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Re: Topband: YCCC 9 circle preamp failure test

To: Lee K7TJR <k7tjr@msn.com>
Subject: Re: Topband: YCCC 9 circle preamp failure test
From: Mike Waters <mikewate@gmail.com>
Date: Tue, 24 Sep 2019 16:40:39 -0500
List-post: <mailto:topband@contesting.com>
I am convinced that there should be a static drain resistor. But since I
don't know anything about this antenna, I cannot suggest a value.

If I owned one, I might even add a GDT (and/or a low-capacitance TVS diode)
in parallel with the resistor, to help prevent damage from close lightning
strikes. They only have about 2 pF of capacitance, IIRC.

Actually, now that I think about it the TVS diode has a much lower voltage
than a GDT (minimum 75 volts). I don't know if any suitable TVS diode has a
20 kA rating like a GDT does.

Only Lee would know whether my ideas here have any merit. :-)

73, Mike
www.w0btu.com

On Tue, Sep 24, 2019, 2:17 PM Mike Waters <mikewate@gmail.com> wrote:

> Can't you install a static drain resistor to keep that voltage from
> building up so high?
>
> 73, Mike
> www.w0btu.com
>
> On Tue, Sep 24, 2019, 2:09 PM Lee STRAHAN <k7tjr@msn.com> wrote:
>
>> Hi Guys,
>>   Assuming your verticals have a very good insulator there is NOTHING to
>> stop that input capacitor from charging to very high like kilovolt static
>> voltage levels. What I don’t understand is why leakage in that capacitor
>> would cause any trouble or differences if it were not even there.  All that
>> would happen is the vertical would assume about 5 volts DC on the elements.
>> This problem rearing its head would indicate the vertical insulators or
>> something in that path must be compromised as well. Or is the 8055 possibly
>> going in to oscillation with a leaky connection to the element.
>>   Something does not add up here.??? What is the clue that tells you the
>> capacitor has failed. Lack of performance/directivity or noise. Noise might
>> indicate oscillation.
>> Lee   K7TJR
>> Hi-Z Antennas
>>  ...
>>
>>
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