[Amps] CB etc Amps

[Roger]

>> Often, money spent on a better feedline or the replacement
>> of an old one
>> might yield better results than trying to squeeze 700w
>> (dirty) out a 600w
>> (clean) amp.
>
> That's true with tubes and many HV FET's, but with bipolar
> transistors the distortion starts to ramp up long before
> anything close to saturation occurs.

I'd like to build a solid state amp capable of running the legal limit plus 
a wide safety margin with the HV (50 and 100) FETs available today, but the 
price of mistakes is a bit steep<:-)) Then the control circuit for over 
current, over voltage, SWR shut down, excessive drive shut down, and drive 
on the wrong band gets a bit more complicated. OTOH with today's ICs the 
shutdown can be done with little delay. Although it's been a while I think I 
could handle the machine language programming. I'm just not so sure about 
the measurements.

My Tokyo HK-1.5Kfx runs almost as much power out on HF as does my old Henry 
2K4 without near the heat. OTOH my *old* Alpha 76A doesn't throw out near as 
much heat as does that 2K4 either.  Then again, I could purchase a lot of 
electricity for difference between what I paid for the 1.5K and the 2K4 
<:-)) Even in good shape and with a good pair of tubes the old Henry amps 
are typically in the $700 range. Some go higher, but they need to be one of 
the *BIG* ones to bring much more. I see quite a few with the initial bids 
around $1200 that end with zero bids. They are big and they are heavy. Not 
exactly table top.

73

Roger (K8RI)