WSGK834

So, I've been thinking: the idea is to have an antenna that is as short as possible and has low wind resistance , while offering high gain and vertical polarization and be omni directional. There is a well forgotten antenna design type that will be very short for 70cm/GMRS band , horizontal by nature, but produces vertical polarization and up to 4db gain. It's called slot antenna and was invented initially for a TV transmission. Here is how it looks like for 2m band, square side is 16.5 inches, 3 inches tall. For 65cm GMRS band it will be proportionally smaller, likely the side of the square will be around 7 inches, it will be around 1.5 inches tall. Expected gain around 3db ( twice the power ) in the middle of the band Slap it on the top of the car using neodymium magnets. Enjoy. This will need to be calculated and tested. Some members of this community could make these and offer for sale on this site, for example. Metal type does not make any difference. You can use aluminum or , if you feel fancy, aluminium. Copper or steel will work just as well. Square shape offers better omnidirectional properties, but you can make it look like a bat or a flower. Is there any interest ? I should be able to figure out dimensions, but will need help building prototypes. I'm in MN. Anton

Here is something to consider: GMRS is in a UHF band and RF wave is expected to be in a vertical polarization. Bending antenna will produce all kinds of polarization from 90 to 0 degree. This alone will lead to a both reception and transmission getting a very significant penalty. And don't forget, using 15ft of RG8x at GMRS frequency already leads to a 20% of power loss. Best antenna would be vertical, unobstructed and at least 1/4 wave length, with a good "ground plane", so mounting an antenna at the edges of a car would be a problem too. Physics is brutal, no compromises Anton

This sure looks like a power problem. Set output power to low and see if this helps. What power supply you are using? Anton