Also check the contacts on the bandswitch. I have that amp and have a
similar problem with 160 operation, apparently from burning out one of the
contacts on the switch. It would be a bear to change out, even if you
could find a replacement, so I just don't run that amp on 160 any more.
Good luck with it.
Vy 73,
Don W4ZYT
On Thu, Dec 17, 2015 at 8:30 PM, Tom W8JI <w8ji@w8ji.com> wrote:
> Just came off 20M, amp working fine. Went to 160 plate and load controls
>> have no control, no output. Plate current climbs high with any added drive
>> (45-50W) and blew both 10amp fuses.Off comes the cover.jimk2hn
>> _________________
>>
>
> It might be something else, but I would bet the contact on the 160
> padding capacitor is burned off. This is what the anti-corona washer
> reduced. Heath did not use that washer.
>
> It arcs there when the loading cap is too far closed (too much grid
> current) for the amount of drive on higher bands, or if the antenna should
> become grossly mismatched when at high power on bands other than 160. The
> worse band for arcing the 160 padding contact is when on 80 meters.
>
>
>
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
--
Don Lynch MD W4ZYT - EI2IM, 5Z4ZK
Virginia Beach, Virginia
ARRL - IRTS - ARSK - Virginia DXCC - PVRC
FOC 1700 - RNARS 4473 - FISTS 3381 - CWOPS 55
w4zyt.don@gmail.com
==
Donald F. Lynch, Jr., MD, FACS
Emeritus Professor of Urology
Eastern Virginia School of Medicine
Norfolk, Virginia, USA
_________________
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