Topband: Re: DX window

[John Kaufmann]

jbattin wrote:

>Forcing Dx to listen outside the window would be a big
> mistake .... The QRM would be terrible. Like 75 meters in a SSB contest ...
> When the DX says listening on 3840 you transmit there no matter who you QRM.

Actually split frequency operation works extremely well on 75m in contests.  Europe transmits below 3750 and listens up in the US phone band.  In contests nearly all my 75m contest contacts in Europe are made this way.  It works because the US cannot transmit below 3750 and QRM the Europeans down there.  Stepping on top of people on your transmit frequency when you are split does happen sometimes, but it happens when people operate simplex, too.

In the old days, which some of you remember (my Top Band experience dates back to the late 1960's), we worked almost all 160m DX by split-frequency operation.  It was no big deal.  Almost everybody had separate receivers and transmitters (early transceivers did not have A/B VFO's).  Many of the Europeans truly ran only 10W and stateside stations were limited typically to 100W at night because of LORAN non-interference restrictions.  Also, antennas were far more primitive than what people use today.  Beverage antennas were pretty rare.  If you think weak signal reception of DX is a problem now, imagine what it was like then!

I rather like the idea of split-frequency operation.  Practically speaking, however, I don't see this idea working now because people simple don't want to change their habits.  Furthermore, different countries have different frequency assignments on 160, which really complicates the idea of DX windows.  There are few places (except maybe above 1900 kHz?) where the US can transmit without potentially stepping on some other DX stations.  

Yes, from New England we have an advantage most of the time into Europe.  However, we slip down the ladder--sometimes to the bottom--when it comes to working Japan, the Pacific, South America, the Caribbean, etc.  Personally I look at the issue of dealing with strong stateside QRM on weak DX stations as part of the challenge of 160.  If it were easy, I probably wouldn't be doing it.

73, John W1FV