JeepCrawler98

What's the make, model and type of duplexer? Duplexers always lose some power, I've measured losses like that first hand on the Jesai, Fumei and other Chinese flatpacks around the 6-7dB range which is exactly the power drop you're measuring. They're really only acceptable down to about a 7mhz split or bigger, not the 5mhz split we're used to.
If it's something with a reputable brand name, it's not normal. a Celwave/Phelps Dodge or Telewave duplexer will have insertion losses around 1.5dB or so, if you take your time tuning those you can get that down to 0.8dB or so; if you get something like that the 42W you measured would be up around 35W after passing through...

What's the make, model and type of duplexer? Duplexers always lose some power, I've measured losses like that first hand on the Jesai, Fumei and other Chinese flatpacks around the 6-7dB range which is exactly the power drop you're measuring. They're really only acceptable down to about a 7mhz split or bigger, not the 5mhz split we're used to.
If it's something with a reputable brand name, it's not normal. a Celwave/Phelps Dodge or Telewave duplexer will have insertion losses around 1.5dB or so, if you take your time tuning those you can get that down to 0.8dB or so; if you get something like that the 42W you measured would be up around 35W after passing through...

Using another repeater falls under the cooperative use clause and restrictions by the owner fall under 'individual licensee duties' of 47 CFR §95.1705:
 
Repeaters are still classified as 'stations.' This section is why many repeater owners require permission, as they're technically required to keep a list of control stations.
Key takeaways:
"Shall determine specifically which individuals, including family members, are allowed to operate (i.e., exercise operational control over) its GMRS station(s)"
(2) May allow any person to use (i.e., benefit from the operation of) its GMRS repeater, or alternatively, may limit the use of its GMRS repeater to specific persons;
(3) May disallow the use of its GMRS repeater by specific persons as may be necessary to carry out its responsibilities under this section.
"Specifically" in that first paragraph implies that a repeater's licensee must specify who you allow to act as a control station (which is any station using a repeater) over your GMRS station (in this case a repeater). This pretty much means that you have a duty as a repeater owner to keep a list of users to be compliant with this rule.
This is aside from helping to tune out the noise caused by people who take others' hard work for granted and cause trouble.
I don't think anyone stumbling onto a GMRS repeater is breaking the rules as a control station since it's hard to post a repeater as locked down in a matter fitting public notice; but the repeater owner does have a legal burden to keep track of you as a permitted user which users need to be aware of and thus should notify repeater owners of their intent. Of course, per the above, they can tell you to get off their equipment too and it's entirely within their rights to do so.
In practice; is this ever enforced and does the FCC care? I doubt it - but it is in the rules.

Good find; the user manual has some interesting tidbits in it - namely mention of a mini XLR connector on the radio for remote headsets.
Looks like they have it channel locked to the standard 22 + 8 arrangement; I wish the consumer oriented manufacturers would get out of the habit of doing that as there's no limitation on the number of memory channels a GMRS radio can have access to, just the frequencies. If they want to keep it newbie proof keep the first 30 channels locked as is and allow the memory channels above 30 to be whatever. An alphanumeric display with an option for more than 30 total memory channels (like 128 or so, like many commercial Part 95 radios and the increasingly popular Wouxun KG805, KG905, and KG1000) would be really nice to have for those who use repeaters a lot. I get that the FCC recommends the 22+8 arrangement for approval in their technical bulletins, but it's not actually a requirement for approval, so if you happen to be a manufacturer reading this (looking at you Midland, Retevis, B-Tech): STOP IT! There's no actual need.
Also sad to report the USB connector on the body is supposedly for charging only; hopefully they have a way to get a programming cable hooked up like the MXT400. As seems to be standard for Midland they have a really attractive physical packaging and decent performing radio, but are being too conservative with the programmable bells and whistles for the price point; these would be so easy to incorporate it's a shame not to IMO.

