[AMRadio] Phone band expansion


Donald Chester k4kyv at hotmail.com
Fri Jun 11 15:39:41 EDT 2004




>From: "Brian Carling" <bcarling at cfl.rr.com>

>... There is a rapid expansion taking
>place in the digital sub-bands below 3700 kHz and there
>are still many CW ops using the spectrum around 3700 to 3725...
>ARRL is VERY interested in promoting digital modes. Sadly the
>main one they are promoting is (in my opinion) very expensive,
>wasteful and inefficient. The unattended Pactor robot stations
>are ruining the CW and digital sub bands on 40m, 30m and 20m
>and they threaten to do the same on 80m too.

Many CW operators are adamant about not giving up a kHz of the CW/digital 
subband, yet I never find this part of the band full.  Even during periods 
when there a lot of active CW ond digital stations, there are still tens of 
kilohertz of unoccupied spectrum in between.  There is no reason why the CW 
and digital ops couldn't move in closer together, resulting in a continuous 
band of frequencies where there is actually some activity going on.

There seems to be considerable friction between the CW ops and digital 
users.  There has even been talk about petitioning the fCC for additional 
subbands - one for CW, one for digital, one for phone.  But if you count the 
available  channels, even with only 100 kHz of CW/digital, there would still 
be room for more narrowband stations to operate simultaneously without 
interference than there would be for phone, even if everyone used SSB.  Even 
if there is surge in interest in digital modes, I doubt there ever will be 
more stations using digital/cw than phone.

Another problem with the present subband situation is that there is no 
possibility of transmitting wide band digital signals.  It is not permitted 
in the CW band, and digital signals are not allowed in the phone band.  
Otherwise, hams could experiment with such things as digital voice and 
possibly digital TV that, unlike slow-scan, would show real-time motion, yet 
not take any more spectrum than AM phone.  Also, with digital techniques it 
might be possible to transmit voice with quality at least as good as 
present-day broadcast quality AM, with less than is now used by conventional 
SSB.

Actually I would like to see what happened if we tried eliminating subbands 
altogether, as the Canadians and Europeans have done, and let voluntary band 
plans be used for whatever separation of modes is needed, as is presently on 
160m even  here in the US.  However, from what the FCC says in the docket, 
they have already already discounted that idea.
>
>Even more so since QRN makes 80m and 160m virtually unusable
>for 8 months out of the year here in Florida.

It's doing a pretty good job of it here as well, this year.  I can count the 
number of times I have been on the air in the past 5 weeks or so on one 
hand.

>I wish we could get the broadcasters off 7100-7300 kc.
>How many decades will THAT take?!

They are supposedly working on it, but look how many decades it took to  get 
LORAN off 160, or even open up the expanded AM broadcast band after it was 
approved by the WARC in 1979.

73, Don K4KYV

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