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Author Topic: DIY antenna stand question (that I can't find here)  (Read 2650 times)

Debbie Dunkley

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Re: DIY antenna stand question (that I can't find here)
« Reply #20 on: July 18, 2018, 01:39:16 am »

Yet when the antennas are connected directly to the receiver, they are only a few inches apart by design.
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Scott Holtzman

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Re: DIY antenna stand question (that I can't find here)
« Reply #21 on: July 18, 2018, 02:45:23 am »

Yet when the antennas are connected directly to the receiver, they are only a few inches apart by design.
Yes and the pattern is effected accordingly.

It is not as big an issue with RX as it is with TX.  I have no doubt the line of sight improvement has far more impact on signal than the pattern distortion.

I am sure Henry or Pete can provide a more complete explanation.

Here is a short paper on pattern obstruction.

http://educypedia.karadimov.info/library/NSI-near-far.pdf

Sent from my VS996 using Tapatalk

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Scott AKA "Skyking" Holtzman

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Jean-Pierre Coetzee

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Re: DIY antenna stand question (that I can't find here)
« Reply #22 on: July 18, 2018, 06:41:35 am »

BTW, If you're handy with a drill, most decent hardware stores sell 6063 aluminum flat stock that's super easy to work with. Just scavenge the parts off of a short one and you'll probably be rocking for under $10.

Sent from my Nexus 5 using Tapatalk

This would be the cheapest.

If you can't find the parts I'm sure you can find a nut that will find the mic stand thread.

Shouldn't be very hard to DIY the kind of mount you need.
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Debbie Dunkley

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Re: DIY antenna stand question (that I can't find here)
« Reply #23 on: July 18, 2018, 02:44:01 pm »

So although I still don't know why it isn't a good idea to use the short distance on the mic mount for diversity considering the Shure receiver connections are within half an inch of the mic mount distance,  I just made this one.
I used stuff I already had. It is aluminum and distance to centers of coax connectors is 16".

Considering I have used mine many times and never noticed any degradation of quality but more importantly only ever noticed improved RF, what would I hope to achieve if I use this longer mount??

Just trying to learn here and always willing to improve on what I have.

Thanks Scott for the info .... its a lot to digest but I will read through again...


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Scott Helmke

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Re: DIY antenna stand question (that I can't find here)
« Reply #24 on: July 18, 2018, 03:12:43 pm »

Considering I have used mine many times and never noticed any degradation of quality but more importantly only ever noticed improved RF, what would I hope to achieve if I use this longer mount??

I tend to look at it as a "best practices add up" kind of thing. Or maybe "sound tech points" - do each little thing the correct way to get another point, and accumulated points tend to result in an easy gig.
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Henry Cohen

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Re: DIY antenna stand question (that I can't find here)
« Reply #25 on: July 18, 2018, 04:12:51 pm »

Here is a short paper on pattern obstruction.

http://educypedia.karadimov.info/library/NSI-near-far.pdf

Great link Scott. Terrific information on near field only testing and far field performance extrapolation.
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Henry Cohen

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Lyle Williams

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Re: DIY antenna stand question (that I can't find here)
« Reply #26 on: July 18, 2018, 05:05:56 pm »

Operate a single linearly polarised antenna with a receiver without AGC.  Move the transmitter/mic around the stage maintaining the orientation of the transmitter/mic.  Observe the depth of RF signal fades.

Go back and rotate the transmitter/mic in 3D at a number of stage locations.  Observe the depth of RF signal fades.

Prioritise your antenna diversity (space and polarisation diversity) based on your findings.
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Mark Hannah

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Re: DIY antenna stand question (that I can't find here)
« Reply #27 on: July 18, 2018, 10:54:06 pm »

Here is a short paper on pattern obstruction.

http://educypedia.karadimov.info/library/NSI-near-far.pdf

Sent from my VS996 using Tapatalk

Do you have additional papers related to the RF world like this?

I visited Nearfields Systems' website.  If you are a regular visitor to this site, could you narrow down some of these papers?

Thanks.
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Loren Miller

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Re: DIY antenna stand question (that I can't find here)
« Reply #28 on: July 26, 2018, 04:00:54 pm »

Just finished drilling two 1/2" holes in a K&M quad mic bar.

This was way to complicated for a simple piece, someone should offer this as an accessory, the demand would probably be in the low 100's. ;-)

Thanks Debbie and everyone else for the inspiration, perspiration and information, I'll report back with field testing this weekend. Antennas are 14" apart, should be enough as 1/2 a wavelength at 500 mhz is 11.23" and 9.36" for 600mhz.

https://drive.google.com/file/d/1w_ZCsodTnCg5ip5VpMA0FYjWZr8MLImU/view?usp=sharing
« Last Edit: July 27, 2018, 08:31:16 am by Loren Miller »
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James Cotton

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Re: DIY antenna stand question (that I can't find here)
« Reply #29 on: August 07, 2018, 08:31:51 am »

Here's an economical and better suited solution. https://www.bhphotovideo.com/c/product/1306972-REG/k_m_23560_500_55_microphone_bar_with_5_8.html
That's exactly what I use for my RX antenna pair, with a couple of K&M universal joints to allow me to put a 45 degree angle on the antennas to couple better with handheld mics (they're never straight up and down). Throw it on a K&M overhead stand and you can get it plenty high.

As an added bonus I was setting up for a small festival a couple of weeks ago and was looking for a way to put the antennae on the lighting truss to reduce stand clutter.
Found some plastic woodworking spring clamps which were ideal but couldn't think where to get any 3/8" BSW screws (yes I'm in the UK and those screws are still weird anywhere other than the end of a mic stand in spite of the B standing for British) at short notice until I spotted the bar and remembered it came with 6 thumbscrews, 4 of which I'd taken off and stashed in the misc. mic storage drawer.
2 minutes on the pillar drill and I had 4 quick clamps with mic threads at the end of the handle, perfect for 3 wireless antennae and a Ubiquiti bullet in a radio mic clip.
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ProSoundWeb Community

Re: DIY antenna stand question (that I can't find here)
« Reply #29 on: August 07, 2018, 08:31:51 am »


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