The shift for the FM (frequency shift keying) is up to +1500 and -1500
about the nominal frequency. This is true for 72 MHz or 50 MHz. This is
used on 53 MHz but is not mandated on this band since the channels are
100 KHz wide.

Dan Thompson

Tim Wescott wrote:
Doug McLaren wrote:

In article ,
Tim Wescott wrote:
-- snip --

... so it looks like there IS a standard now, at least on the six
meter band stuff. I've heard some say that this isn't true, that
brand X 6m RX didn't workt with brand Y 6m TX, but details were never
really given.

That was useful, but I forgot to ask:

Is the space (no pulse) frequency the nominal frequency, or is it (more
sensibly IMHO) 1/2 the shift below -- or at least _some_ amount below
the nominal?

If I were designing such a rig I would have the space frequency (off, no
pulse, whatever) be 1/2 of the shift _below_ the nominal frequency, and
the mark frequency be 1/2 of the shift _above_. I may shade the space
frequency to be a bit closer to the nominal frequency to balance out the
spectrum, but I doubt that I'd stick it right onto the nominal frequency.

Thanks again.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

IFLYJ3 wrote:
The shift for the FM (frequency shift keying) is up to +1500 and -1500
about the nominal frequency. This is true for 72 MHz or 50 MHz. This is
used on 53 MHz but is not mandated on this band since the channels are
100 KHz wide.

Dan Thompson

Thanks Dan. It has to be fairly close in to meet the spectral
requirements, of course -- I just didn't know what the relationship was
between nominal and reality.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/