berkinet

And, the P1225-LS, which is to be avoided since it was designed for trunking systems. I will still work as a basic radio, ut with only 2 channels.

There are plenty of good used quality brand name HTs on ebay at well under $50. BTW, it depends on which CCR you compare prices with. Right now on Amazon the lowest priced radios, 16 channel, no display, are at least $15. On ebay there are several Motorola P1225s listed starting $19. Though you might have to buy an antenna, battery and charger with the super low priced ones. You can easily get a working, ready to go, P1225 for under $40. OTOH, the P1225 is certified for GMRS. And, as far as I know, none of the really cheap CCRs are GMRS certified. Once you add certification, the CCR prices jump to over $50. And keep in mind, GMRS certification is not just snob appeal. It actually means something. Sure, in some cases it just means the radio has limited front panel programming capabilities. But, in other cases, it means the radio is not complete shit.

I understand the observation. However, I think the analogy may be a bit off-base on two counts. 1) Regardless of snob appeal, or whatever, nobody buys: a gun that doesn't shoot straight or blows up in your face; a power mower that is known to remove toes; or model railroad cars that won't stay on the track. The issue there is indeed one of basic utility vs. a more refined and (perhaps) more artistic, even gilded approach. But, low to high, all the options are still expected to deliver the basic functionality. In the case of some CCRs. While they may appear to work to the first time user, they may be actually failing in two important ways: causing interference to other users, and very poor reception making the radios significantly less useful. 2) In the examples you have cited, brand is the issue. That is still somewhat the case in radio. But, it is even more so a question of overall quality. Rather than a differentiation based on brand names, it is based on two broad categories. Inexpensive products based on a very simple "radio on a chip" design (CCRs), versus professional quality products. While different people have their favorites, there is no commonly accepted "you must have" brand. And where one brand seems more popular, Kenwood in the case of GMRS, it is for practical reasons like availability, especially used, access to programming software and general support from a larger user group. When it comes to the discussions on this forum, I have found that rather than snob appeal visa-a-vis price, it is often quality that is the prime consideration. For example, while people may often recommend the "big" names, like Motorola, Kenwood, Icom, Vertex, etc., they also recommend buying that equipment used, where the prices may be very close to the price of new CCR equipment. And for that small price difference, you may get not only much better quality, but also very practical features like expanded memory slots. This seemingly minor feature suddenly becomes critical when, for example, you have 2 rep[eaters you use on the same frequency, but with different access codes. On the typical CCR you can program one, or the other, but not both. With a more capable radio, each can be assigned it's own "channel" with a corresponding screen display. I encourage you to take a little more time looking through the discussions on this site before making up your mind that the suggestions for different radio gear is just snobbism or maybe more practical in nature.

Fixed. Thanks.

Does anyone have any experience or information about the L-Com HG459U antenna? https://www.l-com.com/wireless-antenna-450-470-mhz-9dbi-omni-antenna-n-female-connector-type

Well, clearly there is a market. But, I still find it hard to understand. In-building there are other solutions using DECT, Wi-Fi,etc. And, for mobile applications, $8 to $15 per month voice+text only. https://www.mymoneyblog.com/list-of-cheap-basic-prepaid-cell-phone-plans-under-10-a-month.html Or, just subsidize the employee’s existing phone.

Or, in an age of cheap mobile phones with unlimited calling plans, why would anybody even want a phone patch? (sure, for some isolated corner of the northern plains where even the buffalos don’t want to roam anymore.)

An antenna can be either vertical or horizontal. That determines the signal polarity. Both work fine as far as emitting radio waves. However, the transmit and receive and antennas should match in terms of polarity, otherwise you will have reduced reception quality. Since GMRS is commonly used for mobile and portable applications, and those are much easier to setup with vertical antennas, vertically polarized antennas are the norm. However, should you wish to link some fixed locations, horizontal polarization would work just fine, although it is rarely seen in practice.

For anyone else who, like me, if not familiar with these radios. I was curious about the differences between the XPR7550 and the XPR7550e and found this video. https://youtu.be/5AgLIEgFG-w

True. However... a) he was a guest. Hopefully he will join at some point. Also hopefully, maybe someone else will benefit from this discussion.

