----- Original Message -----
From: "Jim Thomson" <jim.thom@telus.net>
To: <amps@contesting.com>
Sent: Wednesday, April 26, 2017 11:06 AM
Subject: [Amps] Alpha 99
Date: Tue, 25 Apr 2017 18:52:14 -1000
From: Merv Schweigert <k9fd@flex.com>
To: amps@contesting.com
Subject: [Amps] Alpha 99
Any Alpha 99 gurus out there, I have an early model 99 with the tapped
plate choke and clapper system. The clapper has finally a hole burnt
in it,
and I was thinking I have seen a late model 99 with just a choke in place
of
all that relay / clapper junk. I usually use Ameritron chokes in my home
brew amps and hoping one will fit the 99, has any one done this?
Also does any one have updates and setup information on setting the
various
pots on the control board?
Need to pull the amp out of service and replace the rear wafer on the band
switch, it was not aligned when built and the rear wafer is 1/2 step
off, thus
burning a contact or two.
Thanks 73 Merv K9FD/KH6
## I believe the alpha used a 2 section plate choke, and the bandswitch
shorted out
one section of the plate choke, when on the higher bands. Done, so both
windings
wont series resonate on the upper bands. The henry 8 k ultra did the same
thing, but
used a relay. Later alphas ripped off the gapped choke idea from
ameritron, and
came out with their own version. IF the newer alpha gapped choke fits,
and is not
too long vs the oem choke, its should work. The ameritron choke, IF it
fits, should
also work.
Jim VE7RF
Actually Ameritron ripped off one from QST years earlier without giving any
credit.....no surprise there considering who was involved playing injuneer.
Then it took them three tries using amp owners as the test bed to get it to
actually work.
Ived used the Ameritron in several Alpha's in the 76 and 78 series, a bit
tight horizontally but doable with an insulating sleeve going past the
blower. The 87A is also doable if that switched choke and relay becomes
toast.
Carl
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