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My first Duplexer from BuyTwoWay covered the entire GMRS Band and my repeater then was on Ch 22. I had a terrible experience with it, ended up buying a tuned dublexer tuned for Ch 18 and moved there.. Been working great since.. I sent the original duplexer back to BuyTwoWay and had them tune for CH 18 to use for my portable repeater which i mounted to the outside of a FAT 50 Ammo Can. Since this portable set up gets moved around a lot, i'm always concerned that the duplexer will get knocked off tune, but going to almost 3 years now its holding tight on Ch 18.. I did try to tune it myself as Marc did, but didn't have such luck or patience.

any humanitarian efforts in Iran at this point would be fruitless. Considering their government wont allow any help from the West in that effort, the only hlep they are seeking at this point is further destroy Israel. Humanitarian help will be coming to Iran but its weeks away and only after their leadership is gone...

Humanitarian efforts are just that and should be given without political consideration. It's not the people of the country that is the problem, it's their government. I work with an Iranian and he has told me stories of what goes on over there. Trust me, most people over there really don't believe in what they have to live under. If cheap GMRS radios can help the cause it shouldn't matter which country assists in humanitarian aid.

Exactly. They can get bulk discounts, even free Baofeng radios since it's a humanitarian crisis.

11:00 AM EDST Sunday, Home page still a jumbled mess. I cannot access repeater listing but oddly still can access Forums.

Here is a simple to understand description of IP ratings: https://www.iec.ch/ip-ratings The first numeral refers to the protection against solid objects and is rated on a scale from 0 (no protection) to 6 (no ingress of dust). The second numeral rates the enclosure’s protection against liquids and uses a scale from 0 (no protection) to 9 (high-pressure hot water from different angles).

I started playing with a Baufang UV5R (before they locked them) in the HAM bands. Got bored with the HAM world and programed it to the GMRS side and thats when i began having fun with radio... My first GMRS radio (and favorite) was a Wouxun KG935 HT. I still dabble with HAM but for the most part i enjoy the GMRS side. I never did try a UV5G but did program one of my UV5R to GMRS only. Since these radios are all locked now i would recomend a UV5G or a Wouxun GMRS only radio, they have a few versions now..

The 905G is not CHIRP capable although the wouxun software works fine, but if you plan on getting more radios and wish to copy paste between, the CHIRP is your friend there. The 805 is CHIRP capable. .The cable you want is readily available almost anywhere, Amazon or buytwowayradios.com those will work with the 935,905,805 or almost any other radio or radio brand with a std k1 connector. I would suggest buying not from Amazon as Amazon is rife with crappy knockoffs of this type of equipment that uses perhaps questionable driver or just plain won't work. 805 is IP55, 905 is IP66, 935's are IP66. 55 means dust protected and can resist water jets. 66 means dust tite and can resist powerful water jets. I have a yeseau that is IP55 and I've dropped it in a stream, it was not affected. I've also had a 935 fall off my sxs in my back 40 and lay in a puddle for a month, been run over a few times before I found it, it was not affected at all. So anything IP55 or above would be just fine for heavy outdoor use in snow, rain.

@marcspaz thank you for the detailed information on tuning the duplexer. We are lucky in that one of our members retired from Sound Solutions and he still has access to all of their equipment. He has tuned all of our duplexers.

Given the present situation, I doubt that the US State Department would ever authorize any such gesture of aid to any country that is hostile to the United States or it's allies.

Very true, but they are very friendly with China.

I doubt anyone in Iran would ever accept any wireless devices from any country allied with Israel.

I use the UV-9R PRO on our ranch & range and they work great. They work with chirp also. Features： IP67 waterproof and dustproof High & Mid &Low Power Switchover Battery Saving VOX Function Auto-Back Light Time-out Timer (TOT) 50 CTCSS and 104 DCS Codes Voice Prompt ANI Code PC or Manual Program DTMF Code PTT-ID ATUO Keypad Lock Busy Channel Lock Function Dual Display and Dual Standby Emergency Alarm Priory Scanning Function Relay Forwarding Confirmed (1750 HZ) Low Battery Warning U/V Cross Band Dual Watch

I think the KG-935G plus was claimed to be IP 66 or 67, and I'm not sure what the IP ratings were for the 805 & 905 models.

Send them that bug report.

