>> Rich Measure's recent post about running a 8171 at 2.5 KV and 1.5 KW out
>> is interesting too. His comment about cooling at amateur power levels
>> and the chassis space of a 4-1000 frames the question nicely.
>The other concern here is the cost of the 8171 (> $1K new) and the air
>socket ($350 - $500). The cost can be improved by scrounging but I don't
>know if the 8171 solution can be made competetive with a new 4CX1600 or
>8877 pulls. Of course, the 8171 is strictly a homebrew solution ... not
>an option for the majority of hams.
? 8171s with ok emission and cosmetic probs. can be had for a few
hundred dollars. I paid $75 for a surplus sk300a socket. If one spent
$600 for a tube and socket, the cost is $30 per kW pep when the tube is
operated at max. capability. The 8170 and the 8171 are the two most
parasite-damage resistant tubes I know of. There is no gold plating on
the grid to sputter off during an intermittent vhf parasitic-osc. The
cathode design can resist virtually anything except being dropped on a
>> So what if you can heat your shack with the filament power (pun intended).
>You may need the heat "up north" ... I want to cool my shack with the
? The good news is that the 8171 does not need to be left on because it
is "instant on". Thus, it makes no heat when laying in wait. When I
ran one, I found that I needed it only occasionally. During the summer,
I opened the window to let the heat escape. During the Winter, I used it
to take the chill off of the room in the mornings.
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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