Paddles limitations

Rob Spence

Rob Spence

Senior
Jan 11, 2011
897
4
18
Boston Metro North West
www.lynxaudioservices.com
Ok, not so creative this morning with subject line...

I am wondering about the best way to use 2 paddles, 2 receivers and no antenna combiner.

One way is to put one paddle on each and the half wave on the other connector. That is what I did recently and it worked out for a 75' reach to a pair of mics (had to keep all gear out of photos).

What about putting a tee on each input of one receiver and connect to the second and then connect a paddle to each input?

Also, got a quick pointer to loss charts for cable types vs air?

Thanks (first time I had all my wireless in use on one day :-))
Sent from my iPad HD
 
Re: Paddles limitations

Rob Spence said:
I am wondering about the best way to use 2 paddles, 2 receivers and no antenna combiner.
Click to expand...

Hi Rob,

This:
Rob Spence said:
One way is to put one paddle on each and the half wave on the other connector. That is what I did recently and it worked out for a 75' reach to a pair of mics (had to keep all gear out of photos).
Click to expand...

Not this:
Rob Spence said:
What about putting a tee on each input of one receiver and connect to the second and then connect a paddle to each input?
Click to expand...
Simple tee adapters cause all kinds of impedance mismatch problems, with huge losses, and don't isolate the internal oscillators of the receivers from each other. Proper passive RF splitters cut signal strength to both receivers in half.

Rob Spence said:
Also, got a quick pointer to loss charts for cable types vs air?
Click to expand...
Here's an Excel calculator tool for that: http://cleanwirelessaudio.com/Path Loss Comparison Calculator.xls
 
Last edited:
Re: Paddles limitations

David Sturzenbecher said:
While this is still an "antenna combiner" it is the Shure solution. I have used these all over the place with no issues.
http://www.shure.com/americas/produ...ennas/ua221-passive-antenna-splitter-combiner

See the users guide on the page for proper installation instructions. The manual lists a 2dB insertion loss. Any chance on how they get a dB for free?
Click to expand...

Hi David,

It is not mathematically possible for a passive RF splitter to have less than 3dB of loss. Even the best of them usually have around 0.5dB of insertion loss in addition to the splitter loss for total loss of 3.5 dB. The product page also says, "Shure recommends using UA820 1/2 wave antennas with UA221 Splitter/Combiners. The UA820 provides up to 3 dB of additional gain compared to standard 1/4 wave antennas. The additional gain compensates for signal loss in splitting applications." They may be using a system loss spec rather than the more appropriate component loss when stating 2dB loss.

With that in mind, 3.5 dB of loss from a single component is not necessarily a problem, as long as the total system losses end up in the neighborhood of 0dB or better. Since LPDA's have typically 6dBi of axial gain, and most of the 1/2λ dipoles have around 3dBi, they can sometimes make up for other lossy components with room to spare.

The whole RF game is about optimizing the system gain in order to reduce the chances that one or more of a gazillion signal-degrading scenarios will cause a dropout. It may seem like overkill to try to squeeze one more dB of gain out your system until you consider that a single factor like polarization orientation mismatch loss or body absorption loss can suddenly drop a signal level 50dB when a performer turns his body or moves in space by mere inches. At levels that low, one dB can very easily be the difference between a complete audio dropout and an inaudible glitch.
 
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