Are crystal-free radios allowed?

Discuss the IOM class rules and interpretations

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Jamestj
Posts: 63
Joined: 25 Aug 2004, 17:50
Location: Building one at the moment

Are crystal-free radios allowed?

Post by Jamestj » 11 Sep 2006, 00:31

I understand that radios which transmit an ID to the receiver instead of using a specific tuned frequency rely on the receiver transmitting a reply to the transmitter. Are these legal for IOM use please?

Hiljoball
Posts: 270
Joined: 06 Jan 2006, 00:47
Sail number: CAN 307
Design: V8
Location: CAN

Post by Hiljoball » 11 Sep 2006, 01:50

I assume that you are talking about the Spektrum DX6. I read through their technical info and there is nothing to indicate that the receiver is also a transmitter. So there is no conflict with the IOM rules as I see it.

The transmitter finds the open frequency. The receiver is trained to 'lock' onto that transmitter.

Here is an extract from the Spektrum site and the link.

The FCC also mandated that transmitters using Spread Spectrum must have the ability to check for, and find an open frequency on the 2.4 band (there are 80 channels, spread in 1MHz spacing.) before transmitting any signal.

So when you turn on your DX6 transmitter, it scans the 2.4GHz band and picks two frequencies which show the least activity.

Each Spektrum transmitter has a GUID (Globally Unique Identifier) code. Binding is the process of programming the receiver to recognize the GUID of a single, specific transmitter. Binding teaches the receiver the specific GUID of that transmitter so that the receiver will only listen to the information from its previously bound transmitter and ignores everything else. With over 4.2 billion GUID codes, the chances of having a interference from another transmitter is virtually impossible.

It is usually only necessary to bind the receiver once. The only time it'll be necessary to re-bind is if you wish to use a different transmitter, or you want to change failsafe positions


http://www.spektrumrc.com/Articles/Arti ... cleID=1535
John Ball
CRYA #895
IOM CAN 307 V8
In my private capacity

Jamestj
Posts: 63
Joined: 25 Aug 2004, 17:50
Location: Building one at the moment

Post by Jamestj » 11 Sep 2006, 13:11

Many thanks for that information.

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