[amsat-bb] Re: Listening on USB when operating CW

Kevin M n4ufo at yahoo.com
Fri Feb 7 20:52:42 PST 2014

> Many times I have been engaged in a QSO only to have someone CQ'ing on
> CW drift across my existing QSO.  Anyone who operates satellites has
> probably had this happen to them many times.  Sometimes myself or
> others in QSO may try to tell the CW operator "Hello - QSO in
> progress" but it is apparent they are not hearing us.
> My question is, does it make sense for people using CW on the
> satellites to have their receiver set to USB?  Do some operators do
> this? 
At first I was a little confused by the question... CW receive on almost any rig I have ever used IS USB receive (as opposed to LSB), just a different dial setting, perhaps with a slightly narrower bandwidth. Then I realized you are asking because of the passband inverting... Since CW is neither LSB or USB, just a carrier, then yes, the norm is to listen for CW with the down link set to CW or USB depending on preference.

But to address the issue of who is passing over who... is it not also possible from the prospective of the CW op that it is the SSB QSOs that are passing over them causing QRM? I've tried about four times now to write an explanation of how one used to operate, but the bottom line is, if a station is running with manual doppler correction and sending CW, my experience is he doesn't adjust the transmit VFO while sending... the receiving station adjusts the receive VFO while copying and then on the 'over' as he starts to send adjusts his transmit to match where he heard the other station last in the downlink. (It's also my experience that manual tuning SSB stations did the exact same thing.) So compared to doppler correction and possibly the one true rule, the manual tuning stations drifted... BUT, please understand that part of my confusion in remembering is that I mostly worked mode K, which was a different animal; you never adjusted uplink due to being
 on an HF band... you might drift into a terrestrial QSO. I did work a little mode A for a while and we sometimes had mode KA active.

But, it was never a problem that I could tell because the lower half of the passband was CW and the upper half was SSB and usually they were equally occupied. Nowadays SSB far outnumbers CW. (I would work more CW if more stations were on... I prefer it; guess that's a catch 22 thing now, huh.) I am merely suggesting that a CW op is more likely to be an 'old school op' and more likely to use 'manual correction'... in other words, more likely to 'tune the old way'.  I may be way off base here, but it's my honest estimation/recollection. However, if I am right, then your characterization of the CW drifting across the SSB QSO as opposed to the SSB stations drifting across a CW QSO (which happened to me many times last summer) is perspective biased. It boils down to what is considered a 'stable frequency' as another poster said... relative to ground reception or passband edges.

It is a very old discussion in ham radio... AM versus SSB was one of the earliest issues of group norms versus emerging technology. Meaning, the evolving technology began to force a change in accepted norms as the technology was adopted. And the points of view were equally biased... 'SSB does not have good sound quality'... 'AM takes up too much bandwidth'. But people still operate AM today. Room is still made for both and they can co-exist. However, I must admit it is a quandary when the practice in question involves shifting frequencies and how to do it. I'm merely saying, for you the CW station is the offender and for a "seasoned manual tuning op" the fancy computer doppler guys are the offenders. The question is whether to argue or how to co exist?

But to address what I think you were actually asking... As a CW op I can tell you that you will hear a CW signal sweep by with greater "ease" because the intelligence is communicated by simple on/off keying and can therefore be heard and copied over a greater time period. But from the CW ops point of view, sweeping SSB is charlie brown's teacher sounds changing pitch and the period in which the speech is intelligible is a fleeting amount of time... In other words what the ear catches is, "Wub-wub-wub-in QSO-squeak-squeak-squeak", where as you hear the beeping all the way through. Because like most any male we still draw on the genetically passed down ability to narrow our focus to only that prey which we seek to the ignorance of all else. =^D
73 and hope to see you back on the birds soon...

Kevin, N4UFO

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