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OK, while not trying to make this overly complicated, I will only mention these concepts and not the math behind them. First off is that 3 dB of loss is meaningless when you start looking at the overall effect it has on the range of a radio system. Consider that a CB or ham radio with an S meter registered S-1 to S-9. The change of one S unit required the signal to change 6db. So if you were running 10 watts and were being heard with an S-8 you would need to increase your power to 40 watts to bring the meter up to S-9. And what did that really do to the overall signal quality? Not much. Here's the thing NO ONE ever brings up and involves the most math. Path loss. Path loss is the signal level loss though free space between the transmitting and receiving antenna's. And it's going to be over 100 dB. And this it where people fall flat with the idea of cable loss and antenna height. Path loss can indeed be calculated and the attenuation levels changes depending on the medium. The other this that no one takes into account is horizon. UHF signals do NOT bend in the atmosphere. They radiate in a straight line away from the antenna and once they reach the horizon they keep going straight. No amount of power increase will change this but a height increase in the antenna does. The other thing that the height increase changes is the medium that the signal is required to pass through. Meaning if your antenna is 5 feet off the ground, the signal coming from it has to radiate through trees, houses, buildings, and the minute it hits a hill it's done going that way. All of these objects attenuate the signal of block it completely. A typical building is going to be over 30dB of attenuation. So if the building is 90 feet tall, and to get over it requires a 3 dB loss of signal to radiate past it, then you loose the 3 dB in the cable to make up for the 30 dB loss trying to pass the signal through the building. Yes, you can over so it and place an antenna too high in the air. But unless you have a 1000 foot tower this is a topic NOT worth discussing.

I run the MTX series in both my jeeps. I have yet to run into an issue with repeaters or simplex. With that said throw the antenna in the trash that comes with it and put a real NMO mount in the vehicle. If the repeaters are good repeaters at good locations you should not have much trouble.

Yeah, and they can have an FCC engineer there using calibrated equipment to measure the RF field strength and determine who the winner is to receive the top prize of a $10,000 plus fine.

Start here for the context. Findings are linked later in the thread. https://forums.mygmrs.com/topic/2421-side-by-side-range-comparison-wouxun-kg-805g-vs-part-90/

The basic sensitivity of all radios I own open squelch between -124dBm and -119dBm and provide full quieting around 12dBm higher. These are numbers as measured in a closed circuit connected directly to test equipment. All radios are affected by the presence of off-channel signals. The the better the front end filtering the less the radio is affected. The effective sensitivity therefore is the net usable sensitivity of the radio within a given RF environment. Measured effective sensitivity will almost always be worse than basic sensitivity except when the radio is used in a low noise environment. For example. If I measure the basic sensitivity of a radio in a closed circuit it might be -122dBm. If I perform an effective sensitivity of the same radio operating in my shack it might drop to -100dBm. If I then hook that same radio up to the outdoor antenna 40’ in the air, the effective value might change to -110dBm. If I then perform the same tests using a higher end radio under the exact same conditions the basic sensitivity might be exactly the same, but the effective sensitivity number might be -109dBm and -118dBm respectively. So, despite equal base sensitivity, the radios with better front-end filtering will effectively receive better in noisy environments, but will not receive any better in low-noise environments. As a point of reference, a year ago a generous friend of this forum loaned me (7) commercial radios so i could conduct field experiments against less costly products in my low-noise environment. Results were enlightening. Findings were reported on this forum. Michael WRHS965 KE8PLM

