Re: First time loop winder

John H. Bryant <bjohnorcas@...>

This recent exchange with, primarily, Gary DeBock in suburban Seattle-Tacoma and Roy Dyball in Australia helping an Ultralighter who was beginning his first ferrite rod-coil winding is a great example of what makes this group so special....  great positive attitudes and a very real willingness to help each other over our personal rough spots. Bravo, guys!!!

Over 25 years ago, when I was getting back into radio after a 25 year hiatus, Gerry Dexter, who literally wrote the book on SWBC and MW QSLing told me "You know, John, it's not the great DX catches or the QSLs, but rather the many friends that I've made that really make the hobby great!" At the time, I was just back in and climbing up the ladder of SWBC countries QSLed and I said "Yeah, right, Gerry!!!"

Geez, old Gerry was absolutely right!  I've made a passel of new friends here, that I value very much.... and renewed many old ones, too... on top of that, I've learned huge amounts about various aspects of Ultralighting and, really, radio in general and had a BARREL of fun.

I've got to get another cup of coffee and start on over 25 more DXing award certificates that have been checked and verified by Rob Ross this week.... but it sure is nice to stop for a few minutes to think about the bigger picture.  It is very nice to have you all around. It makes my life much richer.  Yours, too, I hope!

John Bryant

At 03:18 AM 1/22/2010 -0500, you wrote:


In a message dated 1/21/2010 11:56:01 P.M. Pacific Standard Time, roy.dyball@... writes:

Also remember if you are dynamically tuning your loopstick by unwinding turns or repositioning it, that with every change you make to the loopstick you must steep off the frequency you are on and then steep back again, this gives the Si4734 a chance to update its varactor and choose a new corresponding value for the change you just made.

Cheers Roy.  

Hello Roy,
Thanks for mentioning this. In the dynamic tuning of the PL-380 "stealth models" (a 40/44 Litz wire coil of about 433 uh inductance on the stock ferrite bar), I found this was very true. In both of my two models, the original coil of about 500 uh had an Si4734 varactor lock-up issue on the high AM band frequencies, and coil turns needed to be subtracted one by one until the radio had a sudden boost of sensitivity on 1700 kHz. (There was no option to use a Slider coil for loopstick tuning purposes, since the flat stock ferrite bar was geometrically unsuitable as a Slider coil base).
After the sudden rush of increased 1700 kHz sensitivity on the PL-380 when the inductance was lowered to 433 uh, it was necessary to move off of the frequency and then back to 1700 kHz, to judge the final RSSI increase after the modification. The dynamic signal "turn-subtracting" strategy (to lower the coil inductance to a level acceptable to the varactor) was a weird idea that ended up giving great results.
73, Gary

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