A discussion with a two-way dealer that I know indicated that the base-loaded low-band antennas can be a bit of a challenge to get them to "play nice" with the radio. The full-length whips seemed to be better, but no one wants one on their vehicle these days.
Back when I ran a Motrac and a full 1/4 wave antenna, it worked well. The same dealer states that with the wide frequency coverage of today's radios, the performance dropped as the front end lets in more noise than the old radios that would only tune about 1 MHz. I would agree. I can be full quieting into a repeater, yet have difficulty hearing it because of all the desense caused by noise. A noise blanker doesn't help much when it is a continuous noise source. Report back with your findings. Chuck WB2EDV ----- Original Message ----- From: "tahrens301" <[email protected]> To: <[email protected]> Sent: Sunday, August 29, 2010 6:48 PM Subject: [Repeater-Builder] Maxrad lowband mobile antenna > Hi folks, > > I was given a couple of LB mobile antennas, and I have moved them up to 6 > meters. (I drilled a hole in the plastic case, and shorted out 2 turns > (soldered across them). It seemed to tune right up to 52 mhz. > > However, I noticed that the position on the back deck of my car really > made a big difference in it's resonant frequency. > > I was using a MFJ259, and in one spot (not centered), I have a perfect > 1:1 @ 50 ohms - a very pronounced 'dip'. When I move it around, the swr > goes up, and the 'dip' is not as pronounced. The Bird confirms that the > transmitter isn't as happy in other places on the back deck. > > The antenna is an effective quarter wave. > > Is this indicative of all LB mobile antennas, or just this type? > > I remember 'way back when', I used a full quarter wave on my car, and it > tuned right up without any funnies. (big spring & all). > > Thanks, > > Tim
