Lscott

By transmitting on the repeater output frequencies. If they’re near by your location they can jam the frequency.

One other thing I forgot to mention. That's the cycle life of the switch. There is usually a max number of switch cycles the device is rated for. After that you can get mechanical failures. Some of those used switches might be near the end of their cycle life and were pulled out of active service and replace with new ones. It might work for a while then fail later. Hopefully the switch wasn't abused by switching under power. That would likely burn the contacts. You don't want to buy somebody's else's problem.

Before spending your money try to track down the data sheet for the switch. Many times you can find it on line. In other cases sending a friendly email off to the company's sales or tech support department might work. The other thing to look at is the power handling capacity of the switch. A switch you're interested in might be cheap because it won't do more than maybe a few watts.

Nice history/background info.

I would very seriously consider getting your Ham license too if you don't have one already. The Tech class exam is easy. The point about getting your Ham license is due to more available repeaters to use and more people you can chat with while travailing around the country. The most popular bands are the VHF 2 meter band and the UHF 70 cm band. GMRS is on UHF a bit above the Ham 70 cm band. There are radios available that will do the Ham 70 cm band and GMRS with some "creative" programming. If you want to stay legal some of the older commercial radios have Part 95 certification and are completely legal to use on GMRS and Ham frequencies. If you stay with just UHF you could find a single radio that will do both. As far as antennas go there is a wide band mobile antenna that would work over the Ham and GMRS bands so you could get away with just one. Some people have had good luck using this one on GMRS. I think there are some other antennas that work over a wide band too others have mentioned in other threads. https://cometantenna.com/wp-content/uploads/2013/09/CA-2x4SR.pdf GMRS only. https://dpdproductions.com/products/gmrs-double-5-8-wave-mobile-antenna?_pos=2&_sid=bf9d19c6a&_ss=r GMRS and MURS. Note that MURS is a license free VHF band with a limit of two watts of power. https://dpdproductions.com/products/dual-band-gmrs-murs-mobile-antenna?_pos=1&_sid=bf9d19c6a&_ss=r Some even use a different antenna depending on the location. A tall high gain antenna works well on flat/level ground. A short 1/4 wave would likely work better in very hilly or mountainous terrain. https://www.americanradiosupply.com/laird-1-4-wave-nmo-mobile-radio-antenna-stainless-black/ https://dpdproductions.com/products/custom-1-4-wave-mobile-antenna As far as mounting the antenna that depends if you want to drill holes in the body etc. There are a lot of options/ideas in this area to choose from.

This is an off beat subject. I've researched this on different occasions and can't find and real data. Apparently there are several different modes in use in the EU, European Union, for their FRS like service, PMR446. There is narrow band FM, Tier 1 DMR and dPMR which is very similar to NXDN. What I was trying to find out which one seems to be the more popular digital mode in use. These modes also appear to be used for commercial radio service as well at higher power. I'm not aware of any dPMR mode radios being used in the US for commercial applications. PMR446 White Paper.pdf

The problem is so many people come here trying to drum up support for their favorite channel/frequency. All that does is confuse the crap out of people new to GMRS.There are endless threads on this topic. Just some samples below. https://forums.mygmrs.com/topic/3516-officialunofficial-gmrs-roadtravel-channel/ https://www.notarubicon.com/gmrs-road-travel-channel/ https://www.fordtremor.com/threads/gmrs-travel-channel.13437/ There is just one major complication with some of the proposals. The below appears on your license. The listed frequency pairs are for channels 19 and 21. For some people, like me living in the Detroit Mi area, Line A reaches well past some major metro areas making any proposal to use channel 19 useless. FRS-GMRS combined channel chart.pdf

You can "stack" them for more power gain too. Using two will give you another 3db.

Good point. Also radios have what are commonly called "Birdies" which are internally generated signals that appear to real. All radios have them. The designers usually do a good job of making sure they don't show up in the intended operational frequency range of the radio. Also when running a radio outside of it's designed frequency range you can get cross modulation interference. This is caused by two or more frequency sources mixing together in the radio's front end electronics where the results may be in the pass band. This also shows up as a phantom signal. I have my old Kenwood TH-G71A dual band shows an almost full scale signal on channel 7. Turning the radio horizontal and rotating around I can null out the signal. Also taking the antenna off does the same thing so the source is external. However using a different model radio to monitor the same exact frequency shows nothing there. I did what you have, just locked that channel out of the scan on the G71A.