Using another repeater falls under the cooperative use clause and restrictions by the owner fall under 'individual licensee duties' of 47 CFR §95.1705:
 
Repeaters are still classified as 'stations.' This section is why many repeater owners require permission, as they're technically required to keep a list of control stations.
Key takeaways:
"Shall determine specifically which individuals, including family members, are allowed to operate (i.e., exercise operational control over) its GMRS station(s)"
(2) May allow any person to use (i.e., benefit from the operation of) its GMRS repeater, or alternatively, may limit the use of its GMRS repeater to specific persons;
(3) May disallow the use of its GMRS repeater by specific persons as may be necessary to carry out its responsibilities under this section.
"Specifically" in that first paragraph implies that a repeater's licensee must specify who you allow to act as a control station (which is any station using a repeater) over your GMRS station (in this case a repeater). This pretty much means that you have a duty as a repeater owner to keep a list of users to be compliant with this rule.
This is aside from helping to tune out the noise caused by people who take others' hard work for granted and cause trouble.
I don't think anyone stumbling onto a GMRS repeater is breaking the rules as a control station since it's hard to post a repeater as locked down in a matter fitting public notice; but the repeater owner does have a legal burden to keep track of you as a permitted user which users need to be aware of and thus should notify repeater owners of their intent. Of course, per the above, they can tell you to get off their equipment too and it's entirely within their rights to do so.
In practice; is this ever enforced and does the FCC care? I doubt it - but it is in the rules.

That did it; thanks Rich!

Fair enough for simplex; but you have to remember that if you're using a repeater you don't own yourself you're actually actively using someone else's radio in addition to your own. This is why repeater owners may have their own rules and practices they want followed when using their hardware; sometimes these rules include not having roger beeps.
Since on repeaters you have people monitoring for traffic from others and are often dependent on them for communications, aside from the fact that they tend to be watering holes for radio traffic - you are forcing other operators to listen to you. Simplex, not so much a problem because you can tune out and not miss anything as you mentioned.

Fair enough for simplex; but you have to remember that if you're using a repeater you don't own yourself you're actually actively using someone else's radio in addition to your own. This is why repeater owners may have their own rules and practices they want followed when using their hardware; sometimes these rules include not having roger beeps.
Since on repeaters you have people monitoring for traffic from others and are often dependent on them for communications, aside from the fact that they tend to be watering holes for radio traffic - you are forcing other operators to listen to you. Simplex, not so much a problem because you can tune out and not miss anything as you mentioned.

I've looked into this in the past; I still believe it's technically legal on GMRS if you want to argue it. I took this up with the FCC and below is what I received back from them. I think there's grounds to argue against their response, but it settled the issue for me (for now) anyways. Justified or not, and while APRS as a protocol is allowed, their stance is that they don't want it unless limited to a certified low-power handheld radio with fixed antenna, which severely limits its application as it eliminates the ability to develop a solid digipeating/gateway infrastructure (which I had planned to start developing at the time on one of the 462 interstitial 'FRS' channels)
My original request to them:
 
Their response:
 

Unless it's a repeater itself making the beep where it's being used to pace a conversation, there's no need for it; just turn it off - the person listening knows when you have released the PTT just fine without it. The only use case I think that could be valid is if a recording is being kept for record purposes that could be referred to later, but again, that's not really something you're likely to encounter on GMRS, moreso the public safety side.
MDC1200 or FleetSync bursts have a purpose; but its real-life usefulness is pretty limited for GMRS and I see it as more of a novelty. If you consider these as data burst transmissions they're also technically not allowed on the 467 Main Channels (repeaters intputs) per the rules - but that's splitting hairs.
I believe most consumer radios that come with the roger beep turned on just have it so that they "sound like the cool radios with the data bursts" but that's just my guess.

Ok; so ran into another interesting development on this today:

I ordered a Retevis RT29 last week; seemed like a durable radio, although I expect the internals to be less than great. The IP67 rating, 2-year warranty, and 3200mah battery appealed to me - for $50, again, a cheap beater radio to throw around the woods that supposedly lasts almost a week on a single charge per some of the reviews (curious to verify that) and is supposedly submersible (also curious to verify that)

This model is listed on FCC ID 2ASNRT76, which uses the RT76 as the primary radio, declaring the RT1, RT26, and RT29 as identical models.

Retevis didn't answer my email I sent them before I ordered to see what the FCC ID's were on this radio (they stated they forwarded it onto engineering but never heard back).

This showed up in the mail today; this radio is indeed badged compliant with the 2ASNRT76 FCC ID... so a legal Part 95E radio???

First impressions on the RT29: Again I don't expect great things from this radio performance wise and I literally got this in my hands with the sole intent of finding out what the manufacturer would send me, so take it with a pound of salt; the build quality feels excellent from a mechanical standpoint - very solid, not a creak to be heard, and feels similar to my TK380s and TK390s in terms of dead weight and general physical solidness. Feels a lot more sturdy than the KG805G which I'll say comes across as lightweight, although the bonus on that one is more so the memory channels and the receiver. I'm pretty sure you could knock someone out with it and still carry on a QSO. Perhaps a good radio for family use while you keep the high end gear for yourself...

