Base antenna, High noise floor tips..

[snippits75]

Cable company amplifiers can, and will peg your receive meter.

It got so bad around here that I was being pegged at 10 S units steady 24/7. Power company was doing some upgrades a couple streets over, and it was causing one of the main line cable amplifiers to leak. That's what the lineman said. Anyway, the cable lineman fix would work for a day or two, and it was right back to pegging my receive needle.

Finally, had to call and escalate the problem. This time they fixed it for good after I explained to them. I saw the amplifier on the line after it was fixed, and they took the black weather wrap off of it. No problems since that time.

The cable lineman did do me a favor. He rode down by my house, and found a leak in my house. He showed me on his meter outside. Asked if he could go inside to find the leak. It was just a loose connection to the cable modem, and he tightened it up. We went back outside, and checked the meter, and the leak was gone. It was a small leak, but all the little leaks add up to a lot of noise.

 

[snippits75]

I have an Antron 99 too.

After looking at the link sp5it posted, I should use five wraps of RG8X around 4.25 inch PVC, and install the choke 9 ft. below the feed point. Would that be correct for CB 11 meter?

I don't understand the 9 ft. distance below feed point thing, but I do know how to follow directions!

 

[HomerBB]

@snippits75
The 9’ thing: a half wave end fed antenna requires a counterpoise despite claims to the contrary. 9’ is chosen because it is about 1/4 wavelength at 27 MHz. Without a supplied counterpoise the RF signal will seek out its own. This RF current manifests as Common Mode Current (CMC).The route CMC takes without a counterpoise can be a conductive mast, nearby gutters or roof flashings, home wiring, appliances, and most certainly the outside of your coax braid. Putting the choke down from the feed point nine feet allows the CMC to flow on the feed line only to the point the choke is placed. It is a method of attempting to control negative behaving currents in a positive way.

 

[snippits75]

@HomerBB

Thanks for explanation!

 

[CB590]

So I put 6 type 31ferrites just outside the shack. Got rid of the 2/70 roll up antenna and installed an 8' ground rod by drilling a hole thru the concrete and used some 8awg wire to run to the mast (HD was out of 6awg).

 

[CB590]

Forgot to mention with the MFJ915 choke up top I fried the cheap net gear wallwart for the internet upstairs. That or it was just junk.

Son installed 1gb hub in its place and all seems well. Though I want to try the MFJ915 choke up top again. Currently choke up top is not installed.

 

[Redbeard U812]

.....and I thought I had bad noise with high tension transmission lines and couple burned out transformers close. Everytime humidity goes high so does noise. A few ferrite helped, but still have to shut down some days.

 

[xm49north7]

I had to do some noise detective work myself. Ended up being a wireless internet router in the next room. I moved it down one floor, and rewired it. Took away 2 -s- units of my noise. All fixed. I now have less than 1 s unit of noise on ssb, and zero showing on am.

 

[CB590]

I had to do some noise detective work myself. Ended up being a wireless internet router in the next room. I moved it down one floor, and rewired it. Took away 2 -s- units of my noise. All fixed. I now have less than 1 s unit of noise on ssb, and zero showing on am.

The issue I have probably is the 3 access points and 2 switches in the house (3 story house and son went overkill on wifi). One access point is less than a foot from the shelves. It's powered thru the Cat 5e (or whatever).

 

[xm49north7]

The issue I have probably is the 3 access points and 2 switches in the house (3 story house and son went overkill on wifi). One access point is less than a foot from the shelves. It's powered thru the Cat 5e (or whatever).

Ya router on the same circuit was a killer for me, even running off another circuit helps a lot, the other big killer, when the wife fires up the washing machine, it just puts 9 S units on the meter. You could try running an extension cord to the router see if powering it from a distance helps.

 

[Slowmover]

.410ga great choice with underhand toss of router.

 

[autotuner]

Being in isolation, and bored, I've been spending a lot of time in the garage, sorting nuts and bolts etc. I have a Washington and 477mhz UHF just idling on the shelf. Just bought a cheap micro stereo to have soft music in the background. WOW, instantly pegs Washington's Meyer with hash, even briefly breaks mute on the 477 rig when I use the stereos radio tune. All plastic case, ferrite on power lead and speaker leads didn't help.
In the bin it goes....

 

[Slowmover]

Bin = Oz?
Rubbish Tip = Mother England?

What’s left for the Canucks & Kiwis?
Or is it they be so green nothing leaves the house?

.

 

[KBIO 3526]

@snippits75
The 9’ thing: a half wave end fed antenna requires a counterpoise despite claims to the contrary. 9’ is chosen because it is about 1/4 wavelength at 27 MHz. Without a supplied counterpoise the RF signal will seek out its own. This RF current manifests as Common Mode Current (CMC).The route CMC takes without a counterpoise can be a conductive mast, nearby gutters or roof flashings, home wiring, appliances, and most certainly the outside of your coax braid. Putting the choke down from the feed point nine feet allows the CMC to flow on the feed line only to the point the choke is placed. It is a method of attempting to control negative behaving currents in a positive way.

Good information and thank you. My question is: I'm getting ready to install my antenna which will be on an antenna tower with the base of the antenna around the 50' mark. I had planned to install a coax wrap near the feed point of the antenna which you posted should be 5 coils, are these tight wraps (each touching) or should there be a spacing between them? Also, should I attach a choke at the 9' point below the antenna?

 

[HomerBB]

Good information and thank you. My question is: I'm getting ready to install my antenna which will be on an antenna tower with the base of the antenna around the 50' mark. I had planned to install a coax wrap near the feed point of the antenna which you posted should be 5 coils, are these tight wraps (each touching) or should there be a spacing between them? Also, should I attach a choke at the 9' point below the antenna?

What kind of antenna will it be?
If it has radials, it can be placed at the feedpoint.
If it does not, my personal preference has become at 9' from the feedpoint. Opinions abound on how to manage the wraps, but because the wraps are essentially an inductor I believe they need to be side by side touching each other uniformly. Use a non conducting former like a 4" section of PVC tubing, or something similar, to wrap around.
I have used plastic bottles, varnished cardboard tubes, etc. Do not permit your choke to touch the metallic tower.
The tower itself will likely absorb any stray rf, but the choke should help mitigate any rf returning by the coax braid into the shack.