[RFI] RFI into house from FT-2K

[Tom Rauch]

> Hello  all-- I am a new subscriber to this reflector and 
> have a problem
> --ie.I recently replaced my FT-1000 MP with a new FT-2000. 
> I changed
> nothing--cables,ground system etc.but the new radio gets 
> into the TV,
> security system,computer speakers etc..I have high / low 
> pass filters in
> the proper places,toroids/chokes,wherever I can put them. 
> Put in a new
> 8' ground rod etc.

Bob,

First let me say Howard has an excellent suggestion. Swap 
the radio out very carefully with NO other changes and see 
what happens.

Now let me interject a few things that deal with some common 
Ham myths and misconceptions.....

1.) The ONLY possible reason to need a ground rod in a 
system with proper antennas is for electrical safety. A safe 
installation requires the ground system be bonded to the 
power mains ground rod outside the house. There is 
absolutely NO reason, RFI wise, to ground the station unless 
you have an antenna system that creates significant common 
mode currents on cables. If you have this problem don't 
band-aide it with grounds and special wiring, fix the RF 
ingress coming back down the cables.

2.) Shield connections at each end of the RF cables are 
hundreds of times more important than the routing of cables 
or the quality of cables, assuming the cable is even 
reasonable construction. A single shielded cable with even 
"80%" or "90%" shield coverage will cause virtually no 
problems if the cable has good connections at each end. RFI 
is normally caused by substantial problems, like an open 
shield or a poor antenna design.

3.) There are also certain pieces of equipment that cause 
problems, one that comes to mind is an antenna tuner with 
paint under the screws. One friend of mind had a tuner that 
actually intentionally insulated the case of the tuner with 
insulators!! The designer intended that to reduce losses, 
but that was sheer nonsense. All it did was cause RF in the 
shack.

If you only changed the radio and disturbed nothing else and 
now have RFI problems, and if you don't have them with a 
dummy load, you probably have two things going on:

1.) You always had an antenna common mode current problem 
but had it hidden by a lucky layout. You perturbed the 
system and your luck went away.

2.) The radio might have a loose or poor ground on a coax 
connector or the cable connecting the radio, or perhaps you 
loosened up another RF cable when you moved the radio.

Many people just throw changes at a system and think they 
magically "fixed" a problem, but what they really did was 
find a way through accidental "monkeying" to make the real 
problem reduce in level enough to stop affecting a device or 
devices. It's an absolute fact that an RF ground is not even 
required if the antenna system up to the connector on the 
radio is proper. Even with cheap coax.

73 Tom