I doubt you'll have much luck with that. The following is my understanding. Typically the trunking systems requires the radios to register, or affiliate, with the system. The trunking systems are designed so any radio that accesses the system has to be preregistered on the system. The radio requires special programming using a system key file that is tied to the specific trunking system and has to be obtained from the system owner, which you most likely will never get. In fact the TK-5220/5320 Kenwood radios I have won't allow you to even edit the trunking system network info in the programming software without first loading the system key file. All you see it the default values which you can't change. The radio when it receives a transmission it's coded such that the radio knows it's from a trunked system. Without the programming with the system key file the radio will not decode the audio. That's how they maintain security. I have a buddy that purchased a used Motorola XTS-5000 on 800MHz. There was a hack he found so the radio could be spoofed in to doing what is called "non-affiliated" scanning. I haven't heard of others using different radios successfully. Even if you did find a way to scan a P25 trunked system your efforts might still be wasted since more agencies are going encrypted. Then there is P25 Phase 2 which is specific for trunking systems. Unless you pay BIG bucks for a newer P25 radio with Phase 2 you're dead in the water if that's what they are using. All my radios are Phase 1 since I use them for Ham and monitoring commercial conventional repeater systems. As far as I know Phase 2 is not used on the Ham bands. The NXDN trunked systems work about the same. I did read someplace where it was claimed some of the Icom radios will do "non-affiliated" scanning. I know the Kenwood radios won't. One other thing about the Kenwood NX-210 radios. I think there is railroad specific firmware for them too, so if you're looking to buy you might want to inquire with the seller if that the case. Since the NX-200's are basically the same radio I haven't been all the interested in getting one so I never worried about it or researched it.

The railroads use VHF while GMRS is on UHF. My understanding is various railroads were intending to switch over to digital voice using NXDN. Analog FM is still frequently used I believe. There are no Ham specific radios that will do NXDN. Your only choice is one of the commercial radios. The two main manufacturers of NXDN radios is Kenwood and Icom. The one radio model I see mentioned frequently for railroad scanning is the Kenwood NX-210. The basically identical radio is the NX-200. These radios you can purchase used on some of the major auction sites. https://pdfs.kenwoodproducts.com/2/NX-200&300Brochure.pdf The UHF version, the 450-520 band split, works fine for GMRS and has the advantage it’s Part 95 certified so there is zero issue if it’s legal to use. I have a code plug built for the NX-200 for all of the VHF railroad frequencies, analog and digital, along with MURS, some Ham simplex frequencies and the NOAA weather channels. If you go that route I can send you a copy.

Not bad. That Ghost antenna transmits signals you can't hear without the help of a clairvoyant receiver. I can see military applications for the technology. It's right up there with fractal antennas. https://en.wikipedia.org/wiki/Fractal_antenna https://www.antenna-theory.com/antennas/fractal.php

Thanks for the info.

The real question is do you really need access to all those bands all the time? If the people in your group are spread out over those you have a bigger problem. You would be better off picking one band and sticking to it.

Looks like Field Day came early this year. ?

I looked at a photo of the mount. No obvious way to disassemble it. Your recommendation I think is the best way to go, cut off the connector then pass the cable through the firewall and install a new connector.

Some of our group have digital radios for Ham. One member is GMRS only so it would be analog only for them.

Thanks. I’ll look into that.

And at 0.5 watts, which was the power limit at the time on FRS, not terribly useful.

I'm going to the Hamvention in Xenia Ohio next month. I was looking to see if there are any usable open GMRS repeaters in the area. The closet one seems to be in Tipp City. One of our potential members going to the event only has his GMRS license. The rest of use have our Ham licenses. https://mygmrs.com/repeater/4895 The Hamvention site at the fairgrounds looks like it's right at the edge of the coverage zone. I was wondering if there are any unlisted ones that could be used with good coverage in the area. If anyone is interested in meeting up there send me a PM and I'll let you know what frequency and tone we will likely be using on 70cm analog for group communications. We might even use digital, DMR or NXDN. Two of us have radios for those modes.

They do. However the ones I’ve seen are designed more for boosting the power output from a hand held radio in the 2 to 5 watt range. I have one myself since I have a rather large collection of handheld radios so it works for me. As mentioned by others if you are using a real mobile radio your best bet is just get one with a 45 to 50 watt output and skip thinking about amps.

I don't know if that NXDN repeater is used much on digital. It's about 25 miles from my house and from what I've seen on the Internet it's not linked either. There are a few P25 repeaters around Michigan. The closest to me is the K8FBI machine on 70cm, which is about 6 to 7 miles away. I monitor it and most of the traffic is analog. US and Canada NXDN Repeaters - 20230113.pdf US and Canada DMR Repeaters - 20230119.pdf US and Canada D-Star Repeaters - 20230120.pdf US and Canada P25 Repeaters - 20230117.pdf

Yeah, I've noticed that frequently many of the commercial digital mode Ham repeaters are using the Mi5 network in Michigan. https://w8cmn.net/dmr/ https://w8cmn.net/p25/ There is nothing for NXDN on their network. In fact there are only two repeaters for the whole state listed in RepeaterBook.com that does NXDN. There is a nice linked NXDN network in west central Florida however. https://ni4ce.org/nxdn-digital-communications/

Which band seems to have the most activity for digital voice modes? Just looking through the listings in RepeaterBook.com most of it appears to be on the 70cm band. There are some repeaters on VHF 2M and a few on UHF 33cm. I don't see any listed for VHF 1.25M. There are some radios out there that will work digital voice on 1.25M but it just doesn't seem to get any interest. IMHO if anyone is looking at getting a radio for digital voice on the Ham bands your money would be better spent on a UHF 70cm radio.