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So even with the engine off you get the whine? I would start by pulling fuses to see when the whine stops. Check your owners manual first to make sure you won’t set some off kind of anti-theft measure. Once you know which circuit produces the whine, then maybe you can figure out how to mitigate the problem. The interference is getting into the radio through either power, ground, or the antenna. The question will be can you stop (maybe reduce is a better word) it at the source or where it enters the radio?

I picked up a Bird 43 wattmeter and some slugs.

Yep, they'll never take me alive! ?

Just heard on the Warrenton, Virginia repeater someone making contact from Claymont Delaware. Perfect 5/5 contact at roughly 150 miles.

No one said it was amateur use.....

Well, a minimum 2 mile range is difficult to guarantee in the mountains. There will be times you can get 20 miles from five watts and times you can only get one mile from 50 watts. Power isn't necessarily the predictor. Terrain has much more to do with it. Almost any mobile GMRS radio will have similar range. If your line of sight range is limited to 1 mile because you're going through a bunch of switchbacks, it won't really matter whether you're using 5 watts or 50. Look at a bunch to see what features you like, rather than using range.

And clowns. They’re terrifying.

They definitely did not have the authority to do that. In the same way only the FAA regulates airspace over the US, the rules of the airwaves are regulated exclusively by the FCC under authority granted by Congress. The rules say that no one owns any frequency, and all operators work on the premise of first come, first serve. There is nothing that says you can't have a conversation in-between conversations, and it's actually pretty common, as long as no one is causing harmful interference and everyone must yield to emergency traffic. I love having that conversation with the idiots that tell me to "get off their frequency". LOL

Gonna get into the weeds here with an explanation. First is antenna separation and attenuation. And an understanding that a duplexer will provide about 90dB of attenuation. Two UHF antenna's that are mounted VERTICALLY apart on the same tower leg, will provide about 20 dB of attenuation. Two UHF antenna's separated by 80 feet horizontally will provide the same 20 dB of attenuation. So if you had a 150 foot tower, and put the receive antenna at the top and the transmit antenna at about 10 feet you MIGHT get 60 dB of attenuation. Still not as good as a duplexer. Now, lets look at the dollars and cents of this. First off you will need some sort of hardline for an install like this. And it's gonna be two runs. Lets say the tower is 30 feet from the building and it's another 20 feet to the radio. So you will need an extra 50 feet of hard line at 4 bucks a foot. Four additional connectors at 25 bucks a piece, two for the ends and two for the additional 90 dollar surge suppressor for the feed line. Then you need two antenna's. A USED DB-408 is about 150. So lets do some math. 50 feet of cable and four 25 dollar connectors comes up to 300 bucks. Now the additional 150 for the antenna, that's 450 bucks plus the surge suppressor and the labor, so 600 bucks for that additional LOW MOUNTED antenna that is gonna talk like crap because it's 10 feet off the ground. To save you HOW MUCH for a duplexer? Hell a new pass notch set is 1300 and used they are around 500 or less. So it's actually CHEAPER to run the duplexer and do it right and have it perform in a manner that would be acceptable. Yeah, gonna go the route of the duplexer every time. Oh, and you say you are gonna cheap out and run RG-8 or 9913 and not hardline. Sure... you are gonna run the RX cable down past the TX antenna in the near field of said antenna and expect the shielding from a BRAIDED CABLE to block 100% of the signal in the near field of a transmit antenna. Sure... have fun with that too.

The short answer is, yes... you can use two antennas instead of a duplexer. The long answer, you can, but you need a separate transmitter and receiver that are directly coupled (linked) with some type of cable to manage keying, audio transfer, etc. (See KG-1000G, for a less than perfect example). Transmitter power levels, antenna types, cable types, etc., will dictate how far apart the antennas need to be, what the elevation differences need to be, and what the gain/sensitivity of the transmit and receive sides should be. If the antennas are not spaced properly, the transmitter can make it so the receiver doesn't hear well, it could cause a transmit loop, and could also damage the receiver. If you make the antennas to far apart, now you're dealing with transmission line losses causing issues instead. There is some art to it, as well as the science. If you are at a stage in learning where you have to ask this question, chances are you don't want to try setting up a repeater right now. This is not ment as an insult, either. If you don't know what you're doing, you can waste a lot of time and money before you learn enough to get a good system stood up. I would recommend finding someone local to you who has a good working repeater and is willing to spend some time teaching you about the details and why things are the way they are.

You either need a duplexer or two antennas with lots of distance between them. The signal transmitted by a repeater must be isolated from the receiver in order for the receiver to simultaneously receive.

Thank you @Sshannon I wonder when this was changed? That language is present in the 2017 ruling, I still see some info online that says GMRS commercial use is verboten. Anyway thanks for clearing this up I am so happy for everyones help and I hope I can make a good contribution to this forum.

It goes deeper than that. They're not even watching.

There is a level of overthinking here I didn't think was actually possible. 1. First off, these are rules, not laws. Secondly (and legally - wife is a lawyer) hidden meaning can only be determined on a case by case basis. I could say "Be sure to deliver the package where it will be seen" and literally mean leave the damn box where the idiot recipient will see it this time. Or I could mean leave the explosives where they would have the most effect. Until something has happened and the audio (just example) is played in court, it's just words spoken OTA. Those rules and regs are specifically there and constructed the way they are so that Uncle Sam can haul your ass off to Gitmo if you decided to use GMRS for terrorist purposes. Again though, until said terrorists do something or are placed under investigation, it's just words OTA. 2. The FCC does not have a 10 codes list because they are regional in nature and are not even uniform across counties, let alone the USA as a whole. They mean if you're using your 10-codes list, then that's OK, it's allowed. 3. At any time, you are not assumed to be hiding anything unless there's proof beyond a reasonable doubt you are. See #1. You can use any 10 codes list you want, including your own, without publishing it anywhere. No one will assume you're hiding something. They will assume you're some type of weirdo nerd radio person though, so be prepared for that. In conclusion, this is just a whole other kind of over analysis. @OffRoaderX made an excellent point in one of his videos: The number of GMRS rule enforcement actions by the FCC is 0. "They don't care." This is something folks who have used 11m band know all too well. 4W main/12W SSB PEP is the legal limit for power there. I can point you to countless FB groups, forums, YT channels, etc. of folks who not only know this, but flaunt it. We're talking 10,000W+ amplifiers, both tube and pill. Giant 7+ element, high gain beam antennas making their ERP 30,000+ watts. Let's make up a number of 100 for example purposes here. Every year, of those 100 wattmongers, maybe 5 will get busted and even then most times it's a fine issued ($5k+ so it does sting). No equipment confiscation, just a fine and a "don't do that again, please". Most times these folks make amps for sale and a "nice" one (one that has a decent LPF) that's say, 2000W will run about $2500-$3000. You can now just imagine how much they care about a $5k fine. "They don't care."

You've come across archaic sections of the FCC rules. Imagine someone telling you that you can't say, "Meet you at the rendezvous, over." vs explicitly saying where and what you are doing. You have a brain. Its okay to use your brain. Its okay to think and reason. You are better, and always will be than ChatGPT and its endless database entries of biased entries.

Short answer most likely yes, with a duplexer. For more info on repeater building go to the link below. https://www.repeater-builder.com/rbtip/index.html