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Thread: Need some diagnostics advice - some HTs not able to communicate with others

  1. #1

    Default Need some diagnostics advice - some HTs not able to communicate with others

    Hey folks!

    I'm a new ham and member of the Yakima County SAR and Mountain Rescue teams in Central Washington, and I need some help diagnosing a problem we've been having with our radios.

    Quite a number of people on the team, myself included, use personal Baofeng HTs for SAR work, and we've discovered an interesting problem in which SOME of the Baofengs cannot be received by SOME of the "official" Icom HT's nor the Kenwood NX-5000 at headquarters, nor the radio in our mobile command post (MCP). Apologies, I don't know the model of the unit's Icom HTs or the make or model of the radio in the MCP truck.

    We frequently have comms issues in the field, but given the complex terrain we work in it's hard to isolate other problems, so I did some experimenting on a recent training and at headquarters and here's the problem as best I can explain it:

    Our main tactical ops channel is in the 156 band, does not use a CTCSS or other carrier signal, and has no offset. On a recent training, we discovered that at least four of our personal Baofengs (including multiple models and power outputs) could not be received by the MCP's radio (I assume a Kenwood or Icom mobile unit) nor by at least one of the unit's Icom HTs. Another of the unit's Icom HTs was able to receive from our Baofengs just fine. The Baofengs were receiving all transmissions from the other radios loud and clear.

    At headquarters, I tried my UV-5R with the Kenwood NX-5000 and had the same problem -- I could hear transmissions from the NX but it could not receive transmissions from my UV-5R. Interestingly, the NX's squelch WOULD open when I pressed the PTT on my Baofeng, but there was no other response to my transmission. I tried the same thing with one of the unit's Icom HTs and it worked normally with my Baofeng; another of the unit's Icoms had the same problem as the NX (and as the MCP radio in the field).

    I tried changing the VFO setting on my UV-5R between narrow and wide to no avail, and I am told that none of the radios are programmed with any kind of CTCSS etc on that frequency.

    So my question is: where should I go from here? I'm a bit at a loss for ideas on what could be wrong. I'd really like to find a solution that allows folks to use their personal radios (there are enough barriers to entry already for our team). But even if the solution ends up being to replace the Baofengs with better quality HTs, I'd at least like to understand what's happening.

    Thanks in advance for your thoughts, and please ask questions. I'm generally technically inclined, but quite new to the radio world so I'm sure I've been confusing or said something that doesn't make sense. Please correct me! I'm a lot more interested in learning than in protecting my ego, just for the record.

    Thanks all!

  2. #2

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    It sure sounds like an CTCSS issue to me, even though you said none of the radios had CTCSS programmed into them. Is there was some way you could check for sure, rather than taking someone's word for it?

    And, now my feelings about using inexpensive radios like the Baofeng for something as critical as search and rescue. I realize this is probably a volunteer endeavor and some of the members may not have the funds to invest, but I'd hate to see a radio fail in a life and death situation. I recommend you research a better alternative to the use of the Baofengs.

  3. #3

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    Thanks K6CPO! I'm working on tracking down the necessary manuals and cables I need to verify that there are no squelch codes programmed into any of the radios, but that might take a while.

    You're right about relying on the baofengs for critical functions. By protocol, each team leader is supposed to carry a radio belonging to the unit so that at least one "official" radio is with each team in the field. Our experience at the recent training was a good example of why that protocol is there and a reminder to us all to ensure we (yes, all volunteers) follow it. Still, if I can help the team sort out this problem, all the better for everyone.

    I posted another thread asking about upgrading from the Baofeng to a better HT. I'd love your input on there!

  4. #4

    Join Date
    May 2020
    Location
    Sumner WA USA
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    Default

    Were you able to figure it out?

  5. #5

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    Could the front ends of those baofengs be getting overloaded? Try gripping the antenna with a tight fist to throw the SWR off (attenuating the signal into the radio) and see if it can pick up the icom. If that works, throw those cheap radios away.

  6. #6

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    Since some of the Baofengs work, just copy the code plug with Chirp of one that does work and load it into the ones that don't. I suspect a channel spacing issue since the suspect radios will open the squelch. If one could examine the code plug of the commercial radios the problem would probably be obvious.
    There is nothing wrong with Baofeng radios. I have several and have given many away over the years to new hams. The only fault I have found with them is some, but not all I have checked do have spurious emissions on both sides of transmit, but the emissions are usually 90-110 db down from the main signal, so really not much of an issue. I have one pair set up as a portable repeater with a 10 watt duplexer in a plastic case that has worked for years during our exercises. It has been hoisted into trees, placed on rooftops, dropped, kicked, baked in the sun, and run completely dead several times. Are they Motorola or Kenwood quality? No. They are frequency stable and clean enough to use on a commercial system.

  7. #7

    Default

    I didn't know that Baofeng's could turn it out of ham bands.

  8. #8

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    Without a single mod...

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