Vintage Radio’s

Vintage Radio’s

  • How about a post that has nothing political in it?
  • How about a post that is instructional and interesting?
  • Think I can do it?

Me personally, sometimes I feel like someone is going to have to develop a twelve step program to break the addiction of collecting and repairing these things.  Truth be known some of these are highly collectable and some are well, just not.

I am guessing that if one saves them long enough the radios that are not collectable today will be at some point in the future.

To that end, I collect those that are “collectible” today as well as radio’s that are unique or sought after for some reason ie the Owl Radio from Clash of the Titans.

Owl Radio from the 60's

More often than not I will purchase a collection of radio’s from different sources.  I might purchase the entire collection because one of the radio’s in that collection is collectable or I might get them because I need parts that I know they will render.

Radio from lot

The bottom line is the case must be intact.  It must look good with no cracks etc.  If it is busted all to hell it turns into a parts piece and devalued substantially.

Today I worked on a radio that was marketed to the US although it is typically marketed to the Russians.

Spica
Repaired, aligned and cleaned up….

Someone had worked on it sometime in the past as the slugs were all out of place.  I guess it is terribly irresistible to resist  putting a screwdriver in the transformers and trimmer caps, as I get more radio’s that have been tweaked, by someone with a screwdriver, instead of the proper alignment tool.

IMG_0590

Having said that this radio defies common logic, in that the wire colors that we come to expect over here in the states is backwards.  Red which normally denotes positive, was the negative lead and of course that made the black wire positive.

IMG_0587

When I first apply power to one of these radios I do so with a variable supply.  Turning the radio on first, then slowly increasing the voltage from 0 to whatever the voltage should be whether it be 3,6 or 9 volts or somewhere in between.  The trick is to have a power supply with an amp meter.

Most transistor radios draw very little current.  If you start to raise the voltage and the current starts to jump and maybe hold at 10 milliamps or so, check your polarity.

Bottom line is that after I figured out that the power leads are opposite of what one might expect the next thing needed was an alignment.

In most radio’s like this you start with injecting a signal at 455khz.  After tuning the proper transformer and trimmer cap for this, than I move on to tweaking the rest of them for maximum sensitivity at 1600, 55 and finally around 800khz.

The process takes less than a five minutes and when finished the radio is as good as new.

Most of these vintage electronics need new caps “electrolytic capacitors.”  Caps made in the day were expensive so the manufacturers used the minimums that they could get by with.   Tracing and/or injecting a signal one can usually tell which if any caps are bad, and within moments, have the audio back to where it should be.

Radio needing new caps.
Radio needing new caps.

Some of the newer capacitors on the market are NP or non-polarized!  Too often I pull out and old cap to find I did not remember which direction to install the new one as I need to keep the negative and positive leg in the correct holes.  With NP caps simply install them and move on.

I suggest that you take pictures before taking too much apart as without a print if a wire pops off, you can have a devil of a time figuring out where it went.

Six transistor radio’s are the most common and really all you need to pull in strong station and actually differentiate between the different stations without too much overlap.

Eight Transistor Radios have much better sensitivity and are able to differentiate strong stations from weak ones thus, you can have much better selectivity.  My favorite radio to actually keep batteries in are the 8 transistor variety.

Some manufacturer’s in the day found that they could use the PN junction as a diode but yet claim that they had 10, 12 or even 16 transistors!  The unknowing public equated that to the “jewels in a watch.”  The more the better and so they had a gimmick until some government agency clamped down on them.  If the transistor is being used as a diode it cannot be counted as a transistor.

Ross to name just one of the brands was one of the manufacturers that became famous for this tactic.

Shortly after Bell labs came out with the transistor Raytheon and a company named Idea came out with the first transistor radio.  It was know as the Regency TR-1.

regencyTR-1

regency_mod_TR1_schematic

These are highly collectible even today.  Around $100 might get you one that the case is basically in tact.

closeup_front_gray
This is a nice looking example of the TR-1

Before this portable radio’s were tube based and used two different batteries to play them.  One of the I believe was a high voltage battery known as the “B” battery, and one drove the filaments and I think it was 1.5 volts.

HARPERS_JAPANESE_SMALL_TUBE_PORTABLE_BROADCAST_PERSONAL_RADIO_GK-501_BATTERY_COMPARTMENT

fasj_worth_feb2012

I have a few of these but, with no availability of the B battery, I think that other than something to sit on a shelf; it is a waste of time and energy to collect.  Your mileage may vary…

If I get enough interest I might post more radio stuff in the future as I work on many of these and it is a hobby.

See, no political rhetoric on this post, I can do it!  🙂

-Best and 73

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