Topband: DX Window

[Roger Parsons]

I agree with the remarks made by others regarding the DX window in the ARRL contest.

I have been more concerned for many years about the various phone contests which take place on 160m. During those contests phone operation takes place right down to the bottom of the band, effectively making any CW operation impossible during those weekends. Last year one ssb contest coincided with a Dxpedtion to 9U - an exceptionally rare country on 160m. Whilst it is true that there are only a few phone contests on the calendar, it is also true that there are only a few weekends where exceptional conditions happen, particularly during sunspot maxima.


Frequency allocations on top band vary from country to country, but it is generally true to say that the 'prime real estate' for phone operation is from 1830 - 1850 kHz, with the 1810 - 1830 kHz segment being next most desirable. Very few countries allow phone (or any) operation below 1810 kHz. A significant number of countries (particularly North America) also allow operation all the way up to 2 MHz..

Even in the busiest contests it is rare to hear any operation above 1900 kHz.

It would be nice if the regulations were changed (particularly in NA) to limit the permissible frequencies for ssb, but I think we all know that will never happen.

However, contest organisers can very easily define the allowable frequency bands for each individual contest, and as has been mentioned by others this is already done for some (particularly European) contests.

I would like to propose that phone contests disallow the use on ssb of any frequency below a dial frequency of 1820 kHz. That leaves 8 kHz of international frequencies for CW operation whilst still giving the ssb contesters 32 kHz of the 'prime real estate' - and 150 kHz of the apparently less desirable frequencies above 150 kHz.

I did suggest this on the contest reflector last year and was immediately flamed, but I honestly think this would be an attainable and reasonable compromise.

73 Roger
VE3ZI