Unfortunately, that test setup results in a rather subjective measurement. You are using a NB receiver and, as is normal, you have adjusted the receive volume to match the received signal from the repeater. So, it sounds fine to you. But, the issue, if and when it arises, is if a listener is hearing both NB and WB originated signals through the repeater. Then there will be a difference between the two. Keep in mind there are two places where the NB/WB "conversion" can be an issue. On the repeater receiver and on the end listener's receiver. Xmtr....Repeater.....Rcvr NB Tx -> NB Rx/Tx -> NB RxNB Tx -> NB Rx/Tx -> WB RxWB Tx -> NB Rx/Tx -> NB RxNB Tx -> NB Rx/Tx -> WB RxNB Tx -> WB Rx/Tx -> NB RxNB Tx -> WB Rx/Tx -> WB RxWB Tx -> WB Rx/Tx -> NB RxWB Tx -> WB Rx/Tx -> WB Rx​​The first and last cases are the only ones that will have no perceived volume issues. In your test, depending on the rep[eater configuration, you have used either the fifth (most likely) or first case.

Well, it is always possible the OP might erect a 100ft tower. But, if he was planning to put the antenna on his roof, then there would be a fairly short coax run. Likely well under 50 feet, depending on the antenna mast height and where in the house the equipment was located. In that case, coax loss would be < ~2.5db with commonly available coax. And, if he installed a solar/wind powered repeater on a hill-top, the coax run would be measured in inches. Just saying, it is important to keep the solution in line with the problem. Perfection is the Enemy of Good.

With an apparent increase in interest in linking repeaters, and posts on that topic appearing in several different sections of this site, would it be a good idea to create a separate, possibly private, section devoted to Linking repeaters?

That is a good point in favor of locating a repeater at the house, local access to use it as a base station in addition to its repeater function for other radios in the field. BTW, rather than dealing with Heliax, why not just use some good quality coax, like RG214, and, if even needed, just crank up the power a bit.

Given the limited amount of information available about the project requirements, it may be too early to be suggesting, rather than simply describing, the alternatives. For all we know, @Guest_Kevin_ may be on horseback or on foot, and might wish to extend the system to allow interaction with neighboring properties, into town, etc.. Relating specifically to a system based on multiple radios on simplex (I.e. no repeater). Given the description of the terrain there is a reasonable possibility that if there were multiple radios out on the property at the same time, they might not all be able to hear each other. One common goal of systems like this is situational awareness, where it is important to know what is going on around you, even if you are not immediately involved. A well placed repeater is more likely to meet that goal that a simplex based system. Also, a repeater will lower the power requirements for the individual radios, allowing for the mix of equipment to be matched to the needs. But, the main point I am trying to make is that such posts as this are best served by a good discussion designed to educate the poster, and other readers, on the technology and possible implementation strategies - including non-GMRS options.

Two comments: As a GMRS group, it is, or should be, expected that we would also advise where GMRS was not the best solution. Expertise on a topic should not imply promotion of that same topic. It is far better to mention the alternatives now, early in @Guest_Kevin_'s project than to have him discover that GMRS was not the best solution after pouring money and time into it. +1 on the UHF handhelds. The standard VHF rubber ducky antenna will have somewhere around a -2dB to -4dB loss. So, the 2 watt MURS transmitter output will likely be down around 1 watt ERP (Effective Radiated Power).

Note that on an FM or Phase modulated radio all transmissions are analog. Digital data is actually represented by the presence or absence of an audible or sub-audible tone. IIRC 131.4hz is used for DCS. If the signal frequency is not stable, the DCS sub-tone will also vary, making detection of the bitstream difficult or impossible.

