Thanks for warming the summit for me Derek. I’ll try to make it even warmer with my 125 watts ERP. Perhaps you might consider going QRO next time you activate the summit.
Sorry to hear about the SSB nil points again. I suspect that many chasers are so busy doing a balancing act between the flourishing 5MHz activity and other bands and modes, that they rely upon an actual spot on SOTAwatch for notification of 2m SSB activity rather than monitor 144.300. This is how it appeared to me on Aran Fawddwy last week when the pile up did not occur until Graham spotted me. I will definitely be using Spotlite in April.
Looks like it could be quite good when I come up now that you have wound up the audience, but I’m sorry to hear that you might not be on dry land.
The 125 watts is ERP, i.e. 25 watts out to the 5 element which has 7dB gain (x5). Now I do have real power to my elbow. I used my big linear to qualify SE-005 and SE-007. That was 150 watts out to the 5 element = 750 watts ERP… and the antenna positioned at just 3 metres on that occasion - I did crouch down!
My usual power source is a 3.3AH sealed lead acid battery which weighs 1.3kg. I have 4 of them and they cost me £8 apiece. I can get 1 hour of SSB operation running 25 watts output with a further 30 minutes on FM out of one battery. I had to resort to a handie to complete my run on FM on Cyrn Y Brain when I stayed for 2 hours. Usually capacity is not a problem. For the 150 watt linear I use a 12AH sealed lead acid battery which weighs 4.2kg and I definitely know when I have this and the linear in the backpack!
I feel that a decent antenna is more critical than the power, especially when you are up one end of the country. It applies equally as much down south as up in the SB’s. 2.5 watts to a simple antenna should get the summits in the middle of the country qualified and I have done this on occasion. However, I still think that it is worth taking a decent beam as it helps the more distant chasers to copy you. I’ll certainly be taking 25 watts and the 5 element up Sighty. The beam dismantles by the way and is strapped to the mast for carrying.
As far as points are concerned, you can only claim them once in a year, but I’m fairly certain the system does award the bonus points if a second activation is undertaken in the winter period, though quite why you’d want to do the Cheviot twice in a year… to view the boggy ground and the mists? It was 10 metres visibility when I was up there last!
Okay about the flying RF - I have been known to hold the beam in my hand running 25 watts output, but that’s me… not really recommended.
Personally I would stick to your 4 element “straight” beam. Designs trying to squeeze gain out of a small size are likely to be more SWR sensitive. With my modified Tonna I never bother with an SWR bridge on a summit - I know the ally mast affects the beam when it is in vertical polarisation, but I still get out okay and the SWR didn’t exceed 1.7:1 at home during tests, so I don’t worry.
Hope you found a suitable SLAB. I bought mine on the internet and saved on postage by buying 4 and overall it worked out quite cheaply. Note SLABs don’t like standard car type chargers as they have too high a voltage. I built mine using an L200CV chip inside an old computer PSU case. It provides voltage and current limiting and cost me just £5, Hi. An alternative to a SLAB could be some of the inexpensive 2500mAH NiMH batteries that can be bought on eBay which would be lighter, but cost a bit more.
If you have seen the photos of my 2m antenna on FlickR you’ll notice that I went for a folded dipole. Two reasons for this:
It’s got a much broader bandwidth than a Gamma match.
As it’s got a 50 Ohm feed point, you can use it on it’s own when the WX gets a bit lively.
These two factors make it much more suited to a life on the hills. If you’re wondering about the weight, the 6 ele weights in at 500g including the mount. At over 11 dBi, the gain is really useful from the more distant summits.
Like Gerald, I don’t do a VSWR check, but I always check the Angus and Wrotham beacons and make sure the beam headings are roughly correct. It they are, I reckon nothing has broken. Doubtless I’ll get caught out one day …
I can recommend NiMH batteries in preference to SLA. The discharge curve is much better, giving a longer useful life before re-charging. They can be re-charged much quicker (unlike SLA) so I can often use the first battery of the day on the third activation, re-charging it off a separate jump battery in the car whilst I’m off doing the second summit. State of the art in Sub-C is now 4300 but 3300 are cheaper. Allied to a Kokam charger or similar, my 3300s have done over 100 activations without sign of deterioration and that’s running reasonable power (can’t believe I just tempted fate …).