moth . wrote:

My HT, power supply and amp are in the living room. The coax runs into
the kitchen with a Diamond 2 meter magmount antenna out the kitchen
window on a steel plate. I have had no problems for 11 years.

Yesterday I keyed down and heard a buzz coming from the kitchen. I had a
friend key down, went to the kitchen to see where the buzz is coming
from and it's coming from the outlet next to the window that has NOTHING
plugged into it! My units are all plugged in in the living room. What's
happening here RF wise? If you have any idea, please either post it here
or email me. I have an Extra Class License but this isn't in the books
:-( Thanks in advance!


Since it has worked for 11 years without a problem, my guess is, perhaps
something has changed in the antenna system. Perhaps a loading coil has
given up the ghost. Maybe the kitchen window has been opened and closed
on the coax a few too many times and has destroyed the braid, broken the
center conductor, or just mashed it to where it is making some sort of
impedence bump in the feedline.

You mention the buzz is coming from an outlet in the kitchen. I suspect
this is a GFCI type outlet that is required by code anywhere an
electrical outlet is near a sink or faucet, etc.

What I am suspecting is, your coax is now radiating a signal instead of
delivering it to the antenna and the RF is getting into the GFCI
circuitry in the outlet.

I would-
(1)-Check SWR on the entire system. If you have high SWR, try replacing
the antenna. If that doesn't solve the problem, then the problem is
most likely in the feedline and that will need to be replaced.
(2)- Visually inspect the feedline for wear, distortion, etc.
(3)- Try routing the feedline differently away from the outlet if possible.

I am curious, how much feedline you have between the transmitter and the
antenna. Since you mentioned the radio was in the living room and went
out the window in the kitchen, I am going to guess you have at least
30-40 ft of feedline. I am also going to guess that you are using RG58
type coax since it is going through a window.

If this is the setup you are using, you are losing a LOT of signal just
getting the tranmitted signal to the antenna (assuming you are using
VHF). If you are using UHF, its even worse. I realize you may not have
much control over where you put your radio or antenna, but the less
feedline you have, the better off you will be, especially if you are
running low power levels such as from an HT.

Andy
WD4KDN