Short answer: In theory, a bit more (50% maybe) if you’re using the same polarisation.
At least turn the J pole on it’s side to make it horizontal though … I think you’ll find that using it vertical will give disappointing results as most people will be using horizontal beams.
To maximise your chances I suggest using something like a 4 element beam, horizontal polarisation and announce your intentions in advance. Depends on many factors of course, but I expect at least 300km under flat conditions. If conditions are really up then >2500km is possible. It also helps if the other station also has a high performance set up. If you can overlap your activation with a contest (there’s one tonight as Tom mentioned) then you won’t get much conversation but you’ll be plesantly surprised with how far you get.
I really like 2m SSB when I’ve got the time and don’t mind carrying the extra kit.
As far as I understand it most 2m ssb is horizontally polarized; my J-pole/slim-jim was designed for vertical use and I have never tried it horizontal. I started SOTA using 2m ssb a lot, dipole or 2 element lightweight beam (or even the stick aerial that comes with the 817) - all horizontal, but there seemed to be more regular activity then. (Locally one activator is rarely out and I now almost never use 2m ssb.)
For 2m I am using a Diamond omnidirectional antenna as well as a vertically polarized Yagi. So why should I not use these antannas for SSB?
Real SSBers of course use horizontal polarisation, so when calling on 144.300 from a summit at least a horizontal HB9CV antenna would be useful.
Years ago I had a fixture to put the HB9CV-antenna vertically or horizontally polarized to the pole.
Joe, when you intend to do SSB let me know, I’ll try to be on air with an old IC202.
Joe, the answer is yes but you need to work at it, you need to make sure people know you will be on and using 2m SSB.
There are many fewer amateurs with 2m beams for SSB than 20 years ago. So you will benefit from having an antenna that you can swap between vertical and horizontally quickly. A dipole made from telescopic aerials means you can use it both vertically and horizontally. Horizontal for those with beams and vertically for people who only have a vertical antenna.
You may find some people reluctant to use vertical and SSB, you need to persuade them to try as some think you can ONLY use horizontal for SSB.
By using the “wrong” polarisation you can expect a cross polarisation loss of about 20dB. It is also known that horizontal polarisation works better than vertical polarisation even with FM. Vertical polarisation has gained its present dominance because it is much more practical for mobile operation.
Hi Brian, not sure where the 20dB figure comes from?
With my little 23cm PCB antenna, it is possible to null out strong signals by tweaking the polarisation, though it is a very sharp null - in practice, you would probably be very unlucky to experience this by chance. Even if the antennas were exactly at 90 degrees, there would likely be some path rotation / reflections etc. Maybe the 20dB is a practical expectation…?
It does feel “wrong” to use SSB with a vertical antenna, but the potential benefits in the context of SOTA activating (assuming a single element dipole / Jpole etc) include: simple universal antenna, omnidirectional, easy to mount high on a fishing pole.
Maybe this thread will encourage me and others to give it a go…
It’s over 30dB. In practice, in a town, there are sufficient buildings and rooves etc. that reflections make the observed loss much less especially if the antenna is not well clear of buildings etc.
Years ago on the 70cms FM contest my club contest group were on Cyrn-y-brain GW/NW-043 with a 10m mast, a 21ele Tonna horizontal and a 19ele Tonna vertical. On a 90km LOS signal we could not detect any signal on horizontal (even with a preamp) and the rig in SSB not FM. Switching back to FM and also to the vertical there was an audible click as the FT-736 S-meter hit the end stop. This would be 1995 or so. If only we’d all had mobile HD video cameras in our phones back then I would have recorded it.
This is so. 20dB is a “real-world” expectation, rather than the infinite theoretical loss. There is an interesting option, which is to devise a way of mounting the antenna at 45 degrees, this would give 3 dB of loss to both horizontally and vertically polarised signals, significantly less than the gain of a beam, though if you encounter another 45 degree polarised signal then you need a matching tilt! One advantage of a horizontal polarisation is that it enables you to take advantage of diffraction enhancements.
I don’t do much V/UHF work nowadays, but my SOTA kit includes a dipole which can be mounted on the mast in either polarisation, it only takes a minute or so to lower the mast and change polarisation.
There is an aircraft enhancement propogation net that runs aroudn 8am local on East coast VK. Its a great place/time to play with 2M SSB and qualify summits courtesy of Qantas and the rest of the crowd that fly overhead. So try AE with 2m SSB.
I was not considering polarization but that’s of course a topic. Will try the horizontal and 45° solution because it’s possible using my equipment. I can use both of my trekking poles and some cord to arrange the slim-jim horizontal.
A HB9CV is a good addon to my SOTA toolbox anyway. Will look into that.
@OE5AUL Danke für das Angebot. Werde es beim Alert dazunehmen bzw. wir stimmen uns ab.
2m… yes, my preferred option, but not always practical if remote from chasers and the weather is bad.
While I generally use the rare Sotabeams SB5 5 element yagi based on the lightweight yagi design by Martin DK7ZB (still going strong after 10 years), for simplicity I sometimes use a 2 element Moxon which rquires no assembly on site. I can recommend the Moxon as it has no element ends to catch on anything.