gman1971

Well, you think its the wrong answer, and I just don't. So... to each his own. G.

I am sorry to hear about this. Is everyone okay? injuries? G.

LMAO... you can have full quieting on 1/2 watt, if you place the little bubblepack radio strapped to a drone, 400 feet up in the air... so... something to remember!! G.

So, they way I've done this was using a preselector tuned to a far away frequency (a VHF one used for UHF, most of those will provide about 80-90 dB of isolation). But you should use a real attenuator (the Preselector has very high SWR when tuned off frequency), (like this https://www.ebay.com/itm/JFW-60-dB-25-W-inline-attenuator-N-Connectors-50FHC-060-25/324149401708?hash=item4b78cf586c:g:hOwAAOSw2qpcTkcy ) remember it needs to be a large one, a small 6-10dB one will not be enough. Plug both ends of the NanoVNA to measure the dB attenuation at the frequency, either for the preselector or the attenuator. After that, plug the radio on the other side of the attenuator (Should look like this: NanoVNA port S21 ---> Attenuator ----> Radio you want to test. ) Put a 50 Ohm dummy load on the S11 port of NanoVNA. Key the radio, you'll see the readings go up, from noise floor to some figure, subtract the attenuation from this figure, and that will give you a good estimate of the power. NanoVNA will also calculate SWR, you just plug the S11 port to the antenna, where the radio would go, and you'll see the the curve with the SWR (or return loss), impedance, etc... which will tell you if the antenna needs to be shorter or longer. G.

Some radios have Ignition sense, which I strongly recommend you hook up to some switched 12V on your car. That way the radios shuts off after all ACC power is off. G.

Anything shorter than a 1/4 wave will have reduced performance, so, the shorter it is, the worse will perform (not two ways about this)... but for UHF it will be less of an impact than for, say, VHF... So there is a tradeoff, between carrying a 6 feet fishing pole that reaches 20 miles, and a 1 inch dummy load that reaches 100 yards... G.

Oh, the Surecom shill... seriously, get a NanoVNA v2 with a 4.3 screen to measure SWR. Tune your antennas to 50 ohms, not to the lowest SWR (return loss). G.

LOL. I will, you too.

Doctor knows? haha... certainly knows when something is garbage... The NanoVNA is what it is. If there is a will, there is a way, and Youtube is full of tutorials on how to use it. I recommend NanoVNA V2 with the 4.3" screen... it sweeps faster, and goes easier on your eyes. You can measure power using a calibrated attenuator... low power is easy, like 5W, etc, but for something like 500 watts, you'll need a lot of dB attenuation to test it. G.

If you live in a very rough terrain area, high gain will be very detrimental. I found that going with lower gain (as in Laird FG4500 unity gain antenna) gave me overall better performance than a 4dBd Hustler G6.... so keep that in mind. G.

Get a NanoVNA v2, a dummy load and test every segment of cable in the system, measure for impedance, if any given segment of cable is not 50 ohms (or close to it ) then its time to buy better cable, test every connector as well. I learned this the hard way, so now I only buy USA made Harbor Industries RG400, with MILSPEC silver plated N-connectors or Mini-UHF (since all my gear is Motorola) for short patches, and for mobile operation. Quality RG400 (or RG142 if you plan on permanent install) cables that are properly made will have impedance well within 1 Ohm of 50 ohms, at any frequency in the UHF range, will vary slightly depending on the length of the cable) You can measure adapters with a dummy load and NanoVNA... Measure the dummy load impedance directly, then place the adapter between NanoVNA and the dummy load, if the impedance changes by more than 1 Ohm, time to buy a better adapter. I recommend silver plated, and/or trimetal adapters only, nothing with chrome. And before I forget, don't expect PL259 to hold 50 Ohm impedance above 300 Mhz, they are severely lacking above 200 Mhz, so my advice, ditch the PL259 stuff, and go with N.... otherwise, the impedance mismatch will thwart any chances of having a decent system. G.