It's a Smith Chart SWR Circle. It's a circle that is drawn centered at the origin frequency, passing through the plotted impedance point. This circle represents a constant SWR through the range. The value where the SWR circle intersects the positive real axis (right side) of the chart indicates the SWR. The closer the red dot is to one of the lines radiating from the right side, the closer to 1:1 the SWR is on that frequency. I tried the TinyVNA and it did not work. It was way off... very inaccurate. A friend of mine (who is a retired RF engineer) uses a SAA-2N VNA when he is in the field. He has great results with it, which is why I went with that specific VNA. It's "good enough" that I would not encourage people who are doing this as a mild hobby to buy a commercial Signal Analyzer. If professionals are using it, the SAA-2N VNA is good enough for me. I have not compared mine to a commercial grade SA, but I have tuned 5 duplexers (UHF and Commercial VHF) with the SAA-2N VNA since I bought it and have had amazing results. With a 2m repeater only having a 600KHz offset, accuracy is extremely critical. My 2m repeater is covering over 8 miles with 5w handheld radios and well over 25 miles with 50w mobiles, and the antenna is only 100' above the ground, 200 feet above average terrain. Those numbers are both further than the theoretical/calculated RF LOS. So, I personally have confidence in the SAA-2N VNA.

Without knowing what frequencies are being used locally there I think that would be a dumb idea. There are warnings all the time against taking FRS, same frequencies as GMRS, radios on foreign vacations since the frequencies could be used by local fire, police etc. services.

I've held off spending money on one of the tiny VNA's since I'm not really convinced they have the dynamic range claimed. I would like to see some verification of the spec's testing against a know high quality lab bench VNA. For tuning these cavity filters you really need the high dynamic range to be sure you have all of the cavities aliened.

You're as bad as me for staying up late. LOL Ya, I saw how they painted the screws. Shot them from one side to help lock them in I suspect. Didn't think about how that might impact re-tuning though. Thanks for the tour. Do you know how to read the circular graph? The curly cue lines are intriguing, really curious how they are read.

I think I've finally sourced the issue. I did another firmware update, and completed another factory reset. This fixed the overall issue (so i thought). As I started piecing settings one by one, to try and source any further issues, i found that when you turn on the weather alert the previous issue happens. Once it is off, the radio works as it should.

To answer question about tools used and how to adjust a duplexer, here is a quick overview. Tools I used: Windows PC SAA-2N VNA VNA View software Box Wrench Screw Driver Brass Brush To tune the duplexer, you have to follow a couple of steps. Calibrate the VNA for the frequency you are testing (via the PC or on the VNA, depending on if you are using the PC or not) I typically set the center frequency to the frequency I am tuning for, with a 10MHz spread. From there, we are going to tune either the low side or high side, separately. For this example, we can start on the low side. Connect the S11 cable to the "antenna" port. Connect the S21 cable to the "LOW" port. Put a dummy load on the "High" port. Refer to Image 1. Set the Trace 1 format to S21 Thru. With a mobile UHF cavity duplexer, you can disable the other traces, but if you want to track your SWR at the same time, set Trace 2 format to S11 SWR, and then disable the remaining traces. Adjust your scaling so you can see at least -110dB Adjust each adjustment screw to create the deepest notch possible, to the transmit frequency. In this example, 467.600MHz. only adjust one tuning screw at a time, loosen the jam nut with the box wrench, just enough to allow the tuning screw to move, and while making adjustments, hold the jam nut with the wrench. Typically, once you set the screw to the proper depth, it can be a bit tricky to set the jam nut without turning the screw a bit at the same time. A trick I learned is that I put the screw just a few degrees off, counter clockwise, so as I tighten the jam nut, it snugs the tuning screw into the correct location. See Image 2 and Image 3 From there, switch the S11 cable to High, and the dummy load to the Low side. Repeat the tuning steps for the high side, but tuning the notch to the receive frequency. In this example, 462.600MHz. This guy has a great video on using a VNA to adjust a duplexer. I have no idea who he is, but it it's good content. The only thing I would add is, he stated he is using 200 sweep points. I would use the highest sweep setting you can that provides a good enough resolution of the frequency spread you are tuning. On the VNA itself, I use 401 points, but on the PC, I use 1024 points. https://www.youtube.com/watch?v=TbEK4v_3Xuo With this duplexer, specifically, the tuning screws are brass. Either the manufacturer or B-Tech spray painted the tuning slugs. I had to spend a bit of time cleaning the paint off the screw threads and heads with a brass cleaning brush to make it so the duplexer could be tuned. If you have a situation like this and want to repaint the screws for cosmetic reasons, be sure to use non-metallic paint, such as Krylon Fusion for Plastic. It must be non-metallic, polyurethane free, and lead free. I am including a few extra pictures displaying the results. Image 1 Image 2 Image 3

I guess the receiver sensitivity is what it is, but if you are able to receive better with the new duplexer that's real world sensitivity not theoretical receiver sensitivity. I get exactly what you are saying. And I'm pretty sure you know what I mean too. If I could hit the repeater at 5 miles and not 6. Then install the new duplexer and can hit the repeater at 7 miles but not 8. I would consider that an increase of sensitivity. But in reality it's the duplexer allowing the receive signal to still be heard while the repeater is re-transmitting and not causing desense.

More waterproof.

Yah, sounds like you bricked it.