WRUW493

Sorry for the late response. Yes, actually I have. This is a common method used on the older cell phones that had external and/or extendable antennas. In those cases there was a metal piece inside the phone that was tuned to 1/4 wave (at the lower freq band if there were multiple bands in use) that ran down the edge or side of the phone.) We would try to put it in an area where the hand was not likely to cover it (much) or come near the face when being held against the face. I have not tried it on a GMRS radio, but RF doesn't know anything about the name of the device of course, just the frequency that is being used and Maxwell's electromagnetics still works. To WSAK691 who also mentioned a 1/4 wave antenna being good: bingo. Get the total system to be a 1/2 wave dipole and you'll get a nice donut radiation pattern that on AVERAGE is going to radiate the best to the radio you are trying to talk to. If possible have both radios held vertically so as to match the polarization as much as possible. At 460MHz there is some cross polarization taking place depending on the propagation path. The good news is outdoor environments are not likely to have as much cross polarization as indoors, so you'll get best distance outdoors with co-polarized hand held orientations. It's a subtle difference, but vertical is less impacted by ground (earth) effects that horizontal is at these frequencies, and holding the radio vertical is going to minimize the ground impact. Hope this helps

Yes, this is all true, nicely said Sshannon. I went on and on a bit, my addiction to jabbering. Glad to hear that you tend to hold the radio vertical when using it. A lot of people do not. Have a great day

Very interesting video. Thanks WRWE456. Well, if I understand him correctly, he had the radios separated by about 3ft for this testing. Yikes, that can make a difference on weak signals (any signal strength but you notice it on weak signals) due to a couple of things: a) RF propagation path changes by a lot over 3ft in paths with lots of reflections (inside a house and/or urban environments) b) he didn't say whether he made sure that both radios were a distance away from RF noise sources such as computers, computer monitors or modern TVs. Any number of electronic devices can be spewing out RF causing receiver "defense". To his point that SOC (System On Chip as I understand it) being as good or maybe better (sensitivity) than Super Het, this could indeed be true. I looked up the one SOC chip that I could find and it's spec states -123dBm sensitivity at 12dB SINAD in 20KHz BW. This calculates to about a 3dB noise figure which is quite good. A Super Het receiver would have a hard time beating this by more than a dB, probably not any better in the real world. Also consider that the SOC technology is similar to that used in modern day cell phone chips where the RF functions are synthesized in silicone. Those work very well. No telling what SOC Wouxoun or any of the Chinese manufactures use, but it seems that it's entirely possible that they use good SOC chips. Having designed Super Het receivers in years gone by, I can say that it is possible to make an outstanding receiver in terms of sensitivity, adjacent channel, IM and blocking. But, a big but, it takes space and $$ to do so. As a GMRS radio manufacturer I'd look long and hard at the price of a good SOC compared to what it takes to make a good Super Het, and probably choose the good SOC in the end. Just IMHO.

Hi Shannon, Thanks for the really good info and testing. Real world testing is always helpful. I see that the 771 antenna is 15.5 inches long, making it about 5/8 wavelength. The radiation pattern of a 5/8 wavelength with very little ground plane (the HT) is a rather high angle of radiation, probably 45 degrees or so. I don't know what the OEM antenna was. Couple of things to consider: 1- Since antennas do not create power, they only direct more in one direction than another direction. So without performing a similar experiment with the HT is quite a few orientations it's hard to say how the 771 (or any antenna for that matter) will behave in a variety of RF environments. This is why antennas are measured in RF anechoic chambers in dozens of orientations and then averaged together for a final evaluation. I have taken real world RF propagation data from a handheld (cell phone) to base station where not only does the best RF path change direction by 10's of degrees with every fraction of a foot change in location, but also inside of buildings with multiple reflections taking place it's not uncommon for the best RF path to be a TX polarization different or even orthogonal polarization to the RX antenna. 2- It's real easy to have poor radiation efficiency on dual band antennas. Loading coils and dual band related compromises all are opportunities for loss, read RF absorption. It could be as simple as the OEM antenna has poorer efficiency than the 771. This too would show up in a test of multiple orientations in a controlled environment. These are why that in the general case one wants a mostly spherical radiation pattern (read low "gain") and high efficiency. Then one has the best chance overall of having good radiation in the direction that the repeater/other mobile appears to be from the HT's perspective. Hope this helps, and keep up the good work

That was on W11. I solved it by going to W10. Thanks for the reply though. ps: too bad that Radioddity does not support W11, but seems like W10 is here to stay for a while despite MS desire to kill it.

Any way you could send me the video? Or more detail on your results? thanks.

Try this one: https://www.amazon.com/gp/product/B0855PVDWS/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Fairly flexible and not quite as long as the OEM on my GM30, yet a really nice and efficient 1/4 wave.

I cannot comment on the quality of these radios or cost or longevity. But I did look up the specs on the one SOC chip (transceiver chip that may or may not be used in the above mentioned CCR radios) It's spec (to be believed or not) sensitivity was -123dBm in 20KHz BW for 12dB SINAD. That translates into about a 3dB noise figure. That is quite good considering there is likely very little loss between the chip and the antenna. And the adjacent channel and blocking performance spec was decent, maybe a real super-het receiver can beat it on those. So I'm wondering if anyone has any actual receiver measurements (on test equipment) that they can share in this regard?

