I just checked mine on 40M and when on CW Temp is
bouncing all over the place. Same into a dummy
load as the antenna 300ft away. It also does it
to a lesser extent on 80M and a little bounce on 17M and 10M.
I suspect its in the amp and not related to common mode RF in the coax.
Probably a cap in the right place would fix it.
- Paul
At 11:20 AM 8/18/2018, you wrote:
Some baluns offer good common mode current
rejection while others offer virtually no common
mode rejection.  {See DJ0IP site and
discussion on baluns.}Â Since the feed line
from the balun runs down the tower to the point
where the feedline runs underground, that
segment of feedline is exposed to radiation from
the antenna. Certainly common mode current can
be a very realistic occurrence in this case.
..........." it's some sort of new
hyper-super-ultra-infina-deluxe type never
before discovered on earth."  Nope, it is
just basic physics regarding the properties of
RF induced currents.   Depending on band, a
choking impedance of 300 to 5000 ohms may be
needed to resolve the issue.  Since it was
disclosed as power related, this supports the
issues of common mode currents. Good luck in
finding and correcting the matter. 73 Bob, K4TAX
On 8/18/2018 12:20 PM, Jeff Blaine wrote: > Odds
are not good there. The antennas have a balun
at the feedpoint, > are on a tower 500 feet from
the shack and the hardline runs under >
ground. If there is common mode involved, it's
some sort of new >
hyper-super-ultra-infina-deluxe type never
before discovered on earth. > > 73/jeff/ac0c >
alpha-charlie-zero-charlie > www.ac0c.com > > On
18-Aug-18 7:12 AM, Bob McGraw K4TAX wrote: >>
I'd say a bit of common mode current on the feed
line.   I see that >> from time to time with
my KPA500 on certain bands/antennas. >> >>
73 >> >> Bob, K4TAX >> >> >> On 8/17/2018 11:45
PM, Jeff Blaine wrote: >>> While running the
KPA1500 in the SARTG tonight, I noticed that
the >>> temp reading drops about 10C when
transmitting. min fan speed 1. >>> >>> Seems
to be related to power - at 1500W it's pretty
close to 10C. At >>> lower powers, it's less of
a difference. I don't recall seeing that >>>
before. >>> >>> Normal? >>> >>> 73/jeff/ac0c >>>
alpha-charlie-zero-charlie >>>
www.ac0c.com >>> >>>
______________________________________________________________
>>> Elecraft mailing list >>> Home:
http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm >>>
Post: mailto:Elecraft@mailman.qth.net >>> >>>
This list hosted by: http://www.qsl.net >>>
Please help support this email list:
http://www.qsl.net/donate.html >>> Message
delivered to rmcg...@blomand.net >> >> >>
______________________________________________________________
>> Elecraft mailing list >> Home:
http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm >>
Post: mailto:Elecraft@mailman.qth.net >> >> This
list hosted by: http://www.qsl.net >> Please
help support this email list:
http://www.qsl.net/donate.html >> Message
delivered to keepwalking...@ac0c.com > >
______________________________________________________________
> Elecraft mailing list > Home:
http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm >
Post: mailto:Elecraft@mailman.qth.net > > This
list hosted by: http://www.qsl.net > Please help
support this email list:
http://www.qsl.net/donate.html > Message
delivered to rmcg...@blomand.net
______________________________________________________________
Elecraft mailing list Home:
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm Post:
mailto:Elecraft@mailman.qth.net This list hosted
by: http://www.qsl.net Please help support this
email list: http://www.qsl.net/donate.html
Message delivered to p...@paulbaldock.com
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
