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Author Topic: RF link for festival  (Read 7490 times)

Keith Broughton

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RF link for festival
« on: July 06, 2014, 01:26:06 PM »

I am going to try setting up an RF link to run main stage sound to a remote location.
Sennheiser G2 IEM transmitte to a helical antenna at the main stage.
Remote will be a log periodic ( no helical available) to mic receiver.
Given the frequency is clear and I have clear line of sight and good weather, what would be a fair estimate of the distance I could reliably cover?
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Jerome Malsack

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Re: RF link for festival
« Reply #1 on: July 06, 2014, 04:55:44 PM »

It would be far better to test and be positive at the location on the distance and signal strength. 

The wireless mic receivers are stated as 300 ft ??   150 to 400 ?? 

You will be limited by how much the transmitter will allow along with FCC legal questions. 

You may want to ask around about a ham radio club and see what they can do for you and the signal?
More power available and good publicity for them. 
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Mac Kerr

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Re: RF link for festival
« Reply #2 on: July 06, 2014, 05:09:40 PM »

I am going to try setting up an RF link to run main stage sound to a remote location.
Sennheiser G2 IEM transmitte to a helical antenna at the main stage.
Remote will be a log periodic ( no helical available) to mic receiver.
Given the frequency is clear and I have clear line of sight and good weather, what would be a fair estimate of the distance I could reliably cover?

I would try first with a pair of LPDA paddles. There is no real advantage to the helical when you can set up the polarity of both the send and receive antennas. Get them up high and keep them both vertical or both horizontal.

How far do you need to go?

Mac
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Scott Helmke

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Re: RF link for festival
« Reply #3 on: July 06, 2014, 07:47:31 PM »

Ditto what Mac said about making all antennas paddles - you lose a little bit when you go from helical to linear polarization, and with a fixed situation you control the polarization angles instead of things being moved around by performers.
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Cameron Stuckey

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Re: RF link for festival
« Reply #4 on: July 06, 2014, 09:53:41 PM »

There is no real advantage to the helical when you can set up the polarity of both the send and receive antennas.

What's a few dB between friends?

All antenna discussion aside, the G2 transmitter is only about 30mW and won't get you fantastic distances even with line of sight between directional antennas. My estimate with a single helical and paddle is 850ft, +/-50ft.

Edit: given the right conditions...
« Last Edit: July 07, 2014, 12:49:22 AM by Cameron Stuckey »
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Greg Bellotte

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Re: RF link for festival
« Reply #5 on: July 06, 2014, 09:57:11 PM »

what would be a fair estimate of the distance I could reliably cover?
the G2's can go 1000 ft under the right conditions and antennas. Even at 30mW :-) i say go for it and let us know how it works out.
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Jason Glass

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Re: RF link for festival
« Reply #6 on: July 06, 2014, 10:40:51 PM »

I am going to try setting up an RF link to run main stage sound to a remote location.
Sennheiser G2 IEM transmitte to a helical antenna at the main stage.
Remote will be a log periodic ( no helical available) to mic receiver.
Given the frequency is clear and I have clear line of sight and good weather, what would be a fair estimate of the distance I could reliably cover?

Hi Keith,

I did the math for you, using a prototype of my soon-to-be-released Android app that calculates RSSI estimates for the "big 3" wireless systems sold in USA.

These calculations are for a G2 system, as you described, in low power TX mode (10mW, for the sake of being conservative), with a paddle on one end and a helical on the other, and with 25ft. of low-loss cable on each.  These results are for a theoretically perfect line-of-sight fixed link in open space.  I would cut this estimate in at least half for real world.

The calculation results show 2250ft. to 2500ft. before the RSSI begins to drop below a Sennheiser's nominal 40dBμV.

You can see detailed results in the following screen shots:


« Last Edit: July 06, 2014, 11:15:49 PM by Jason Glass »
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Jason Glass

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Re: RF link for festival
« Reply #7 on: July 06, 2014, 10:41:54 PM »

Hi Keith,

I did the math for you, using a prototype of my soon-to-be-released Android app that calculates RSSI estimates for the "big 3" wireless systems sold in USA.

These calculations are for a G2 system, as you described, in low power TX mode (10mW, for the sake of being conservative), with a paddle on one end and a helical on the other, and with 25ft. of low-loss cable on each.  These results are for a theoretically perfect line-of-sight fixed link in open space.  I would cut this estimate in at least half for real world.

The calculation results show 2250ft. to 2500ft. before the RSSI begins to drop below a Sennheiser's nominal 40dBμV.

You can see detailed results in the following screen shots:
« Last Edit: July 06, 2014, 11:15:26 PM by Jason Glass »
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Ryan McLeod

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Re: RF link for festival
« Reply #8 on: July 06, 2014, 10:53:48 PM »

I am going to try setting up an RF link to run main stage sound to a remote location.
Sennheiser G2 IEM transmitte to a helical antenna at the main stage.
Remote will be a log periodic ( no helical available) to mic receiver.
Given the frequency is clear and I have clear line of sight and good weather, what would be a fair estimate of the distance I could reliably cover?

I did exactly the same thing a few weeks ago using G3's, a helical and a log periodic, and had no issues with the 500' or so I was shooting for.
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Keith Broughton

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Re: RF link for festival
« Reply #9 on: July 07, 2014, 01:11:33 PM »

I did exactly the same thing a few weeks ago using G3's, a helical and a log periodic, and had no issues with the 500' or so I was shooting for.
I was thinking about the fact that it would probably be better with the LPDA antennas at both ends as polarity would be fixed.
 500' would be the real world distance so it looks like a go.
We will run XLR as well, just to have backup.
BTW...that app looks killer!
Thanks for the responses. Will post results.
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ProSoundWeb Community

Re: RF link for festival
« Reply #9 on: July 07, 2014, 01:11:33 PM »


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