I hate to burst y'all's bubble, but the longer antenna on an HT won't help. That 771G Nagoya is a 5/8 wavelength antenna, which in order to have "gain" in the plane normal to the antenna would require a ground plane diameter of at least 1 wavelength. Obviously the radio is not that. What you really want is a simple 1/4 wavelength antenna (about 6 inches at GMRS) that has LOW LOSS, meaning it's efficient. With the GMRS HTs being also about 6 inches tall this makes for a really nice dipole antenna. A simple piece of heavy gauge copper wire would work just fine, but would not be so good mechanically. And that would not be so good for VHF, only tuned to UHF. I took a chance on this antenna and found it to be excellent since it's just a copper wire encased in flexible plastic. https://www.amazon.com/gp/product/B0855PVDWS/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 You will find that Motorola uses this concept on their HT's and for a good reason: it works the best for a handheld. The bottom line: for a handheld radio, you want radiation efficiency. Any antenna that has fancy coils to tune them is by definition low efficiency. Radiation pattern make little to no difference, and radiation pattern is the only thing you get with an antenna system longer than 1/2 wave dipole. Consider that over a propagation path you have no idea what the best path is to the other station at any point in time. Consider an urban or forest environment: reflections off of a building, car, tree is frequently the best path, and that changes literally by the foot as you walk around. Hope this helps.

This is a great question. A little background: I worked at Motorola for over 30 years and asked this very question to some of the RF guys there. The resounding answer is to "go high baby". Well, in a case like yours where your high-gain and low height option is not really very high, then yes some extra maybe 10-20ft with a somewhat lower gain will be better. Now if you were already at 100ft with high gain and could go up another 20ft with low gain, this could be a different story. That would depend on the surrounding terrain. But in short "go high baby". As evidence of how this works, I too ran a repeater during the above mentioned time period, that being a 450MHz ham band repeater at my house. I lived on a small hill in the Chicago suburbs, maybe a 40ft above average terrain. Sounds like not much, but in the Chicago suburbs that's all you get for a hill I chose to go high baby, and put a 6dBi gain antenna as high as I could get away with, about 60ft above the hill. I was afraid to put a larger higher gain antenna at that height due to tower strength limitations. And wow, did it have great coverage for being just a home brew repeater. In the direction where the land sloped down slightly it easily had a 40 mile mobile coverage and I had people 80 miles away using it from simple base stations. Now granted this was one high performance repeater: 25 watts TX (yea, not huge I know) but the receiver was souped up by me, being an RF receiver guy, it had less than 2dB noise figure counting the duplexer loss (for those who don't get noise figure, 2dB in that case is outstanding). Hope this helps.

I agree with the responses above and add the following: Any end fed antenna (like we are certainly talking about here) is really just the top part of the actual radiating structure. The bottom part is the "ground plane", or in practice that metal stuff that the base of the antenna is connected to. If you put the antenna in the middle of the trunk lid of a sedan, or on the roof with a large metal roof, then, and only then, will you get close to the "gain" and radiation pattern that the manufacturer states. But this is rarely a practical way of mounting the antenna to the vehicle. Further, consider that any phase delay, read length of metal, between the base of the antenna and the "large" metal surface of the vehicle only serves to mess up the phase relationship between the whip and the ground, thus messing up the radiation pattern. I've seen lots of installations where people mount the antenna to the edge of the front hood of a pickup truck, but the mounting bracket is inches long between the antenna base and it's connection to the hood. This is a phase delay, see previous sentence. This is the reason that you'll see a lot of police cars with the antenna mounted via NMO in the center of the roof or trunk lid. Is the trunk lid lower to the ground than the roof? yes, does it matter? no. The improved radiation angle and direction symmetry benefit out weighs any height loss and even "blockage" by the passenger compartment. Hope this helps.

Hi all, this is one of my first posts on this forum. Please keep in mind that a longer antenna, such as advertised 5/8 wavelength, is of no added value on a handheld. The reason is that ANY antenna longer than 1/4 wavelength requires a ground plane of 2-3 wavelengths (yea, like feet) for the true advertised "gain" to be realized. The standard method of measuring mobile antenna gain in a real antenna chamber is to mount it on a 1 meter diameter metal plate. The GMRS handheld is no where near that. You are better off, usually by quite a bit, by going with a good 1/4 wave antenna. Fortunately at 462MHz that's about 6 inches, which by chance happens to be the length of many handhelds. So this combination makes for a 1/2 wave dipole type mode. This is as good as you can get in the real world on a handheld. Oh, this is the reason that I choose the larger, ie 6 inch tall, handhelds and stay away from the really small ones. In those cases the radio is just too short to resonate properly at 462MHz. I replaced the OEM dual band antenna on my GM-30 with a simple 6 inch long (single band) whip I took a chance on Amazon. It works phenomenally well, better than the OEM antenna noticeably. Not that the OEM antenna is a bad design, but it is dual band so there are compromises needed to make it work outside of GMRS. I only want the best GMRS performance I can get. Here's the link if anyone is interested: 1/4 wave GMRS antenna I know there are a lot of opinions on this topic, and some people make claims to the contrary. All I can tell you to about this is that I worked for a US cell phone manufacturer for 30 years as an antenna design engineer. We used the above philosophy utilizing the radio/phone as the bottom half of the dipole numerous times, it works, really. Enjoy.

Hello, I've installed the Radioditty CPS v2.06 software programming (for use on GM-30). But when trying to use the software it has the columns and rows all bunched together. Is there any way to adjust the display format? I tried the display resolution but that only makes it bigger or smaller, does not change the ability to read the individual cells which are bunched together. And advice appreciated. thanks.