WSFF627

Just tuned one today. Confirmed at 0.6dB insertion loss on the service monitor. https://www.bridgecomsystems.com/products/4-cavity-txrx-350w-uhf-duplexer?currency=USD&variant=41431623172261&utm_source=google&utm_medium=cpc&utm_campaign=Google Shopping&stkn=d6eaad281b8a&utm_source=Google_Ads&utm_medium=Duplexers_Shopping&utm_campaign=Duplexers_Shopping_Campaign&tw_source=google&tw_adid=664925858611&tw_campaign=20342176746&gad_source=1&gclid=Cj0KCQiAlbW-BhCMARIsADnwasqZg1QSmh5e4yADfPU4xLrwHKAbWB9BFk2ZIo6jHxDCf44DJQ4fp-AaAj7BEALw_wcB

Thats correct. TXRX duplexers have the lowest loss of any duplexer I have seen. 0.6dB, some loss, yes, you should see 50w in and 41-43w out of the duplexer. A lot less loss on the RX path, which in my opinion is more important than TX power.

Sorry for being short,, only got a sec... Bridgecom not bad, set tx at legal 50w out of the rpt. A good TXRX 4 can 350 watt duplexer, 0.6dB insertion loss will offer the best post duplexer wattage. Obvioulsy dont forget loss is a two way street.. Advanced Receiver makes nice pre amps. I run them on all my projects.

Nice!! That's quite a lot of feedline. Doesn't surprise me. All probably using the same type of feedline. 2M VHF doesn't loose nearly as much in the line as 70cm UHF. GMRS (UHF not far from 70cm, as I'm sure you know quite well) with 500 +/- less feedline. Any pre amp will also play a part on the RX side. For the sake of argument lets assume the tower is using Heliax LDF6-50 1-1/4 inch feedline. Feedline loss only, in addition to any combiner or duplexer, etc. loss. Rough numbers only. VHF at 900 feet is about 2.89 dB loss (125w TX,48% power loss) UHF at 900 feet is about 5.27 dB loss (125w TX, 70% power loss) GMRS UHF at 400 feet is 2.44 dB loss (50w TX, 43% power loss)

Line of site theoretical vs practical, in theory in space with nothing to attenuate the signal, very, very far. ISS contacts happen all the time with 5w or less. In practical application on earth, it boils down to terrain, geology, height above average terrain, occasionally ducting, and the equipment in use. There are simply too many variables in play to say it will go X miles. All transceivers and repeaters are not created equal. My Motorola's have the best receivers, my Baofeng's the worst. A repeaters performance varies greatly based on its antenna height above average terrain, antenna type, quality and gain, overall losses from feedline, duplexer and jumpers, if there is an RX pre amp, RF environment (other RF at repeater site) etc. I can have a conversation on my repeater at 30 miles from some locations with a 4 watt Motorola portable. Standing in that same spot, a 5 watt, $15 Baofeng sometimes works, sometimes does not. I can also move 10 feet and it will no longer work.

Yes, the way I read and understand the rules, you can and always could RF link them.

I understand what your trying to do, its a cool idea and I sincerely hope it works out for you. However, I believe the FCC is going to tell you you cant do it because it is a clear violation of the rules as written. POC uses the Cell telephone / data network. It is a network in every sense of the word. As I and others have stated before, yes you can connect a repeater for remote control of the repeater, you cant do it to carry messages / voice comms. In any case, please keep us posted with the FCCs answer. This is and has been a good conversation.

It is clear in my head. I understand how to read the law. BTW, the FCC "Just rules" are Title 47 of the Code of Federal Regulations. The Communications Act of 1934 gave the FCC the authority create and enforce rules and laws, ie Title 47, Chapter I, Subchapter D, Part 95

Please go read the Law. Its clear you cant operate on digital modes on GMRS. Its clear you cant connect GMRS to another network for comms. I don't need an attorney to take it to court to show its illegal, its written in the law. This horse is dead. If you don't want to read the law or are looking for bits and pieces to justify what you want to do, go hire an attorney for a few hundred to review it and give you a legal opinion. Or do it anyway and end up on the FCC enforcement radar and risk it. Telling people what your doing and selling them a product or service that is not legal opens you up to liability. Hire an attorney and get a legal opinion from them.

I'm not saying it wouldn't be a win, but currently what your doing is not legal. Also, it sounds a lot like your talking about DMR talk groups on GMRS and taking a page out of the HAM / DMR / Brandmeister playbook and marketing it. All of which is available on the HAM bands for free, including linked and worldwide repeater network, hotspots, etc. as I'm sure you know. Now I'm knocking you for trying this, cant really fault you for it. But at the end of the day, GMRS does not allow it and does not have the bandwidth other radio services do, like HAM, which is easily accessible to the public.

I understand your frustration. GMRS is easier to get into than HAM, especially for families. No, there is not enough bandwidth, that's why linking untimely isn't allowed.

"remote control" and conveying "messages" are not the same thing as defined by the law and FCC. Remote control would be activating / deactivating transmitting function of the station, changing the channel, tone, etc. messages, wireline control link - every network everywhere travels along a wireline All cell towers are on a fiber and copper wire network.

Please see my post above citing the law on linking / connecting repeaters. I sure lots of GMRS users are using equipment that is not type accepted equipment. There is no type acceptance requirement for HAM. That's why its HAM, you can build and use, legally, your own radio.

From your website... Digital modes are not permitted in GMRS. "Other networks" is the internet, and literally any other network... LTE networks included. The law: § 95.1749 GMRS network connection. Operation of a GMRS station with a telephone connection is prohibited, as in § 95.349. GMRS repeater, base and fixed stations, however, may be connected to the public switched network or other networks for the sole purpose of operation by remote control pursuant to § 95.1745. § 95.1731 Permissible GMRS uses. The operator of a GMRS station may use that station for two-way plain language voice communications with other GMRS stations and with FRS units concerning personal or business activities. (d) Digital data. GMRS hand-held portable units may transmit digital data containing location information, or requesting location information from one or more other GMRS or FRS units, or containing a brief text message to another specific GMRS or FRS unit 95.1733 Prohibited GMRS uses. (8) Messages which are both conveyed by a wireline control link and transmitted by a GMRS station;

X2 BoxCar. I'm also quite curious about this.... you website clearly states its connecting the GMRS repeater to an LTE network. FCC Rules state "Linking multiple repeaters to enable a repeater outside the communications range of the handheld or mobile device to retransmit messages violates sections 95.1733(a)(8) and 95.1749 of the Commission’s rules, and potentially other rules in 47 C.F.R. Repeaters may be connected to the telephone network or other networks only for purposes of remote control of a GMRS station, not for carrying communication signals."