In general it's good to plan on UHF being line of sight for reliability purposes. With that said, VHF and UHF can go beyond what you can see pretty readily. It's not going to bounce off the atmosphere (short of rare atmospheric conditions), but you do have refraction and reflection within the environment. If you're standing on a perfect marble - yup it's going to go into space like you mention. Same for the most part with rolling hills or paths over sustained topography; it's what you can see for the most part. Down in my neck of the woods (Tucson), there's a lot of isolated mountain ranges. If you're on the other side of a mountain and the topography is such that the top of the mountain forms a somewhat clean 'knife edge' between you and another station roughly perpendicular to your path; the signal can actually bend over the top pretty easily and you can get a pretty appreciable signal even thought here's a huge mass of rock in your way. Likewise, UHF can also reflect on large planar-ish surfaces such as rock faces. I have a few repeaters I can hit/hear from Phoenix at my house decently (over in the northern end of Tucson) even though I have a small mountain range in the way. When I point the yagi at Pusch ridge (a large rock face/cliff formation about 15 miles from my location), they actually come in with a solid signal, if I try and point it at the direct path to the repeater, it's nothing but noise. Plotting the path on Google Earth actually revealed that this rock face is at almost a perfect angle to act as a reflector in this direction where both my station and the repeater have line of sight to it, but not between my station and the repeater directly. This has actually proven to be a reliable tool for me for hitting those machines - works every time.

My Anytone AT-779UV is outperforming my Yaesu FT-857d on 2 meters and 440!

If you find the need for a repeater, and you choose the Retevis RT97, you could use (if the farm has this) the grain bin tower which most likely has electrical service at the top platform for fans and augurs. Place your weatherproof RT97 repeater and antenna at the top of the structure (with minimal feed line) and you should easily realize significant results. Just a thought. Good luck with your quest. JC woops ! Just realized I already posted a reply prior to today.........my bad

Hey Radioguy7268 & kb2ztx, Thanks for replying and enlightening me. I was hoping for better news but it’s all good. I’ll continue to keep my eyes open for a good, used MTR2000 at a decent price. It would seem that the majority of owners know just how good they are and the prices for used units stays up there. I already own three of the R1225, one RKR1225 and a Hytera RD982 but it’s not advisable to run any of the 1225’s at full power so running all of them at 25-27 watts after the duplexers and the Hytera at 43 after duplexer. Wanting a reliable 100% duty cycle @ 50 watts and the only make & model that I’m aware of that has a great track record, is the MTR2000 but I’ll never know for sure unless I ask those folks like yourselves, who have the knowledge. Thanks again for your replies and information. Stay safe JC

60 ft is difficult without a building/tower/structure to lean on - or some guy wires. I've done some 40 ft. utility poles with 10 ft. mast, and I can tell you they do sway and move in the breeze, even with just a simple fiberglass omni, but they work. Forget the fiberglass telescoping fishing poles. More than 10 ft. of unsupported pipe/mast is asking for trouble. You might get away with it for a week, a month, a year, but you won't last through the first decent storm. If you plan to use mostly portables - you will probably need to 'de-tune' the receive side sensitivity by a few dB in Radio Mobile to reflect real world conditions of fade, foliage, and poor portable positioning. I haven't seen too many hobby type repeater systems at 50 or 60 ft. that would receive a portable reliably at 30 miles. I usually figure portable coverage will be about 50 - 60% of what a high powered mobile would be. You might be able to key the system, but you'll always know when someone is working a portable at the fringes. I believe the standard receive side sensitivity for Radio Mobile is set @ .45 uV - which is right around -114 dBm. That's a weak signal, but most decent receivers can operate below that level, you just won't have full quieting. I'd want a Portable coverage map that represents something closer to -110dB for modeling on-street coverage, which would be @ .70 uV

@WRKC935 This is also the argument (both GMRS/HAM/LMR) when one claims they want to put up a "high power repeater" or "add more power" to their repeater. The question is why? Thinking logically, at the same antenna elevation, 99.99% of your users are going to be 50W or less. It doesn't help if the repeater can get out 1000 miles your users can't use it. Most repeaters utilize good antennas (9-12db gain), and after you figure your cable losses, fittings, jumpers, duplexer, etc. you end up at a break even point, or a small amount of gain. Anything between 100W and 50W to the feedline ends up with a nearly identical in/out range and decent coverage, provided the antenna placement is decent. For GMRS, your primary concern is build something that the duty cycle won't burn up.

Got it. Yes you can do that. For proper control over the radio I would expect the electronics interface to have the ability to regulate the flow of audio from one radio to the next so that when the someone is talking remotely over the network that the local receiver’s audio and COR are ignored, so that when someone is talking locally audio is passed through to the transmitter, and so CW can be injected/mixed with audio from either network or local receiver to comply with station identification requirements. Michael WRHS965 KE8PLM

The XPR is built like an old school radio. Its basically got 2 mobile radios inside with special firmware. Alot of times they burn up the TX radio so guys swap them around. All the ones we had went thru an external PA to keep the radios from. I'd probably grab the R1225 before an XPR for GMRS. The only + the XPR will allow is DMR on Ham and Commercial channels.

The XPR8400 is decent, but it is nothing more than two XPR mobiles in a box. The transmit brick has an extra set of fins attached to aid in cooling, but I wouldn't call it 100% duty cycle at high power. I wouldn't even call it 100% duty cycle at 25 watts, but I wouldn't be scared to run one for GMRS at 25 watts for 2 or 3 hours of transmit time per day. If you're looking for something smaller that will truly run 100% duty cycle at high power with digital capabilities, check out the SLR5700. I have yet to replace one of those because it burned up. If you want something for GMRS that's similar in price to the XPR8400 and is truly 100% duty cycle - check out the analog MTR2000.

Side comment: I entered all the scanning freq's, into the 935G, that I have in my other HT (GM30) but there's one it wouldn't let me write back to the radio, 482.86250 (LACSO-dispatch), which is past the listed frequency range (136.174, 400-470MHz) in the manual. This did kind of surprise me since I was able to write to my other HT and it picks up the signal just fine, with the same listed range.

THANKS FOR THE CALL, TOM, IT WAS NICE TALKING WITH YOU. THOUGH WE DIDN'T FIGURE IT OUT, AT THE TIME, I KEPT EXPLORING AND WAS DETERMINED. FINAL FIXED IT (CALLING THIS ONE-USER ERROR ?)...IT SEEMS MY DISPLAY SETTING, NOT RESOLUTION, WAS SET AT "CUSTOM" (DON'T REMEMBER EVER DOING THAT?). DISABLED IT AND RESTARTED THE PC...ISSUE FIX, ALL COLUMNS AND ROWS ARE NOW VISIBLE. ?

1) I think "307" was picked only because it is also the phone area code for Wyoming (easy to remember) 2) Using a PL filter allows us to monitor a distress channel (freq + PL) without having to listen to everything else on that frequency. Short of outlawing the use of one of our very limited frequencies for any use other that distress, using a PL filter is a good way to encourage more people to monitor for distress calls.

