This was more than a memory jog. It was RE-education on these baluns.
I was from the misconception school of the "scramble winding" for these things. I will be re-building to the "better way" shortly
Thank you very much
Fred
Fred,
http://www.k1ttt.net/technote/airbalun.html Best literature you'll find, IMHO. Gives impedance of windings Vs freq and geometry.
I've had REALLY good luck using electric tape when winding my baluns like this... I was doing them on forms, but found the edges would always end up eating into the coax... Paint cans, home depot 5 gallon buckets, etc. So, I finally just started to take one apart, and did each winding by itself, taping it to the winding next to it.
That assy went up in the air, taken from the K1TTT above, in temp variations from +5 degrees to +115 degrees, and had ice sheeting up to almost a foot wide on it. It's still together, and works great. Also, no problems with 800 watts carrier, modulated to 150 percent, so it will take the power, as well.
Another method that works really well is using PVC for the inner form, and then winding your balun on it, and then another PVC sleeve on the outside that fits SNUGLY around the coax. Put N connectors on the end pipe caps (4 and 5 inch, 5 and 6 inch, etc..), and you have a nice balun assembly that SHOULD be waterproof as well. Did one for a friend in the same environment as above, no problems to this day. HOWEVER, if you don't prep the end of the PVC, you CAN cut into the coax sheath, if it's not done carefully.
--Shane
