Field Day 2020

2020-Jun-28

I took a break from satellites and decided to work HF for field day. The weather was a bit mixed with thunderstorms and rain forecast, but it looked like there would be a few hours on Sunday afternoon that was not too bad. I decided to do a short operating session portable and from battery power.

I picked an out of the way spot at the edge of a farmers field in Quebec. Given the Covid-19 pandemic I wanted to be away from anyone else. The antenna support was a 16 foot fishing pole. I used a 40m Inverted V to hold it in place, with the V providing two of the guy ropes. A third guy rope stopped it from falling over. The center of the inverted V is one of my 3d printed dipole centers. I ran a 20m vertical up the fishing pole, with 3 radials on the ground.

As a battery I used two LiPo radio control car batteries in series. They are 5000mAh each. The packs are nominally 7.2V so it is 14.4V with two together. In fact it is nearer 16V when fully charged. I can run my Elecraft K2 tranceiver at 100W from the two batteries.

I started on 20m and conditions seemed to be decent. I quickly worked a station in Maryland using 40 watts of SSB. I operated as AC2CZ/VE2 and given the small portable operation my class was 1B, so the exchange I sent was 1B QC. I could hear almost all of the north east and most of the east coast. There were no signals from the middle of the US or from Canada, but I could hear Texas and San Diego in California. My best DX was Peurto Rico.

Unfortunately the 40m inverted V did not work. It had a 7:1 SWR according to the K2. I pulled the antenna down and looked for obvious issues but could find none. I'll have to put it up at home and troubleshoot it.

I worked 10 stations over a couple of hours. It only rained once and the radio was tucked under an umbrella. The sun only came out a couple of times, which was fortunate because it was baking hot. With everything running from battery power the log was on paper in my notebook. I will have to type it into my logbook later.

The battery pack held up well. Initially I called stations with 50 watts but after an hour the battery was still at 15 volts. So I pushed the power up to 80W or sometimes 100W. By the end of the session the battery had dropped to 14.8 volts, which is still above its nominal level and a long way from the minimum value of 12.8 volts. SSB is quite a low duty cycle mode, but I was transmitting a lot, trying to call many stations. 20 meters is quite competitive in an event like field day. Strong stations are using a yagi and 1000 watts. So it was difficult to be heard with 50 - 100 watts and a quarter wave vertical pretty much at sea level in a farmers field.

This was a lot of fun and I was glad to be able to work a few stations from a completely portable setup. Here is a closing shot showing the antenna on the right and thunderstorms brewing in the distance.

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