Telamon wrote in message ...
In article ,
"DJB" wrote:
Question to the group,
Is it better to have a separate ground for you random wire short wave
antenna (w/9:1 transformer) and a separate ground for your receiver (station
ground) or can both use the same ground? If both were connected to the same
ground, wouldn't that cause ground loop problems?
Thank you in advance
It prevents a ground loop problem to use isolated grounds.
Huh???? This doesn't make sense to me. Using separate grounds is the
fastest way to cause a ground loop. All grounds should always be tied
together at a common point. It's in the NEC. And all gear should use
it's own single wire to that single ground point. "star configuration"
This assures no ground loops.
It will help
reduce noise from the AC powering your radio from being part of the
³measurement³ in this case the signal of the station you are trying to
receive at the input to the radio from also seeing noise on the AC power
system.
How will grounding a radio reduce AC power noise? If you have AC
noise, you need AC line filtering, not a ground. Or seems to me
anyway...I haven't grounded any of my radios in years. I don't have AC
noise problems, unless I pick up radiated line noise. No grounding
will cure that.
Creating a ground
for the antenna that is isolated from the power ground through the
³transformer² will help reduce the noise floor on received signals.
I don't see how. But even ignoring that, what you propose is a
violation of NEC.
And it's also a way to ensure severe lightning damage if that ever
occurs due to the differences in ground potentials.
If you built a balanced or complete antenna like a dipole the antenna
ground would not help much at all.
True.
The transformer would still help to
isolate the antenna circuit from the virtual RF ground to the AC system
reducing the noise floor.
This confuses me though...What virtual RF ground? Normally, the AC
system should not be an issue if using a dipole. Best way to ensure a
quiet dipole is to use good decoupling. IE: balun, chokes, etc to
reduce noise ingress...
Myself, and this is open to debate of course...I would use a single
ground point. I would use a ground rod at the balun. And that ground
would be bonded to the main house ground system to keep at the same
potential. I probably would not bother grounding the radio, but if I
did, I would use a single wire to the same ground outside the shack at
the balun. There is no way this will cause a ground loop. And will
reduce problems if lightning strikes. Remember the recent lightning
post where all gear in the house was trashed? Thats what happens when
you don't bond all grounds together to keep them at the same
potential.
Of course, I don't consider mine the last word, but I do have to
respectably disagree with your separate grounding proposal...I would
never do that myself. MK
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