Topband: [psk31] Re: PSK31 frequencies

Tom Rauch w8ji at
Sat Feb 25 08:42:29 EST 2006

> The IARU region 1 bandplan has agreed 1838-1840kHz for
digital modes on
> topband, and this is where PSK31 activity is to be found,
certainly in
> Europe. The recent IARU region 1 conference confirmed this
and re-asserted
> that SSB stations should not operate with LSB on a dial
frequency below
> 1843. This is showing results, and there is far less
conflict between
> digital modes and SSB activity here now.
> I am not sure what custom and practice might be in region
3. I think the
> band does extend down to 1800kHz, but the IARU region
bandplan doesn't show
> a specific sub-band for digital modes.

Peter and all,

The ARRL formed a "bandplan committee" a few years ago. They
came up with a plan that says digital modes below 1810.
This was largely due to two things:

1.) PSK and other digital modes using SSB sections of
transceivers have limited dynamic range. This causes
occasional problems when transmitting and receiving.
Receivers are overloaded by strong signals, and transmitters
at times have a tendency to be a bit dirty (largely due to
operator error).

2.) There always has been considerable trans-Atlantic CW
activity and occasional phone activity in the area between
1835 and 1840. 160 meters has a very small area for CW and
most phone ops, even those just talking across town, have an
odd fixation about operating in the area below 1850 or 1855.
It's almost like, for some people, the band ends at 1875kHz.

3.) Mixed modes cannot communicate well, and cannot exchange
information to each other about problems like QRM.

CW, when the band is open on winter nights, fills up to
about 1838 or so with CW. I often park above 1837 so I can
work weaker Europeans without bothering people in the very
crowded areas below 1835.

During contests SSB operators have few qualms about going
all the way to 1800 if it suits them, even if the area above
1850 is empty. 1830-1850 is prime spectrum everyone wants on
160 meters, and inconsiderate phone ops would like to have
it down to 1800. Just this morning, even though there was
very little activity above 1850, very strong USA SSB
stations were calling endless CQ's below 1825 kHz.

When digi modes are tossed into the prime area, we now have
a new problem. People on digital modes almost always cannot
copy CW or SSB, and people on SSB or CW cannot copy digital.
They cannot communicate to tell each other they are causing

The solution to all of this in the USA was to have a
bandplan. I objected to pushing digimodes below 1810, I
personally thought they should be just above 1810, but that
conflicts with DX activity in the prime area of 1810-1838
kHz. Wherever the digi modes go, if they are run through the
SSB section of a transceiver they need to be in their own
3kHz window. This reduces problems from bad operators or bad
equipment using digital modes to other modes. It also
reduces problems of strong signals from CW and SSB causing
problems to digital modes because of the very limited
dynamic range of narrow signals processed through wide IF

So now we have a new problem. I assume DXers, largely in the
northeast, have pushed to have the less than perfectly clean
signal from W1AW moved out of the area used by weak signals.
W1AW has decided to break the ARRL's own bandplan and
operate on 1807.5.

I have a big problem with this. DXers do not own 160.  They
can bend a little bit. The ARRL also sets a terrible
example. In one breath they open claim bandplans work, in
the next breath they move W1AW to a frequency in direct
violation of their own bandplan. This is just like when W1AW
operated a SSB contest, and W1AW was working local stations
on SSB below 1840. How can the ARRL claim bandplans work,
and then ignore their own bandplans?

Apparently it is OK for the ARRL and DX'ers to tell others
one thing, and then do exactly the opposite themselves.
Either that or they simply cannot "think" logically about
how their actions appear to others. The ARRL appears to be
trying to sabotage the very bandplan they claim makes
mandatory mode restrictions unnecessary!

Perhaps they should change their callsign to W1VLN, and give
W1AW to a more responsible operation that follows bandplans.
The ARRL should explain why they break their own bandplans.

73 Tom

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