tweiss3

Based on the specs from bridgecom, its 4dB (60%).

Yes, LMR400 will drop your loss from 60%+ to less than 30%.

Those Siro antennas look decent. Do they make a phasing harness? Their instruction provide spacing for making an array, but the biggest issue with an array is the phasing harness.

RG8U is good only for extremely short runs (like a mobile mag mount) at UHF frequencies. You are seeing 8.6 dB loss per 100' of cable, or greater than 60% power loss in the cable. Not only does that mean at maximum you are only transmitting 18W, but it also means that received signals are weakened significantly as well.

The thread here sparked an internal debate in my head. 47 CFR 95.1767(a)(1) states "The transmitter output power of mobile, repeater and base stations must not exceed 50 Watts." In the other thread, that version of the Bridgecom hardware provides 4dB of insertion loss before you even connect the antenna feed line, loosing 60% of your power right off the bat. In otherwords, before you eve get to feed line loss if you have 50W out of the repeater, you are down to 19W. Again, this further points to the importance of proper feed line choice and a great antenna (why skimp if you are already dropping $4k+ on a combiner). Even with hardline, you could only see 6.8W/10.7W/12.7W to the antenna with 1/2"/7/8"/1.25" on a halfway decent tower site (300'). Potentially, a manufacturer could potentially provide a 8U complete box with a single coaxial connector that puts out exactly 50W at that connector, but has all the combiner, transmitter & receiver in the single box, and if that enclosure package was tested and achieved the part 97 certification, would be acceptable for use for GMRS. The obvious would be that the transmitter would output higher than 50W to overcome the losses internal to the box, but since its "one piece" could potentially pass the transmitter based on that. This is slightly different from most repeaters, since the duplexer may have a spot in the case, the jumpers are exterior, and the rating is for the raw transmitter output before the duplexer. Now I have my opinion/interpretation, but I'd like to hear from others. Where is that power limit taken from and why? This is not to say that anyone would know/notice/care if you ran an amplifier to make exactly 50W come out of the duplexer or combiner. Not saying you should, but its not impossible, not that there are part 95 certified amplifiers available that could handle the duty cycle needed.

It's on their website: https://www.bridgecomsystems.com/collections/uhf-duplexers/products/bridgecom-bcd-combiner-duplexer So it appears they used two duplexers then added in the wide notch "combiner" which would balance the system and maintain 50 ohms. Here is their diagram: This group of hardware will not work for a ham repeater + gmrs repeater. This way only worked because the two repeaters were close enough to each other the wide notch duplexer could pass two TX on one channel and two RX on the other.

Do you have a link to the video? Most transmit combiners are not much different from duplexer cans. I'm not 100% sure, but I would think that for a two repeater system, you would need a 4-channel https://www.sinctech.com/collections/cavity-combiner-1/products/combiner-4-ch-8-5-cavities-dual-stage-7-16-din-406-512-mhz.

Repeaters are opposite of general programming, the TX frequency of a radio is the RX frequency of the repeater, and the RX frequency of the radio is the TX frequency of the repeater, for GMRS that mean repeaters listen on 467, and transmit of 462. In other radio services, the TX could be above or below the RX frequency, but it's laid only one way in the GMRS regs.

There is a window between the passenger compartment and the rear compartment where the engine is. I wouldn't recommend putting the antenna in the engine compartment. On a whim, I started looking a Dubai exotic police vehicles, and I don't see an antenna on a single one.

Depending if you have a passanger, you could do something like this: https://www.arcantenna.com/products/trab4500np-m2m-400-490-mhz-black-low-profile-omni-antenna Mount it in the rear window behind the passenger seat (2'8" from you for RF exposure requirements at 20W), could make a bracket off the seat bolt. There really aren't many options, other than to find a window lip mount and roll the window up on it.

Find out what radio shops service WISCOM and give them a call. I know MARCS-IP have all their dealers/shops listed, perhaps WI has the same thing?

You do need the RF adapter assembly: It does look like the rest of the alignment/testing can be done with the standard programming cable though.

I have to say this brings up another point. When running high power at 200W, who cares about the loss of a meter inline, especially on VHF. It is a very different scenario running barefoot on UHF with an already pretty long feed line.

YSF does this, atleast on the FT3DR and FTM-400XDR, but only with YSF.

I just sent you a message. Kenwood TK-3140's can be had for the same price as the GM-30, and in my opinion works much better. You loose front panel programming, but lets be honest, with some good thinking, and the ability to program up to 250 channels, its not an issue by any means.

I was without "my" truck yesterday, so I had the 7550e sitting in the cup holder, and could hear just as well over the hill on the XPR as I do on my mobile rig. My office is just on the other side of the ridge, but it's 200+' in elevation difference (1050ish to 1270ish). I normally don't pay attention because there usually isn't a conversation going on when I get out, but I could hear it all the way up the hill.

I will say, I think the "behind the keypad" speaker and microphone is a negative as well.

I see a few additions, most of which I saw on RR's thread: 1) Better wifi 2) 0.8W more power 3) as noted, bigger screen 4) new battery, but can use old chargers if you update the charger firmware

To be clear the NX-300 Type 2 400-470 (ALH378501) does not but they Type 2 450-520 (ALH378500) does.

Beyond system stress testing, and for something to do, it also helps improve each user's listening skills, practice for proper protocol to pass traffic, and in some cases, help one understand the system coverage/dead spots when mobile. Practice makes perfect.

Well, I installed the commercial antenna I had just above the roof line because the wife said I needed to clean up my office, and 1-1/4" feedline and parts were all over the place. I have a few months to maybe find a better antenna deal, but for now, I'd say that X300NA is not good for GMRS. If I could find two folded dipole arrays, I'd combine them onto a single mast, or even if I could find a DB-315 (no longer in production, super hard to find). Not looking to spend huge money, as I'm still going to be limited on height.

It makes a boom like firecrackers (and shook windows).

I've replaced a few well working older computers with recycled workstations, more power and better efficiency on the electric bill. We use some high-pressure wireless hole punches ? on our hard drives, sometimes we also used some "make it disappear powder".

This was a test setup just to measure where it landed in GMRS, knowing it was a ham antenna. I think you have some serious masking in your feedline, because my measurements aligned directly with the claimed SWR for the ham band. My hope was that outside of the band, it wasn't too steep and would work, but it is a bit too far out of band.

The Laird is a commercial antenna designed for that frequency range, with the golden metal tip and golden base. It came with the repeater.