I operate two multi-wire multiband dipoles mounted orthogonally to each other (feed points within a foot of each other and running perpendicular to each other). One is a four band 160-75-60-40 voice antenna all fed from the same balun. The other antenna is a 160-80-40 meter data antenna which runs my Winlink RMS Pactor/Winmor gateway station, all fed from its own balun.
I have operated this configuration for a year and a half with no problems. I have some de-sensing when the Winlink station transmits, but this is minimal outside of the data transmitting band. Configured orthogonally assures significant cancelling between the two antennas. I have also constructed several of these for our RACES mobile communications vans and will soon have one at our County EOC. The trick is to insure that none of the bands are odd multiple frequencies of each other and present low impedance at the same frequency, such as the low end of 160M (1.8 MHz X 3 = 5.4 MHz) and the upper end of 60M. My voice antenna is cut for the high end of 160M (1950 KHz) to ensure this. I can tap from either antenna feed at the Flex 5000A RX1 Out to RX1 In Loop and then split (Mini-Circuits ZFSC-2-4) for multiple receivers on different bands. I even use this configuration for polarization diversity reception of NVIS signals and the Flex Enhanced Signal Clarity feature. These antennas are very low noise. Typically my low band noise floor on the morning nets is between S1-S3. I am known on the Arizona State RACES net as one of the best ears and often asked to relay. When constructed properly, Multiband/Multi-wire dipoles are truly viable antennas that are simple, efficient, low noise, and versatile. Bill AB7AA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, August 01, 2012 10:00 AM To: [email protected] Subject: Flexedge Digest, Vol 38, Issue 1 Send Flexedge mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of Flexedge digest..." ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5168 - Release Date: 07/31/12 _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
