gman1971

Radio as a service is a thing now, and the firmware SUM scam is just another way to keep milking the cow... and for that seems that older radios might increase in resale value, due to being considered "unlocked" as most users don't have to deal with incompatible radios, or potentially bricked radios down the road, etc. Multiple CPS files/profiles is an absolute PITA... Also, its not like good radios from 20-30 years ago (like the HT1250, etc) are obsolete anyways. Sure, those don't do digital, but then again some users abhor digital modes... and those radios are known to work reliably without dialing home and none of the "milk the cow SUM/RAAS racket..." G.

Power is always limited, the antenna cannot always be changed, so, given equal power and a similar radiator, a better receiver will always beat a lesser one. The DLR 900 vs TK UHF range similarities hints me that there might be a good 6-7 dBm difference in noise threshold between the two bands. Surprising how well these DTR/DLR radios work given the limited amount of power they have. G.

It really depends on what you want to achieve. For a non-base, non-repeater mobile radio usage (moving), for GMRS, I would just buy a large aluminum plate and drill the NMO hole in the center and use a 1/2 wave NMO no ground antenna, or even a 1/4 wave (6 inch) then secure the AL plate to the roof with heavy duty double sided tape, and run the cable from the radio outside via one of the many electrical connectors you already have poking out from the RV cabin. If cable For a stationary base/repeater, I would skip the 1/4 wave, the 1/2 wave and go for a collinear 5/8 over 5/8 mobile antenna. Know that the gain on those antennas are overly exaggerated, but it will certainly have more gain than the 1/4 wave for sure, with a more concentrated radiation pattern towards horizon, which is probably desirable for a repeater/base setup. G.

We can take this offline.

@Lscott You know this isn't a hobby for me, it never was. Even when I was very active in GMRS, my ultimate goal was always to build a bulletproof family intercom system; not a tinker toy, not hacking radios just to see what happens. Now, when anyone is trying to convince me (and what appears to me as misleading others) with hypotheticals, diagrams, or whatever other gimmicky buzzwords, claiming that certain radio brand, radio model or a radio equivalent to what I've tested (and deemed inferior) are "just as good" to any other brand, be it Motorola, Wertex, Kenwood, for example if someone tells me a BF-1801 is "just as good" as a Vertex EVX-539, then I call it out, and the thread turns into this. Motorola happens to be ATM at the top of the food chain, regardless of your opinion, agreement or lack thereof. Having range, reliability, battery endurance, and radios that mesh and work seamlessly together as a system, with ZERO tinkering are paramount qualities I seek in a radio system, so I buy accordingly. Keyword: Radio System, as in: a bunch of radios that seamlessly work together under my own infrastructure; and it so happens that Motorola, for all their faults, they've spent a great deal of effort in trying to make just that, even though sometimes they screw up. Now, what makes you think that I just simply "claim Motorola is better" without any proof? Let's see.... when these qualities I've listed above are required in a radio system, Motorola is almost always the radio system of choice, and not Kenwood. Now, I do see brands like Kenwood, and other lower tier brands used in budget conscious applications, when not all the above qualities are required. In fact, it would've been great (to me, and my wallet) finding another less expensive brand than Moto$$$ that provided what I needed. Unfortunately, tho, after giving it a good try (and rather expensive in the long run), it became rather clear that budgety stuff, tinkering and being cheap wasn't going to cut it for my application, so I had to go all the way, and as it turns out, I've never looked back since then. Just like the guy with the Quantar, or a few other people who I've talked to over the years in different forums. There is a reason why everyone is competing with Motorola. Heck, even a former engineer from Kenwood states that their radios are not that great. And to reiterate, cheaper radios and CCRs DO they do have their place and purpose, as they can get people interested in radios, but not necessarily keep them interested for long once the shortcomings start to pop. Nowadays, given the sole fact that cellphones exist, and that people don't want to tinker with stuff anymore, and that they just want reliable comms, which is what a cellphone offers, when they get sucked into the cheap radio utopia that they'll have great everything for pennies on the dollar, etc, so they march on based on this premise, tinkering with their new toys at first, until realization that its harder than they thought sets in, then no more. Personally, I hated every minute of tinkering with substandard equipment just to barely get the dang thing to work, (and the next day it wouldn't work anymore), nor it should be for anyone aspiring to have a viable alternative to a cellphone system using GMRS or LMR. Oh, and IIRC, GMRS was never meant to be a hobby, right? ham radio IS a hobby, GMRS is a family communication service. Using GMRS radio as a hobby is just missing out, if you really like tinkering with radios, then get the technician ticket. Now, while both "licenses" use radios, each serves a completely different purpose: Ham is meant to tinker with radios, for the sake of radios, to talk about radios, dream about radios and ego-stroking each other over 2m until the TOT timer in the repeater runs out..., whereas GMRS is meant for me using a radio so I can ask my wife if she wanted carrots or broccoli b/c I don't see neither of those two listed in the shopping list... and preferably with a range exceeding the corner down at the end of your street. G.

