Palomar Model 150 Amp questions

[Robb]

Local op that often comes by my house and brings several CB radios for me to fix, has just plopped down a Palomar 150 amp to for me to look at and see if it is working. It uses a pair of 6DQ6's in it, which are not the original tubes. The originals were 8950's according to the schematic.
http://www.cbtricks.com/Amp/palomar/150/graphics/palomar_150_tube_sch.pdf


Now, The instruction sheet from CB Tricks says that it is a 150w amp and requires 3w to drive it.
Q: What is the PEP maximum that can go into this amp with the 6DQ6's?

http://www.cbtricks.com/Amp/palomar/150/graphics/palomar_150_tube_inst_sheet.pdf

There is also a wire that is dangling on the back coming out of a rubber grommet; what is that for?

Now I have little/no experience with CB tube amps; mostly have worked on the solid state amps, so I have little experience with the tube amps.

Anyone that can give me any tips or tricks to know or general knowledge, I would much appreciate it.
Thanks!

 

[Robb]

Guessing that nobody knows anything about this amp?


Kinda hoping the Xit13, NomadRadio, or someone with experience with this amp would know something about it.

 

[wavrider]

basic straight forward tube type schizio
Wire hanging out the back is most likely the Power wire going to battery.
what usually fails are the transistors, in this case the 2n4048.

Basic safety rules apply,
Test caps for shorts,,check diodes to see if they are good, test transistors
If all ohm out and check out with the ohm meter
then test the tubes if you have a tube tester.
Seems like they wired a couple 6.3v filament tubes in series to use 12,6v to light up the filaments.

when done with all the preliminary testing, put a fuse inline, connect to power source and see if any thing smokes

 

[Robb]

Thanks wavrider.

No; the wire coming out of the back is like a 22ga wire. Real thin. I can see where the + and - terminals are for the amp power in; just cannot figure out what this stringy piece of wire is for. I've seen a picture of this same amp on the net and it shows the same stringy piece of wire coming out of that amp thru the same grommet.
Weird.

 

[wavrider]

Robb where does the wire connect inside the amplifier?
My guess external control connection for standby/operate
Most people hunt down an old transformer from a sweep tube amp and convert the mobil amps to base type amps with external transformer.

 

[melaza]

Hi,

Set 3W and 80 ~ 85% mod.