gman1971

You are right, actually. The EVX-5xxxx radios use both, they use a regular double conversion superhet, with a traditional 1st stage, but the 2nd stage is a direct conversion Rodinia chip. I think the AT-578 uses a similar approach as well, but not Rodinia on the 2nd stage... some POS 2nd stage that allows intermod galore... Its certainly not impossible, it only costs circa $13,000 dollars for a new IC-7810 radio... or around $5,000 for a new APX8000 radio... or around $1k or so for a new XPR7550e... not impossible, just be prepared to pay for it. You won't find such luck in CCRs I am afraid. Anything designed poorly (regardless of what it is) will have horrible performance... G.

@gortex2 I think the suggested CD1550 in my previous post would work, but could you please corroborate if the radio will in fact work? This is the link to the eBay auction: https://www.ebay.com/itm/125105278398?hash=item1d20db0dbe:g:VLIAAOSw1mBhbyCH Thanks!! G.

This is what I would get to start, should you decide to try this route, PM me, and I'll help you get started. Radio CDM1550 UHF: https://www.ebay.com/itm/125105278398?hash=item1d20db0dbe:g:VLIAAOSw1mBhbyCH Microphone (DTMF mic for the CDM1550): https://www.ebay.com/itm/302350359152?hash=item46657c5a70:g:LukAAOSwmLlYBXr3 Power cable (standard for all Moto radios): https://www.ebay.com/itm/224581351109?hash=item344a1776c5:g:G6YAAOSwrKlhIZS8 Programming cable (Verified works): https://www.ebay.com/itm/153254242963?epid=20051160527&hash=item23aeaa2a93:g:aj4AAOSwWelfZB5W G.

Hi, 60' feet above the ground, for just a mast, and not a tower, I recommend, like others, using the house or the tallest property structure for support and/or to start the mast there, so you can reduce the amount of actual mast you'll need to raise to get to the desired height. I honestly think going with a 2-bay or 4-bay folded dipole will also produce very good results even with something that isn't above 50 feet. Also I recommend acquiring a good radio to be mated to this antenna, as it will be exposed to all kinds of RF from nearby super high power transmitters, so a cheap radio might be more detrimental to your range aspirations. If you must start on the ground, then I would use 10' foot galvanized water pipe steel sections, starting from the thickest diameter you can find, either 1 1/2 inch or 2 inch, etc, using the thicker tube as a sleeve for the next smaller section, like a telescopic antenna. At 60 feet, do not thread things with couplers, or they will snap, and trust me, its not pretty when that happens. As for guying, I would use two guy wires per direction, one at 40% of the height, and one at 95% of the height in a triangular 120 degree fashion. To raise this I would use a vehicle, along with a 10 foot section as fulcrum to get it off the ground, along with a helper so the pipe doesn't bend too much when first being raised. Source: I've done this myself. G.

Glad I could help, Yes, you probably don't want to run the anaconda heliax to the radio. Sorry for leaving this important bit out... what I do is run the Heliax up to the main ground plate, where all the N bulkhead connectors are (this plate is usually grounded), and on the other side of the bulkhead N connector I run short 4-feet patch cables of RG-400 with silver N-connectors to the filters, and then another 3-4 feet RG-400 from the filters to the radio/repeater. G.

Hi there, as gortex2 stated, cable is rather important, especially at UHF or above freqs. Personally, I would dump the RG-8/U and go with LDF-50 1/2 inch heliax with trimetal N-connectors. BUT.... big if.... if all you are going to do is simplex then I would entertain genuine LMR600. With either silver or trimetal N-connectors, especially for indoor runs. I wouldn't waste any money on PL259/SO239 for anything above 300 MHz, it can't hold impedance well at higher freqs, so you might end up going down a very deep rabbit hole ... not fun. Personally, I run multiple 40 foot sections of LMR600 with silver plated N-connectors for my UHF GMRS base setup (no repeater) at home. Loss is very small. For anything else I have, everything is heliax LDF-50 1/2" The Effective Sensitivity (or dynamic sensitivity) is not the advertised sensitivity figure on the radio. In order to determine the dynamic sensitivity figure you need to perform an isotee test on the radio. Nowadays, it seems that noise floor is pretty much the limiting factor as to how far you'll be able to hear the base. As for Antenna, after trying over two dozens of ham grade stuff, I wouldn't waste my money on anything vertical, go straight to either a half wave dipole or a half wave folded dipole. You will not be disappointed. G.

