Monday, 27 July 2015

Ramblings in the QRM

Pretty quiet radio-wise lately. I've had some fun with data modes but the novelty is wearing off now. I think they are best used when there's no voice activity.

I recently made up a 40m dipole and had better results than with the end fed but the dreaded touch lamp problem reared it's ugly head again. The end fed doesn't cause any problems but my new dipole seems to set the neighbours lamps off (and one in our house). A re design of the dipole is in order - I guess a balun might be needed instead of the open dipole centre that I have used - something to experiment with. I haven't got into how to make and use filters for interference so I will have to read up on it and get cracking so I can use the dipole again.

I don't want to cause friction, as we have nice neighbours so I am continuing to use the end fed for HF at the moment.

I went along to the Horncastle Rally yesterday (26/07/15) and, as usual, I bought something unnecessarily.  Another Standard radio. This one is a C8900 2m FM set from the '80's and works well. I have it coupled up to my VHF linear amplifier into a 2m dipole that I use for local contacts. I have stated before my interest in these older radios and I am constantly stunned by the quality.

I've gone all Chinese again and bought a 20w dual band thing - but it was cheap. It's a small scale but fully featured rig and I intend to test it before installing it in the car in place of the dreadful Baojie radio that I bought. That one will be the basis of an experiment involving APRS, details will follow.

As Ofcom have withdrawn the right of Intermediate Licensees to operate I - gates,  I'm not sure where I stand with APRS, so this might be another idea that will be dead in the water until I get around to studying for the Full Licence - which I intend to embark upon later in the year.

73 for the moment de 2E0ENN

Tuesday, 14 July 2015

Digital Ramblings

Just had my first foray into Digimodes. I thought it was about time that I made use of my ZLP Minipro data interface and after experimenting with SSTV I decided to give PSK31 a try.

Using Ham Radio Deluxe digital software,  I found it quite difficult to configure the radio and sound card and as such it was nigh on impossible to work with. After a few test transmissions with Stewart (M0SDM) it soon became clear that I wasn't making it work. I installed Digipan software and with a little trial and error I managed to find ideal settings and soon found myself operating PSK31 with some success. I'm hooked now, it's still a bit of a learning curve as I need to create a set of macros to speed up my replies but that will come, I'm sure.

I have had some minor problems with my QRP set up. The Platinum X1M was suffering from low receive audio levels. A delve into the innards uncovered the problem. There are two pcb's which are connected via a socket and plug, which had become dislodged. I separated the boards and gave the connections a good clean with switch cleaner then reassembled the radio. Problem sorted. I have a 40m mobile vertical aerial and that constitutes my mobile QRP arrangement. I intend to find some high ground and operate from the car during what remains of the summer. For portable use, I will build a mono band dipole and sling that in a tree, with power coming from a SLA battery or my old 3 amp PSU and the trusty little generator. I have looked into Photovoltaic panels for charging the battery but that seems a little bit like overkill for a radio with such a low operating requirement. I haven't quite made my mind up but for contests etc the generator is a no - no so a little more thought will be required.

I have acquired a VHF linear amplifier/preamplifier for use with the two Standard radios. With a 1W input I get 35W out and with 8W that goes up to 40W, which is a big jump from the 8W that the C8800 gives. The C5800 gives 16W on full power so the increase is useful. Speaking of the C5800, I will be looking at increasing the full power output to its original 25W and I will post another blog outlining the project. For some reason the output was decreased by a previous owner - quite why is a mystery to me so we will have to see if it works. The next project will be to add CTCSS capability as well - I have seen some boards that can be fitted with only three wires to connect.  A little time to study the schematic will be required and I will also report on that.

In September SKARS will be operating from St. Anne's Church in Grantham for Churches and Chapels on the Air weekend. GB2SAG will operate from the church. SKARS has a connection with the church as we use the Church Hall for our meetings, so there will be a mutual benefit to be had. October sees Jamboree on the Air weekend and we will also be operating from the Grantham area in association with the Scouting Organisation. We operated JOTA for the first time last year and it is hoped that we will operate from a proper tent next to the Scout Hut - last year we operated from within the Scout Hut and noise levels with lots of youngsters having fun affected operation. The tent idea is apt for the Scouts and we will all have a really fun time.

73 de 2E0ENN

Wednesday, 1 July 2015

Eggbound Ramblings

GB2EGG took place on the 28th June and was a little disappointing due to weather conditions at the Swaton Vintage Day. We set up our operating base on the previous day - the mast and dipole going up smoothly and tested with Stewart's Yaesu FT 897 but the gazebo that I  had bought especially for the event was a different matter. Half way through putting it up a gust of wind launched it into the air, bending some of the structure into the bargain. Having straightened out the frame and successfully erecting the gazebo we put a strap over the gazebo to hold it in place overnight. I was first on site on the day and was relieved to find it intact and proceeded to install the generator, which started and ran fine. Andrew arrived next and he proceeded to the event ring to set up the launch of Eggsplorer1, the HAB. Nigel then arrived with the radios and the organisers supplied us with tables and the station was set up. Graham then arrived and he and Nigel commenced operating the SES.

We were all carrying handhelds and I then made my way to the ring to assist Andrew, Stewart already being with him. The balloon was filled with helium and as the launch time approached all was going well. I received a radio message from the radio operators,  advising me of a problem with the generator and, after the successful launch of the balloon, I went over to sort it out. It turned out to be a minor hitch and was soon sorted out.

The balloon soared into the air with the payload slung beneath and it became apparent that the image telemetry was not being sent, however the tracking system was working fine and the balloon attained a height of just over 31000m before the balloon burst (as it was supposed to) over the North Sea. Numerous Amateur Radio Operators tracked its progress and it was a great success. A while later a smaller balloon was sent up, again with tracking facilities, which did not go as high but entered the jetstream and travelled at 120 kph heading towards Scandinavia, being brought down short of Denmark by the weather.

Meanwhile, back at the radio station, things weren't going as swimmingly. The generator was struggling ( mainly due to the amount of power being drawn by the PSU at 100 watts power) so it was supplemented by a leisure battery, which solved the power issue. The weather, though, was a different matter. It was very gusty and the poor old gazebo was taking a battering, so much that it gave up the ghost spectacularly and collapsed into a mangled heap of metal and PVC.  Nigel went into panic mode and hastily removed the radios and without discussion he took them away and left for home. As he was the NoV holder, this left us in the lurch. We couldn't continue with the event call and Stewart stepped in with his radio and the event sponsors allowed us to use their gazebo, which was vacant next to where ours had been. We continued operation using our club call (MX0SKR) for a while but band conditions didn't make for a lot of contacts.

There were a few lessons learned :

1.  Don't use cheapo gazebos, they just are not suitable

2.  Always have a back up radio, as some people just panic at the slightest setback.

3.  Make sure the NoV holder is committed enough to stay on site for the whole of the event.

To be honest I was a little embarrassed by the way things turned out and I won't be put in that situation again. There are a few of us in the club who are dedicated to these types of event and I think it will be those people who will be invited to participate in the future.

Churches on the Air next,  followed by JOTA in October. Plans are afoot for both events. Gazebo not required, so here's to a couple of good events.

73 for now