I work, or try to work, many EU activations on 10 m SSB which are extremely difficult to hear.
Not because the activator’s signal is weak per se, but because they are unwittingly overlapped in frequency by much louder, fixed stations in EU who are calling CQ. This problem occurs most often in the very busy segment from 28.350 to 28.550 MHz (roughly typical range – of course it varies quite a bit).
In many cases, if the activator were “in the clear” he could be heard easily and would likely work more interesting DX than the eastern U.S.!
In the interest of encouraging SSB activators to take full advantage of the large amount of spectrum available on 10 m, I made this graphic:
Thanks for the reminder Matt. I suppose the main reason everyone congregates below 28.500 is all US hams can operate between 28.300 and 28.500 and we’d like to work them. But your usage waterfall suggests we should all operate above 28.600 and only when the chasers appear to be drying up, spot for a frequency below 28.500 to work the others.
There are indeed a ton of holders of the Technician license (the class which can’t go above 28.500) in the U.S… But my impression is that there are very few of them who are active on 10 m at all, let alone straining their ears for the very niche pursuit of working DX QRP SOTA buried in the rubble of QRM Alley.
It’s so easy to get a General- or even Extra-class license now, anyone motivated enough to get on 10 m is likely also going to upgrade and have access to the whole band anyway.
It would be interesting if any activators by chance have numbers on the U.S. “Techs” they work on 10 m.
Hi @W4GO,
Great to work you on 10m. This is very useful. I 100% agree. So many times I’m trying a difficult S2S and just can’t because of adjacent signals.
I must admit I usually aim for about 28.420 ish because it’s busy and chance of logging a unique callsign for the 10m challenge is higher.
But the amount of times a station parks next to me after I’ve spotted, without enough space and spatters all over my quiet band….
I can see a couple of reasons why EU SSB and CW ops don’t activate in the 10m 28.6 to 28.9MHz sub-band:
It might well be easier to hear them (due to lack of activity) but nobody probably is listening there for SSB and CW CQs unless they see the senders’ self-spots. The very crowdedness of 28.300–28.500 MHz is no doubt because, worldwide, operation in this band segment is almost exclusively SSB, which is what attracts activators to operate there.
In the UK at least, the band plan recommends those frequencies for wideband signals like digital images.
Very interesting post. And another four weeks of the Challenge to try to benefit from it!
No mention of datamode frequencies I see. Well, FWIW, I would suggest that FT4 (28.180) offers a higher probability for a contact than FT8 (28.074) at the present time. Though this can flip, so I tend to try both these on a 10m activation.
On both CW and SSB, there are obvious advantages and disadvantages of choosing either the busy part of the band, and the quieter areas. In the “thick of it” there is generally more activity - but as pointed out above, you could be unwittingly burying yourself underneath a QRO EU station within the skip zone. On the quieter frequencies the QSO rate might be slower - but more chance of working DX and chasers. Again, I try to do a bit of both.
No mention of FM or AM. I do like to have a look at those frequencies and try a few calls, but very rarely do any actual QSOs materialise. There does seem to be AM activity around 29.050 - 29.100 daily at present. With FM, I’m still not sure whether to use QRGs around 29.200, or those between 29.500 and 29.575.
Anyway, to try and cover all bases, my current 10m activations tend to see me trying calls on (+/-QRM):
28.017 CW
28.059 CW
28.075 FT8
28.181 FT4
28.365 SSB
28.470 SSB
28.595 SSB
29.200 FM
29.550 FM
This will continue to be the case until the end of the year, except for time-limited activations - like Gaulfest when we are trying to squeeze 3 summits in before the bakery social.
Since starting the thread about a week ago, it does seem that more SSB activators in EU are picking frequencies in the less crowded parts of 10 m during the daily opening to North America. Thanks for the (much easier) contacts!
Of course, not every activator is a regular reader here.
Here’s a spectrogram showing one of the activations which I’ve recently worked with difficulty. The faint signal at the cursor, 28.346 MHz, is him; the strong signal is me.
Notice that the activator is overlapped by a stronger signal out of Europe at 28.344. Even if the interfering station were to have zero spurious emissions (“splatter”), the overlap from his intentional emissions, nominally 3 kHz wide, makes the target signal difficult to copy, even with a modern receiver with brick-wall DSP filtering at the IF stage.
Predictably, he had few callers before moving on to another band.
It’s simply a matter of probability. In QRM Alley (roughly 28.350-28.550 MHz on a typical weekday), the odds that a frequency which sounds clear to you is actually clear are quite bad. Outside that range, the odds are much better – and continue to improve the farther you go.
Note: this is largely not a problem for the minority of activators who run > 50 W to a directive antenna. Their extended pile-ups tend to keep the frequency clear even in the crowded part of the band.
I used 28.605 today for 10m activity from Green hill GM/SS-123. I got only EU qso’s today, I was too early for Transatlantic contacts and couldn’t stay too long due to the bitterly cold wind. 12m was busy today, AC1EV was strong signal to me from Mass. But unfortunately he didn’t hear me.
Andy
MM7MOX
On my way to the summit I had a different idea and gave it a try:
I searched for a quiet spot on the 10m band with my radio and then visited a random KiwiSDR from the US east coast to check whether the frequency was clear there too. After a bit back and forward, I found a frequency that was clear on both sides but still somewhere in the main SSB area: 28.420
Note that the spectrum did not look too crowded at this moment but it still took several checks to find the best QRG.
It worked really well for about an hour until the propagation went down when the night set in.
Thanks chasers! I had some great DX and no reports of QRM. Several chasers across the US confirmed that the frequency was otherwise clear.
And the S2S with @W8BRY on W4V/SH-017 was one highlight of this cold and dark winter activation.
Tried 28.605MHz again late yesterday afternoon for 10m activity from Calf Top [G/NP-022]. Good to get you in the log plus three other transatlantic QSOs, two EU and a ground wave over to Blackpool. Then a second transatlantic QSO on 20m.
There was a bitterly cold wind when I arrived but it eased as the sun set. It all made for an interesting descent not helped when I missed the path down!
I was intending to try this approach on Saturday 14 Dec during a triple-activation run I have planned for the Linville Gorge in NC. Completely forgot about the 10m ARRL contest that will be going on, so I have a feeling the tactic will be a fools errand. I will still try to get at least one or two 10m QSO’s on each summit since it’s likely my last opportunity to participate in the challenge, here’s hoping I don’t freeze while trying.
