[RFI] Weird RFI Episode

[Pete Smith N4ZR]

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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