Firmware wise the RT29 is not locked to GMRS, and will do 400-480Mhz and will also do wideband and high power on the 467Mhz interstitial channels (I should note that dual part 90/95A surplus can do this too so that's probably not an actual deal-breaker and its up to the programmer to get it right). The radio I received is only listed for Part 95E, you could use it on the ham radio service but of course that's also not allowed per the FCC rules if you use it on GMRS as well.... so really just a legal GMRS or ham radio (not both), and even then you probably can only use it on medium power (5 watts) since that's what the 95E cert is limited to.

First Impressions on the KG805G: now that i've had it for a few days with real-world use; it's indeed not a very selective receiver and does pick up and suffer from adjacent noise and interference fairly readily, it does do better than my UV82 (consider that a GMRS-V1 analogue) overall which is its competing market, but I will say that in low noise environments the receiver is very sensitive even with the stock antenna. In a clean environment, it seems to have a slightly easier time picking out signals than my Kenwood TK380, 390 and 3180 so its not without merit for a starter radio I'd say, and not a bad deal at all for a new radio with part 95 cert. Audio is generally very clear although lacking lows, but I'm also spoiled by Kenwood on this, transmit audio sounds excellent. The UV82 provided a richer sound due to the larger speaker, but it's also not as clear and easy to understand. Programming the channels beyond channel 30 works as advertised and is a big advantage over other panel-programmable GMRS radios in the current consumer market. I wish the radio felt more solid and had some more 'oomph' to it but honestly it's probably fine for most users.

Havent thrown either of these on the spectrum analyser and power meter to see what they put out; but will get to that in time. If causing interference is indicative of transmitter cleanliness and used as an unscientific benchmark, the KG805G does readily knock my computer monitors offline, causes Lucifer himself to type random incantations on my keyboard, and also puts my computer in sleep mode as does the UV82. The RT29 also does, but less easily and only at 10W high power. The Kenwood commercial radios do not do this at all even though they put out the same amount of power as the 805 and 82.... things that make you go hmmmmmmm....

I had someone here in town look into renewing their expired license but the waiver fee was hundreds of dollars; I'd call it a loss and just apply for a new one.

Yeah it looks like the WXVTWOUXUN08 includes the KG805; I assume with KG-805G you mean WXVWOUXUN16 since they've pulled it out separately as you pointed out, but the KG-805 appears to have 95A (prior to the rule change) as well. Both the 08 and 16 application seems to take the same approach of including multiple models. It's my understanding that manufacturers are allowed to revise their radios so long as it's not a major deviation from the original design; at who's discretion is a major deviation made? I suspect it's probably the manufacturer's best judgement, which doesn't necessarily ensure good judgement.
 
The question always remains is what label comes with it; that's the crux of all these import radios - it can be hard to determine before hand that what you end up with even has any FCC ID imprinted on it somewhere, let alone the one you need; the 16 application lists a lot more models, and they could take the approach that Retevis does on the RT97 repeater where depending on what 'option' you select it comes with a different FCC ID even though the basic radio is model number remains the same. Motorola does this too with some of their radios which often have shared 'marketing' model numbers (I can think of the Radius radios at the moment) the only way to identify what you're getting is to look at the part numbers, but often the FCC ID label is easier. Kenwood on the other hand has a different model number for every radio variant.
 
I'll see if I can dig up the reddit thread on the WVTWOUXUN08 discussion. Edit: https://www.reddit.com/r/gmrs/comments/e9ytiy/new_wouxun_kg805g_professional_gmrs_radio/

Modulation or how you use that power does too - narrow-band FM (11.5khz width) vs wideband FM (16Khz width) has by the equivalent of about 6db penalty on SNR when looking at highest modulating freq (2.75khz vs 3.00khz) & peak deviation (3khz vs 5khz) per Carson's rule.
 
https://urgentcomm.com/2010/04/01/cut-your-losses/
 
edit: I see this topic was already heavily discussed in this thread; carry on!

Can you talk back? I’m sure their users would be perturbed if their monitors started talking back at random times.
 
Fixed stations are allowed to communicate with other fixed stations at up to 15 watts on the repeater input frequencies if you read the Part 95 rules to a tee - can a parked car be considered a fixed station?
 
Park a car on both sides of the building and have a conversation with your fixed station buddy about the prevalence of illegal baby monitors on federally regulated GMRS channels. It’s not intentional interference if you’re trying to work around pre-existing interference.