tube amplifiers

[Kevin 84]

I have two tube amplifiers my friend gave me the first one says illegal on 11meters amateur scout it has 8 tubes.
The second one is a varmint 350 XL.
Any input or opinion good or bad on these two amps would be greatly appreciated.

 

[Johnnybgood]

Any amp is only as good as how its used. There are set ways to use it regarding drive levels and loading and tuning. If neither of these are done correctly, the amp will exceed its specs and throw out splatter. Many amps sol off are either faulty or exceed spec, or too expensive to repair. There is more to having an amp than tuning it for maximum output.

 

[Captain Kilowatt]

There is more to having an amp than tuning it for maximum output.

THERE IS?? WELL HELL!! WHY DIDN'T I THINK TO TELL PEOPLE THAT!!

No seriously, there really is and I wish more people realized that and thought that way.

 

[GnG8d]

Tuning at max out and driving to max out are quite different.

 

[Johnnybgood]

I was taught that "IGNORANCE IS NO EXCUSE ". Even with my amp, I am learning something new every day. I am slowly improving on it which can be a steep learning curve.

 

[Captain Kilowatt]

Tuning at max out and driving to max out are quite different.

You know that and I know that and some others know that but unfortunately not everyone that runs an amp knows that.

 

[johnny9]

id be happy just getting to the point of adjustment lol..
from what ive read the varmit was a good amp with strict quality control..i read the guy in charge seen to it every amp they put together was checked by him before final assembly.

im learning myself and have not got far,so good luck with your amp

 

[Johnnybgood]

Ok, well lets remember that some of these cb/ham amps are quite old by the latest standards and to tune or load them properly, each amp will have a handbook which states how its done. Solid state amps.. ie those without tubes, dont need tuning. I suggest you try and get a users manual for the amps or copies thereof, then read it from the front page to the back page, then read it again. Then connect up the amp to the radio and a power meter and put a suitable dummy load on the antenna socket of the amp. This way, you can practice tuning the amp until you get the stated output as per the manual. Also, dont key the amp for long periods, as the tube will get excessively hot and destroy them. Short burst of keying with longer cool down periods is best. Make sure the fan is running as well.

The radio antenna socket connects to the tube input or tvr/transceiver socket. The amps antenna socket connects to the power/swr meter tvcr/input socket and the output socket connects to the dummy load or the antenna. A dummy load is always used during testing to prevent your signal from interfering with others on the channel or frequency.