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Aluminum antenna ground radials
- Thread starter 455monte
- Start date
You can't. Antenna won't work without them. Result would be opposite.
But... you can remove antenna. Noise floor will drop down for sure.
But... you can remove antenna. Noise floor will drop down for sure.
When i unscrew coax from radio and leave center conductor inserted into radio a little bit i still have good receive but noise floor drops 4 s levels.
So i installed a palomar common mode choke at the radio. It didnt help noise floor any. Still same noise floor as before when cmc wasnt there
So i installed a palomar common mode choke at the radio. It didnt help noise floor any. Still same noise floor as before when cmc wasnt there
the common mode current exists because there are not enough radials to uncouple the feedline from the antenna. manufacturers don't care about this because no one is going to pay for it (another 12-13 radials, another 108 to 117 feet of aluminum tubing; can you imagine the added weight and windloading?) and they can allow this loss in the system to guarantee you that low swr that you're mistakenly looking for, no extra charge for that feedline and mast re-radiation current. it's on the house.
personally, i haven't used commercially manufactured hf antennas for many years and i'll never go back.
personally, i haven't used commercially manufactured hf antennas for many years and i'll never go back.
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if there is interference, try to find out the source of the noise. for example a fluorescent lamp, noisy motor from air conditioner or refrigerator. all kinds of interference out there.
on edit;
not to mention power lines and transformers..and hoping you don't have a huge industrial complex nearby..
on edit;
not to mention power lines and transformers..and hoping you don't have a huge industrial complex nearby..
You put it in wrong place. Common mode choke should be placed right under antenna. Also you should insulate antenna from mast. And coax choke at coax entrance to house would help.
I live out in the country
All power lines are buried in my community.
Cb runs off of a 12 volt battery on the bench.
Ive flipped main breaker in shop and noise level doesnt change.
I will try to place the cmc at antenna instead of inside shop at radio to see if noise floor changes.
My radials on antenna are partially shrouded by the eve of the shop.
Will that have any effect on my antennas performance or noise floor?
I always get good audio reports locally to approx 25 miles
All power lines are buried in my community.
Cb runs off of a 12 volt battery on the bench.
Ive flipped main breaker in shop and noise level doesnt change.
I will try to place the cmc at antenna instead of inside shop at radio to see if noise floor changes.
My radials on antenna are partially shrouded by the eve of the shop.
Will that have any effect on my antennas performance or noise floor?
I always get good audio reports locally to approx 25 miles
445 monte posted:
"My radials on antenna are partially shrouded by the eve of the shop.
Will that have any effect on my antennas performance or noise floor?"
just how high above the ground is the feedpoint of the antenna?
what is the shortest distance between any one radial & the "eve?"
what material is this eve constructed from?
"My radials on antenna are partially shrouded by the eve of the shop.
Will that have any effect on my antennas performance or noise floor?"
just how high above the ground is the feedpoint of the antenna?
what is the shortest distance between any one radial & the "eve?"
what material is this eve constructed from?
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Antenna feedpoint is approx 18 feet from ground.
Probably a few inches from the eve on 2 of the 3 radials. 3rd radial sticks straight out away from eve. Shop is all wood with regular shingles but where antenna mount bracket is screwed against eve is on aluminum flashing.
Probably a few inches from the eve on 2 of the 3 radials. 3rd radial sticks straight out away from eve. Shop is all wood with regular shingles but where antenna mount bracket is screwed against eve is on aluminum flashing.
you might want to try moving the choke to the feedpoint of the antenna.
So I went up the ladder and put the Palomar common mode choke at the feed of my antenna. But I can't really get any results because of all the skip rolling. Maybe when I get up early in the morning it will be quiet and I can get a s reading to find out if it helped the noise floor.