@Lscott Respectfully, no, they are not. If you believe that they are, then that is where the problem lies. Again, respectfully, chip encoding/mode is irrelevant to the conversation, AMBE, IMBE, EMBE... we are talking receiver performance here. Vocoder is the same on all those radios, AFAIK. Maybe Kenwood used the "economy vocoder model..." but we'll probably never know.... Generating RF signals is not relevant to this conversation either, again, we are talking receiver performance. If the DSP can't get the signals in, then there is nothing a DSP can do. Simple as that. I am also well aware what DSP can and cannot do, and magic is not on the list. A system is measured by its weakest link, and in Kenwood's case, its the receiver, which happens to be the first link in the chain, which is utterly inferior. If you don't believe this, then again, that is another thing you need to come to grips with. The receiver of a radio is exactly the same for digital and analog, or do you believe digital signals are different than analog signals? Or is it a lens HD or SD? or does the muffler need new bearings? or maybe need to add some blinker fluid? Sorry to break this to you, but Kenwood didn't skimp on stuff on purpose, otherwise if they could've one-up Motorola in receiver performance, they would've done it... but they lack the technology and the know-how that Motorola has at this particular moment in time. In 10 years, who knows, right?, but now, here and then, they just don't. Remember that Quantar thread smashing the teeth of a Kenwood repeater?, yep, well, that is not just a one-off lone instance in this forum, that is everwhere, everyone, every person I've talked to who've made the move from other brands to Motorola... they all report increased performance in coverage and audio quality... and this is my experience as well. Again, why do you think professionals use Motorola equipment everywhere? If they could save a buck, or two (or a thousand), they would've used 50 dollar Kenwood NX-200 b/c they are the same as APX900 (XPR7550e) performance... right. An ISOtee of -120 dBm vs an ISOtee of -112 dBm, you have a 8dBm dynamic sensitivity difference that no amount of DSPing in this Universe will make up for it... and that is the kind of dismal performance between the two brands. This is an XPR7550e, not an APX4000, which probably has even better dynamic sensitivity over an XPR7550e... but hey, they are "about the same" as the NX-200 right? Benchmarking any receiver can be done with an ISOtee test, if you don't believe that then that is another thing you need to work on. 'll repeat what I said on the Quantar thread here again: I sold ALL my inferior radios and went Motorola all the way. Never looked back. Now, if you so strongly believe Kenwood is "just as good", then by all means, believe whatever you want to believe, but believing in something when there is ample data and usage statistics from professionals from all over the world that disprove your belief, along with my own measured data, seems kinda weird to me... but again, its not my money. G.

@Lscott They might be cheaper, but cheaper is always relative, right?, as they are not comparable in terms of performance, so yeah, you pay less, but you also get a lot less performance too. Also, the statement "Almost the same specs" is rather misleading, and it sounds just like a used car salesman trying to sell you a clunker, as Kenwood radios have measurably inferior receivers compared to the Motorola XPR/R7 radios, and the APX radios are one level above the XPR/R7 radios. I was referring to a company upgrading radio equipment from the Motorola XPR series, then I'd go with APX900/APX4000 over the R7 route, you get to keep all your accessories and batteries. The only other radio manufacturer I'd consider trying at this point (and that is b/c I don't have any ISOtee data on them) is ICOM... G.

I think at this point the APX900 is a better deal than the R7. IMO. With the APX900 you get an XPR7550e with SMA, full FPP, and all the accessories/batteries of the APX4000. G.

Side by side of the two radios. XPR7550e and R7. In this pic its noticeable bigger too... yet another Con in my book... G.

There are multiple things at play here, right? Without knowing the cable impedance and the actual cable loss (not the SWR), you really can't tell what is going on. I recommend getting a NanoVNA, ideally with N connectors, even though the SMA one will works just fine, but those SMA tend to wear out if you use them too much... anyhow. The cable length will change the insertion loss, a longer cable has more loss, shorter cable less loss, etc, but varying the length will also alter the SWR readings by a hair, depending on the frequency, along with varying the impedance by a hair as well. Not by much tho. Once you know the cable insertion loss, the impedance and the SWR for that given patch of cable, then you need to tune the antenna for 50 Ohms, and not for the best SWR, and so long that at 50 Ohms the SWR is better than 2:1, it should perform well. If the antenna is not tunable, then you need a new antenna. G.

