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That is called “desense”. The radio that is transmitting, although transmitting on a different frequency, is actually desensitizing the receiving radio thus rendering it incapable of extracting the desired signal. It is the same effect you and your eyes suffer when you look in the direction of a bright light. Suddenly your eyes cannot make out the detail of the less bright items around you until the bright light is gone. The better the receiver design is within the radio the less it is affected by this. As Skyline said, put some space between the radios so the off-frequency transmitting radio is “less bright” to your receiving radio. Michael WRHS965 KE8PLM

Move them father apart. Have somebody take one into the front yard and try.

Just an update that the switching converter is working great with a bench supply on my desk so far, and I am slowly getting everything pieced together. Thanks for the Samlex recommendation @mbrun! ocm

Could always just sit and key up and key down with roger beep going off......I'm sure someone would speak up at some point.....;)

What were the error codes you got on the Kenwood 3170? I know the radios with generate a low battery alarm at some point then the radio will shut down at about 6 VDC. You can't depend on measuring the open circuit voltage of the battery pack to determine if its completely discharged. When batteries discharge their internal resistance increases so under load the terminal voltage is lower than the open circuit voltage. I've used an electronic load to test a pile of used battery packs for my Kenwood radios. The test automatically terminates once the pack voltage under load drops to 6 VDC. Then when the now open circuited battery pack is checked the terminal voltage jumps up to 6.5 VDC to 6.7 VDC. The nominal battery pack open circuit voltage is around 7.2 VDC to 7.4 VDC. It will be a bit higher right after you take the radio/battery pack out of the charger, maybe as high as 8 VDC or so. Even fresh batteries will show a voltage drop under load. Different battery chemistries have different internal resistance characteristics. Some of the worst ones for heavy loads are your common carbon-zinc types.

Most of us use the Larsen NMOKHFUD NMO Mount. It isn't 100% waterproof but way better than the others. I normally slip a piece of self sealing heat shrink over the cable and I have yet to have one get water in them. My JK is at least 10 years old and still works fine. They work really well. https://www.theantennafarm.com/catalog/index.php?main_page=product_info&cPath=264_266_291&products_id=1125

Thanks. That did it. Appreciate it.

Think I misunderstood your original post. I had always thought that mounting one upside down also accomplished the something. Reading your second post I think we are on the same page. Sent from my SM-G975U using Tapatalk

Every bit helps, but not significantly. Let me help by giving you a very, very crude illustration. A 5 watt radio provides 37dBm output. A typically radio has a receive sensitivity of -120dBm (the lowest level the radio needs to produce usable audio). That is 157dBm of difference. Now, imagine all 157dBm is lost in only 1 mile due to all the obstructions in the path, for an average of 1 dB loss per 33 ft. So now lets say you increase your radio power from 5 to 50 watts. That is an increase of 10dBm (37 to 47dBm). Ok, so now that you have increased your power 10 fold. How much further will you get if you assume the same linear average path poss of 1 dBm per 33 ft. You got it, 330’. So in this example, you increased your power by 10 fold yet your effective distance increased only from 5280 to 5610’. Now, if you were not battling the losses from all the obstructions in the path and went into outer space that same 5 watts would get you 225 miles, and 50 watts would get you 700 miles. There, signal level will drop based purely on inverse square law. The point I am trying to illustrate here is that presence of attenuation of signal caused by obstacles in the signal path plays a significant role in how far your signal will and will not travel. It takes a lot of extra power to “burn” through the obstacles. Much better to raise the antenna to remove the obstacles from the path in the first place. I hope this helps a bit. Michael WRHS965 KE8PLM

Coming from the perspective of a radio listener, I think 1 min is a good value as well as a serves as a reminder to keep one’s transmissions short and keep the dialog moving. However, as the talker, I admit I have personally settled on 2 min. One just proved to be to short and restrictive in way to many cases. While the TOT is a great way aid in keeping the duty cycle down, I like the security it provides knowing that if the PTT gets stuck unknowingly and accidentally that the radio will stop transmitting automatically after the TOT time has expired. Michael WRHS965 KE8PLM

I just received the AT-779UV and played with the programming software for a little while. I was able to add channels beyond the 30 that come programmed, and I was able to change the PL tones as well. Besides the "open" (no tones) repeater channels that were included, I added 16 additional repeater channels, this time with "travel" tones on the first 8, and custom tones on the second 8. I couldn't change anything directly in the cell at first, but then realized that if I double click the cell, I could change some fields. For the fields I could not change directly, I was able to change it when I double-clicked the "more" (>>) cell. That would bring up the channel edit dialog box where you can change almost all the settings for that channel, such as channel name, power level, bandwidth, CTCSS/DCS tones (even custom ones). There's even a Tx Off option that I believe prevents transmitting on that channel, although I haven't confirmed if it works because I haven't tried it yet. All-in-all, the software is a bit "clunky," but it gets the job done. Once you create your desired file, you can save it and upload it to your radio. From there, it's pretty easy to download from the radio, make minor changes, save it, then upload it again to the radio.

As SWR is a constant topic in radio, and since it may be difficult initially to grasp the concept of, I thought it would be helpful to provide a link to an incredibly effective video that allows you see it in action. The video is 60 years old and was produced by AT&T labs. It is worth watching from start to finish. You will get to see standing waves, reflected waves, impedance matches, mismatches, shorts and opens. It does not get visually any clearer than this. Enjoy. Michael WRHS965 KE8PLM