Topband: Re: [psk31] PSK on 160

[Tom Rauch]

Hi Peter and all,

Having been involved in 160 since 1962 and watched things evolve over the
years, I can give some input that may be useful (or ignored).

> The recent IARU region 1 conference in San Marino, although it approved
> an eventual change to HF bandplanning from separation-by-type to
> separation-by-bandwidth, has kept the existing 1838-1842 segment for
> digital modes, just splitting it into 1838-1840 for narrow-band modes
> and 1840-1842 for wide digital modes. Some good news is that it is now
> recognised that SSB stations should NOT transmit LSB with their dials
> set below 1843kHz. This may take some time to be understood, but with
> the PSK31 activity on 160m increasing in the 1838-1840 region in Europe,
> we should start to see an improvement in the problem of SSB interference
> below 1840.

The fact is, band useage throughout the world dictates that area be left
open for SSB and CW. It is the only common frequency range available
worldwide (excluding Japan) for long distance communications, which is
primarily on SSB and CW. These modes, SSB and CW, will always be dominant,
at least until someone comes out with a digital voice mode. 160, unlike
other bands, has unique problems that require special thought and
consideration, not just blindly sticking things in new places.

"Improving things" by ruining things for other people who have been active
in certain patterns for many years, and who will no longer will be able to
operate, will not be perceived as an improvement by many long-time operators
on 160.

> If there is likely to be any trans-atlantic PSK31 tests, I suggest the
> best idea would be to work split-frequency, with the USA stations
> transmitting in 1800-1810, which is fairly quiet over here in Europe,
> and listening for European PSK31 stations in 1838-1840, which is within
> the USA "dx window" and therefore should not be heavily congested with
> local stations.

Split operation would be good for everyone, but I'm afraid this idea still
places strong SSB and CW signals from big stations working DX right on top
or next to any digital window. The digital window really belongs off to the
side someplace, not smack in the middle of the primary DX area of the band.
Consideration must be given for everyone already on the band before a new
exclusive area is created, and through planning with existing operators
rather than dictatorship, or the result will be a real mess and many hard
feelings will be created.

Before extracting several kHz from a prime area, we should make sure the
other operators already there will have a place and be willing to move.

I initially thought PSK would be a good "buffer" between SSB and CW
operation, but after listening to some of the signals and operators I
changed my mind. It is far too easy to have hum and harmonic distortion, and
still some people don't understand how to calculate the exact operating
frequency of PSK or how one mode impacts another. Better to put digi modes
run through a wide-filtered SSB transmitter and (sometimes) receiver off to
one side or another. Dynamic range and spectral purity limitations or errors
will cause big headaches for years to come if we don't plan carefully.

We need a long-term plan that does not displace primary users. The IARU
needs to seek input for 160 operators before they mess things up for
everyone, and cause a lot of hard feelings that last for many years.

73 Tom