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There are two other repeaters in Missouri using the same channel and PL tones as our repeater. One is in the Kansas City area and the other is just outside of St Louis. We are located towards the middle of the state. Here lately with the temperature inversions, one or both of those repeaters have been opening up our repeater. The closest one is 80 miles away. And no we do not see anywhere near 100-200 miles of coverage on UHF here in Missouri.

On the Silverado. I have a Tacoma and mounted a MTXA26 on a mount that attaches to tailgate area using existing bolts. I happen to have a steel bed cover from Peragon. This works very well. There as several repeaters some distance from me that I can hit. I have an NMO mount on the bracket. Being tailgate level it is easy to remove the antenna before going to the car wash.

In the early 70's the USAF fire department used Motorolas, MX330's (?). They were bulky and heavy but we had stubby antennas. One thing we found is they didn't like heat and water was death to them.

Don't forget the barn door effect. If a conversation is going on on one repeater and someone keys up on the other repeater, it is highly likely that they will be close enough to hit both repeaters, and what will happen is that they will come across the other repeater as long as someone is talking which would cause the receive to be open. It would make it sound like someone was keying over the person talking. PL tones only keep the receive from opening up unless someone with the proper tone keys up. Once that person with the proper tone keys up, it opens the receive allowing everything in, hence the "barn door effect, however, in normal circumstances, just the person using that repeater should be heard. I have a repeater right down the road that is local. There is another repeater 35 miles from me that, when you are on the hill tops around here, you can get into it and definitely hear it well. I know there have probably been many times where I probably clobbered a person talking on the other repeater when I put my callsign out on the local repeater near me. The two repeaters? Same deal as what you are asking about. Same frequency, different tones.

I don't think there would be room for the Anina NMO+90 degree adapter between the headliner and roof of either of my vehicles. You probably should do some measurements before you decide.

I was a police officer in the early 1980s and that's pretty much how we all felt, but we accepted it because there weren't any other options.

I like either the AR-5RM or the XTS5000, depending on how many monies you want to blow and how strongly your radio-dork gene is presenting.

(Asking for a friend) So, what would the Queen-of-all-that-oscillates recommend in the way of an unlocked HT, hmm?

Agreed. Results exactly as expected.

^ This. Just have your friend use something other than 8-14.

If he is a licensed GMRS users he does not need to lower his power down to 2 watts to legally communicate on FRS channels 1-7 and 15-22. He is allowed to use 5 watts on channels 1-7 and 50 watts on channels 15-22 even if he is communicating with a FRS user on those channrels.

His request doesn’t make sense. Any GMRS mobile radio will talk to FRS radios except for channels 8-14 which may only be handheld portable units by regulation. GMRS handheld radios can talk on 8-14.

Trying to assist someone... He is looking for a mobile radio recomendation. He wants a Mobile rig to use with FRS at 2 Watts and GMRS 5Watts for Comms with his rock climbing friends. They all have Rocky Talkies and he wants a Mobile that will work with Rocky Talkies-- both the FRS and GMRS versions. He threw out around a Mobile in the 10-15 watts unit-ballpark. Any ideas on a GMRS Mobile rig that has that 2 watt pwr. option for TX on FRS and is not locked out on FRS? Thank you!! Best Regards!

Keep talking guys. I am learning a lot.

The simple explanation is one is used to isolate the transmitter from the receiver. Since the repeater is a full duplex operation, transmit and receives at the same time, any RF energy from the transmitter will get into the receiver. When this happens the receiver will trigger the transmitter. Now you have a feedback loop where the system will stay locked up on transmit until the power is yanked, destruction of the receiver's input at worse, or simply kills the sensitivity of the receiver then it becomes deaf to weak signals. The typical notch/bandpass duplexer filter is setup such that the receive half of the filter is tuned to notch out the transmitter's frequency as much as possible. The bandpass filter on the transmitter side is tuned to eliminate as much of a spurious signals that are not on the exact transmitter's frequency, thus preventing them from entering the receiver's circuits. For the above to work a certain frequency minimum difference between the transmit and receive frequencies are required. This minimum depends on the quality (design) of the duplexer. https://horwin.info/en/pro-dupleksery/ https://www.repeater-builder.com/antenna/pdf/w6nbc-duplexer-book.pdf

If you look at the table, it's performance narrows and insertion loss increases as you approach 5MHz spacing. There is no way in hell that will have acceptable performance at 3MHz spacing.

Since it's in my repeater and my repeater has 5MHz spacing I would say that it can be tuned for that spacing.

Conflicting info 50W RF Power Handling 6 Cavity Design Minimum Tx and Rx frequency difference: UHF 3MHz Maximum Tx and Rx frequency difference: UHF 12MHz Fequency Range: UHF 400-470MHz(the full band) Bandwidth:±500kHz Standard Termination: N Connector Frequency Spacing: 8-10MHz Insertion Loss:≤1.0dB Nominal Impedance: 50Ω V.S.W.R:≤1.5 Suppression:>75 Isolation:>75dB Free Frequency Tuning Easy to build your repeater Weight:1.8Kg

Be careful, that specification indicates a minimum spacing of 8-10MHz between RX and TX, but the US standard for UHF is 5MHz.

That's the one.

Google is sending me to the same link as i found earlier ... Repeater Duplexer 50W UHF 6 Cavity Duplexer SGQ-450D -

If you broaden your search to “SQG duplexer” you’ll find several hits.

No reference to my-450-sqg-50 on the interwebby And the other number had no reference either.

That would be awesome to mess with for an afternoon. It's small, so it should be cheap to ship, too. If you want me to take a look at it, PM me and I'll send you my info.

I had an Uncle who was an Admiral in the Navy out of Groton. Passed away and only my Aunt is survived. No one in Rhode Island that I know of LOL