In thinking about selling my VHF amp, as I no longer use it, having
replaced it with a HB 8877, I'm just wondering what the typical value might
be.
A military AM-494/R with a PP-638/U power supply all in the original
cabinet. I obtained it in its original form and condition. Built by
Motorola.
It is fitted with the following: The original pair of 4X150 tubes replaced
with a pair of 4CX250B's. The mercury vapor rectifiers, sockets, fil xfmr
and 4 MFD capacitor removed and replaced with K2AW silicon stacks, 2 new 10
MFD (non-pcb) 2500 VDC oil filled caps installed (capacitor input filter).
Screen clamp tube circuit removed and replaced with a solid state regulated
supply (250 V & 350 V switch selectable) with MOV's and OVP and over current
protection. Solid state adjustable bias supply added.
Amp mods are very clean and very professional so as to obtain the original
appearance but with enhanced performance. Operationally, at 1800 VDC and
600 ma on the anodes, it produces some 700+ watts output. Very clean and
very stable in all modes. Class C or AB1. Heavy, weighs in at nearly 200
lbs. This is a real work-horse and would make someone a good medium power
amp.
Any ideas or thoughts would be appreciated.
73
Bob, K4TAX
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