This is the follow-up report based on findings in my environment from a set of side-by-side comparisons. If you are looking for a short read, I suggest you move on now and not look back or forever hold your piece. [emoji23]. You have been warned. Before I begin, I want to give special thanks and credit to RadioGuy7268 for his graciousness and the trust he placed in me with his equipment for this effort. It would not have been possible without you. Thank You! What was the comparison all about and why did I undertake it? Manufacturer specifications really are an important thing to review when purchasing a radio. Most humans don’t ‘think’ numbers however. Instead we think about and relate to real world outcomes. What we want to know is if a product will or will not meet our expectations and ‘what can I reasonably expect.’ Sadly the manufacturer’s marketing information, by design, can lead folks into a fantasy world that may have one believing we can have the sky and life will be rosy if we only purchased and used their product. Everyone reading this can relate to the absurd advertising claim on the Midland (and other’s) radio package of a 36 mile range for their top-end GMRS hand-held radio. They do this conscientiously knowing no soul on earth will ever achieve this range in practical use. Sadly though, fantasy sells, even in radio. The more technical the person, the more numbers have meaning. They gain more meaning when they can be related to real life. For example: To the uninitiated, if I ask them how loud something might sound if I doubled the sound power of something they were listening too they might say it would sound twice as load. But that would not be the case. In real life testing researchers found that if the power was doubled (3dB louder) it would be just barely noticeable to the average human. In reality, the power would actually need to increased by 10dB (10-times the power) before the person (on average) would subjectively conclude the level had actually doubled. It is through this type of learning that gives meaning to the various numbers that appear in technical specifications a manufacture may publish. Then we have experiences and opinions. Both are yours, neither of them may be the same as mine. If I shared with you (and I have) that I have communicated successfully well via a GMRS repeater 50 miles away, you might start to believe that if you switched to the use to the same equipment as I then you would be able to do the same. Maybe, maybe not. In the same way, when I read the experiences (or opinions) of others I may start to thinking I too could experience much better results if I switched to the equipment they use. Maybe, maybe not. My conditions are different than yours. When I purchased my current and now primary GMRS handheld I had high hopes for its performance. I bought it because I wanted simplex capability substantially better than I had. I also wanted repeater support, and ability to use it with an external antenna. Imagine my surprise when I experienced only marginally (barely noticeable) better simplex distance over the model it replaced. What a disappointment! I spent 2-3/4 times the price and ended with a radio that, in my environment, achieved maybe 5%-10% increase in range (HT-HT). While disappointed, I am pleased with my purchase and have publicly admitted I would buy the radio again. The features and qualities of the radio that are currently meaningful to me more than justify the additional price. But I really did want much better simplex distance. Like many of you I have read the posts of others sharing their opinions and experiences with regards to the use of ‘commercial’ part 90 radios. Many great experiences (or opinions) have been shared, and some very bold statements have been made (e.g. ‘10x the range’). Such comments caused me naturally to think that perhaps I too should consider such options. Maybe then I could achieve my simplex goals. The commercial prophets had sowed their seeds and thus I have been seriously considering obtaining higher priced commercial-grade stuff. However, my knowledge and life experiences have provided me enough wisdom and little angel on the other shoulder whispering in my ear saying “trust but verify”. Would this equipment really make a difference ‘in my environment?’. I have never owned nor operated ‘commercial grade’ radio equipment for any extensive use. Instead I have always owned consumer grade and ‘amateur’ stuff. As a consequence of my experience I could not say first hand if commercial performs obviously better in practice like others have said it does. I do admit that I almost blindly accept that commercial equipment will likely be built to last longer, stand up to more rigorous use, perhaps even in harsh environments, but before I am willing to make a greater investment for personal-use, I really want to know that the equipment will result in noticeably better outcomes material to me. It is hard to image a scenario again where I find myself investing 2-10 times as much and getting nothing more of what I really want in return. So that leads us to here. I reached out to this community for some assistance, and assistance is what I graciously received. I sought the opportunity to do some side by side field comparisons between my current GMRS HTs (KG-805G) and some ‘commercial’ grade HTs. I had hoped for perhaps one or two premium models. I ended up being blessed with 5. All Motorolas. I told myself that if I could double or nearly double the range in my environment I would plan to switch. So in full disclosure, I tell that when I went into