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Hello all, I am brand new to GMRS and got one to install in my off roader (along with a license to operate it). I am in the middle of Atlanta GA and have a question about the NGGMRS group that has been referenced in this thread. How do they keep folks from using their repeaters? I ask because it looks like they have a list of all the repeaters, channels on which they TX/RX and the list includes RX and TX tones. Isn't that all you would need? Sorry for the off topic newb question, just trying to understand how this is going to limit my GMRS use.

Thanks for explaining AM to a forum full of radio people. Data showing the actual bandwidth of a CB radio in FM vs. AM, please.

Update: I went to open area yesterday and took Steve's advice. All antennas have a 3+ SWR using the trucked mounted NMO. I connected the magnet base with the unity gain antenna that came with the radio and the SWR was 1.1 and the Ghost had 1.124 SWR. The only thing it could be now is the through hole NMO/cable. I'm going to put a new PL-259 on and if that doesn't work then I'll have to drop the headliner again and install a new mount/cable.

in FM the modulation stays the same it uses all the bandwidth, In AM the amplitude of the carrier wave changes with the instantaneous amplitude of the modulationg signal. AM essentiality uses less bandwidth with more emphasis on the modulating carrier

This was a couple years before there was an NTIA, so unsure. But what's done is done!

That was probably Jack. He has that effect on people. LoL I was with him in the beginning of the project. It was his idea. Mike is the one with the experience. So Mike is driving the proposal. Jack is a nice kid and has good intentions, but he is very abrasive (can't accept being wrong) so it makes it hard to get along with him. Sadly, while I like him, he is the #1 reason I dropped out of the project. Agreed. There is no one solution. Personally, I like the idea because it has potential to do some good for Joe Q. Homeowner who doesn't need an experimental or business class radio license. However, Amateur Radio 80m through 70cm, combined with Satellite and Cellular is the closest thing we can get to having a complete tool kit. I'm pretty sure that is not correct. Everything I can find says that Amateur Radio is the primary assigned service, and the military and other federal agencies are authorized to utilize the 50-54 MHz band in the United States as a secondary or non-interference basis to amateur operations. If there is something different, I would love to see if you can share it with us... I can't find anything. https://www.ntia.gov/files/ntia/Spectrum_Use_Summary_Master-06212010.pdf#:~:text=The military agencies operate radio communication systems,in this band on a non-interference basis. https://www.ntia.gov/sites/default/files/2023-11/4_2021_edition_rev_2023.pdf

Well, no, narrowband FM is typically only 6.25 kHz and the few AM transmitters I’ve used do 6 kHz (up to 4 kHz per sideband on SSB on my ham radio). I would believe data sheets on modern am/fm CB radios if you want to do some research.

You are correct, the signal doesn't travel any farther. It is the inverse, an FM receiver will reject a stronger signal until it is strong enough to "lock on".

When I was at Ft Devens learning the whys and wherefores of ECM/ECCM, we had a window of time to Jam the FM Audio on a local TV station. Using a Dummy Load running 1500w, we would still jam TV sets within a 1 mile radius of the Transmitter (AN/TLQ-17). Lotsa of fun changing the dialog on the Soaps. That and SERE Training were the most fun I had before my PCS.

Authorized, yes. But FM requires all of that bandwidth and AM doesn't.

We got in trouble with the local TV station in Rolla, MO when I was stationed at Ft Leonardwood. We would have the basic trainees tune the PRC77 radios to the TV station and one trainee keyed up the mic. It didn't take long for the TV station to call the post commander's office to complain. We would occasionally upset some sad ham within the 6m band. But as you stated, once we told them whoever we were and that we were the primary users, complaints stopped. The PRC25 and PRC77, along with vehicle mounted radios have a low band (30 - 50 MHz) and a high band (51 - 70 MHZ). The SINCGARS frequency hopping radios use 30 - 88 MHz. The state of Missouri still uses 42, 44, and 46 MHZ for public safety and emergency management. Granted these frequencies are more as a backup system now days. And other states still use the VHF low band also. So that will need to be taken into consideration with the propels to add VHF Low to GMRS or even to amateur radio.

