Topband: 'Hairpin' matching

2013-09-19 Thread Tom Boucher
The excellent web site for calculating matching network values should have been: http://home.sandiego.edu/~ekim/e194rfs01/jwmatcher/matcher2.html not the one I posted yesterday. 73, Tom G3OLB _ Topband Reflector

Re: Topband: Hairpin Matching Coil Questions - "Shunt"?

2013-09-19 Thread Tom W8JI
Thankyou Charlie. I got those Q numbers from http://www.m0ukd.com/Calculators/air_core_inductor_calculator/ Maybe a decimal point was left out. Jim, I thought something was misleading you somewhere. Be careful with online calculators. The one in the link uses pi out to 39 places (which migh

Topband: 'Hairpin' matching

2013-09-19 Thread Tom Boucher
Just to add a comment on this thread: I do not use an inductor to match my inverted 'L', just a capacitor from coax centre/bottom of wire to the radial point. Further I do not use big wide space 'toast-rack' Cs, but tiny ceramic ones rated at 6.3KV which will handle very decent amounts of powe

Re: Topband: Hairpin Matching Coil Questions - "Shunt"?

2013-09-19 Thread Jim GM
Thankyou Charlie. I got those Q numbers from http://www.m0ukd.com/Calculators/air_core_inductor_calculator/ Maybe a decimal point was left out. Thanks Tom -- Jim K9TF _ Topband Reflector

Re: Topband: 75 ohm coax to twisted pair Adaptors

2013-09-19 Thread Victor Goncharsky
Hope this will be of some interest for those using twisted pair instead of coax. The company I work for is manufacuring all kinds of 75 Ohm / UTP balun adapters and surge protection units. The one I am using for my phased biderectional flags is "УПВ-МВ" http://www.elsy.com.ua/ru/pasivnie-priemni

Re: Topband: Hairpin Matching Coil Questions

2013-09-19 Thread Mike Waters
Hi Jim, I'm glad to hear you (and others) liked our L-network inverted-L tuner design. All the info I have is posted in the Topband thread. I thought I had more info and pictures, but I guess I'll have to take some new photos sometime. I suppose if you made the elevated radials long, then you co