@WRKC935 I understand that adapters are not ideal, right?, but when you are trying to get something together then that qualifies as "testing" in my book. Also, the OP wasn't being forced to buy that particular cavity I posted a link to. But then again, having anything PL-259 terminated cable is a total waste in my book, even if it is the right connector to that cavity as you state. I wouldn't buy a PL-259 cable, I'll just change the SO-239 of the radio, as I've already done for many radios, to an N female, again, just to not have to buy anything with a POS SO-239 cable. Personally I would've swapped these two SO-239 on that cavity to N connectors, and not have to use adapters, but the OP might not feel like doing that, hence the adapter. The reason for the adapters was so the OP could start by buying N-to-N cables from the get go... and then just ditch the SO-239 adapters when moving to a better N terminated cavity, or replacing the SO-239 in the cavity, etc, but I guess you didn't read into that. Also, since you are into what not to do, here is what I would advise the OP NOT to do: don't use RG142 as a jumper cable. Wny? b/c its a solid steel copper inner and it WILL develop micro cracks after bending it a few times, or bending it too much and the unbending it, and cause a crap ton of PIM when using duplex (two radios), while you might've not experienced it, well, I have and it sucks. Solution: if you can splurge it, get RG400 patch cables instead, with either silver N connectors or trimetal, and since RG400 has a stranded inner core, it can take the bending all day long. Oh, yeah, be aware, the RG400 has a hair more loss, but don't buy into the BS that a 0.03 dB extra loss will affect your range much. It wont affect your range the slightest bit, actually. I currently have ~2.3dB Insertion Loss in my feedline setup and my range to portable is over 20 miles... Heck, one can get fancy and recommend using 1 5/8" Heliax, Quantars and Telewave folded dipole arrays on 1400 foot towers here too, but the OP just wants to get something going, and there is a middle ground between the Quantar/Telewave and the KMR POS cables that fall apart just from sitting outside two days under the Sun... A simple cavity, any cavity really, will always help any radio front end and intermodulation from getting into the TX as well. If you don't have the cables, then an adapter is fine to get you going. LMR400 with chrome plated connectors will works on a pinch, to get you going, and so long people are aware that they'll most likely be buying twice, its fine. In addition, from my experience using LMR400, the dreaded PIM on genuine LMR400 cable usually takes a while to develop, so it should be fine just to get started. Also, so you know, I'be been running LMR600 with silver plated N connectors on two of the longest runs on the premises here for a few years now without a problem. No PIM detected. The takeaway here is that LMR cable works just fine for simplex stuff. Now, my only strong recommendation would be to at least start with all N connectors on all cables, if possible. @OffRoaderX You must be living either in really flat terrain, and/or on top of a hill/mountain, b/c to get those kind of numbers, reliably, here in WI for a UHF repeater (keyword UHF, not VHF), you'll need at least double that height in the tower due to the roughness of the terrain. G.

High loss cable would act more like a dummy load, eating the radio power and the reflected power as well, so it looks like you have a better antenna than it is. You also need to measure impedance, not just SWR, and check the cable patch alone, to see the loss and the impedance of just the bare cable. Connectors could also be problematic. A bad connector can ruin the entire setup as well. G.

Alright, holy batman thread derailment with horses... The point is, don't use hacked anything in a commercial, or LEO tower/setting, as it might cause other problems that can (and will) quickly go over the money it was "cheaped out" by cutting corners. G.

I guess its all perspective, right? No issue with owning legacy stuff, just use it accordingly, same deal with the horse... just don't ride on the highway and you'll be fine. G.

Just remember the keyword "hacked". The moment something is not built to the specifications that it was built for, be it for extended coverage, be it a different band, etc, then its no longer certified for anything. At that point its not a Motorola radio anymore, its "Happy Joe's Ham science experiment" radio. This was another reason why all the non Motorola stuff was dumped, one gets tired of having to hack, tune, fiddle with crap to just get it to work the way it should work. In a nutshell: If someone plans to use a 70 year old piece of gear (any brand) radio that has been "hacked" for a Ham repeater, on a modern commercial tower then I am sorry, but they are doing something wrong; much the same way as me driving a horse on the highway... while horse is perfectly fine as transportation means, however, its really not the right choice for highway transportation. G.

