Hey guys! When I was the radio puke for the City of Lompoc, I got an almost identical one for use by the PD during emergencies. (mostly for hams manning the EOC) For some reason several SWR meters, including a Bird 43, would not give me a very good reading on any frequency. I knew it WAS working ok, but didn't see it! I finally used an MFJ-269 and it showed good impedance and fair SWRs. The ONLY thing that said it was resonant (in little skips, looked like a sawtooth plotted out) was an AEA 140-525! I had to sell it after being laid of as head Engineer of Hendry Telephone Products R&D down in Goleta. Wish I still had it. I think it was the only instrument I ever used that was always right, and seemed impervious to some problems, like others. With a log periodic, you can have a fine impedance match at a frequency, and still show a horrible SWR, even though it really is working right. there are so many harmonics that are being reflected back and forth along with the primary signal, that you have a mixing, of third order on to infinity! (and beyond! Quiet, Buzz!) If anyone has an AEA available to borrow, that should give you real world readings. I have an MFJ-269, but don't completely trust it on a log periodic with it's literally thousands of harmonic balances and unbalances. Even John Kraus, in "Antennas", which most commercial and ham related folks consider the "antenna Bible" says that log periodic performance can only be measured as tested ERP (new term, same meaning as his, he said tested at a distance relative to known sources), rather than at the feed point.
Just my 2 cents worth. Paul Andreasen, K1JAN ARRL Technical Coordinator, Santa Barbara Section ARRL Technical Advisor, Southwestern Division SARC Chair Holderdowner _______________________________________________ You have received this because you are subscribed to the Satellite Amateur Radio Club Members Mailing List To post on the mailing list, simply send email to sarcmembers@xxxxxxxxxxxxxx This mailing list will only accept email from subscribed members so SPAMMERS will not get your email address To unsubscribe, send an email to sarcmembers-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field OR by logging into the Web interface at: //www.freelists.org/cgi-bin/lsg2.cgi
