Sunday, June 29, 2014

2014 ARRL Field Day Ops with Panama City ARC

My Field Day was short and sweet.  I was on the site with the Panama City ARC using call W4RYZ about ten hours and operated about nine. Since last year I have put together a 100 watt go box based on the Icom 7100 and a 30 ah LiFePO4 battery. To complete the set is a SGC 237 tuner and a 100 watt solar panel.  This year I decided do a 100 foot doublet with the SGC 237 at the center. The SGC was at the top of  camo poles off a hitch mount on the truck. The ends were supported by 31 foot jackite poles. The ground was hard so we drove in a length of angle iron with a sledge hammer and strapped the poles to them. The antenna was maybe 27 feet up with a little sag. My fellow club member Phil N4STC helped set this up, did logging and got in some operating on the rig.

The SGC needs 12 volts and being at the top of a pole I had planned to use MFJ Bias Tees but they failed on me in a pre field day checkout. Not having time to mess with them I used a 3AH battery strapped to the pole. It worked but would be a pain to change out. the SGC seems draw about 250 ma steady for the relays. I had a 70 foot run of coax from the tuner to the operating table. We we able to take advantage of some shade and avoided using a pop-up canopy. The weather was hot but comfortable in the shade.

The 100 watt solar panel was in the sun and with a LiFePO4 controller it fed the battery. The sun was blocked by clouds early but had a good run of sunshine for most of the time. I had some meters on the controller and out of the battery to the rig. The charge was about 1.25 ah per hour and that was just what we were using to the rig running at 80 watts. Our contacts were hunt and ponce so the duty cycle was not all that high. The bottom line is we were running solar while the sun was shining.

The 100 foot doublet was just the ticket. We did well on 20 meters and best on 40 meters. We were able to snag the Virgin Islands and Puerto Rico on 15 meters which was otherwise dead. We also picked up 80 meter contacts after dark.

I can say I am ready for the next Field Day class event at the higher power. I would go with the 100 foot doublet again. Last year we operated the KX3 at 10 watts for the whole duration off a 15 AH battery so that is a good way to go as well. You just have to work a bit harder for those contacts. At 80 watts almost every one we heard came back to us and only had to give up on a few big pile ups. I still want to do a QRP entry someday. Marv KK4DKT had the other rig on the site. He brought a nice travel trailer and enjoyed the air conditioning. He did well making digital contacts.


100 foot doublet with the SGC 237 at the center

camo poles off the hitch mount.

31 foot jackite pole holding up one end of the doublet

100 watt solar panel

Icom 7100 setup

Phil N4STC operating after dark