Friday, April 17, 2009

AM vs. SSB -- retro battle or much ado about nothing?

For those who don't know, the amateur radio world is abuzz over a recent positive change. International treaties recently required that shortwave broadcasters who have filled up a good portion of the 40-meter amateur radio band to move to a new allocation...above the ham band and out of our passbands! The newly vacated bit of spectrum is wonderful. Propagation--especially at night--is interesting and promising. Many hams in foreign countries are now being allowed to operate above 7.125, so we can talk to each without having to use split frequencies. But the really great thing is we don't have to listen to all those squealing, squalling AM signals and their tinkly splatter

All is right with the world! Almost.

Some amateurs who enjoy operating AM instead of SSB have chosen the vicinity of 7.160 in the pristine newly quiet band to talk to each other. You would have thought somebody dropped a cow patty into the punch bowl! The amateur discussion forums teem with people who want to lynch anybody who dares to insert carrier and un-suppress that other sideband and sully up that nice, new bunch of frequencies.

Never mind that many of the guys who decry the spectrum taken up by AMers are dyed-in-the-wool DXers. And DXers still work a ton of split-frequency, thus taking twice the bandwidth a simplex QSO requires. That's roughly the same slab of spectrum the AM guys use. Others seem unable to make a simple adjustment to their receive bandwidth or move up or down a few kilohertz, only to be completely outraged by even the hint of a heterodyne way up or down the band. And all of them forget that SSB ops are typically causing the AM guys far more QRM than the AM folks could ever cause them.

It reminds me so much of the SSB vs. AM wars way back in the late-50s/early-60s, except this squabble is 180 degrees out of phase with that one. I was there for the end of that, when guys who clung to AM cussed the "Slop Bucket Boys" and tuned up on top of them for hours to demonstrate their disdain. It got ugly, but for the very reason cited above--who gets the worst of the QRM--it eventually was won by SSB (Yes, there were other reasons...SSB is simply a better mode, more efficient).

I maintain that hearing an occasional heterodyne is a small price to pay for the freedom of being able to operate using whatever legal mode that interests you and that you want to. If we say, "No dang AM on my band!" then how long is it before somebody else says, "Yeah, and no SSTV, either?" Or "Get rid of those digital modes so I can work CW there!"

It is that old "if you don't like what I like then what you like is wrong!" mentality.

Most every radio has a VFO. Use it. There is plenty of spectrum for everybody to be able to enjoy their favorite activity or mode.

What do you say?


Don N4KC


goody said...

I'm convinced if AMers ran QRP on 7.295, people would still complain. AMers tend to attract angst and interference wherever they go. Even though they usually sit on one frequency on a band, sidebanders seem to crowd in on both sides of them, even when there is 50 Khz open down the band. I don't mind them taking up twice the bandwidth; I find their conversations three or four times more interesting than the SSB roundtables I hear at night.

Anonymous said...

Paul is going to kick your butt!!

Anonymous said...

If you mean "logically," I doubt it, but bring it on! If you mean in a good, old-fashioned fistfight, possibly.

But I am undefeated!


Don N4KC

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VE3LYX said...

Well you may think SSB is the "more better "but QRM wise i find the an SSB soignal messes up a lot more of the band than an Am signal. An SSb signal isnt where it appears to be if you have the rX on AMwhere AM is just where it is period. Now I operate both modes. I use SSB for Dx or serious work but I find AM very interesting as well. The freq wherethey are are pretty well known. 3705 for instance. Why SSb there? mutual consideration. VE3LYX

Don Keith N4KC said...

I have nothing against AM. I use it sometimes myself. But I don't agree that SSB takes more bandwidth than AM. Not if it is run properly.

There's room for all modes on our bands.

Don N4KC

Anonymous said...


Addressing your title, AM vs SSB, and maybe I am imagining things, but it seems that AM has a sound-quality depth that's missing in SSB.

As a slight aside, aren't broadcast AM radio stations putting out signal in full AM (not supressed carrier)?

Thanks for reading and responding.

73 de KB 9 PRC Milwaukee.

Anonymous said...

AM can sound good. AM can sound terrible. SSB can sound bad. SSB can sound really good. With my receiver opened up to, say, 50 hz to 3200 hz, and with a station using good processing and a reasonably broad EQ, I think anyone would be hard-pressed to tell the difference between that and AM.

Yes, AM stations use what you term "full AM," that is with no suppressed carrier. AM broadcast is a bit different than ham radio since everyone on the AM band uses, well, AM. Hams have to share spectrum with other modes.

Thanks for dredging up a 4-year-old topic! Glad somebody is paying attention.


Don Keith N4KC

(Author of the new book RIDING THE SHORTWAVES: