I made an early-morning run up to Evansburg State Park (US-1351, KFF-1351) for a quick activation. My plan for this activation was to try out my Gabil GRA-CFP2600 carbon fiber whip in the “Gabil-on-a-Table” configuration I have been using lately.
The weather forecast was showing a chance of late morning rain, so I headed out a little earlier than I normally do. On arrival, I grabbed my gear and headed for a picnic table in a wooded area that I’ve used many times over the years. It only took a few minutes to get the antenna set up with two 16.5-foot radials laid out on the ground. I easily found a good match on 40M and got started.
My first 15 contacts came fairly easily, so I checked 30M and 20M. I picked up one contact on each of those bands. I could tell from the POTA spots that most of the activity was on 40M. That’s usually a good indicator of which bands are working. So, back to 40M I went. I picked up eight more contacts, bringing my total to 25. Subtracting out my time playing around with the antenna, I was on the air for about 40 minutes.
One thing I noticed was that 20M was a little touchy to tune up. That’s something I’ve experienced a time or two in the past. This morning, the best I could do was an SWR of 2.0:1. The KH1’s ATU handled that easily. I’m sure I could have gotten the SWR lower by adding more radials—which I didn’t have with me. I’ll have to remember to pack a couple more radials next time.
In any event, it was a beautiful morning to be out in the park. Plus, I got home before the rain started. Timing is everything.
72, Craig WB3GCK
Craig :
FWIW, I mostly use my GRA-7350TC with a Buddipole TRSB (triple ratio switched balun) and I find that I get a better match. The TRSB is a switchable broadband matching transformer with a selectable 1:1, 1:2, 1:4 step up transformer and it also includes a 1:1 choke balun at the transmitter side. I find that the 1:2 position usually works best to step up the nominal 25-35 ohms from the vertical to something closer to 50 ohms at resonance. I have noticed with the GRA-CF5200 carbon fiber whip (201.6″) that 1:1 seems to give me the best match on most bands. I am not sure if this has something to do with the carbon fiber radiator or the longer length of the whip, or possibly both.
Cheers
Michael VE3WMB
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