Does anyone have an audio recording of what micro-arcing sounds like they could
post somewhere?
Sam(N3XZ)
-----Original Message-----
From: Topband [mailto:topband-bounces+samjos=epix.net@contesting.com] On Behalf
Of GEORGE WALLNER
Sent: Wednesday, October 07, 2020 10:05 AM
To: Dennis W0JX; Dennis W0JX via Topband
Subject: Re: Topband: RX Power over Coax
I use a 600 foot long run of CATV coax to power a remote pre-amp at the
DHDL-s, delivering +12V/100 mA via the central conductor (return via the
shield). Prior to installing the F plugs I spray the cleaned and prepped
ends of the coax with DeOxIt. I also spray the inside of the female F
connectors. I add a small amount of SS-30 grease to the thread of the each F
connector, tighten the connector using a small wrench (!) and tape the
outside of each mated F connector.
So far, no no noise, micro-arching or other.
Further, I believe that the DC current keeps the contacts vetted, which
makes them more reliable.
73,
George,
C6AGU/AA7JV
On Tue, 6 Oct 2020 04:44:51 +0000 (UTC)
Dennis W0JX via Topband <topband@contesting.com> wrote:
> Regarding the issue of voltage over coax to power the preamps used at the
> base of short verticals, Lee, K7TJR, developed an alternative power feed
> system for his new SMD preamps using a separate RG6 coax. Apparently, K3LR is
> using such an approach to avoid sending voltage down the coax in his 8
> element HiZ array at his contest station.
> DXE has begun selling the new version 2 preamps but the description in their
> catalog does not mention this separate power feed system. The older HiZ
> preamps, and the YCCC preamps, can probably be modified to the voltage with a
> separate wire from the combiner box to each vertical antenna preamp.
> One question I have with this approach is whether an external power wire
> would also need a common mode choke on it. Perhaps Lee could offer some
> opinions on this alternative power approach.
> 73, Dennis W0JXMilan, OH
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|