The tuning of the Centurion antenna is very simple, tune the trimmer cap for maximum transmitted signal. Use anything that gives an indication; service monitor, field strength meter, whatever. You will only cover at most 1 MHz with ANY antenna on low band other than a couple of specially designed broadband split-ball mount mobile whip designs. Since you say the primary usage will be fixed, use the antenna adaptor attachment that screws onto the universal connector and get a 50 ohm connection to whatever fixed antenna you want. Use the Centurion antenna for portable operation.
If you absolutly have to waste time screwing around with different antennas then remove the existing antenna connector and rework the design of the portable to use a coaxial antenna connector. Milt N3LTQ ----- Original Message ----- From: "Albert" <hitekgearh...@hotmail.com> To: <Repeater-Builder@yahoogroups.com> Sent: Sunday, July 12, 2009 2:25 AM Subject: [Repeater-Builder] Re: Building HT antennas > Let me first say thanks to everyone for all of their input and > information. > > I am familiar with the NAB6064A/B heliflex antenna but do not actually > have one of those. I do actually own one of the Centurion/Antennex model > EXL antennas that Milt mentioned. The only down side is I do not have the > tuning information. Maybe if I called them I could acquire that > information. > > I do plan on only using the radio for the 6m amateur band, so I would > roughly only be covering three to four MHz. I was hoping to get away with > a single antenna for that purpose. Maybe I could incorporate a small > telescopic section into my design to compensate for the width of the band. > > Also, this project is designed to use in a mostly stationary situation, > and I was thinking of incorporating a spring or something similar at the > base of the antenna to minimize the shock to the antenna connector. > > It might be best to take this a different direction though, and just > utilize the public safety mic with it's antenna connector. That way I > could easily attach an expedient antenna for increased range in the field > while stationary, and then replace it with a duck type antenna while on > the move. ((Yes, I know Motorola never made a low band rubber duck antenna > for the PSM. That would be another undertaking) > > So thanks again for the input. I will let you know what I come up with. > > Albert > KI4ORI > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.375 / Virus Database: 270.13.11/2232 - Release Date: 07/11/09 17:56:00
