Tag Archives: g8ocv

Some VHF Tinkering

On the way home from work on Friday, my attention was brought to my mobile APRS setup, which was showing received callsigns from Germany, Netherlands, Belgium and France. Once home I decided to connect up my KAM KPC-9612+ TNC to an old Kenwood PMR and see what I heard. The antenna is just a loft-mounted Diamond V-2000, so nothing fancy. About 1 metre of RG58 into the radio. The map is pretty impressive, showing what good conditions were around on VHF at the time. The orange circle shows the ALOHA circle (local reliable APRS network size) – more here – basically the area to which your transmissions would normally be in contention with.


My usual small station EME setup consists of two 9 element DK7ZB Yagi’s bayed at 13 metres. Combined with a Yaseu G5400 Az/El, K3NG’s Arduino rotator interface and YO3SMU’s PstRotator, this is a reasonable attempt at a small station EME setup. Of course you can do it with less, but, it becomes somewhat laborious. With the moon tracking facility of PstRotator, I can set up once, and allow the software to keep the antennas pointing in the correct direction.

The antennas look like this:

At least we don’t have neighbours!

In the shack, I used my Icom IC7100 (since my Anglian transverter was having issues), a homebrew 1kW solid state amplifier, and PGA144 preamp based on the PGA-103+.

Most of the spare time during the weekend was taken up by relearning everything I had forgotten since I last tried EME and VHF data modes. I was able to confirm the setup was working correctly using GB3NGI beacon as well as some others on the make-more-miles on VHF site. Within around an hour I was successfully receiving SP4KM, ZS4TX and K5QE via the moon on 144 MHz.

The screens above are rather busy with the rotator controller, NetworkTime program for keeping the PC clock synchronised via NTP, and CAT7200 which usefully translates the DTS/RTS line style PTT interface to a newer CAT/CI-V instruction.

As mentioned, when the moon was below the horizon, I also played around with other modes. SSB resulted in few contacts, but more than the ‘none’ I managed on CW. I quickly found my feet again on FT8, working into Germany, Denmark and the Netherlands. At the end of the weekend, PskReporter was showing the below map for M1GEO on VHF:

I have promised myself two things:

  1. To get on VHF more often. Well, do do more radio, basically!
  2. To finish the 144 MHz amplifier off. I have the basic functionality, but it’s lacking a user interface and other nice features. The hardware is there, but there’s no translation onto the nice graphics LCD.

Rosmalen Hamfest 2017

This weekend I drove to the 42nd Dutch National Radio Fleamarket hosted by the Bossche Radio Amateur Club and held in Rosmalen at the Autotron, Graafsebaan 133, 5284 The Netherlands.

This year, Dave G7UVW couldn’t make the trip, so Dave M0MBD jumped in at the last moment. In total, five of us were crammed in my car: Chris G8OCV, Peter G0IAP, Dave M0TAZ and Dave M0MBD and myself, M1GEO. Dave M0TAZ drove Peter G0IAP and Dave M0MBD from London to my home in south Norfolk. And from there we all headed to the Harwich International Ferry Port for our sailing at 23:00 to the Hook of Holland (courtesy of StenaLine). We always aim to arrive at the ferry early, put our luggage in our cabins, and then head to the bar for discussion and drinks!

In the morning, an all you can eat buffet starts the day well. The Rosmalen Autotron conference centre is about 50 minutes by car from the Hoek Van Holland port. After paying the entrance fee (€8, 2017) we were free to roam around from about 9am till 3pm when the conference centre closes.

As well as providing a great chance to purchase some parts for constructing projects, the hamfest also provides a good opportunity to catch up with friends from around western Europe. It was good to catch up with Niels PA1DSP and Pieter PA3FWM (of WebSDR fame), among many others.

Returning to the ferry terminal, we had a short wait before the check-in opened. We passed this time in the terminal building, using the remaining few Euro coins to buy coffee from the vending machine. Once we had boarded the ferry we offloaded our cases into our cabins once again and convened at the bar for a drink before our 3-course evening meal.

Another breakfast starts off the Sunday morning well. Departing the ferry at about 7am allows you to get home early and still have most of the day to yourself, to enjoy your hamfest purchases! All in all, the total cost of this year’s trip was £158 per person, including all food and fuel. Not too bad at all!