Lscott

I typically do that with my radios as well, no RX tone. It also eliminates the stupid hassle with RX tones, or split tones, when using a repeater.

It could be just as the OP mentioned. I have an old Kenwood Ham HT, TK-G71A, with the GMRS frequencies in it for monitoring. On one channel I get almost full scale signal. It will change as I move the radio around so it seems directional. When I use several other radios to monitor the same channel I get zero, nothing there. The logical conclusion is there exists a strong signal mixing with an internal signal that shows up on the channel in question.

Sounds like someone is running a “parrot” repeater.

Yes the antenna has to match, of course. One gentleman did a number of field strength tests on HT antennas since trying to get good SWR sweeps was really difficult. That was a far better indicator of which HT antenna(s) performed the best.

All the sweep will tell you is how well the match is. The model I ran also showed a reasonably good match but the radiation pattern was poor. What is really useful is making some "far field" signal strength tests. Remember a dummy load can show a nearly perfect match, but that doesn't imply it's a good antenna to use on a radio to communicate with other people.

Hum... Just for grins I looked at a photo of the UT72 antenna. I'm rather suspicious of it's claim to be a "dual band" or tuned for GMRS. You would normally expect to see a loading coil part way up the vertical element, which I don't see, for a simple antenna like this. What I think is going on it's really a 5/8 wave VHF antenna, I read it has a base loading coil which a 5/8 wave will have, but tweaked to run on the third harmonic to get it resonate on UHF. I ran a simple EZNEC model, didn't extensively test it, but it does work with the major caveat the radiation pattern's main lobe is at a very high angle. That results in greatly reduced power in a nearly horizontal direction. This tends to suggest any gains in power from the amplifier are offset by most of it being shot up in the air due to the antenna's poor radiation pattern when use at the third harmonic of the VHF frequency. I could be way wrong on this but it's something to think about.

Walmart uses a Motorola RDM2070D radio on the MURS frequencies. I believe it's specifically manufactured just for Walmart's use. https://www.twowayradiocenter.com/motorola-rdm2070d-walmart-two-way-radio/ The very similar RDM2050 I think anyone can buy. I use a Kenwood TK-270G radio. It's not certified for MURS because it got the license grant before MURS existed. I think the radio would be legal to use as long as it's programed to meet the power, bandwidth and frequencies used. https://forums.mygmrs.com/topic/1239-old-part-90-radios-predating-murs-service-legal-use/

I'm using a slightly older Linux distro, OpenSuse 15, and Firefox in a VM. It can't open those WEBLOC files to get at the URL.

They are nice radios. What is a negative for me is the funky antenna connector. I often use an external antenna with my HT's so having something I can screw an adapter into is important. I take my HT's on trips sometimes etc. so in hotel rooms I like to use a portable antenna stuck by the window and run a cable between it and the radio. Same with rental cars. Stick a cheap short magnet mount on the roof and run the cable inside to the radio.

I wished people wouldn't use WEBLOC files as links. Just copy and paste the URL.

The main problem is finding a repeater controller that will work with the equipment at hand. People will build a cheap repeater using a couple of HT's or a couple of mobile radios. A lucky few can afford a real purposely designed repeater with the required interface for a controller available. Most often there are no provisions for access to a COR, carrier operated relay, etc. so the builder ends up hacking the radios to gain access to necessary signals. When the builder's family are the only users then simply cross coupling the mic and audio outputs, with VOX enabled, is sufficient for basic functioning, because at least no ID is required. I picked up a simple interface box to do the cross coupling between two HT's, with VOX contol, to experiment with a cross-band repeater for Ham use. A simple duplexer like the below is sufficient to get the isolation at a 5 watt level. https://mfjenterprises.com/products/mfj-916bn#description https://www.buytwowayradios.com/surecom-sr-628.html

Disclaimer, I haven't purchased anything from this company but they have been around for a long time and seem to have reasonable prices. They have a verity of cheap notch type duplexers. Might be worth buying one to experiment with. Then later go with some notch/band-pass types for more isolation. https://www.409shop.com/409shop_shopcat.php?&usercat=4942 http://www.repeater-builder.com/antenna/pdf/chinese-mobile-duplexer-measurements.pdf SGQ-450D-N.pdf

The attached files give some info on isolation requirements and using cavity filters to get it. Calculating Required Isolation.pdf Duplexers and Repeaters.pdf Understanding Maintaining and Re-Tuning Antenna Duplexers.pdf

Forgot to mention that more TX power is going to require more isolation on the RX input side. A few people have experienced RX desense with the power being too high. They did what would at first appear to be counter intuitive, they decreased the TX power.

