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Frequency Coordination video example
Pete Erskine:
I rushed through this and didn't explain in detail what some of the IAS app was doing. I wanted to show how easy and quick a medium size show could be coordinated.
Granted the city isn't Houston or Buffalo, two of the hardest cities to coordinate shows in but...
Please, If you have any specific questions I'd be glad to expand on the video.
Simple frequency coordination
Mac Kerr:
Thanks Pete.
Mac
Thomas Harkin:
--- Quote from: Pete Erskine on August 28, 2015, 09:48:34 PM ---I rushed through this and didn't explain in detail what some of the IAS app was doing. I wanted to show how easy and quick a medium size show could be coordinated.
Granted the city isn't Houston or Buffalo, two of the hardest cities to coordinate shows in but...
Please, If you have any specific questions I'd be glad to expand on the video.
Simple frequency coordination
--- End quote ---
Thank you. Thank you. Thank you. I doubt, as a weekend warrior/HOW guy, that I'll ever need to do that. But who knows?
Justice C. Bigler:
Oh...he heh...Tulsa, Oklahoma, huh? ::)
IAS looks like it's a lot easier to use than RF Guru.
Thanks for the video Pete.
Can you explain the meaning of triple beats? In RFG I can never get enough open frequencies unless I turn the settings down to the lowest or second to lowest intermod settings.
Pete Erskine:
--- Quote from: Justice C. Bigler on August 29, 2015, 01:22:40 AM ---Can you explain the meaning of triple beats? In RFG I can never get enough open frequencies unless I turn the settings down to the lowest or second to lowest intermod settings.
--- End quote ---
Triple beat is IM distortion among three frequencies. Two frequencies create 3rd order intermod frequencies. A third frequency now not only interacts with the original primary frequencies making more 3rd order IM but the intermod frequencies as well making even more IM. The number if created frequencies becomes large very quickly.
The worst IM is created in non linear amplifiers like the type used in RF combiners. This is where the highest concentration of rf is mixed together and subjected to the non linearities of the amplifier making IM and 3IM.
So use tripple beat IM when selecting frequencies which will be actively combined. Turn off the triple beat IM when searching for mic freqs since these freqs are not actively combined.
IM is created also when Transmitter antennas are near and each carrier is allowed to feed back into the others amplifier output. Another reason to separate the TX antennas. However because of the added loss of over the air RF the levels are much lower and even lower for triple beats.
Wireless mics can cause IM when sitting near each other on a table. Ever try using a BTR beltpack near a table filled with wireless mics? It doesn't work well die to the mess if OTA intermod. As soon as these mics are separated by a couple of feet in use there is no appreciable IM. Always use baking tins for each mic to shield it from the other live transmitters.
If you are interested in more explanation read this or for the math read this
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