And more quotes, with pun intended... btw, did writing that post give you a headache too?

@MichaelLAXGood... I don't want to waste my time any further... Oh, more quotes... your favorite... and "Factually wrong" is, once again, your opinion. When I say something was insulting to me, it was insulting to me. That is a fact, or you believe that facts are just what you believe? How many people agree with your opinion is also 100% irrelevant, and doesn't change the fact that your statement did in fact made me feel insulted.

@MichaelLAX You seem to apologize to me all the time, yet you just keep doing it, time and time again. I rarely read CCR threads these days, but sometimes I do, only to find the same pattern everywhere: reading post from another member calling you the "grammar" police, then you go full "pedantic" on the guy, or on another thread, when the OP asked for a selective receiver, you then posted a CCR POS... and when confronted, you "double down on it"... and that is just a couple of examples. For someone who claims holding an Extra Class amateur license, all I hear coming from you is bad radio choice advice, feelings and opinions, which none seems useful to solve radio related problem, on a radio forum. Ah, just to reiterate: There was nothing humorous about your reply, and the emoticon made it worse... but those jokes of yours are rarely understood by the many, only the few who are the true "legends in their own minds." G.

Hi, I would determine what the noise floor in your area is, I've seen rural areas with a surprisingly high noise floor... Then, after you determine that, I would then measure the effective sensitivity of these radios, by performing an ISOtee with the antenna(s) you plan on using. Once you determine the noise floor and the effective sensitivity, you'll be ready to start making educated decisions, rather than just going down the rabbit trail without knowing why something is happening. G.

TM-V71a is a nice radio, indeed, and the install seems top notch; but I will point out that the TM-V71a doesn't have a particularly selective receiver, that is if selectivity is what the OP wants. CDM1550, those can be found < 100 bucks in near mint conditions. can be remote mounted. XPR4550, fairly good receiver, can be remote mounted. Obviously, the XPR5550e, which can also be remote mounted, but that one is more expensive.

Same for the APX radios, you need a keyloader device.

All those radios are basically modified ham gear. There should be no reason why GMRS radios couldn't have great filtering, as they only need to listen to a handful of frequencies... but again, any filtering just piles on the cost... and we all know that everything these days needs to be free... G.

I would've thanked you if your comment would've, in fact, read to me as a compliment; when in fact, nothing coming from you as of lately seems like a compliment to me. So, please, spare me the "I feel bad" drama, which you seem to really enjoy, btw. Applying your same logic to your post: your comment did in fact read as a condescending "off the cuff" insult towards me, a simple "cool, seems like good info on that post, thank you."... would've sufficed. G.

