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Author Topic: Antenna guy wires "singing" in the wind  (Read 2471 times)
KJ6HYC
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Posts: 103




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« on: December 25, 2012, 09:47:19 AM »

I have a 50ft Pushup pole that I have just installed, it is guyed every 10ft. Our area gets a lot of wind, and the Pushup pole guy wire sings at > 20MPH. The guy wire is a uninsulated 14 Ga hard drawn aluminum.

Anyone experance this? How can I stop the singing?

Thanks;

Wayne - KJ6HYC
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VE7TIT
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Posts: 62




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« Reply #1 on: December 25, 2012, 10:42:43 AM »

"When air passes by an object at certain speeds, a strong pure tone, known as a Karman tone, can be produced. This can be prevented by making the object longer in the direction of flow, such as with a "tail," or by making the object's shape irregular." -- http://www.nonoise.org/hearing/noisecon/noisecon.htm#SOUND PRODUCTION IN AIR OR GASES

You could wrap weatherproof cord (Dacron is good, if I remember correctly) around the guy wires at about one turn per foot or so. That is supposed to affect how the wind spills over the wire and break up the flow. I have seen that recommended for stabilizing tribander elements that are vibrating in strong wind (discussed in the Antenna Book, IIRC), but you see the technique used everywhere--from the spiral around modern car antennas (no, that's not a helical antenna Wink) to smokestacks http://www.nonoise.org/hearing/noisecon/c1exam.gif.

As an alternative, you could also use different gauges and tensions for each of the guy wires to get your antenna play a nice chord. Experiment! Smiley
« Last Edit: December 25, 2012, 11:35:46 AM by VE7TIT » Logged
K7KBN
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« Reply #2 on: December 25, 2012, 11:33:38 AM »

http://www.youtube.com/watch?v=SPpyCfSqcgk

Just like Prof. Peter Schickele wrote one of the sections of P.D.Q. Bach's "Erotica" Variations for Banned Instruments and Piano.

The cure for the wires singing is to use the same principle as muting the strings of a violin.
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73
Pat K7KBN
CWO4 USNR Ret.
N7WR
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« Reply #3 on: December 25, 2012, 04:06:09 PM »

Curious why you used a conductive material for your guys.  I use paracord for guys on a 38 ft vertical and we get a lot of wind...no singing
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KJ6HYC
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« Reply #4 on: December 25, 2012, 05:48:55 PM »

Curious why you used a conductive material for your guys.  I use paracord for guys on a 38 ft vertical and we get a lot of wind...no singing

I used aluminum wire because I had a large spool of it, and it is lower cost than the daycron (Alum = $48.00/1250ft). As to its conductivity, this is guyed 80 ft from the dwelling and guyed to the ground, so it should not make much of a differance.

I will be re-doing the guying with 2 strands of the aluminum 14ga but twisted together to stop the singing, and double the strength.

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N4CR
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« Reply #5 on: December 25, 2012, 06:58:02 PM »

Aluminum is crappy guy wire. It stretches. And as soon as it stretches, it stretches faster because your mast starts moving and banging against it. Eventually it becomes hard drawn and becomes less stretchy. Hopefully, what you have is hard drawn because if it isn't, it will be.
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73 de N4CR, Phil

We are Coulomb of Borg. Resistance is futile. Voltage, on the other hand, has potential.
W4VR
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« Reply #6 on: December 26, 2012, 08:44:10 AM »

As long as they don't start galloping I would not worry about the singing.
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KJ6HYC
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« Reply #7 on: December 27, 2012, 07:47:24 AM »

As long as they don't start galloping I would not worry about the singing.

I am planning not to overtwist the twined wire, enough to stop the singing, aluminum is light weight, and I am hopeing that there won't be any galloping.
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KC4MOP
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« Reply #8 on: December 27, 2012, 08:36:21 AM »

http://www.youtube.com/watch?v=SPpyCfSqcgk

Just like Prof. Peter Schickele wrote one of the sections of P.D.Q. Bach's "Erotica" Variations for Banned Instruments and Piano.

The cure for the wires singing is to use the same principle as muting the strings of a violin.

Don't try to change notes too fast
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