I recently traded for a linear that has a strange input circuit, at least to
me. The amp is built in a 18 " Bud rack mount cabinet weighting about 150 lbs.
To heavy for 1 person to handle so I deceided to split the RF deck from the
power supply and put it in a taller cabinet along with the exciter. No info
was with the unit. I have used it a couple of times and it works fine . It
uses a pair of 813's in parallel. I started to draw out the circuit finding
that the drive goes to a tuned circuit and then to the sceen grids of the
813's. The control grids are connected together and go to a 10K resistor, the
grid current meter and then to grd. No connection to the drive circuit at all
other than the interelectrode cap. I guess. The plate circuit seems to be
normal. Just wondering if any one has seen something like this before.
Bill K5PML
From [EMAIL PROTECTED] Tue May 23 09:05:13 2006
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Date: Tue, 23 May 2006 09:00:12 -0400
From: "Todd, KA1KAQ" <[EMAIL PROTECTED]>
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Subject: [AMRadio] Great conditions on 75 last night
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Quite a group on the air from the northeast last evening, with an
unusually quiet band to enjoy. Has to be related to the cold snap
we're having, no noise from T-storms adding to the mix.
Some of the guys worked a mobile station in Michigan while I was away
from the switch, and later in the evening we heard Sonny, N3UOF ('up
on frequency') who was using a Collins 30K-1 recently returned to the
air. Nice signal into Vermont and even better into southern NH. W1IA
and WA1HZK made recordings of Sonny and played them back so he could
assess his progress.
One of the more interesting moments came when Chris, KD2XA relayed a
story of his run-in with a rather durable Adirondak mouse at his
cabin. My high point of the night was switching on the transmitter and
being shocked to see the meters barely lift off the pegs, only to
discover I had forgotten to switch from 'Tune' back to 'Operate' after
making a quick check of my bias setting. CRS is setting in.
Never a dull moment with this crew!
~ Todd, KA1KAQ
