Just to be clear - before this, I have had zero problems from hand-tight
PL-259 connectors, going back as far as I can remember (50+ years).
That's why this instance struck me as so remarkable. I've been using
these monitors for 3-5 years.
I've spent a fair amount of time dealing with RFI, both in and out, and
RFI in is negligible except for recurrent powerline problems . My
station is much less complex than it was at one time, but is fully
RF-proofed with toroid chokes where needed and/or recommended, with a
good short ground and a 3/4" copper tubing ground bus along the back of
my desk, to which RF-handling devices are connected by short, direct,
heavy conductors.
73, Pete N4ZR
On 9/25/2023 5:53 AM, Jim Brown wrote:
On 9/25/2023 2:10 AM, Jack Ference wrote:
You must always “Frank” all PL-259 connectors using a small wrench to
complete the physical and electrical connection.
And Frank emphasizes, as do I, that all connectors, including barrels
and adapters, must be first quality. For me, that means Amphenol
83-!SP for cable-mount males, and comparable adapters; in the case of
adapters, stamped MIL-spec used/surplus parts that I buy at ham flea
markets. I'm not familiar with qualifications of components in parts
of the world other than North America.
While there may be decent parts by other vendors sold as OEM parts to
mfrs, some of which have the capabilities to QC them, I have learned
not to trust anything but Amphenol and MIL stuff. If it isn't that
top-quality Amphenol or MIL, I consider it JUNK.
When getting back on the air in 2003, I built a parts stash of various
adapters from hamfest vendors, including those who advertise in QST.
Over 5-10 years, those parts caused me all sorts of grief. Tees and
elbows had tiny wire springs rather than the solid centers of real
adapters; I had one melt during a contest. Others generated
intermittents that were a pain to troubleshoot. A three-way female
tee, supplied by a mfr of a VHF antenna, fell apart mechanically!
And don't get me going on the glorified zip-cord sold for power and
speakers, which has super-thick insulation but with copper that's much
smaller than the advertised gauge. AND the zip cord is LOUSY for RFI;
ALL power and audio cables should be TWISTED PAIR, which strongly
resists RFI, HUM, and NOISE, while zip cord does NOT! Cables for ALL
such installations should be twisted pair, including those when they
carry PULSED DC for applications like solar systems, where the charge
current PULSE-MODULATED DC rectangular waves; that content is DC plus
a VERY strong broadband RF component. The same is true of what goes
into and comes out of CD-AC inverters. BTW -- the ARRL book on
alternative power is a train wreck about this stuff!
This reflector is about RFI, so I'm going into the weeds, which is
where the bodies are buried!
73, Jim K9YC
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