WRQI583 Posted July 21, 2022 Report Posted July 21, 2022 I decided to go on the cheap end of things with my antenna only. I tried ordering a Comet antenna for GMRS and of course, the company must have jumped on the "Shortage" bandwagon. I checked high and low and could not find a Comet antenna anywhere. So I settled for a Harvest BC200-U which claims to be tuned for the GMRS band, absolutely no tuning needed. Well, after having the issues and reading more reviews, that is a lie. My antenna wasn't even close to being ok on the GMRS band, at least for the repeater input. The 462MHz portion was around a 1.6:1 SWR. 467MHz was around a 2.5:1 SWR or higher. So I took it apart and found a very poor design. The spots where the pieces connected together were pinched together with these little brass pieces. About 2/3 of the way up was a split in the radiator where 2 ceramic capacitors were soldered, bridging the gap to the upper part. They use pieces of foam to keep the radiator from smacking around inside and one of the pieces was loosely wrapped around the capacitors and glued in place causing it to rip the capacitors apart with even a slight touch wiggling the foam. The capacitor on the lower coil was not even glued in place. So, I did a bunch of experimenting to get the antenna to resonate on the GMRS band. I had another antenna that was specifically set on 466MHz and I decided to copy that design which was very similar to the harvest antenna design. The difference was that the other antenna didn't use capacitors and it didn't have a loading coil at the bottom. I removed all of the capacitors off of the harvest antennas and just put pieces of copper wire to connect straight through. I soldered all the joints on the radiator to make them more electrically secure. At the bottom of the antenna where the main radiator connects in it has a set screw evidently for tuning. I trimmed the whole radiator down until it came into an acceptable range (sorry, I cannot tell you how much I cut off because I was pretty flustered at this point after having to do so much soldering and unsoldering) and I put the antenna back together. I made a coax choke out of RG8U coax (wound 4 times in a 2.5" diameter) and placed that below the antenna and connected my coax into it. I now have an antenna with less than a 1.4:1 SWR across the band from 462.55-467.725MHz. The performance of this antenna didn't really change. The only thing that was noticed is that coverage is slightly better in spots where it was dead or static. So, UNLESS you happen to own an antenna analyzer or know someone who does, and you are smart with antennas, I would not purchase this antenna. It DOES work pretty decent once modified, but for the plug and play person who just wants to set up GMRS and talk, I would NOT recommend it. It is cheaply made compared to other commercial antennas. BUT if you are on a budget and have the knowledge and equipment, you can make it work. I have included a picture of my antenna analyzer for proof on the reading AFTER I made modifications. I get on average 2.5-5 miles on simplex (not using a repeater) at 45 watts. I have to include in here that I live in Maine in a low spot directly at the base of a hill that immediately goes up 100 more feet. I am at around 310 feet above sea level with hills spreading out from me going up as high as 1,000 feet but also including valleys in with that, so what happens is that my signal will travel down these valleys pretty far but once a tall hill is hit, my signal is not reaching over the other side at all. WRUK711 and SteveShannon 2 Quote
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