Following the success of the VK-EU S2S SOTA event on Saturday October 22nd, a similar one for November 19th. was planned but this time for EU-NA contacts. Having only ever managed one S2S with NA and that on 15m, I decided to build a 15m halfwave, coax fed end-fed vertical (aka J-Pole) antenna. After several attempts to build one using the dimensions given by the same calculator I used to build the 20m one that I tested on Weichberg, I eventually managed to get the antenna resonant by using a frequency 800 KHz lower than the required frequency. After getting this working in the garden, I found out why the calculator appeared to be giving the wrong lengths – my thin coax that I thought was foam insulator RG-174, with a velocity factor of 0.735, was actually RG-179 with a velocity factor of 0.700! As I had got the antenna resonant in any case, my activation of Buchberg, which surprisingly I hadn’t yet activated in 2016 would serve to test the antenna and to see if communications across the Atlantic are even possible with the current propagation conditions.
The best time for EU-NA contacts is between 1330 and 1530 UTC at present. As we have just put our clocks back an hour for Winter, this equates to between 2:30pm and 4:30pm local time, so this would be a nice afternoon outing. In case I wasn’t successful with the new antenna, I also took the trusted linked dipole and the 20 metre vertical (and the unreliable 10 metre pole) along. As it turned out, thankfully, I did not need these.
Buchberg is located near to Bad Tölz in southern Bavaria and is a favourite spot for walkers to come out to from the town (as I found out). My new “Navi” in the Chinese car multimedia unit, to which I have loaded the SOA DL & DM summit kml file, did a great job of directing me the correct way to the nearest place to park for the summit. Unlike Google maps which routes you up a private forestry only road (see report on my first activation of this summit).
On arriving at the parking spot, I saw the field had several cows in it (no bulls as far as I could see) and an electric fence around it. I looked for another approach but then decided to sling my bags under the electric rope and duck under (as all the walkers did in the following couple of hours). I asked whether this was OK and was told, no problem the farmer allows access (which I know from talking with him on my previous two visits) and it’s just to keep the cows in, not people out. It was turned on however as became obvious when I later turned the rig on. But it was at a bearable level and QSOs easy to make despite the slight “clicking”.
I talked with several of the walkers who were interested in what I was doing and once I got down to operating, things kicked off very well with four North American contacts – all 5-9 plus in the first 25 minutes. The first one a “search & pounce” by me, competing with other callers, the other three in quick succession after 20 minutes, in response to my spot on SOTAWatch.
The contacts were:
Henry, N1HEN in Maine,
Luther, N4DA in Georgia,
Phillip, VE1WT in Nova Scotia, Canada,
Walter, NE4TN, in Tennessee
After these four however getting contacts via spots or using Search & Pounce was difficult, there were a couple of special DX stations booming in from Guadeloupe (Jule, FJ4NN) and Curaçao (Pete PJ2/K8PGM) as well as Fahed A61FK in Abu Dhabi but all of these had so many callers, I couldn’t break through. I then checked the amp and it appeared not to be switching on to TX – I have an LED that shows green on Rx and Red on Tx. No red light – so it’s possible that instead of my expected 20w, I was only running 5w output, possibly even on the first contacts.
I had just about given up and then Carlos, CT1HIX kindly gave me a call and we exchanged 5-9 / 5-5 reports – which is what I would expect with 5w output.
Upon arriving home the amp was taken down to the workshop to get looked at and it turns out one of the two power transistors has blown taking out the main fuse and effectively switching the amp out of circuit. This failure appears to have happened on the last activation, meaning all of todays contacts were with just 5 watts!.
Following this activation I think I can say, that 15m band conditions to North America are quite good at the moment!
Modified Ramsey power amplifier ( in circuit but not working ).
CO-AX fed half-wave end-fed 15m vertical.
LamdaHalbe 6 metre fibreglass mast.
The antenna worked. I will need to check out what is wrong with the amplifier and sort that out before the 19th. The chaep 6m mast is far, far more reliable than the expensive DX-Wire 10m mini mast. If I have to take 20 metres along, I’ll possibly just take the Inverted-V dipole rather than a vertical. First of all, I need to decide on a summit ….
73 – until (hopefully) the 19th. November 2016 for the SOTA EU-NA S2S activity event.
You must be logged in to post a comment.