There are a lot of security issues with the old IPV4 protocols. The new IPV6 tried to fixed them. The packet redirect was part of the DNS poisoning issue. It had more to do with the firmware running on the DNS servers that didn't dump their cash often enough as outlined by the protocol. The reason given it cut down the time spent updating the lookup tables. The attack would target a DNS server by sending it spoofed updates from a higher level authoritative DNS server trying to get the requesting lower level DNS server to read it's spoofed update first. The spoofed update would send the IP address of the spoofed web site etc. in-place of the real correct address when an inquiry was made to the poisoned DNS server. Because the now "poisoned" DNS server isn't dumping it's cash frequently the poisoned DNS server could be returning the spoofed address for an extended length of time. The above is just a basic outline how the scheme worked.

As a matter of practice I don't program in RX tones unless there is something else on frequency that is interfering with the repeater's output.

If they are so worried about "back-doors" then anything electronic coming from the Chinese mainland would be suspect. A few short years ago there were warnings about USB photo frames that came with a virus. https://www.sfgate.com/business/article/Virus-from-China-the-gift-that-keeps-on-giving-3227869.php

Simple, buy new cable. Then do a better job of water proofing the ends. https://youtu.be/s92i2WALXcQ

The attached file outlines one way to do it. MOTOTRBO too 927MHz Code Plug Mod.pdf

Not that I’m aware of at least for Amateur Radio. There are a few FM repeaters around on the band. One of the very few Motorola radios I have besides the XPR-6550’s is an XPR-6580. It’s the only radio I have for 33cm so far. And added bonus is it will do DMR too. The code plug was hacked, using in memory radio CPS changes, to get the radio on the 33cm band. The radio didn’t require any hardware modifications like the Kenwood radios I researched at the beginning. XPR-6550_6580 Brochure.pdf

Good luck on the test. I’ll bet you’ll find it easy. If you can find the 400-470 band split radios they are definitely worth getting. I seemed to have better luck finding this band split with the digital Kenwood’s. Those would be for the big three, DMR-P25-NXDN. I think that band split were the first ones available so that’s what got sold mostly. https://forums.mygmrs.com/gallery/image/255-tk-d300e-fmdmr/ https://forums.mygmrs.com/gallery/image/254-tk-5320-1jpg/ https://forums.mygmrs.com/gallery/image/251-nx-300jpg/ The VHF radios are even more attractive. They usually cover 136-174. That will work for the Ham 2M band, MURS, VHF marine, VHF railroad FM and the NOAA weather stations. That’s all in the above range. The asking price is significantly more than the UHF radios. If you’re interested in Ham digital voice modes then look primarily for the UHF radios. Most of the digital voice operations for Ham are on the 70cm band. The DMR and NXDN radios aren’t too highly priced. Now the P25 radios are just plain stupidly high priced. Myself I’m still looking for a second TK-5220 VHF P25 radio. I have one now in my collection, I want a second radio if I can find one that isn’t price like it was Gold.

Take a look at the example code plug. Shows how to setup the memory channels for zones. I have two zones setup for GMRS/FRS. One is set for wide-band, normal GMRS. The other is set for narrow band to talk normally to those with FRS type radios. It also has some Ham stuff in it too. Since the radio is not front panel programmable, and you don't have a real VFO mode. I sort of cheated by using one zone for Ham simplex and used the frequency as the channel name. That way when you flip through the memory channels it looks like you have a VFO with a 25KHz step. You don't need to enter in every 25KHz frequency step in the band because there are only several sections recommended for simplex only so that keeps the required number of channels down while providing good coverage. The 450MHz-520MHz band split you can "push" down out of band to around 440MHz, maybe lower, and it will work. Two out of the three Ham simplex sub-bands are between 440MHz and 450MHz along with the repeater section. Now you have one radio that will work for most of the Ham 70cm band, GMRS and is Part 95 certified. Not a bad deal. You'll also see I have some Part 90 frequencies in several zones for monitoring use. I like to go for walks at some of the local malls when not at the gym so I monitor the local shops and mall security frequencies etc. It's legal so long as you don't TX on them. The TX function is inhibited by leaving the TX frequency entry empty for those. If you get the 400MHz-470MHz band split, harder to find and are not Part 95 certified either, are usable over both the complete Ham and GMRS bands if you aren't worried about the certification issue. US Amature Band Plan 2020.pdf TK-3180 - Example Ham GMRS.dat

That is sort of funny since they are not vanity plates. You have to provide your FCC license to get one, and at least here in Michigan, the cost is the same as a regular plate.

That's stretching it a bit! I tried once from the old Place location, by the land fill, and it was a bit noisy. When I got to Lake Orion, nothing. That's with a big high gain mobile antenna.

I'm not interested as well. I already have a Ham call sign license plate as it is.