AM is easier to decode when it's all scrambled up from the atmosphere. You can hear the voice even with lots of static. In FM if the signal is garbled the decoding doesn't work well at all.

On CB, FM and AM are authorized to use exactly the same bandwidth: 95.973 CBRS authorized bandwidth. Each CBRS transmitter type must be designed such that the occupied bandwidth does not exceed the authorized bandwidth for the emission type under test. (a) AM and FM. The authorized bandwidth for emission types A3E and F3E is 8 kHz. (b) SSB. The authorized bandwidth for emission types J3E, R3E, and H3E is 4 kHz.

i think AM is going to be the winner in shooting skip over FM just because AM uses much less bandwidth which lessens the effects of the atmosphere and other conditions.. FM will be more clear in audio in shorter range but also be more acceptable to degradation over range because of its bandwidth characteristics... AM transmission is defianlty better for longer distance transmission

For $25 you won't get the performance you expect. There are other things you should look at such as RX sensitivity, de-sense, channel isolation, spectrum free from harmonics, spur response, frequency accuracy and stability etc. Most people don't have the equipment to do these kinds of tests. If you know somebody with a good quality commercial radio grade service monitor I would stick the radio on it and run some tests. Some decent used ones run around $1K plus used. I believe one of the members of this forum got a used one in this price range a while back specifically for testing his radios and repeaters. A few that can do auto tune up, radio calibration, and digital mode testing can run over $10K to $20K plus used. For example the cheap, $25, Baofeng UV-5R early version had dirty transmitters. They were multi-band radios. You could talk on several all at the same time! I'm not knocking your desire to do a video on the radio. But remember you give people the idea the radio is the best thing since sliced bread, people buy them because they're cheap, and now the local bands have issues with crappy signals on the air. UV-5R VHF Harmonics Test.pdf

I don't see why not. I talk on 10m FM simplex all over the states when the band is open, especially to the West Coast from MN, and have had a few contacts into Europe as well.

Don't recall the Group name, but recently I did see some photos and a posting on a FB CB page with some very much massive set ups, with congrats to the "Key Down" winners, etc.

So, FM CB should be able to "shoot skip" about as effectively as AM? That's a new thought to me.

So, FM CB should be able to "shoot skip" about as effectively as AM? That's a new thought to me.

I wrote the FCC in favor of this petition and also suggested in my letter if the FCC favored this proposal they should also use this opportunity to clean up the exisitng GMRS rules and clarify existting rules. I.e. Limit GMRS repeater ownership to 3 or less, do not permit cross state GMRS Repeater ownership, clarify rules related to 'charging for use of a repeater". Rewrite current rules on Linking so that it is clear the practice is simply illegal and take the confusion of other networks out of the rules. .. This wold be a great opportunity for the FCC to clean up all the gray areas with the rules.. One of my buddies in Riverside (FCC) office says this proposal actulliy has some traction.. The more we write in favor of this the better chance it has.

https://ised-isde.canada.ca/site/spectrum-management-telecommunications/en/official-publications/policies/spectrum-utilization-policies-sp/sp-462467-mhz-spectrum-utilization-policy-permit-licence-exempt-devices-land-mobile-frequency-sub

Back in my ASA/INSCOM days we used to mess with the poor hams on 6m when we were practicing ECM. Most were pretty cool once we explained that A, we weren't governed by any FCC regulations and B, we were the primary users of the band. Some got a bit "Sad Hammy" on us, but 1500 watts does wonders on VHF.

It looks like GMRS is limited to 0.5 watts on some channels and 2 watts on others and they aren't allowed to use repeaters. GMRS shares some channels with FRS and it's limited to 0.5 watts on those channels. FRS has 6 channels shared with GMRS and 9 that are FRS only and FRS is limited to 0.5 watts. It makes me wonder why they have two separate services. It seems they could just lump them all together with designated power limits on each channel.

its got a way better chance of happening then Linking on GMRS.. You might be wrong on this one.. I woild give it a better chance though. maybe in 2 years.. Lets Bookmark that comment... Looser buys the other a ice cold tall beer

I agree..