my comparisons cautiously optimistic that I would achieve confirmation of the following: 1. Commercial Part-90 Radios will exhibit notably greater range, in my environment, than any equipment I own. 2. Commercial Part-90 Radios will exhibit the continued ability to receive and produce intelligible audio at notably increased distances than any equipment I own when receiving in the presence of adjacent channel interference. Now, let me set the stage for comparisons. I live in a semi rural area about 20 miles southeast of Cincinnati. My elevation above sea level is just about 875’ which I believe to be in higher-most percentile of the region, and on par with the ground elevation of one of the highest profile repeaters in the area. The terrain around me is mostly flat to slightly rolling. I estimate that within a few miles of my home the land is 60% or more trees with the rest a mixture of residential, open fields and light single story commercial. When I walk down my street using my existing GMRS HTs I experience simplex coverage that goes from perfect (full quieting) at the home and out to a distance of 4/10 miles. Thereafter, noise emerges but communications remains 100% reliable out to about 6/10ths mile. Beyond 6/10ths mile and out to 1.4 miles, communication is unreliable at best. Within this unreliable zone communication quality ranges from noisy but intelligble to very noisy and partially copiable, to non-existent. All this within 1.4 miles distance by way the crow flies. Range or “Sensitivity” Testing Because my street allows me to experience everything from great to nothing, it offers a great initial test bed. I theory that any radio with notably better receive capability will pop its head above the rest while operated in the unreliable (fringe) area between 6/10 and 1.4 miles. My plan was that when I identify radio(s) that stand out I will perform more extensive distance testing at greater distances and in different directions. For my range tests, all operations were HT to HT, theoretically enabling the ability to spot notable sensitivity differences in a short physical distance. My wife operated an HT on the coach near the front window of our home while I went pedestrian. Where model-matched pairs of radios were available, my wife and I each operated two models, a KG-805G and another identical model. Where we did not have identical models for both ends, my wife used a single radio at the house (KG-805G) for consistency, while I carried a KG-805G plus another model. For each comparison, I would walk on the street while walking and talking with her on the radios. I would stop about every 200-300 feet. We would communicate using identical models, then perform cross-model communications. If we could communicate, we noted that location and moved on. When we entered the unreliable (fringe) area we continued with the pattern. When neither receiver would receive a signal at the location we moved on. When we encountered a location where one radio opened up and the other did not, we spent a little more time. Heavy noise on one or both models was an indication we were at the fringe for that radio. When presented with this his condition I would alternate between both models on my end while my wife consistently used the same radio on her end. I would hold each radio in the air in the same way (overhead and in front of me, with my body out of the receive path). I would move each radio around slightly looking to see if minor repositioning made a difference in the ability to receive and in quality of audio. If we found a model that worked in a fringe area where another would not, even after minor repositioning, we would know that we had found a candidate that exhibited more effective sensitivity and that would probably work better in many other environments as well. See the summary below. Adjacent Channel Interference Testing. The next set of tests were practical adjacent-channel selectivity tests. The intent of these tests was to ascertain which radios where obviously less subject to desense in the presence of adjacent channel interference, based on the use of a common desense source. The hope was to identify, in relative terms, how much further a given receiver could receive satisfactorily when subjected to a consistent level of adjacent channel interference. For this test, one additional radio was added to the mix, a Midland GXT1000. For these tests, my wife operated a single model radio in the house for the duration of the tests. For this test her radio was hooked up to a Ed-Fong roll-up J-pole antenna hanging inside at the front picture window. I went pedestrian. I took 7 models of radios with me to evaluate each back to back at each location I stopped. My wife read from the US Constitution while I confirmed I had reception on each model. Once good reception was confirmed I would hold each radio overhead at about 45 degree elevation in front of me, while below and behind me I held and keyed up a 1/2 watt ERP radio. I always made sure that my body was between the two radios I held and that my body was out of the RF path from my wife to the device under test. Separation between the radios I held is estimated at 6 feet (two arm lengths). Tests were performed at various distances along the same 1.4 mile stretch of my street. Findings from my Comparisons I found only minor (but not notable) differences between (4) of the Motorola’s and the KG-805G on the day of the tests. (2) Models, the EVX-S24 and VX-261, both seemed to exhibit the same sensitivity compared to the KG-805G, but struggled to open squelch just a hair more when