Remember that the traffic doesn't have to be on the right frequency to be heard on these Baoturds. I can hear the same kids talking on their FRS bubblepacks nearby in 3 different channels on my Retevis ... my XPR7550e can't pick the kids except on the actual channel they are using... My Retevis RT-52 could hear the NOAA 162.550 in MURS2 and MURS4... along with some other random junk... none of my Motorola radios can hear NOAA 162.550 anywhere, well, except when they are tuned to the right 162.550 MHz frequency, that is. So, be aware that these radios are just that, garbage... and those garbage receivers are so wide open that can certainly pick your local FM music station if parked at the right frequency due to intermodulation IF frequencies... so... I trust the Kenwood is actually doing the right thing, and not picking the intermodulation... welcome to intermodulation on garbage radios!! Its more common than you think... G.

Garbage. Like AdmiralCochrane just said in the previous post: get a NanoVNA. G.

LOL, 1.5 kW? hahaha, that's basically centimetre band radar!! just make sure you're several hundred feet under the antenna when you key that thing... 3 1/2 years!! and counting... but... who is counting? G.

You're welcome, NCRick. Which one of the radios you asking? The HT1250 software is been EOL for a while now, I am sure it can be found on eBay for very cheap. The CPS you probably want for the HT1250/CDM radios is called "Professional Radio CPS" and the version you want is probably R06.12.02, which is what some of the people I know use while still allowing for 25/20 wideband operation. These are really great radios, most people don't think much of those, but they are absolutely bargains... and the receivers are really really good. They make those in a variety of frequencies, from 29 MHz all the way to 800 MHz I think. The XPR6550 is a FM/DMR radio, and the sotware used is called MotoTRBO CPS16 which is EOL, and can be found on eBay for very cheap, although you can also get a Motorola subscription which will get you 3 years of firmware upgrades for all the newest MotoTRBO radios, etc... probably not what you need for just GMRS... I personally find CPS16 a far better product than the newest CPS 2.0 contraption.... which IMO, is a huge step back, almost to the point of being as clumsy as the clunky-a$$ ancient Professioan Radios CPS from two decades ago... so... The cables for XPR6550 portables runs from 30-80 bucks, depending on if you want a genuine cable or the BlueMaxers49 eBay one, which works too... I have both... so if you just need to get by, the 39 dollar one will work. The EVX-539 CPS the software was free from VSOL (Vertex Standard Online) It can still be found if you look around, and worst case you just buy it for a few bucks. There are two versions of this radio, which use different CPS, so, for the older segment LCD version you'll need CE142 and for the newer, Dot Matrix display you'll need CE151. The cable is the same for both, however, you'll probably need to get a genuine FIF-12, b/c I've tried a couple of the cheaper ones and none worked... so, the FIF-12 will set you back ~100 dollars, but its guaranteed to work. The EVX-539 have a fairly good receivers, but IMO, after trying the Motorola Professional Series, including the HT1250/CDM750 combo, I think the HT1250 is a better radio in terms of overall FM performance, easier to tune and I think better audio. I also found that the CDMxxxx mobile radios to be absolutely spectacular in terms of receiver performance, too, on par with the mighty XPR5550e I've ISO-teed... so... if you don't need digital, my vote goes to the CDM750/1250/1550 mobiles and for the HT750/1250/1550 portables (walkies) (The nomenclature is 750 = no screen, 1250 = screen with limited keypad, 1550 = screen with full numeric keypad) EDIT: I think there is an option to make an HT1550 FPP, (front panel programmable) but I would ask around for more info. The 1250 not sure if there is an FPP since it has a minimal set of keys), the 750 is just a rotary switch with a couple of buttons, so that one you'll need the CPS. I've seen on Youtube people doing FPP with the 6550, so I know there is a way to make it FPP, but I am not sure how to do it. The EVX-539 I don't think there is an FPP option, or at least not that I am aware of, so you'll need the CPS for this radio. Good luck! G.

I prefer a shorter antenna for belt worn radios. G.

