Re: 4SQRP Kits recently built


Larry Ryan
 

About the Transformer Experimentation Board:  I got a quick reply from the designer, Bryan K0EMT who requested a photo. I sent it and he saw the problem right away: wrong number of turns plus my cross over didn't run under the toroid and start turns the other way. I rewound the toroid correctly this time and used #22 wire making it easier to wind and solder into the board. The results were amazing! After adjusting my antenna length a bit, it's 53 ohms and no reactance at 7.030 and 14.030 measured with my MFJ antenna analyzer. Fairly broad too and covers nearly the whole band.  It will work on 15 and 10 but not as well. I could do more antenna wire length adjustments but I'm not too concerned with the other bands.  My goal was to learn how to make my own EFHW and use it on 40m with the Bayou Jumper. Mission accomplished thanks to help from K0EMT. 
I experimented with counterpoise lengths from 2 ft (recommended in experimentation board doc), 7 ft (recommended by Bryan) and 30 ft (used with a tuneable EFHW I used in the past).  Neither of them made any difference. As pointed out by Jerry above, my 6 ft of coax from rig to the board probably served as counterpoise.  And Don, thanks for your offer of help. 
My next project will be an 80M EFHW that handles 500W. Of course, I'll have to use big toroids and wire but I can get away with 2 turns of twisted and a total of 14 turns.   I live on a heavily wooded property and there are a few really tall Doug Firs to support that longer antenna wire. 

73, Larry W7DGP

73, Larry W7DGP

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