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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Sun 15, 2020 2:29 pm 
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Location: Rockford, IL
I suspected this was better as you eliminate ground loops and similar effects. I do only power one up at a time and never run two - or have two plugged in - at the same time. I have only one antenna out (of the window) connection and do not multiplex it. I think a 10 pos SPDT switch box is my answer for dedicated 1-to-1 connections.


bob91343 wrote:
In general, a 'star' connection, with each radio going to ground separately, is better than a chain. The former avoids ground currents from one radio affecting the others.


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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Sun 15, 2020 3:41 pm 
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For the SWL receivers I use a 50 foot longwire that runs to nearby tree... I use the chain link fence as the counterpoise and have a ferrite common mode choke on the coax coming into the shop to decouple any possible noise pickup on the coax shield.

For ham use, there are the antennas on the tower, and a 30/40 meter dipole and a modified K2AV FCP at 75 feet for 160 and 80 meters.

Pete


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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Mon 16, 2020 2:51 am 
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Peter Bertini wrote:
For the SWL receivers I use a 50 foot longwire that runs to nearby tree... I use the chain link fence as the counterpoise and have a ferrite common mode choke on the coax coming into the shop to decouple any possible noise pickup on the coax shield.

For ham use, there are the antennas on the tower, and a 30/40 meter dipole and a modified K2AV FCP at 75 feet for 160 and 80 meters.

Pete

Nice!

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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Fri 20, 2020 3:29 pm 
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Location: Rockford, IL
I have a running experiment of a HOA-proof covert antenna I am working on. This one hides behind the hedges along the side of the house about a foot off of the ground. I ran a second wire and joined it at one end basically making a 70 or so foot antenna folded in half.

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I was told that I might experience cancelation effect as the two sections are rather close to gather (5 or less inches apart).

My question is can there be a cancelation effect by having this antenna? It has worked great but there seems to be a lot of QRN/QRM in the last week making reception for listening touch and go over the last 10 days. Hard for me to tell but initially it seemed to work great. And hooking up a radio gives a big jump in sound when connected (as an antenna should).

As always, please take pity on me if I am asking a very dumb question :-)


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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Fri 20, 2020 5:59 pm 
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Peter Bertini wrote:
and have a ferrite common mode choke on the coax coming into the shop to decouple any possible noise pickup on the coax shield.


Pete

Can you elaborate? Pics? design? link?

Thanks

Bill


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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Sun 22, 2020 1:49 am 
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I don't believe that a choke will cancel out noise. A choke is used to cancel common mode currents. But noise?

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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Sun 22, 2020 3:35 pm 
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Phil Coe wrote:
I don't believe that a choke will cancel out noise. A choke is used to cancel common mode currents. But noise?


Exactly... and that is why there is a need for a common mode choke on coaxial lines, especially those feeding unbalanced receiving antennas with a poor counterpoise. The coax shield becomes part of the receiving antenna and carries noise back to the antenna.


http://www.yccc.org/Articles/W1HIS/Comm ... 6Apr06.pdf


https://owenduffy.net/blog/?p=428



https://www.w8ji.com/common-mode_noise. ... se%20floor

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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Sun 22, 2020 4:07 pm 
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Location: Tucson, Arizona, 85704
I'm in a new development with an HOA, so a beam antenna is out of the question. For VHF/UHF work, a magnetic antenna (100 Watt rated) atop a metal trash can in back yard work well and tickles the repeaters. A long wire or stock antenna for BCB and shortwave.

Plans for the future involve a sloper antenna in the rear to work 40 meter.

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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Nov Sat 28, 2020 12:33 am 
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With the help of a couple friends from the ham club, I have modified the G5RV into an inverted V doublet, using a 1 to 1 current balun. Initial tuneups look very good, and I was able to get on the ten meter net with it on Wednesday night. 80 looks good, but I haven't tried it on 40 yet.

I still plan to put up a dipole cut for ten meters, as soon as I can arrange some helpers. The next antenna projects are a long wire with lightning arrestor, and a remote coax switch.

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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Dec Fri 04, 2020 7:17 pm 
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Location: Lexington, MA
For ham usage with the average 100 watt rig, there's no need for heavy gauge wire. For a stealth antenna, I once used two 30 foot lengths of magnet wire from a 2nd floor apartment window to a nearby garage: it formed a kind of "horizontal vee". Each wire was connected to one of the balanced output binding posts of a small MFJ tuner. I worked stations from coast to coast with this antenna that no one could see.

(See photo) Wire antennas made with gray 24 AWG insulated wire are also virtually invisible up in the air, unless you're looking for it. I made a center insulator from a hacksawed and drilled IKEA plastic cutting board, but you can create much less visible versions from a ballpoint pen body or other plastic scrap.

If neighbors in an HOA development noticed a stealthy wire antenna, I'd be surprised. Most likely they would only notice the feedline. And if they did, I'd mumble something about "fiber optic high speed internet" or "5G". Most people assume any visible wires are from cable companies and internet providers.


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 Post subject: Re: What Are You Useing For Antenna?
PostPosted: Dec Fri 04, 2020 9:14 pm 
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A short length of sprinkler PVC pipe, or coupler makes an excellent and weatherproof isolated connector.

If there is a concern about the line sagging and shorting the two together, simply wrap one around the outside circumference, and feed the other one through, as pictured.


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