Absolutely, Superheterodyne is nowadays a marketing buzzword; and with that said, superhets of old used to be really good, b/c they spent a lot of time/effort in making them work very well because there wasn't any other practical way to do it... Heck, if done well, those can be quite amazing.... in fact, a member from another forum shared with me some data, showing that the best selectivity he's ever measured was in a double conversion superhet radio made in 80s... I'll have to find the PM somewhere for the model, but yeah, superhets can be made extremely well. But I also agree that DSP and SDR radios are the way forward. The XPR7550e uses basically a direct conversion architecture. However, they have something inside that radio that no other radio can, short of the APX radios, can top in terms of performance. Its probably filtering coupled with DSP and who knows what else... A lot of the Icom radios like the 7300, etc, all seem to use direct conversion SDR, and those are nothing but amazing radios, I would love to own one when cash allows, but if you look at the crazy filtering they use in those radios is just insane... heck, even tracking filters, and those are not cheap... and the radio price tag shows, 3500 and 13000 for the two top performers in the Icom HF base rigs catalog... I bet most that of the price tag was due to the impressive filtering and DSP-wizardry stuff... otherwise it would be no different than the 29 dollar SDR POS running some SDRsharp on Windows. Well, the oversimplistic superhet and oversimplistic SDR are the ways of the CCRs, they took the basic SDR and surrounded in a case with a screen and an antenna, or they got some reference design from all these radios made in China, and made it as cheap as possible, and once again, shoved it inside a fancy box with a fancy screen and sells them for x100 the price it costs to make... Sometimes, going to a "blank piece of paper" is the only way to go. If you take someone else's design you are also taking all the assumptions and design factors that went into that design, which might work in the short term, but once you start iterating, you'll certainly bump into those; and the end result is that to meet deadlines you'll resort to hacking everything together, again, been there done that. Weeeell.... not sure if "Front end improvements" are as easy to implement as the "throw some improvements there" makes it feel like it is; those are rather expensive, and time consuming, otherwise the ICOM IC-7810 would go for 130 bucks, and not for 13,000 dollars, I would think. I also suspect the IC-7810 has its own custom everything, they probably scrapped a lot of stuff from the previous generation radio designs just to get that extra performance they needed, just like I've done before in my career, because hacking the previous design just wasn't going to cut it. G.

Probably listening to yourself gives you a headache too... but that would be expected.

Ah, the good old ISO-tee test... special thanks to repeater-builder.com for putting information on how to perform the procedure. "I am a simple man with a directional coupler... only an ISOtee away from the truth." G.

Still, FHSS, like @BoxCar said, will require more than your basic listening equipment, but in theory is not that hard. As for encryption goes, it really depends what was used... GD77 privacy? Probably a piece of cake. XPR6550 Enhanced Privacy? a tad harder, but easy, an XPR7550e with AES256? The only chance is if they get their hands on the radio. An APX8k P25 with AES256? Not a chance, even if they get their hands on the radio, they still have to defeat all the security protocols just to get to the AES keys inside the radio, that is if the radio doesn't self-wipe when tampered with. G.

Dang conifers.... but don't despair... never underestimate what some extra dBs can get you... 500kW on a highly directional antenna will probably melt the conifer forests, and anything in your path to reliable comms... so... problem solved... range will be assured. VHF seems to outpeform UHF nearly on all scenarios I've tried. However, the VHF noise floor in certain areas around town gets high enough that its sometimes challenging to get reception, even for signals as strong as -90 dBm, and especially around traffic light controlled intersections, where you get some serious RFI on those dang traffic lights... UHF seems to be much less affected, but then again, you have other things that eat up UHF like its going out of style... like those conifers... or water... rain... etc. G.

Radio waves coming from the antenna are just like the light coming from a flashlight. If you light it up atop of a lighthouse, someone will be able to see your light from tens of miles away, now, if you light up the same flashlight at ground level, it won't be seen from very far away at all. Repeaters are like lighthouses, they are placed high above the ground. G.

So were mine... just stopped buying them because after trying literally every model out there, I realized they all sucked by about the same amount... G.

Exactly, and hot dang, HT600... by today's forced obsolescence standards those would belong in a museum... but those guys still using them is a testament that these radios are indestructible... and that they will, indeed, last a life time. That is the plan for my XPR7000 fleet... Battery availability, yeah, that is why I am stocking up on batteries for the long haul on my XPR7000 and SL7000 fleet... but I know all things always come to an end... so we'll see.... G.

MURS can also be used for data transmissions AFAIK... @marcspazthat is my understanding as well. G.

A good radio will always be a good radio. The HT1000 is one of those good radios, rugged and with a decent receiver... obviously no screens nor none of these fancy bells and whistles we have on radios today, but the receiver was very decent. I remember seeing these used all over the place in the 90s. I still use CDM radios for light duty repeater application. Radios in the past used to be built to last a lifetime... nowadays, everything has been "forced obsolescence..." G.

Right, anything can burn, no doubt; but it seems that using LMR/LEO grade equipment reduces the chances of such event vs. the cheap CCR stuff and the super cheap ham grade radios. The fact the 5550e survived reverse polarity speaks a lot... I wouldn't want to test that on any other radio... G.