Bob...
I don't think you have anything to worry about, and there's really no need to
use ALC - fixed OR feedback type - to protect the tubes. 4CX800s in the ALPHA
99 are very well protected, as are the tubes in all modern ALPHAs. My guess is
that leading edge drive spikes will scarcely be noticed, if at all.
To minimize on-air distortion and interference from such spikes, though, it is
important to set up the transceiver properly. IMO, the most commonly-made error
is to set the xcvr's internal "drive" control - sometimes labeled differently,
e.g., "processor out" - too high. Transceiver internal ALC peak action
shouldn't exceed roughly 6 dB, or about half-scale on the ALC meter range (if
the xcvr has one).
If you want more specific details relative to the '99, you might talk with John
Brosnahan or one of the techs at ALPHA/POWER: (970) 535-4173. E-mail
<w0un@aol.com> or <apicontact@aol.com>.
Good luck!
73, Dick W0ID
-----Original Message-----
From: robert kirkland [SMTP:w5pvr@benzie.com]
Sent: Friday, September 17, 1999 11:16 AM
To: amps@contesting.com
Subject: [AMPS] Alpha 99
Am thinking about buying a Alpha 99, would like to use tetrodes again but
concerned
about the ability of those Russian tubes to hold up under the leading edge
spikes from
the Icom 706. Would a constant negative 3 volts or so bias on the alc input
prevent this ?. Any and all comments appreciated. Bob, w5pvr@benzie.com
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