Thursday, October 21, 2010

Tulsa Tech Net for 10/8/10

The subject is antennas

I'm sure to those that have noticed that I'm having a time keeping up on the blog !!!
The tech net started with me having some mic troubles and i got them resolved. Then Clarence, AE5UB, was wanting some help on choosing a directional array for 6 and 10 meters. I suggested a rotatable dipole for 6 meters. One issue that was brought up is antenna regulations for being in the vicinity of an airport. If anybody has a link to this info please send me a line so I can post it. Multi-band quad was also brought up as an option and there are many plans for multi-band quads on the internet. There was also metion for the log periodic antenna for multi-band use. The Log Periodic is an array that consist of multiple dipoles to cover a wide range of frequency's. The look similar in construction the the old vhf television arrays that everyone had on their house until the mid 90's. As you change frequency the active region shifts along the array.

The windom is a dipole that is commonly used for multi band use. It is an off-center fed dipole. At certain bands and a certain distance that the dipole is fed off center there comes a point that the feed point impedance will be the same . Then the dipole is fed with an impedance transforming balun to bring that high impedance down to 50 ohm.

Tim, KF5FSJ, had an oddity about pouring water at the base of the push-up pole of his 2 meter beam to cure some performance issues he was having.

Dave, NB5B, Is putting up a digipeater in Manford to bring APRS coverage to that area.

Thanks to all that participated and it was a good turnout being that the football game was on.

here is a link to the MP3 of the net to save it right click on the link and click Save Link
http://www.w5bbs.us/?file_id=11

No comments: