bunch of iron implements such as small screwdrivers, screws, x-acto knives etc. laying around, it tends to pick them up from a distance of couple inches and fling them at the paper cone through the cutouts at the back, perforating the speaker before you remember that you should have placed it somewhere else.

      It is literally a screwdriver magnet.

  1. I would love working with you if you have more radios to bring yo life. Anyway, where are you getting the vacuum tubes for replacement or probably is this a transistorized version ?
    I can be easily reach at my email – sabalahaseptsebd@yahoo.co.uk
    Will be waiting for response.
    Thank you for your help.
    Best regards,
    A. S . Davies

  2. Golden Throat was RCA’s magic formula that essentially said if the bass cuts off at a higher point than full range, then the treble has to cut off at a lower point as well “to balance the highs and lows”. So of the bass was poor then the treble had to be as well. The low cut off in cps times the treble cut off in cps had to equal 10,000 or something like that. With AM only 5k at the top, the bass had to suffer. Marketing.

  3. At least a proper old tech restoration, instead of the dreadful gutting of old radio to put contemporary stuff inside.
    It requires a bit of hacking more but the results are better.
    Besides if you really want Bluetooth control on an old radio, you could do it without destroying the existing circuitry.

    1. Exactly! Most radios already have a gramophone (line level) input. Even in hot chassis/ACDC sets, you can do this safely because the bluetooth receiver can stay inside the cabinet and not require extra isolation.
      Usually you can power the little bluetooth receiver from the filament or pilot light supply. Else, just plop a little PSU board in there.

      There is a very smart guy in the Netherlands who made a circuit to convert an AM only radio to an FM radio by hooking up the tuning cap to a microcontroller circuit, that measures the tuning cap capacity, sends a tuning signal via i2c to a suitable digitally controlled modern FM receiver IC, and then feeding the receiver output into the gramophone input. This way the original circuitery stays completely intact.

      You could use that same principle to send a command to a media player to skip tracks (tune upwards -> skip to the next tracks, tune downwards, go back to previous tracks etc)
      The guy actually managed to get a patent on it!

      1. Also in the 50s and 60s there was a bit of a trend of modularisation where the tuner was separate from the amplifier. Hence they could mix and match for various models, low end might get the AM only tuner and 3 transistor amp, high end got the AM/SW/LW tuner and 8 transistor amp. So you can find radios from that era where it’s super simple to find the audio input into the amp side and hook into.

      2. In any case there are also audio transformer, that are easily available and normally used in mic preamps or similar applications.
        And anyway some transistor era set are awesome, like the Brionvega RR 126. In this particular case the BT expansion is easy because the receiver has a tape recorder input,

    2. Indeed only reason to do that sort of job is if the old electronics are beyond repair or the part perhaps a weird vac tube is no longer available but the case is still good.. For me though the old electronics should remain even then so as you learn more or find parts it might be restored – Be a damn strange old device that can’t find the space to stuff tiny modern parts and It is nice keeping the history of the device present even if it doesn’t work anymore.

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