View Full Version : Please confirm my understanding


Mike Hanlon
January 31st, 2011, 06:37 PM
Sorry if this sounds lame, but I heard something from an audio "expert" the other day that I know is incorrect, but wanted to verify my correct (?) understanding with this trusted body.

The discussion involved wireless microphones such as those commonly used in live theater, with regard to frequency use. The "expert" told me that the spectrum is divided such that individual manufacturers are allocated specific ranges so that they don't interfere with each other.

A quick search at B&H showed me that there are some manufacturers that overlap each other on some products, so I know exclusive allocation cannot be true, i.e. my expert is wrong.

Is there perhaps an aspect of the expert's assertion, some grain of truth, that I am not aware of?

Thanks for the help,
Mike.

Robert Wiejak
January 31st, 2011, 08:35 PM
There is no such thing as “…individual manufacturers are allocated specific ranges…”. They all share the frequencies on a secondary basis with TV.

Bill Davis
January 31st, 2011, 09:28 PM
Perhaps they're confusing RF mics with Cel Phones?

In cel phones, manufacturers and retailers are often issued "banks" of cel numbers that they can use for their customers purchases.

But in low power radio mics, the FCC regulations are such that every manufacturer has to work within the spectrum that every one else has access to.

John Willett
February 1st, 2011, 07:35 AM
Sorry if this sounds lame, but I heard something from an audio "expert" the other day that I know is incorrect, but wanted to verify my correct (?) understanding with this trusted body.

The discussion involved wireless microphones such as those commonly used in live theater, with regard to frequency use. The "expert" told me that the spectrum is divided such that individual manufacturers are allocated specific ranges so that they don't interfere with each other.

A quick search at B&H showed me that there are some manufacturers that overlap each other on some products, so I know exclusive allocation cannot be true, i.e. my expert is wrong.

Is there perhaps an aspect of the expert's assertion, some grain of truth, that I am not aware of?


It all depends on which country you are in.

Firstly - manufacturers are definitely not allocated specific ranges.

Where you can legally use radiomics varies from country to country and region to region within that country, not from manufacturer to manufacturer.

Each manufacturer will calculate intermodulation-free frequencies differently - so it's very important to get the manufacturer of your radio to calculate the frequency set for you - they will give you the best and safest set.

So IM-free frequency sets will vary with manufacturer, but it's nothing to do will allocation.

Mike Hanlon
February 1st, 2011, 11:42 AM
That's a relief, glad to know I wasn't wrong about something so basic.

Thanks again for the help.

Mike.