@WROZ250 Thanks. It really never had anything to do with snobbery, but everything with being tired of crap equipment not working, crap stuff needing constant attention, stuff not delivering on any promises, etc.... but whatever, let people fumbling around with trash equipment wasting some money in the process, always wondering the same things I wondered, and certainly let them think its all about being a Moto-snob... because the sooner they give up on their radio "excursion" due to piss poor equipment and range measured in tenths of a mile, then the more RF space left and available for the rest of us to use with our Moto-snob radios. @Lscott Hacking part 90 equipment to work on the ham bands is not the same as using unmodified Part 90 equipment for GMRS. Doing that would be the same thing that hams frown upon: when non-hams are using hacked Ham gear to run on GMRS or MURS, etc; and while that might work, just don't expect top performance out of modified equipment (any equipment). Let alone on a tower... where it can cause all kinds of problems. The moment a Part 90 device is hacked to do something they were not designed to do, then they are no longer Part anything certified, so that should be no grounds to call that Part 90 stuff will get black SUVs or fines rolling on your driveway. That is pure BS. G.

Mighty impressive coverage... a few more miles would've reached Madison WI!! G.

Double vocoding nullifies all the benefits of a digital repeater. You lose the ability to send data, radio checks, use ARS services, text messages, etc. Double vocoding is probably fine for a short range vehicular repeater, but IMO, its not useful for anything else... it should be a last ditch effort to get a repeater going. G.

Yes, I think so. I've had an FG4500 up for 2 years in freezing winters and scorching summers, going strong without a single hitch. The FG4603 is basically the same antenna construction with higher gain (and realistic gain) G

FG4603 perfect as well. Good choice.

https://www.ebay.com/itm/224684607008?epid=1800453427&hash=item34503f0620:g:VfgAAOSwdh9gAbBL

If the FCC admits in writing that Part 90 equipment is perfectly legal to use in GMRS, again, in a written memo that you can show to the tower owner, then that would be "by the book". I don't understand what the issue is here. Again, without reading the memo, and the proper legal representation on the matter, anything said here is just speculation, hearsay, and to me its also fear mongering from the Kenwood guys that after a Motorola repeater beat the crap out of a Kenwood repeater... so now lets attack Motorola superior equipment because it lacks certification, and that black SUVs and fines can come piling down your door.... so you should instead buy inferior Part 95 equipment... Sorry, I've played that game before: and I'll stick with Motorola and their superior Part 90 stuff. In fact, in my opinion, the Quantar is most likely superior to anything repeater Kenwood has ever made (hence why it costs x10 times more, right?), and the OP post just confirms it. Also, the OP post also confirms what I've been seeing for the past two years from ISOteeing different brand radios. The question is, why is it so hard to admit that the Quantar its just a better repeater out of the box? Get one, stop complaining that the Kenwood could be better if tuned, etc... just get a Quantar and be done with it, just like the OP did, or just like I did I went Motorola on all my equipment, sold the inferior stuff, and never looked back. Making any claims that the XPR7550e could be an equal to the APX8000 with some tuning or whatever will server no purpose, these two radios will never be equal, not even close. So when I see threads of APX guys bashing the XPR radios I simply steer clear, there is no point in denying a fact, except indicate someone might be jealous. Now, what I can tell you I'll do is that when I have enough cash burning holes in my pockets I'll get myself a whole fleet of these shiny APX8000 radios and join the Luxury Transceiver exclusive club with style, and probably dump the inferior XPR7550e... until then, the order of things is APX8000 > XPR7550e G.

Most of those antennas develop water ingestion due to the foam absorbing humidity. I've had multiple antennas like that, that within a few months developed super high SWR. Hopefully you have better luck than I did. G.

Depending on the radio you end up using, you might want to look into a UHF cavity to help the front end. Something like this guy https://www.ebay.com/itm/194836529443?hash=item2d5d298123:g:JYgAAOSw5oFh6Yqw I know it uses the PL/SO-239 UHF connectors which are not ideal for 462 mhz stuff, but its quite affordable a pair of UHF to N adapters should work on a pinch. G.

Height is king. Noise floor seems to be less of a problem in UHF, even at <1 mile from a big 1400' angry RF firebreathing tower, the measured RSSI noise floor in the GMRS channels is always in the high -120dBm range.. that's pretty good. The issue with UHF is the 10dB attenuation loss over VHF in long range distances, and the fact that anything it touches attenuates the signal like its going out of style... rain? boom, range goes to crap, snow? boom, range goes to crap, vegetation nearby? boom, there goes some more range... The only thing, like you've stated, that will will fix this is more height. And a good antenna setup. G.