Guy Wire Resonance

[HomerBB]

I decided to do a primitive test on my guy wires to my 2 Element Quad.

Someone suggested the guy wires were too close to the beam, so . .

I hooked a CB up to one of the guy wires. Radio -- 50ohm jumper -- SWR meter -- 50ohm coax -- 75ohm section -- guy wire. Center coax lead to guy wire and coax shield to dangling wire for counter poise. I realize the 75ohm matching section changes the radio's read on the guy wire's resonance, but I wanted no harm to the little radio shack set.

I tested SWR at 1.8:1 on channel 20, and a 3.1:1 on ch 40 and 3.2:1 on ch 1.

I asked for a radio check on ch 19 and got the usual trucker's "Your radio's working" answer. I got a conversation on ch 31. It appears to be resonant close to my operating freq.

Where my guy wires tie to the mast brings them very close to the tip ends of my 2 el quad spreaders.

Is this, in your opinion, having a possible negative affect on my f/b and gain on the beam?

 

[Wire Weasel]

It's possible. To be safe & sure, replace them with that black dacron rope. That's what the hams (including me) use to string up our wire antennas. It's the only synthetic rope that is permanent and will not rot by the sun's UV rays, or any weather. Available at ham stores, The Wireman, ebay, other places.

 

[HomerBB]

It's possible. To be safe & sure, replace them with that black dacron rope.

I'll do that.

Additionally, I wondered whether I ought to utilize one of them as a possible 3/4 wave zepa or other type of end fed antenna?

How far from the beam should I get the top end of the guy wire/antenna in a case like that?

 

[Wire Weasel]

That's hard to say. Most wire antennas except loops like to be in free space....away from nearby objects. In an installation like this maybe all you can do is try it and see it works. If your use is 11 meters, then you can probably go by the 1/4 wave rule. Which is about 9 feet. So the end of the wire would have to stop 9 feet away from the mast to prevent reflection interaction.

Good luck

 

[HomerBB]

Thanks.

 

[W5LZ]

Just for grins, and if you don't have anything else to do, try using those guy wires as antennas, a lot of people do. Of course, it helps if those guy-wire antennas are not 'related' to other antennas on the tower, different bands. Or, same band but configured in such a way that they can be of some particular use. That didn't make a lot of sense, did it? For example, a vertical on top of that tower, and horizontal polarization in the guys, slopers, whatever. Or feed the tower and use the guys as directors/reflectors?
Or just don't worry about any losses in the guy wires. You don't 'insulate' that tower or pole every 6 - 7 feet, about the same difference really.
- 'Doc

 

[HomerBB]

Just for grins, and if you don't have anything else to do, try using those guy wires as antennas, a lot of people do. Of course, it helps if those guy-wire antennas are not 'related' to other antennas on the tower, different bands. Or, same band but configured in such a way that they can be of some particular use. That didn't make a lot of sense, did it? For example, a vertical on top of that tower, and horizontal polarization in the guys, slopers, whatever. Or feed the tower and use the guys as directors/reflectors?
Or just don't worry about any losses in the guy wires. You don't 'insulate' that tower or pole every 6 - 7 feet, about the same difference really.
- 'Doc

lol

I will try to make at least one of them a 3/4 ^l Zepa.
just for grins.

 

[Gearhead]

I used "Phillystran" guy wires. They're made of kevlar, and are RF transparent

 

[Mr Clean]

I have been using Dacron rope on a tower for 5 years. 0 signs of wear.

 

[HomerBB]

Thanks, everyone.

 

[CDX-007]

I've had good performance from my Quad by cutting and insulating my metallic guy wires at 1/3 wavelengths, 12' on 11m.

And the non-metallic guy line which I find most preferred is Dacron covered Kevlar, ~3/16" - 1/4".

Kevlar does not stretch and is stronger than steel for it's size / weight, but not impervious to UV, Dacron stretches but is impervious to UV, Cover Kevlar in Dacron & you've got UV protected strength.

 

[Robb]

After the Booty Monster told me about the Dacron guy cable at Ham Radio outlet, I bought some and installed it.

No resonace or TVI being thrown off, it is an excellent solution - IMO...

 

[HomerBB]

Appreciate the feedback on this.