in the fringe area. Both of these radios also seemed to exhibited a bit more audible noise when squelch did open up. (2) Models, the XPR-6550 and XPR-7550, both exhibited just the opposite. These two models seemed to open squelch just a bit sooner than the KG-805G, but on par nearly the same. (1) Motorola, the EVX-534 exhibited only about 1/2 mile of usable distance (A1 on Map) which suggests it was not functioning properly or perhaps its squelch setting was too high. Although two models appeared to open squelch a hair better and two a hair less, there was never a case (except for the EVX-534) where one radio opened squelch and the others did not when held in the same or nearly identical location (+/- 6 inches). My results suggests there is insignificant difference in the effective sensitivity between the KG-805G and the (4) Motorolas, as none of them reproduced audio at a spot in the fringe area where the KG-805G did not receive and reproduce audio. Since no radio demonstrated better sensitivity in the fringe area I concluded that no further range comparisons were warranted. So this concluded my sensitivity comparisons. Findings from my Adjacent Channel Interference Comparisons Findings here are significant in that it was observed that in the presence of my adjacent channel interference signal, not a single radio (KG-805G or other) opened squelch nor would reproduce audio under test conditions beyond a distance of about 3/10 mile (B1 on map). At 3/10 of a mile and less, all models tested, except the GTX1000, opened squelch. Even as close as 1/10 mile (B2 on map) the GTX1000 would not open up squelch, showing a significantly reduced usable distance compared to the other models. It was noted that when the radios opened squelch that the quality of audio through all the radios was significantly degraded. Even with the audio degraded, with carefully listening, the words could be understood from all radios that did open squelch. As the radios moved closer and closer to the home, the degree of audio degradation decreased. Subjectively speaking, I ranked the radios in the following order in terms of intelligibility when subjected to the interference condition at the 3/10 mile. XPR7550, XPR6550, KG-805G, VX-261, EVX-S24, EVX-534. Then again at 1/10 mile I ranked that as follows: XPR7550, XPR6550, KG-805G, EVX-534, EVX-S24, VX-261 at 1/10 mile. Conclusions Staying within the bounds of what I set out to do, here are my conclusions. In my physical and RF environment, given the objective of maximum simplex range (HT-HT) there is was no material benefit to switching to commercial grade part 90 radios from my current KG-805G radio. No part 90 radio model demonstrated any materially better sensitivity nor increased range under static RF conditions; no radio demonstrated a materially increased range under adjacent interference conditions. All were equally as effective and I found zero increased range benefit to justify a model change. Saying it another way. In my environment, with locally strongly attenuated signals, the difference between the KG-805G and the part 90 radios was not significant. The GTX1000 radio, Midland’s long-time flagship bubble-wrap radio, while reasonably sensitive, is an inferior performer in the presence of adjacent channel interference, giving credibility to the many assertions that radio-on-a chip radios can/will have limited usability in high RF environments. Opinion The cost difference between the KG-805G and Midland GTX-1000 can be justified considering the KG-805G outperformed it by a factor of 3 when exposed to adjacent channel interference as was the case in my comparisons. Users of the GTX1000 (or any like performer) at high-occupancy public events may find their usable range substantially and undesirably reduced compared to users of better models when there are a lot of GMRS and FRS radios in active use in the vicinity. The cost difference between a KG-805G and a new Motorola radio is not justifiable when the key objective is maximum range (HT-HT), while it may be justified when other qualities are deemed more important. For those interested, here is a google earth image with annotations of where the tests were conducted. I personally found this effort very beneficial. Nothing like getting your feet wet and experiencing something first hand. If you made it this far, thanks for sticking with me. And once again, Thanks to RadioGuy7268. Best regards to you all. Michael WRHS965 KE8PLM Edited for spelling. Edited to amend conclusion.

The report can be found here. Side-by-Side Range Comparison (KG-805G vs Part 90) - The Findings https://r.tapatalk.com/shareLink/topic?share_fid=112680&share_tid=2536&url=https://forums.mygmrs.com/index.php?/topic/2536-Side-by-Side-Range-Comparison-%28KG-805G-vs-Part-90%29---The-Findings&share_type=t&link_source=app Michael WRHS965 KE8PLM

Guy comes to myGMRS.com - asks about a GMRS solution, and the first 2 answers he gets suggest MURS & CB? C'mon folks. This is why people get frustrated with asking for advice online. YES! GMRS is a good solution for what you're looking to do. You might be able to get 1 mile or so out of UHF handheld portables - but a simple GMRS repeater at roof level will probably get you between 2 and 5 miles without even trying. Now - you're going to need to do some reading and educate yourself to a certain level if you want to do this on your own. Otherwise, open up your wallet & call the local two-way radio shop, and purchase their parts & experience. https://forums.mygmrs.com/topic/1402-you-just-got-your-gmrs-license-now-you-want-your-own-repeater/