Date: Thu, 23 Feb 2017 15:29:28 -0800
From: Tom Osborne <w7why1@gmail.com>
To: amps@contesting.com
Subject: Re: [Amps] Memories of Many 11 Meter Amps
WRL Galaxy amp had a bank of 10 sweep tubes in it for 2k input. Real
touchy on 10 meters :-) 73
Tom W7WHY
## 1000 volts at 2A of plate current for 2 kw dc input. Thats 20A of
circulating current
in the poor bandswitch + tank coils. Plate load Z = 294 ohms. That would
require massive
amounts of C for both the tune and load caps..and a tiny value tank coil..but
with huge gauge wire
+ tubing..to handle the current. To get around that gong show, they used a V
divider, and stepped
the plate load Z UP to something they could actually build a pi net around.
Then try and balance
the drive power between 10 tubes, then tweak the idle current for each
individual tube. Then try
and get each tube to draw the same current. No thanks.
## It all worked though. Nobody puts 10 x engs in their pick up truck, 1
is good enough.
Not big enough, get a bigger eng. Single tube GG triode amps are easy to
trbl shoot.
2 tubes max.
## OK Roger, race out and get one of those OM power, FCC approved, 4 kw pep
output
auto tune amps, with the pair of chinese FU- tubes in it. Bargain at $7k...
and way less for the
manual tune version. Weighs 100 lbs, comes with a pair of 3 kva CCS rated
torroid plate
xfmrs. Then evaluate it for us. 2.5 kw CCS RTTY + FM, 4 kw pep out SSB +
CW.
That should be plenty of head room for anybody. Array solutions sells both
versions. Tubes are cheap.
Jim VE7RF
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