You did so well with the last amp......

[SuperLid]

Any memory of the actual value of the resistors?
I can't believe that this thing is that old!!!!

Is it even possible that the transistors COULD be good anymore???

Here is the schematic. I saw that yours has the AB mod installed. It would be the same as the 1010SB. Most of the component values are not on the diagram.

 

[Shummy]

Here is the schematic. I saw that yours has the AB mod installed. It would be the same as the 1010SB. Most of the component values are not on the diagram.

Indeed! https://cbtricks.org/Amp/digital_sport_systems/500_1010/tour.html

 

[guitar_199]

Wow! My hat is off to you two. AB mod??? That would seem to imply to me that this was originall an "AM ONLY" amp.... but was modded to class AB for SSB operation. Is that anywhere close to true?

I am kind of confused though... this amp has an SSB/AM switch on it....and that switch is on the schematic.... so it would seem that they THOUGHT it was fit for SSB......... but from my understanding... SSB only works with AB biasing.

Maybe I ought to shut up!!!!!!!

But seriously, thanks for being able to find all of this!!!

Bob

 

[BC Coyote]

this amp has an SSB/AM switch on it

Prior to being modded for A/B operation, that switch simply switched in a small delay so the amp didn't chatter in SSB operation.

 

[SuperLid]

Wow! My hat is off to you two. AB mod??? That would seem to imply to me that this was originall an "AM ONLY" amp.... but was modded to class AB for SSB operation. Is that anywhere close to true?

I am kind of confused though... this amp has an SSB/AM switch on it....and that switch is on the schematic.... so it would seem that they THOUGHT it was fit for SSB......... but from my understanding... SSB only works with AB biasing.

Maybe I ought to shut up!!!!!!!

But seriously, thanks for being able to find all of this!!!

Bob

I am intimately familiar with it. I have two of them, that I have completely redone my way. I have one that does 100 watts but very clean and the other around 200. I fitted bigger devices in the 200 watter. One is a Firebird, the other is a DSS.

 

[unit_399]

Looks similar to an old Skeleton that Texas Star used to make. This one looks older though maybe 1980’s.

The TS "Skeleton" did not have a pc board. It was inexpensive at the time, and actually worked very well as a driver amp. It was a total bitch to trouble shoot, and replacing parts was an even bigger PITA. The big problem with them was that the long lead wires from the input and output transformers made them susceptible to self-oscillation. So. . . they weren't very popular.

- J.J. 399

 

[nomadradio]

The chemistry inside the RF transistors should be stable for a very long time. Not like an electrolytic capacitor that degrades predictably.

TRW did get out of the transistor business a long time ago. Finding a data sheet will be like pulling a rabbit out of a coffee cup.

But you only have to overdrive them once to poof them forever.

73

 

[SuperLid]

I thought I would try this one. I know it is a Fire Bird. The model is F100/BM. Just by the name only, someone else said it was a 2 tube linear capable of around 300 watts. This thing is small.... plus..... this thing has two transistors in it. I can not find any information about this (the /BM) model at all. any attempt to search F100/BM comes back as a F100 and it is a whole different kettle of fish. Has anyone seen one of these?

 

[SuperLid]

The Firebird experiment.

It has been reworked several times since these were taken. The transistors in this photo didn't work out, nor did their AB mod. I used a solid state AB switch and the transistors that were from the factory for the best result. I had tried some bigger devices in it too, but they are in the DSS amp now. The T/R relay doesn't like the higher power in that amp.

The amps were crap and a bitch to work on IMHO, but it was an experiment to me.

SL