Hi Guys,
I'm getting an old His Master's Voice radio tomorrow, and it probably requires
a 9 or 12 Volt battery that isn't made anymore.
I'm just wondering what the standard deal is for swapping battery connectors
and battery holders.
Is this the done thing?
Or are you supposed to make some arrangement that fits to the original battery connector?
Cheers, Art.

 

I don't have a clue, but I would look into making an adaptor that would convert a modern style battery into an older style. Can you show the older battery dimensions?

 

Not yet, but I suspect it will be one of those long rectangular ones
with two push in terminals.
I think 8 AA batteries could fit in it.
I've seen one in another radio.

 

Good luck. I love the old designs. If I didn't have so many other things going on I could see myself getting into that as a hobby.

 

Those old batteries like you describe might have been "B" batteries with a potential of close to 45 volts. If one of the terminals goes to a plate resistor, check the tube to see what it wanted for B+. There might have been an "A" battery or two. These were big cylinders of 1 1/2 volt output for the tube heaters.

 

Which battery is needed will depend on which of several RCA radio models you've got. Nipper's image was associated with nearly everything RCA made from the time they bought out Victor until the early sixties. My dad had a "his master's voice" radio with transistors, powered by a 9v PP3 battery.

 

I've got a hint that it is a transistor radio going by what Mum said,
but who knows.. I'll find out today anyway. I'd love a working valve radio though.
It might have actually said "transistor radio" on it since I imagine that would have
been a selling point in the day.

Not much of a hobby 'yet".. this one just happened to come my way.
The only radio I fell in love with was an old STC floor standing model that belongs
in a lounge room.

 

I'm too old if I don't see how a transistor radio can be classed as "antique". Better go for the 9 volt battery.

By the way, we did have a 1950's vintage GE portable tube radio. Lots of thorium in the cathodes for emission, 1 1/2 volt heaters, and a "B" battery for the plates.

 

"Transistorized" was a definite selling point! Those radios were so darn tiny you could carry them like a college textbook!

 

I didn't call it antique just "vintage".
Indeed there are certain HMV models that I'd just recirculate,
but some are nice enough to hold on to.

 

Here it is:

And this thing has multiple issues. First of all I know the speaker doesn't work!
How unlikely is that?!
Then there is some other problem which I think is one of the transistors.
These transistors have BCE connections on the schematic inside the case,
but the physical transistors all have four legs so I don't know how to replace one that looks burned.

Considering their relatively low value on eBay, I would guess it's not worth putting
a lot of effort into it.

I'd like to know why the transistors have four legs though....

 

The early BJTs had a something like a second base. Biasing techniques on this lead helped improve the frequency response.

This link may be of help identifying your transistors: http://users.arczip.com/rmcgarra2/xstrcode.html

 

I think that all of it's problems on the PCB are caused because the speaker went close to short circuit.
Replacing it with an arbitrary PNP transistor didn't help.
The fourth lead of all six transistors are connected to ground.

 

These guys really take vintage repair seriously.

http://level1.midwestinternet.com/

http://www.vintage-radio.net/forum/showthread.php?t=19207

 

That first link is just a graphic. Do they have a site?

 

That first link is just a graphic. Do they have a site?

Sorry about that, he's just an enthusiast - I'll try to find it.

This has some instructive pics too


http://ampex.hughescatalog.com/electronics/electronics.html