A 4? Where did you get these antennas from? If these antennas indeed had a 4:1 SWR, like you claim, all my XPR 6550s would've probably be blown long ago, and not have simplex radio-to-radio range of almost 3 miles, ground to ground ... I have a bunch of those in service, and these (and IF these are genuine Motorola) they should read around ~1.67 : 1 at ~462.6 Mhz... You really need a better SWR meter, that sw33 thing is a dog... My choice is NanoVNA v2.0, with N connectors. Its not an HP/Agilent, etc, but at the cost, and size, is good enough to suit most light duty stuff. G.

N connectors, from the get go. Start right, otherwise, when you realize these PL259 are just inferior, and you have like a ton of cables, adapters, etc... it will be like steering the Titanic... G.

If you just want to give the radio hobby a try then just get a Baofeng BF-888S: its a 9 dollar radio. It programs with CHIRP, and the cable is like 9 dollars: in short, it should be the simplest and cheapest thing to get going. If you don't like the hobby, or for whatever reason you decide this is not your thing, then you can smash the thing with a hammer, set it on fire, blow it up with tannerite... and not much will be lost. All other CCR radios mentioned here, the Wouxun, the Retevis, et. all, all those will have similar low performance to the Baofeng BF-888S, except they cost a ton more (rip off??) and are equally bad in terms of receiver performance. Yes Yes... I know... here are the buzzwords to be aware of: Superhet, Hyperhet, Megahet, Turbohet... etc all those buzzwords are designed to sell overpriced cheap radios without the most important component: a proper TUNED FRONT END (to filter all the unwanted signals out there) which is what most LMR Part 90 radios will have... so the radios will work inside Best Buy and not blank out due to all the electronic noise present. But, OTOH, if you do like the radio hobby, the next radio should be a quality LMR radio, not a cheap china radio (CCR). Personally, I would chose a Motorola, the HT1250 is a fairly inexpensive radio, or the Motorola XPR6550, or the Vertex Standard EVX-539 etc, but also Kenwood, or Icom LMR radios are pretty decent too. Remember that GMRS is NOT Ham radio, so, you don't need a VFO, nor the ability to transmit in 100 bands, or in fifteen different modulations. All you need for GMRS is a FM UHF radio that transmits and receives from 462.5 to 467.8 MHz, can store at least 22 channels, do repeater offsets and have the ability to set PL tones. That's about it. Most commercial grade radios will suit your needs. G.

Pretty badass radio... its a Part 90 radio. Just keep it and use it for GMRS. It will serve you well... certainly a great starter radio over the CCR garbage. G.

two CDM750, a 29 dollar programming cable, a 10 dollar repeater link cable, a used UHF duplexer, a few feet of RG213 cable, two 10 feet metal pipe sections, and a Laird FG4500 UHF unity antenna atop those 20 feet. That will give you one of the best FM GMRS repeater options, for a fairly modest price tag. G. EDIT: Forgot the 20 Amp 12VDC power supply.

Yep, for LMR we use only the three letter acronym security, but even Basic Privacy on most Motorola XPR radios will thwart all CCRs and scanners. DTR radios will also stop guys like Lscott in their tracks... LOLOL G.

Which year Corvette, or which Generation (C3, C4, C5) ? Some people have used aluminum foil under the trunk lid (on notchbacks, for C5s), but if you have a coupe, then your options go down quick, especially if your AM/FM antenna is in-glass. Previous poster is pretty much right, most of the through glass antennas will be too big and will make the car look horrible, and won't perform that well, especially for simplex, non repeater assisted. If your car has an AM/FM antenna post, I would use that, take the antenna mount out and repurpose with an SMA male, and stick an APX8000 antenna there. That thing will be better than most "China tuned" paper clips...err. antennas. Factory tint won't affect the antenna performance. I've tried on several cars. Aftermarket, that I cannot confirm. G.

I think the DTR is a much better alternative for site radios than the FRS garbage. Yes, its more expensive, but they are quite hard to scan, and offer pretty decent privacy, maybe not as secure as AES but, they will be far better than anything CCR FRS... The display is the same used in the XPR7550 radios, which is nice. G.

You need a long socket Hirose, so you don't need to do any of that. As for coming off, well, its fine for ISO-tee, but I did cobble together a simple support (bolts to the antenna) that holds it in place even when I am walking around. G.