To: <amps@contesting.com>
>> Date: Sun, 24 May 1998 00:47:12 -0500
>> From: Jon Ogden <jono@webspun.com>
>
>Hi Jon,
>
>Despite your questions about how to get your 4-1000 to work
>right on ten meters, you seem to suddenly now not have problems with
>performance.
>
>> >The tube might forgive you, but you might not forgive it! 4-1000A's
>> >are notoriously unstable at high anode voltages, and getting a
>> >bit scarce.
>
>> I haven't found the tube to be any more unstable at 6 KV.
>
>They absolutely are less stable with more voltage. A tube in
>a circuit that is perfectly stable at 3000-4000 volts will often
>oscillate like crazy at 5000-6000 volts.
yea, verily. More volts means more gain.
>If the builder uses enough
>conventional non-resonant suppression
Is not vhf suppression anti-resonant? There is undoubtedly no way to
make the anode-circuit non-resonant.
>to stabilize the system at
>higher voltages, ten and fifteen meter performance will almost
>ceratinly suffer greatly.
Greatly increased losses have not been reported by those who tried a
lossier vhf suppressor in 4-1000A amplifiers. Is 1% or so of additional
loss at 28 or so MHz a serious drawback if the lossier suppressor
improves stability at 82 or so MHz?
>..........
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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