One of the challenges of VHF PA is to try to work as many multipliers as possible—that is, stations from locator squares. In the rare KN08 grid square, behind a wall of hills and even more hills, lies OM3KSI. How can such a contact be made?
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Minus 10°C in December
Just in time for the December round of the VKV PA, a significant cold snap hit, with temperatures dropping below 10°C. Setting up a portable station is no easy task at such temperatures. So I had to resort to the backup plan—I set up my 8-element DK7ZB antenna on a small mast at my home QTH, the village of Ivanovce, JN88WT. The elevation here is approximately 200 meters, and in most directions there are hills of varying sizes, dominated by Považský Inovec (JN98AS).
This is what the terrain profile between OM0AAO and OM3KSI looks like:
OM3KSI in KN08PR behind the hills
The distance isn’t great, but the barrier of hills causes significant attenuation of the VHF signal. It is not possible to establish a connection using conventional methods along this route.
This is where airplane scatter comes to the rescue—the reflection of the signal off an aircraft flying along the line between the stations.
How do you establish a reliable connection?
If we don’t want to rely on luck to hit a passing aircraft, we’ll need the AirScout software from DL2ALF (it’s enough for just one of the stations to have it). Using air traffic data, it can identify flights that are suitable for establishing a connection.
The second step is coordinating the contact, for which the ON4KST chat is most commonly used. There are several interfaces through which stations can coordinate. These include wtKST, KST2You, or others.
Here’s what the coordination with OM3KSI looked like
Here’s what the coordination with OM3KSI looked like
As you can see, the contact was successful and made me very happy! On my end, I used 100 W from the TS-2000, 10 m of RF-240 coaxial cable (approx. 1 dB) connected to the aforementioned 8-element DK7ZB Yagi antenna (12 dBd gain). Perhaps this will inspire others to attempt similar contacts.
VHF PA Summary
I have 68 points and 8 multipliers, which totals 544 points. However, I also spent time testing some technical improvements that are intended for use in 2023, and I wasn’t on the air the entire time. Thank you to Peťo OM8WG from OM3KSI and Dušan OM3WAK for their willingness and eagerness to make QSOs. I wish you a pleasant and peaceful Christmas, good health, and hope we’ll be in touch again in 2023!