Some good ideas there. A few minor comments. If the hill is higher than the house and you can see all of your property from the hill, that might be the best place to locate the repeater. Keep in mind, the only extra element needed for a repeater, other than the radios, antenna and duplexer, is power. There is no need for any other local equipment, phone line, microphone, etc. So, if you have power available in an otherwise good location, that would work fine. But, even if you do not have power, solar and/or wind generation plus a good sized battery, will suffice. Of course, on a hill you would need some type of shelter for the equipment. But that could just be a good sized weatherproof utility box. While UHF is essentially line of site, there is a slight bending that can take place. I think I noted the fresnel effect on another post here recently. So, depending on the depth of a valley and the angle from a radio to the top of the hill, you may still get a usable signal. Also, if you will be installing radios in vehicles, they will have more power and better antennas and may work better in bad locations. As for the testing. If it is safe to be on your roof (I.e. safe for a person and the roof) have your tester stand on the roof to give you a better idea of the range. As others have already noted. UHF/GMRS is probably as good a bet as any for your needs. While VHF may give slightly better theoretical coverage, the basic VHF antennas are longer and many people will use antennas that are shorter and work electrically, but result in poorer performance. So, if you are looking at handhelds, it might be a wash between UHF and VHF. And lastly, just to amplify what has already been noted about licensing. A GMRS license allows immediate family members to operate radios using your call sign (station identifier). According to the FCC... Immediate family members are the licensee's spouse, children, grandchildren, stepchildren, parents, grandparents, stepparents, brothers, sisters, aunts, uncles, nieces, nephews, and in-laws. However, as also noted, non-family members, employees, friends, neighbors, etc. would be required to have their own license. They must apply for their licenses on their own. However, you can repay them for the licensing fee. And, of course, if a group of other users all fall into an immediate family, they can share their license just as you would.

Also, Fresnel zone effect: http://radiomobile.pe1mew.nl/?Calculations:Propagation_calculation:Fresnel_zones BTW, At UHF frequencies, once you have LOS, power makes little additional difference. The higher you go in frequency, the more true that becomes.

Apparently not... See: https://www.changpuak.ch/electronics/J-Pole_Antenna-Designer.php

I don't know of any commercial full-wave antennas. Even a theoretical full wave antenna would actually be comprised of two 1/2 wave dipoles, and such an antenna is rather inefficient. Most antennas are based on a fraction of the wavelength, usually 1/2 wave, or 1/4 wave with a ground plane... which ends up being a 1/2 wave. Note also, many antenna designs may be longer than a single wavelength. Designs such as the Ed Fong stack elements to modify the radiation pattern and create apparent gain is some direction or plane. Also keep in mind many antennas use a loading coil at the base or mid-point to better match impedance. So, when you are all done, though there is indeed a specific relationship between an antenna's measured length and operating band, it may not be immediately apparent to the casual observer.

Power supply. The key thing to avoid is crap. But, you also do not need some lab quality power supply either. I'd look for something on Amazon that had the capacity @BoxCar noted and generally good reviews. If you want a little meter or digital display, that's fine, but you don't need things like that, especially if you have your own meter available to check the output if there are problems. Antenna. Are you actually going to have the antenna inside your apartment, like near a window? If that is the case, I would buy the cheapest 1/4 wave antenna I could find and then mount it on a ground plane. You could then mount it on a baking pan or similar as long as it was at least 13" x 13" or buy something like this. OTOH the internet is full of plans to build your own 1/4 wave dipole for close to nothing. I would not worry about buying an antenna now that you can later move to a house. Once you get the house, you may well find your needs are different. Also, if you do have the antenna indoors, you should probably keep your transmit power as low as possible. Best would be under 5 watts.

Probably worth a try. But, I wouldn’t have much hope. The MXT275 appears to be based on a completely different OEM product and, as of yet anyway, nobody seems to have identified it.

Yes, if the FCC seemed to be ok with that. But, there is no evidence they are. Failure to cite people for use of Part90 equipment is not the same as being OK with the use of such equipment. On the other hand, since they clearly are not actively opposing use of such equipment, I don't see any difference in using a Part95 radio for FM or SSB. Of course, as @kidphc points out, there may be other reasons to not use SSB. But, other than for experimentation's sake, and maybe a slight increase in simplex range, why bother? Isn't that what amateur radio is for?

There is a world of difference between finding a site to be in compliance and not finding any problems. Also, even if a site is in compliance, that does not make the radios themselves compliant. It only means the FCC did not choose to cite them for being out of compliance.