ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2] 3  All   Go Down

Author Topic: Mixing Antenna Types for near / far coverage  (Read 4500 times)

Keith Broughton

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3395
  • Toronto
Re: Mixing Antenna Types for near / far coverage
« Reply #10 on: November 10, 2017, 09:06:34 am »

You can actually have the best of both worlds by using both on "A" and "B". This can be done with a simple BNC "T" connector or by using the passive combiners that many suppliers (like the Shure UA221. I use the PWS and Mini Circuits products) sell.
As long as the antenna patterns and coverage area don't overlap too much, you'll be fine.
I have used multiple Rx antennas on every job I've done in the past 12 months. On really large stages, you pretty much have to.
It was my understanding that a T connector would "work" but something like a UA221 is preferable.
Ike or John, any chance you have been able to do a comparison?
Logged
I don't care enough to be apathetic

Jason Glass

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 783
    • CleanWirelessAudio.com
Re: Mixing Antenna Types for near / far coverage
« Reply #11 on: November 10, 2017, 06:29:47 pm »

The paddle antenna has a cardioid coverage pattern. There is significant PU in all directions except directly behind it. Your best solution should involve a couple of tall tripod speaker stands to get both antennas up high, but not co-located. I would try to get the antennas up at least 7'-8'.

Mac
This is by far the best advice given here for the described scenario.  TX located 20' away from typical LPDA's at 90° off axis should be rock solid.

Sent from my Nexus 5 using Tapatalk

Jason Glass

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 783
    • CleanWirelessAudio.com
Re: Mixing Antenna Types for near / far coverage
« Reply #12 on: November 10, 2017, 06:32:25 pm »


So a simple BNC "T" connector will work just as well as a much more expensive  passive power divider/combiner?  I thought there were some sort of internal reflection problems with a simple "T".


All of the antennae are passive so I don't need DC power sent through the cables.
NO! The simple T connector is an abomination. The proper device is much more complex inside and is known as a passive splitter/combiner.

Sorry, Ike! I'm almost certain that you were referring to Shure's simple T splits, which are actually proper splitter/combiners, but way too many people will assume that they're the same as $2 junk T's.

Sent from my Nexus 5 using Tapatalk
« Last Edit: November 10, 2017, 06:40:00 pm by Jason Glass »
Logged

Jason Glass

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 783
    • CleanWirelessAudio.com
Re: Mixing Antenna Types for near / far coverage
« Reply #13 on: November 10, 2017, 06:48:51 pm »

This is by far the best advice given here for the described scenario.  TX located 20' away from typical LPDA's at 90° off axis should be rock solid.

Sent from my Nexus 5 using Tapatalk
The optimal antenna scheme for your scenario is two high gain helicals such as the RF Venue CP Beam or PWS HA8089, one each on diversity A & B, mounted high and pointing down the street away from the choir. They are high gain along their axis in front of the antenna. They are least sensitive along a roughly 60° to 90° hollow conical pattern behind the antenna, but also have a narrow moderate gain lobe on axis inside the cone.

Sent from my Nexus 5 using Tapatalk
« Last Edit: November 10, 2017, 06:56:13 pm by Jason Glass »
Logged

Jordan Wolf

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1374
  • Location: Collingswood, NJ
Re: Mixing Antenna Types for near / far coverage
« Reply #14 on: November 11, 2017, 12:57:16 pm »

The optimal antenna scheme for your scenario is two high gain helicals such as the RF Venue CP Beam or PWS HA8089, one each on diversity A & B, mounted high and pointing down the street away from the choir. They are high gain along their axis in front of the antenna. They are least sensitive along a roughly 60° to 90° hollow conical pattern behind the antenna, but also have a narrow moderate gain lobe on axis inside the cone.

Sent from my Nexus 5 using Tapatalk
So, they’re the hypercardioid mic of the RF world? Nifty!
Logged
Jordan Wolf
<><

"We want our sound to go into the soul of the audience, and see if it can awaken some little thing in their minds... Cause there are so many sleeping people." - Jimi Hendrix

Jason Glass

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 783
    • CleanWirelessAudio.com
Re: Mixing Antenna Types for near / far coverage
« Reply #15 on: November 11, 2017, 01:00:43 pm »

So, they’re the hypercardioid mic of the RF world? Nifty!
Indeed they are. Think of helicals as hypercardioid, LPDA's as cardioid, and domes as wide cardioid.

