Amp issue?

Ranch55 said:

At least two of these, plus about maybe $20.00 or so in misc. parts, plus any labor......

2SC2879A Transistor "Red Dot" Pb Free, RoHS compliant, Toshiba (Not for Export)

$104.95 ..... at today's current price, can change

2SC2879A Transistor "Red Dot" Pb Free, RoHS Compliant, MFR: Toshiba, No longer available for Export, (NOS)

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357magnum said:

First thing I'll say is I'm No Tech ! I sent my Gray out for repair . But I notice a Black wire w/ white core , in center , runs front - back , connected to a switch on the panel . After where it's soldered it looks burnt , especially in the back , is that just caused from soldering ? In the back it looks like it might have burned a Red wire or something ? Believe me I know nothing on fixing these !

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AudioShockwav said:

Very good statement.
MTBF
Andy is correct.
In Gatekeepers video you see him" put the slug in the corner"
The Toshiba transistors in the amp are capable of doing that, however in this amp it is not built to withstand doing that for very long.
The bias on the TS amps and supporting hardware are not capable of maintaining that kind of out put, my Hot Rod Lincoln comment.
When you start changing negative feedback components and other values to boost power levels you lose any margin of safety that you had in the original design.
The guys at Texas Star put the swamping resistors on the SSB delay because they wanted to pad the input.
That is how they wanted it to be.

I run a TS 500 in my truck and I am happy to let it run at 340/360 watts levels.
I get the power increase I need and it runs clean and cool.
And I have been running it for years like that.
At one time I had a base amp with 4 2879s that would " put the slug in the corner" but it was built from the ground up to run on high voltage and not die.
Even then I always made sure all my ducks were lined up in a row because you are running the thing on the edge.
No I don't have it anymore.
Side note.
If you want that big of an increase in output go big and drive it softly because the transistors are expensive.

Best of luck.
73
Jeff

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Crusher said:

325w deadkey? That was the problem. 150 carrier closer to what it should be.

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AudioShockwav said:

I have to agree with Crusher.

Yeah that was recently before this with the meter after the amp, the radio was at 5 watts swing to around 20ish peak. On a mfj a couple years ago it was saying 325 dk with 575 swing. On low power it was like 225 if i remember right. It's an old amplifire I would say at least 15 years old. It had work done on it around a few times in its life and 5 years ago by gatekeepr that i know. My friend probably had his hand in it a few times and then I got it and I've been using it probably 5 years.

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