To: topband@contesting.com; TopBand List topband@contesting.com
Sent: Wednesday, January 29, 2014 10:53 PM
Subject: Re: Topband: Bad tower shunt capacitor
Wouldn't 1 5/8 hardline make a better HV RF capacitor?
Herb, KV4FZ
On 1/29/2014 11:34 PM, HAROLD SMITH JR wrote:
Jamie,
The VSWR would change
: Herb Schoenbohm he...@vitelcom.net
To: topband@contesting.com; TopBand List topband@contesting.com
Sent: Wednesday, January 29, 2014 10:53 PM
Subject: Re: Topband: Bad tower shunt capacitor
Wouldn't 1 5/8 hardline make a better HV RF capacitor?
Herb, KV4FZ
On 1/29/2014 11:34 PM
Look closely and you may see a hairline crack on the bad one.
Also look for other possibilities. A number of times I've swapped out
bad matching capacitors without solving the problem, only to find
later it was simply an oxidized connection that needed to be cleaned up
and tightened down.
-boun...@contesting.com] On Behalf Of James C.
Hall, MD
Sent: 30 January 2014 00:27
To: topband@contesting.com
Subject: Topband: Bad tower shunt capacitor
I have an omega matched 120 foot tower and I apparently have a bad vacuum
variable capacitor. Upon applying more than about 300 watts, the SWR goes
Wouldn't 1 5/8 hardline make a better HV RF capacitor?
Herb, KV4FZ
On 1/29/2014 11:34 PM, HAROLD SMITH JR wrote:
Jamie,
The VSWR would change because the arc would change the impedance at the Arc
point. From perhaps several hundred or thousand ohms to
near Zero during the Arc..
73, Price
I have an omega matched 120 foot tower and I apparently have a bad vacuum
variable capacitor. Upon applying more than about 300 watts, the SWR goes off
scale. Tuning it out and trying again, yields the same thing.
The question is which capacitor is the culprit. These are surplus Soviet caps
I have an omega matched 120 foot tower and I apparently have a bad vacuum
variable capacitor. Upon applying more than about 300 watts, the SWR goes
off scale. Tuning it out and trying again, yields the same thing.
The question is which capacitor is the culprit. These are surplus Soviet
caps
Thanks Steve:
Not bad - I may try that ! :)
The question in my mind was if there was an arc outside the caps, why would the
SWR change ? Anyway, I may be missing something. I haven't been inside the cap
box at the tower for many months so I'll get into it - may be something easy.
73, Jamie
Jamie,
The VSWR would change because the arc would change the impedance at the Arc
point. From perhaps several hundred or thousand ohms to
near Zero during the Arc..
73, Price W0RI
Thanks Steve:
Not bad - I may try that ! :)
The question in my mind was if there was an arc outside the
