Sounds like you're trying to fry the fish while they're still in the ocean,
there, Jim.
WB2WIK/6
"Each success only buys an admission ticket to a more difficult problem." --
Henry Kissinger
> -----Original Message-----
> From: Jim Reid [SMTP:jimr.reid@verizon.net]
> Sent: Tuesday, October 09, 2001 4:16 PM
> To: Phil Clements; 2; AMPS
> Subject: [AMPS] Re: CW/SSB Tune Up
>
>
> Hi again,
>
> And thanks a bunch to the several who have commented
> and made specific tune up recommendations! Have
> followed them this morning. Rich, I chickened out at
> just about 345 watts of drive, hi. The grid current was
> approaching/bit exceeding 300 mA; Henry manual says
> to not exceed 350 mA. All of this into the Bird
> load, of course. Bird 43 with a 5kW slug was of no use,
> it is way too slow and does not respond to the 50 wpm
> dits.
>
> Anyway I found that once the tune and load controls were
> at resonance, they did not seem to need to be tweaked
> as the drive was increased beyond 100 watts or so. Hope
> this is correct, or perhaps I need better instrumentation
> to "see" the correct peak output power. But see the next
> paragraph!
>
> I dug out the data sheets which came from Henry when the
> unit was delivered. Per the factory data, there is a difference
> in the tune/load settings between 2500 and 5000 watts out.
> I presume this to be constant Pout, not just peak. For example,
> on 20 meters (14200 test freq.), the dial calibrations for 100
> watts drive, yielding about 2500 watts out, tune is at a dial
> reading of 155, and the load capacitor at 700 (a 1000 reading
> would indicated full load C "mesh" or max C). With 200 watts
> drive, factory data shows tune dial at 160, and the load C is lower,
> at a dial of 460 or seemingly significantly heavier loading of
> the output. Maybe I should do this all over again and just
> use constant key down for the final tweaking.
>
> Another interesting point from the Henry manual. The amp has
> two plate voltage selections. With today's mains voltage here
> on the island, in the SSB "mode", amp not keyed, the plate
> voltage sits at about 5800 V. In the CW "mode", the voltage
> is dropped to about 4300 V. The Henry manual asks that one
> tune up in the CW mode for max output. THEN switching to the
> SSB mode higher voltage "As long as your load has not changed,
> the amplifier should still be in tune. You can fine tune by alternately
> adjusting TUNE and LOAD while driving the amp with a
> constant input."
>
> Well, maybe all of this fiddling is of no point, as I lower
> the drive well down before going to the antenna set up!
>
> 73, Jim KH7M
>
>
>
>
>
>
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