Thanks for the additional ideas regarding my 160M woes... =20
Wattmeter lies: I've not noticed that in other applications. I added a =
Nye Viking RFM-5 in series and get similar readings.=20
Skin effect: Hmmm... the coil stock for 40 thru 160 is #10 wire, would =
expect that to be OK. I do have a rather huge plate L from a broadcast =
rig I could use, but would have to call on Bob Vila to add a room :-)
What's got me baffled is the behaviour of C2 (Load). I have carefully =
measured and charted both C1 and C2 capacitance versus their turns =
counters so I can easily preset them to their calculated values & =
validate my C1 / L / C2 calculations. Have measured the C and L with an =
AADE LC meter (handy tool !). 10 thru 80 end up 'on the money', on 160 =
load C has to be reduced to abt 600 pF (calculated is 1700 pF) to keep =
screen current safe.
Increasing the plate blocker from 800 pF to 2000 pF helped - Load C =
ended up at abt 1200 pF. Still way off. =20
I have not yet looked at the input side. The input load R is a =
series/parallel pile of 47 ohm 2W resistors. Quite frankly I had =
expected this mess to give me fits on 10M. On 10 thru 40 the input is =
tuned by a coil against the tube input C & works great. No tuning on 80 =
and 160. Input SWR < 2:1 on both 80 & 160. But for drill I am going to =
tack a coil in there for 160. =20
Will post progress.
~~~~~~~~~~~~~~~~
Bill Coleman N2BC
http://home.stny.rr.com/n2bc
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