Sent from my Nexus 5 using Tapatalk

Scott Holtzman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 6065
  • Ghost AV - Avon Lake, OH
    • Ghost Audio Visual Systems, LLC
Re: Mixing Antenna Types for near / far coverage
« Reply #16 on: November 12, 2017, 09:13:11 pm »

NO! The simple T connector is an abomination. The proper device is much more complex inside and is known as a passive splitter/combiner.

Sorry, Ike! I'm almost certain that you were referring to Shure's simple T splits, which are actually proper splitter/combiners, but way too many people will assume that they're the same as $2 junk T's.

Sent from my Nexus 5 using Tapatalk
Factory phasing harnesses just use T connectors.  For a 50 ohm load you run 75ohm coax off the T to the antennas.  The jumpers must be the same length.  Any impedance differences between the antenna's will cause issues.

Sent from my VS995 using Tapatalk

Logged
Scott AKA "Skyking" Holtzman

Ghost Audio Visual Solutions, LLC
Cleveland OH
www.ghostav.rocks

Mike Karseboom

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 251
Re: Mixing Antenna Types for near / far coverage
« Reply #17 on: November 12, 2017, 11:43:17 pm »

Well, as usual,  simple questions on this forum quickly escalate into complex technical discussions!  I'm more of a weekend warrior that  likes to do a good job with limited resources so I went for a pair of MiniCircuits power dividers  on ebay. 


I will try the dual antennae setup with the existing 1/2 wave units "t"'d in with the paddle antennae via the power dividers.  I will put the paddles on 10' poles at two adjacent corners of the popup canopy for good line of site down the street.  I will also get  the rack with the 1/2 wave antennae up to about 7' high for good short range coverage. 


One thing it seems that I am adding a paddle antenna with potential +6dB gain but then introducing a splitter that results in -3dB gain for both legs.   I guess +3dB is significant but it does seem like a lot of work for this a little improvement.  Maybe the good line of site changes will be the main factors that give better reception.
Logged
--Mike
"If you're not confused, you don't know what is going on"

Live Sound for the Mt. Shasta area
http://www.shastalivesound.com

hugovanmeijeren

  • Newbie
  • *
  • Offline Offline
  • Posts: 32
Re: Mixing Antenna Types for near / far coverage
« Reply #18 on: November 13, 2017, 03:59:00 am »

What I often do in these situations is use 2 different types of paddle antennas. We only have Sennheiser antennas, so I'll use these as an example.

We use the Sennheiser A1031 omnidirectional antenna together with a Sennheiser A2003 directional one. One goes to the A side of the distributor, the other to the B side (so no multiple antennas to the same inputs). You can use a simple stereo-bar to mount both antennas to one mic stand. I always mount one antenna to the top of the stereo-bar and one to the bottom (so neither antenna is blocking the other one). This works very well in these situations.

With this setup you will maintain full diversity. The receiver will always pick the antenna that gets the strongest signal. For the choir, this will be the omnidirectional paddle most of the time (with the directional one as a backup for diversity). The directional one will work great for larger distances, because it will be better at differentiating your signal from the noise.
Logged
Hugo van Meijeren

Henry Cohen

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1014
  • Westchester Co., NY, USA
Re: Mixing Antenna Types for near / far coverage
« Reply #19 on: November 13, 2017, 11:51:51 am »

Factory phasing harnesses just use T connectors.  For a 50 ohm load you run 75ohm coax off the T to the antennas.  The jumpers must be the same length.  Any impedance differences between the antenna's will cause issues.

These are phase matched pairs (or triples, or quadruples) and thus are the same electrical length, not necessarily the same physical length.
Logged
Henry Cohen

CP Communications    www.cpcomms.com
Radio Active Designs   www.radioactiverf.com

ProSoundWeb Community

Re: Mixing Antenna Types for near / far coverage
« Reply #19 on: November 13, 2017, 11:51:51 am »


Pages: 1 [2] 3  All   Go Up
 



Page created in 0.068 seconds with 24 queries.