Any info on old Stam Comm SC-50T-BIL ??

[Tony LI]

I picked one up at a garage sale a couple years ago. Tried it and it worked fine, but never ran it on anything. Any info on it would be appreciated....I know very little about this stuff.

How many watts output? (I assume about 50?)
How many watts dead-key should I drive it with?
I opened it...it has two relays?...and two finals? (marked TRW PT9805 7617....if that helps any). Were these good finals?
Somebody told me they were predecessor to Black Jack or Black Cat?

Thank you for any help you can give.

Tony.

 

[bushwacker]

Its hard to find info on those old TRW transistors..... expect about 80watts out of the pair( this depends on how its driven) . Its actually a decent amp..... there are many of them still working and kicking around. I seem to run into alot of them up here in Canada. I have a few of them kicking around here in the parts bins.
They are basically just a small little class c amp..... they do have a cool output transformer... but besides that they are built on the "light " side.
The input tuning isn't the best, but its nothing to worry about.
1 relay is used for keying, and the other for a pre amp. The reason alot of these have lasted is you can drive them with a little higher carrier ( if they are stock)... these were built during a period where it was naturally expected that if anyone hooked up a CB amp, they would be driving it with a 4 watt carrier ( stock output power for cb). So they built their amps like alot of companies did during that period and put a resistor in line with the rf input to the push pull circuit. Even though you may be driving the amp with 4 watt carrier.... the wattage that makes it to the actually rf amp is alot less.
I've personally found that these type of amps will tend to put out a good amount of carrier power but not alot of swing ( provided they haven't been modified). Regardless its still a decent working amp that you can hit with a little higher carrier. If you look to the right of the larger output transformer you should see 2 bigger resistors....those resistors are what drops the rf input down... Alot of guys might call it a "swamp resistor"...if you follow down that same trace you will get to the input transformer and tuning cap ( input). If you really wanted to, you could retune the input ... but I would'nt bother.

I don't know what else to tell you about it..... you can drive it with a higher carrier than whats normally used in the cb community. Its not a big swinging amp.... but should put out a decent amount of carrier and some swing on top. Its kinda harder to get big swing out of it.

The amp may not be meant for the "big power guys" or the "key down " scene.... but its an OK amp for the average user, and someone that would want to plug in a stock cb and go.

Take care.

 

[Tony LI]

Thank you....

That's exactly what I was looking for. I have no way of knowing what it puts out. Don't think my ParaDynamics multi-meter reads power output all that well, but can't expect much for the price. Thanks again.

Tony.

 

[74IN]

Sounds something like this.

 

[Tony LI]

That sure looks like it.

It's slightly different on the outside (lettering, etc), but the inside looks identical from what I remember (don't have it in front of me).

 

[Switch Kit]

1 watt in and let the amp take care of the rest , if you really want to know and do it right , you can have a tech bench your radio and amp together and he will match them and tell you what's really going on. But I'd say about 1 watt in should be more then enough and on the safe side. Better safe then sorry. Good luck to you Tony LI

 

[Mikey1966]

Its hard to find info on those old TRW transistors..... expect about 80watts out of the pair( this depends on how its driven) . Its actually a decent amp..... there are many of them still working and kicking around. I seem to run into alot of them up here in Canada. I have a few of them kicking around here in the parts bins.
They are basically just a small little class c amp..... they do have a cool output transformer... but besides that they are built on the "light " side.
The input tuning isn't the best, but its nothing to worry about.
1 relay is used for keying, and the other for a pre amp. The reason alot of these have lasted is you can drive them with a little higher carrier ( if they are stock)... these were built during a period where it was naturally expected that if anyone hooked up a CB amp, they would be driving it with a 4 watt carrier ( stock output power for cb). So they built their amps like alot of companies did during that period and put a resistor in line with the rf input to the push pull circuit. Even though you may be driving the amp with 4 watt carrier.... the wattage that makes it to the actually rf amp is alot less.
I've personally found that these type of amps will tend to put out a good amount of carrier power but not alot of swing ( provided they haven't been modified). Regardless its still a decent working amp that you can hit with a little higher carrier. If you look to the right of the larger output transformer you should see 2 bigger resistors....those resistors are what drops the rf input down... Alot of guys might call it a "swamp resistor"...if you follow down that same trace you will get to the input transformer and tuning cap ( input). If you really wanted to, you could retune the input ... but I would'nt bother.

I don't know what else to tell you about it..... you can drive it with a higher carrier than whats normally used in the cb community. Its not a big swinging amp.... but should put out a decent amount of carrier and some swing on top. Its kinda harder to get big swing out of it.

The amp may not be meant for the "big power guys" or the "key down " scene.... but its an OK amp for the average user, and someone that would want to plug in a stock cb and go.

Take care.

They are class C for SSB use. I have one that peaks 200 watts with 15 swing on SSB. On AM I use a 2 watt carrier & swing 15 , gives me 40 watt dead key & swings 200 with 15 pep swing. The tuned input on mine is perfect, 1.2 SWR. Mine has adjustable tuning on the input & output transformer. I barely moved it & it was 1.2 maximum output peak 200. Nice sideband bi-Leanear.