Does anyone have an audio recording of what micro-arcing sounds like they could post somewhere?
Sam(N3XZ) -----Original Message----- From: Topband [mailto:[email protected]] 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 <[email protected]> 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
