MXT400 scan always stops on channel 5

[tkruppa]

Hi everyone, weird question here:

 

I currently have a Midland MXT400 with 6db Gain antenna set up in my vehicle. I enjoy leaving the radio on scan just to see whos out there, especially when driving. However, its been extremely frustrating as my radio constantly gets hung up as channel 5 continuously breaks squelch. There is nobody on the other end, just loud static, almost as if I was using the monitor function. Ive checked and I don't think my squelch can be set channel specific, the value is the same across all channels. (Unless this was somehow done through the programming software which I used to program a local repeater, but I'm pretty sure this was happening before I did that.)

 

While the problem is intermittent depending on my location, I would say scan stops on this channel and blasts me with loud static 80% of the time. I've been on trips where I've driven 3+ hours away and still had it happen. I am located in NYC. I would rather not have to make channel scan skip any channels but I don't see any other option. I currenly cannot use channel scan without keeping a hand on the radio to skip over channel 5 every 7 seconds. Any ideas as to what might be happening here?

[wayoverthere]

2 hours ago, tkruppa said:

Hi everyone, weird question here:

 

I currently have a Midland MXT400 with 6db Gain antenna set up in my vehicle. I enjoy leaving the radio on scan just to see whos out there, especially when driving. However, its been extremely frustrating as my radio constantly gets hung up as channel 5 continuously breaks squelch. There is nobody on the other end, just loud static, almost as if I was using the monitor function. Ive checked and I don't think my squelch can be set channel specific, the value is the same across all channels. (Unless this was somehow done through the programming software which I used to program a local repeater, but I'm pretty sure this was happening before I did that.)

 

While the problem is intermittent depending on my location, I would say scan stops on this channel and blasts me with loud static 80% of the time. I've been on trips where I've driven 3+ hours away and still had it happen. I am located in NYC. I would rather not have to make channel scan skip any channels but I don't see any other option. I currenly cannot use channel scan without keeping a hand on the radio to skip over channel 5 every 7 seconds. Any ideas as to what might be happening here?

That it's location independent would seem to point to a noise source in the vehicle. I know both my Midland handhelds and wouxun 805g pick up noise on channels 3&6 from the Samsung monitor on my desk. Wireless charging pad or a display are the first things that come to mind.

On the mxt115 I have in the truck, I generally have a "privacy" code set on channel 1 (I want to say I just picked a random DCS code), since traffic there is largely just kids pounding the call button incessantly on their bubble pack radios. This way, it doesn't open squelch for anything without the expected tone, and it scans right past channel 1.

[tkruppa]

4 minutes ago, wayoverthere said:

That it's location independent would seem to point to a noise source in the vehicle. I know both my Midland handhelds and wouxun 805g pick up noise on channels 3&6 from the Samsung monitor on my desk. Wireless charging pad or a display are the first things that come to mind.

On the mxt115 I have in the truck, I generally have a "privacy" code set on channel 1 (I want to say I just picked a random DCS code), since traffic there is largely just kids pounding the call button incessantly on their bubble pack radios. This way, it doesn't open squelch for anything without the expected tone, and it scans right past channel 1.

Cant believe I didnt think of slapping a code on the channel...great quick fix. Interesting point on the interference I will have to look into this more! I do have a wireless charger. Will investigate and report back.

[mbrun]

That it's location independent would seem to point to a noise source in the vehicle. I know both my Midland handhelds and wouxun 805g pick up noise on channels 3&6 from the Samsung monitor on my desk. Wireless charging pad or a display are the first things that come to mind.
On the mxt115 I have in the truck, I generally have a "privacy" code set on channel 1 (I want to say I just picked a random DCS code), since traffic there is largely just kids pounding the call button incessantly on their bubble pack radios. This way, it doesn't open squelch for anything without the expected tone, and it scans right past channel 1.

I largely agree with noise in the vehicle being a factor. My cheap GXT1000s cannot be used to scan in the vehicle while running. The KG-805 will act up to much lesser degree while using a rubber duck inside the vehicle, but when using the external mag mount antenna it is not an issue.


Michael
WRHS965
KE8PLM

[SkylinesSuck]

I had the same issue with my KG1000.  Turned out me reverse camera was causing interference on a specific channel.

[djxs]

I just find it strange that you said that the issue started after running the software through to make repeater channel updates. If it was me, I would troubleshoot by resetting the radio to stock.

Quote

"To set Repeater Channel Function: 1.Press and hold the Menu button for 3 seconds to enter the Menu Mode. 2. Use the Call or Plvl buttons to scroll through the Menu options until the LCD displays REP. 3. Turn the Channel knob to select the setting you desire. 4.Press and release the Select button to confirm your choice. 5.Press the Scn/Mon button to exit the Repeater Channel Function." - Midland

Further information can be found on the attached .pdf

If after running the reset procedure and it still open squelch on channel 5 and channel 5 only, then well...I don't know! I am learning. Since my background is in technology, I jumped to the conclusion that it could possibly be software based at some level due what you mentioned.

MXT400-Owners-Manual.pdf

[tkruppa]

So upon further investigation interference is absolutely the issue. With the vehicle completely off (radio running on my auxiliary battery, no power to the truck itself) no noise at all on channel 5. As soon as the vehicle gets power (not engine on, just power on) I get blasted with noise. I've narrowed it down so far to both my head unit and dash cam. Turning the dash cam off will reduce the noise, and turning my head unit to FM radio instead of bluetooth eliminates it. Unfortunately I dont think this is an issue I'll be able to solve, I need my dash cam and radio. So I might just have to deal with it.

[djxs]

22 minutes ago, tkruppa said:

So upon further investigation interference is absolutely the issue. With the vehicle completely off (radio running on my auxiliary battery, no power to the truck itself) no noise at all on channel 5. As soon as the vehicle gets power (not engine on, just power on) I get blasted with noise. I've narrowed it down so far to both my head unit and dash cam. Turning the dash cam off will reduce the noise, and turning my head unit to FM radio instead of bluetooth eliminates it. Unfortunately I dont think this is an issue I'll be able to solve, I need my dash cam and radio. So I might just have to deal with it.

I do not presume to know much about where this noise might be coming from on your vehicle, but I do know that I had a similar situation (without a GMRS radio) when I installed a car amp and new radio head unit. It turns out that despite the perfect installation (grounding was perfect), I still exhibited noise. I was told to try installing a ferrite noise isolator. It worked for me. 

[tkruppa]

I will have to look into this, maybe this is the answer. I definitely would like to fix the issue if possible.

[dwmitchell61]

18 hours ago, tkruppa said:

So upon further investigation interference is absolutely the issue. With the vehicle completely off (radio running on my auxiliary battery, no power to the truck itself) no noise at all on channel 5. As soon as the vehicle gets power (not engine on, just power on) I get blasted with noise. I've narrowed it down so far to both my head unit and dash cam. Turning the dash cam off will reduce the noise, and turning my head unit to FM radio instead of bluetooth eliminates it. Unfortunately I dont think this is an issue I'll be able to solve, I need my dash cam and radio. So I might just have to deal with it.

If you are lucky, it is in the DC power to the radio, from the car. Get a big CAPACITOR from electronics supply house or auto stereo shop and connect it across the wires

 

[tkruppa]

10 hours ago, dwmitchell61 said:

If you are lucky, it is in the DC power to the radio, from the car. Get a big CAPACITOR from electronics supply house or auto stereo shop and connect it across the wires

 

Could you elaborate a little bit? What size capacitor? Does it matter if its on the positive or negative?

[WRNA710AZ]

I've experienced that with Ham repeaters running digital and programed the radio to skip the channel.