We went up to the Great Orme last week…Armed only with the handhelds at the time, we noticed that there is an enormous amount of hash generated by the nearby antenna arrays.
My question is, is it acceptable to move away from the trig point far enough to decrease the interference level and still remain within the rules for activation?
If not, are there any steps that I can take to help reduce the interference?
Any help or advice appreciated!
The rules allow you to operate within 25m vertically of the summit. Great Orme is 207m ASL, so this implies that you may conduct your SOTA activation anywhere in the area above 182m.
To be safe, you could make that 190m, then it is straightforward to look at the 190m contour on a map and operate from within that area.
Great Orme is a horrid location for QRM on VHF. The following are some of the techniques used by activators to counter the QRM:
- Move away from the summit within the 25m activation zone (as indeed you suggested)
- Use a beam antenna
- Use horizontal polarisation (even if just turning your handheld on its side)
- Use 2m SSB
- Use HF
- Use an FT-817 (or similar) - a decent rig will withstand the mush better than a hand-portable
I can personally vouch for all these techniques. As I say, it is an awful location for VHF, and most of these won’t eliminate the problem - but they will help you cope with it better and allow you to get your 4 (or more) contacts.
For further info, check out the links on the summit page at http://sotawatch.org/summits.php?summit=GW/NW-070
In reply to M1EYP:
Roger MW0IDX told me many years ago that he uses the attenuator on his handy when on NW-070. I was a rank amateur at the time and didn’t get it - some years later I now see the wisdom of his words, hi.
I found that my ancient Trio handheld copes with the noise up there much better than my newer Yaesu barndoor VX6 =)
In reply to M1EYP:
Many thanks for the response Tom…
I did think that there would be a provision within the rules for such eventualities but wanted clarification to be safe.
We intend to pop up to Macclesfield soon and have a look at the Sota beams so that should help with the 2m side of things.
As for H.F., we’re still undecided as to which radio to buy as yet but we do have a shortlist!
I did try turning the handheld on its side and it did help but was still less than ideal.
Thanks again Tom…Regards, Neil.
In reply to M0MYA:
Hi Dave…I’d not thought about using an attenuator but do wonder if that somewhat defeats the object too much by desensing the weaker (and needed) stations?
The handies we have are older models (TH 78/TH79) plus the 290 as well so perhaps more immune than newer models.
Ah well, onwards and upwards!
Cheers Dave…ATB, Neil.
In reply to 2E0TDX:
QRM on Great Orme seems to be everywhere from HF right up to micro-wave, but single band radios seem to generally be the best for being immune. Modern radios tend to do all bands and be more susceptible to interference. It probably does not help trying to operate 2m when you are within a few feet of a 2m repeater as well as the commercial pagers and data transmissions just out of band.
Strangely I have been up there when I had no problems but when I returned with the same gear I had a torrid time. You can get lucky or not depending on when you go. I suspect that there would be much less commercial traffic using the gear up there after 6pm on a Sunday than during a 9-5 on a weekday.
The very best time to work is probably when the North Wales Radio Rally is on, early on Sat/Sun morning as all the amateurs are driving down.
73 Steve GW7AAV
In reply to GW7AAV:
It was fairly late when we arrived at the trig point…around 20:30ish and the noise level made 2m pretty unworkable at that time.
Good call on op from there when the rally is on, although I suspect that there will probably be a few extra activators now with that comment!