Tom, I suggest that you experiment with various types of VSWR meters
before opening your mouth. Many currently in use meters, and including
articles published recently, will lie to you when the load is reactive.
This was driven home to me over 25 years ago while at National Radio. We
had a military contract for a 5KW out, 2-30MHz amplifier. The contract
required that it work over a 4:1 VSWR range since it would be mobile
mounted into various, less than perfect, whip antennas. We finally had to
design a variable, reactive dummy load to satisfy the contract and even
with all Bird components in the system we found ambiguities. Without any
of those old notes to go by, I can only remember that the reactance
became a major issue when combined with very low resistance, and
contributed severely to wrong readings....even on the 10KW Bird
instrument.
Also, please at least read down to the bottom line and spell my name
correctly.
For some of us, adapting the amplifier may make more sense than going
thru the time and expense at the antenna. Particularly when the antenna
end requires expensive components and/or an enviromentally happy
enclosure.
All I made is a suggestion based upon my experience...if you cannot
contribute in a positive vein, without insults, I suggest you take a
deep breath and try again in a few hours.
My Ameritron comments were made as a result of conversations with
engineering AFTER you left the Ohio operation Tom.....1989 or so..I
forget. If they were wrong, I apologize. BUT, it is certainly a bit
cheaper to use a 190pf 4.5KV Tune cap as is in the Ameritrons than to
use the old 250pf 3Kv in the old Dentrons, Amp Supply, etc....all from
the same Oren Elliott supplier too. The 800pf Load cap hasnt changed for
20 years....Heath, Dentron, Amp Supply, Ameritron and some has-beens all
use the exact same part....1KW to 5KW.
Tom..if you wish to continue ANY discussion civilly I will be glad to
participate...otherwise the delete key will rule.
73........Carl KM1H
Your continued comments always welcome....as long as you keep it
technical and not personal.
73........Carl KM1H
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