2018-09-02 Ok weather and time for outdoor radio 1 year ago
Last Friday I had time available for outdoor radio and the weather prediction looked nice. Fellow radio amateur PA5Z had time available too and joined me. We cycled to the local park and found a nice spot for some radio, complete with a bench available to sit and run the radio. First decision was which band, because changing the band after raising the linked dipole means having to take it all down again. It was a tough decision between 40 and 20 meters, both looked not too promising. We decided on 40 meters. I also extended the mast and tie-wrapped the balun of the linked dipole to the mast (three segments below the top) before getting the mast upright. This worked nicer for me on an earlier setup. The downside is that we had to be very careful in where the guy-wires and the dipole wires are around the fiber mast to avoid tangled lines and twists. And the right way to lengthen the mast is twisting the segments to lock them together. With two people it is a lot easier to get the mast straight and it looked very nice. Soon contacts were made, but after a few tries I received a report that the audio sounded like I had RF interference. I heard this remark before at the end of my testing the mast at Trintelhaven and this time I found out what the problem was: the lead-acid battery I was using was running low and when the voltage drops from 12.0 to 9.6 volts on transmitting the output gets distorted. The fix was to lower the output power, a local radio amateur who we contacted was willing to help test this and confirm my theory that the drop in voltage was causing distortion. Eventually it started to rain a bit, the batteries started to get depleted even at lower power and we decided it was time to pack up and go back home. A nice day for radio, I ordered a new battery to replace the failing ones and I'll be doing this again some day! In preparation I used Amateur Radio Portable Activation Checklist NPOTA/SOTA to make sure I had everything required. Update 2018-09-12: Two of the contacts were to World Wide Flora and Fauna "activators", fellow radio amateurs who transmit from within a park listed in that program. Those are now confirmed for me on the World Wide Flora and Fauna site.
Outdoor radio, picture by PA5Z