[Lowfer] Mylar caps???

Sun, 3 Aug 2003 00:49:32 -0500

Excellent. I have an ample supply of big transmitting mica's for the high
power tuner box. I run a Mylar in the final amp now and it seems to be fine.
I have noticed lately after running the beacon for several months that the
output toroid in the lowpass filter is warm. Not hot but warmer than the
outside temp all the time. The finals you sent run stone cold all the time.
I was thinking of jumping around the filter and seeing what the loop current
would do without it. I am pretty sure there is power being used to heat that
toroid that could be more well used in the loop instead. Oh well, I have to
get this loop back in shape as the wind made it grow a bit this summer. I
had to add 200pf to it to get it back in resonance 2 weeks ago.

Mike>WE0H

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Bill Ashlock
Sent: Sunday, August 03, 2003 12:37 AM
To: [email protected]
Subject: RE: [Lowfer] Mylar caps???

>Only DC-200kc projects. I was just digging around a site
>http://www.goldmine-elec.com/ tonight and seen various Mylar caps at decent
>prices.

These will work fine as the series capacitor between the transistor pair and
the output transformer where the circuit impedance is ~70 ohms (24v supply),
BUT not in the resonant capacitor bank that resonates the loop where the
circuit impedance is ~1 ohm.  One time I tried them in this application and
the Q was way down.

Bill A

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