Radio Question

I was going to suggest this but thought I'd read the rest before doing so. :-) If it was for a specific freq it could even still be grounded at the base and fed with a Gamma match. :-) ...lew...

I think we're saying the same thing here. He should go with the kind of antenna that fits his need for stealth, be it vertical, horizontal, or loop.

Heh. Somebody had a birthday recently, and netted a copy of "The Antenna Book" by the ARRL. This may be the same book you are referring to. It's great.

Jim

In this RV park..the only flag that wouldnt get stolen is the Mexican flag. Few of my neighbors are english speakers.

But its an idea.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

I really want to listen to the SW bands. I think Ill dig into my Stuff when finally go home this weekend and see what Ive got stashed in my comm gear bins. I like the idea of the wire on standoffs around the edge of the roof. Attaching them is going to be problematic.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

Actually..the only one in this park is on my truck. I do have a spare K40 48" whip somewhere around the homestead, and Ill dig it out this weekend and make up a mount and run some coax and give it a try.

Im sure Im going to need a power line filter though. The radio may be run off 12vt dc, or line, or 8 D batteries. I may simply use a DC supply and see if that kills some of the noise from the puter.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

Exactly. They'll have different gains and different angles of reception, which will produce different levels of performance, but polarization is not a factor when you're dealing with sky waves.

The primary goals should be to get some wire out in the clear and get it away from sources of electrical noise. If you have a lot of noise, making the wire longer should help, up to a point.

Mine is the 1968 edition. BTW, our recent discussion got me interested in getting my license again, so I went out last week and took the Tech and General class tests. I got my General-class call today but it's a 2-over-3: KC2NZT. I'll go after the Extra and see if I can get a shorter call.

Also BTW, an antenna that a friend and I shared in college, which we used for both transmitting and receiving, was a twin-lead vertical combined with the TV antenna mast, for a three-wire vertical in total. We ran the twin-lead up but didn't connect it to the TV antenna terminals. Instead, we soldered the two wires together about a foot below the TV antenna, and then soldered them to the mast. We soldered all three together again at the bottom of the mast. Maybe we got some top-hat capacitance out of the TV antenna.

Anyway, it worked pretty well. We had a commercial antenna tuner (Drake? I forget), and we could load it on just about any band and get out fairly effectively, of course better on some bands than others.

It was like Gunner's situation: almost any TV antenna was acceptable there, but nothing else was.

-- Ed Huntress

Would the park allow you to have a patio umbrella? Maybe you could attach a loop antenna to the underside of it. I wouldn't be surprised if you could get away with a 20' square umbrella.

Pete Stanaitis

In Message-ID: posted on Wed, 06 Apr 2005 03:58:29 GMT, Gunner wrote: Begin

Don't get your hopes up, puter noise is airborne (RF), IOW comes in through the antenna. Read about that phase inversion box I mentioned (ANC-4)

In Message-ID: posted on Wed, 06 Apr 2005 03:51:35 GMT, Gunner wrote: Begin

How about the UFW flag

I'm quite sure that gunner had to block up his RV and remove the wheels/tires to:

A) keep his RV from getting stolen

B) keeps his RV's wheels and tires from getting stolen.

How long do you think gunner would remain the owner of such an umbrella ? Minutes ? hours ? day or two ? Remember the universal trailer park law "If it ain't inside, it ain't yours (anymore)"

n.

Or the variation: If it ain't nailed down, it's mine, and if I can pry/jackhammer/chainsaw/hoist/dynamite/otherwise get it loose, it wasn't nailed down" :)

One pair "C Rural" telephone wire, interesting stuff. Two 14-ga copper plated steel wires in an oval molded hard jacket - was rubber, now polyolefin. The copper carried the signal, the steel gave it the strength. You hang it from the pole with steel wire preforms like on steel strand.

This wire was designed for feeding that one lone farmhouse 3 or 4 miles off the main road. One big problem, the stuff is a bear to splice, Nicopress sleeves and solder, then lots of tape... So you'd take a whole reel of it out, enough to string the whole run as one piece, and use the tap-feed fittings at each end. Add more taps in the middle if you needed bridge tap drops for the barn or outbuildings.

And no twist to it, so it could still pick up noise from power.

This stuff wouldn't make a good SW/MW antenna, unless you were going for a /really/ long long-wire. And I'm not sure what effects the two wires in parallel would have, even if you shorted them together at each end.

-->-- Ex-Construction Cable Splicer.

I had the same problem with my PC, I could pick up noise all over the house, especially bad below 4-5 MHz. I put ferrite cores on every power cord I involved with the PC & the radio as well & that improved it quite a bit. later on I replaced my CRT monitor with a LCD & now the problem seems to be gone all togeather :). YMMV.

H.

Also follow the instructions about bonding the coax as it exits the RV shell.

Because the metal skin is a good faraday shield as you say, it will keep the rf noise from getting *outside* where the antenna is. So all you need to do is make sure that the rf does not ride along the sheild of the coax and get to the antenna. By bonding the shield (stopping off at a bulkhead fitting) to the skin, you prevent this.

Jim

I don't know if this would work or not, but it's certainly stealthy. It depends on the RV not being grounded to RF. If it is grounded to the utility, an RF choke in the ground line would fix that: just a few turns of #14 on a large ferrite toroid. I can send you a toroid.

Think of the RV itself as a fat whip. It is certainly more than 4 feet high. It will have a large capacitance to ground, but a whip is just a capacitive E-field probe and radiation resistance for short antennae is very very low.

For "ground", you then create a counterpoise on the ground under the RV. It could be a length of wire, radials, or even chicken wire. It is out of sight and essentially invisible.

I actually have one of them. Long story.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

OOOOO...sneaky!

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

Just get a big wire, connect it to your rig and throw it into a tree (if one is nearby your RV)

This is what I do at home and I hear all kinds of stuff...