[Amps] The cost of amplifiers

[Bill Coleman]

This discussion has been fun to follow - and it generated a lot of 
activity on the reflector!

I have a military amp, designed in 1962 as I recall.  A Harris RF-110 RF 
deck & RF-124 power supply.  2-30 MHz in 19 bands, no-tune, 1000W output 
(per spec) continuous duty.  I picked mine up for $900 about 20 years 
ago at a military surplus outfit in Virginia.  There are still a couple 
of sources, last I saw the units offered were brand new - 50 years ago - 
and priced at $3.5K.

Inside, there is a pair of 4CX1500Bs driven by a pair of 8122s. Outside, 
80lbs or so of RF deck and 100+lbs of power supply.  Not exactly portable.

You need to find some military spec connectors and make cables, an 
attenuator for the input (only needs 100mW), and there are some fun 
homebrew opportunities for an easy to build remote control box (needs to 
be remote as the amp is not exactly quiet because of its 11,000 RPM 
cooling fan).

Oh, 1000W output....  I have a picture of my LP-100 showing 2400W on 40M 
- into a dummy load of course.  1500W output is easy.... well, actually 
it is kind to hard to hold it to 1500W at times.    Plus if you run the 
your exciter into a 30dB attenuator, the exciter is always happy 
"looking" into a 50 ohm resistive load.

Tubes $:  Recently picked up a new pair of 4CX1500Bs for $500, and a new 
matched pair of 8122s for $150 - ready for the next 50 years.

However.....  a failure in the right place (driver plate orPA plate 
matching networks) could be fatal, they are full of  custom made parts.  
But.... $3500 for a parts unit and I would still be well below the $10K 
mentioned at the start of this thread - and that would add one more set 
of tubes to the spares inventory. Heck, a brand new pair of 4CX1500Bs at 
Richardson are the best part of $3500.

The last 20 years of using this amp has been a combination of superb 
performance by the amp and fun building projects.

Thanks to all on the reflector!   73, Bill   N2BC