[Lowfer] 185 overnight

[Bill Ashlock]

Mike R,

>>Awesome. I will look up my test data for the variable inductor I made 
>> >>and post it on the reflector. I wrote it down in a notebook when I 
>> >>did the tests.

>I was using #12 THHN insulated copper for my inductors. I achieved a 
> >maximum change in inductance of .584uh by using two turns of #12 and >two 
>Steward (Digi P/N 240-2081-ND) ferrite beads being movable inside >the two 
>wire turns.

Assume the two turns were larger than the diameter of the Steward cores?

This morning when the sun hit the test loop and final box the dip in current 
was much less than the previous morning when the variable capacitor was 
used.

We have been receiving light rain since about 8:00 this evening and there 
was no consequential reduction in current for the test loop while there was 
a 25% drop in the current for the big loop. This drop is almost totally 
recoverable by changing the frequency so it is suspected that moisture in 
the trimmer capacitor is the cause (similar to the way the old variable in 
the final for the test loop behaved).

I'm beginning to subscribe to the theory that air-variables cannot be used 
in outdoor high Q circuits. Moisture collecting on the plates apparently 
causes a significant change in capacity (sometimes a lowering of Q as well). 
A few nights ago, when it was 15 deg outside, I could blow on the VC and 
lower the loop current by 15%. Another advantage for the variable inductor 
replacement is that it will work far better in the 100w situation where the 
voltage is 10 times higher.

More later.

Bill


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