Down on the corner from me is a distribution amplifier for cable television.
They were using PVC conduit from the meter loop to their switching power supply
charger for the standby power system in the box. The RF from the switching
power supply was radiating from the black and white THHN 12 gauge wires.
Took a lot of work to get them to replace the PVC with EMT. Apparently they put
in all of their distribution amplifiers this way. I wouldn't be surprised if
it's like this in other areas of the country.
The difference with your situation is that here the EMC was continuous, and the
function of these installations is only to distribute cable video.
Parker W5ADD
> On Nov 13, 2016, at 14:42, Tim Duffy <k3lr@k3lr.com> wrote:
>
> Has anyone ever encountered broad bad RFI from a CATV trunk line amp?
> Suspect is 10 feet off a power pole (mid span) - with three quarter inch
> CATV hardline connections. RFI occurs "some days from 10 AM to 4 PM. Covers
> 1 MHz to 50 MHz - pretty equal sig strength end to end. There is CATV,
> Telco, Fiber and AC transmission and distribution all on this same pole.
>
> Your experience with CATV line amps?
>
> 73
>
> Tim K3LR
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