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PT9797A's Linear Power Amp Amnesia

Robb

Honorary Member Silent Key
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Dec 18, 2008
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Silicon Valley CA, Storm Lake IA
I was found in the garage today.
What am I?
A blue box that has been sitting for years with no brand name on me anywhere.
Covered in dust, but intact.
Opened up and I have two output transistors and four Sigma relays.
The numbers on the output transistors are "PT9797A" x2 = how much power am I?
I am narrow (3 1/2" wide), 10 1/3 long, and about 3" high.
I have a low/high mini-switch on the right, a SSB/AM-FM mini-switch on the left, and a 'on' LED center-left and a 'on/off mini-switch center right.
My aluminum heatsink on top is ribbed but not painted.
What is my name and model, and how much power am I good for?
 

100 watt 10-12 meter amp of some kind. From what I can find, that transistor is the same as the MRF450A (also not made anymore), which was a 50 watt, 30 mhz device. Take some pics of it inside and out and post them.
 
it sounds like the blue bilinears with pep/rms on the high low power switch, if it is they were 100w as mole says.
 
Robb,

Was the amp you found, like this one?:

$T2eC16ZHJGIE9nnWrP1CBQcEubc9wg~~60_57.JPG


And here's the pills...

$T2eC16VHJGoE9nuQffD0BQcEuFBMl!~~60_57.JPG


I just purchased the one in the pics. I can't seem to find much on these, other than they were made as far back as 1977, and there's another like amp labeled "Hooker" on it.
 
I have one of those from back in the mid-70's, labeled "Bimbo Bilinear" as in the above post. Mine has PT9784A's for transistors which, IIRC were listed as 75W devices. As Bob85 said, the PEP/RMS switch is just a Hi/Lo switch. Mine would do 90W/60W, again IIRC. I beat the snot out of the thing and only ever had to replace a relay. Just my $.02, FWIW.
 
This is an old thread. Thing is, I still have this box and it still works the last time I tested it. Mine has no markings on it other than the lettering for the switches. The heat sink fins are not painted either. Other than that, it is the same size, shape, and looks exactly the same as the picture you posted above, TurboT.
 
It was a fairly common design. Lots of them produced under names like LDO, Golden Hooker, Bimbo, DSS, and a few others I can't think of right now.
 

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