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X-PAND Compression Technology

Posted: Sat Jul 15, 2006 12:53 am
by losangelescop
1. Whats it sposed to do and is it any good at all ?
2. to the jedi radios have it or just the waris ones
3. i have heard that if you use a radio with xpand and talk 2 a radio without xpand, the signal clarity is crap..is that true
4. getting radios reprogrammed soon, 3 waris radios and 1 jedi, should i put xpand on the waris radios or not, seing as they would make waris comms better, but they will also have to talk with the jedi.

thanks 4 the help pplz

Posted: Sat Jul 15, 2006 1:15 am
by MTS2000des
X-pand is a compander noise reduction system, it operates similar to Dolby NR in that signals are compressed on transmssion and emphasised (the high end particularly) and the expanded on reception and the high freqs de-emphasisied, in the process of doing this, noise is reduced greatly. It's pretty effective, and is especially helpful on narrowband channels.

Using radios without Xpand enabled results in unnatural sounding audio, similar effects of playing a non-Dolby encoded cassette or open reel tape with Dolby turned on....you experience "pumping" sound of the decoder and frequency response is off, some say it sounds like someone is talking through a sock, etc. An Xpand transmission sounds overly bright and compressed when recieved without Xpand, again, similar to Dolby playback of encoded tape without Dolby decoding turned on.

No Jedi radio offered expand that I am aware of.

As far as enabling it, I would keep it turned off if you have radios you want to communicate with that lack a compander (some other radio mfr's have similar compatilbe compander cirucits...most Kenwood, Icom and Vertex radios of late offer this feature on a per channel/mode basis).