[Poor transmit quality with Midland MXT400 Micromobile]

Thanks for the in depth responses all.

As far as turning down the power, we usually stay on channel 6 which by default reduces the radio output to 5 watts, so nothing I can do there unfortunately. I haven't noticed any difference based on proximity to convoy but I will look out for that now.

Quote

do you sound better if vehicles are a mile apart vs a few car lengths?

I'm not sure I've ever been able to to talk to anyone near a mile away before, but we do live in NY with lots of hills and obstructions, and I'm the only one in the group with a high power radio.

Re changing from narrow band to wide band, I can give this a try, I do have the programming cable if I can find it. Truthfully my radio knowledge is not in depth enough to know how that effects anything but I'll give it a try.

Regarding the battery charger, its a redarc BCDC 1250D, does both float and high amp charging, and the aux battery is a new optima yellow top, and majority of the time the only thing running on it is this radio, so I'm hoping that will rule out the power draw theory.

Re changing where I hold the mic, a very quick test should yield some results so I'll try this as well!

[Poor transmit quality with Midland MXT400 Micromobile]

Hello everyone,

I currently have a Midland MXT400 set up in my jeep. I'm using the MXTA26 6DB gain whip antenna. Radio is wired directly to an auxiliary battery, does not see alternator voltage but does however see battery charger voltages. Antenna cable is loosely coiled with no sharp bends.

I am having a very frustrating and consistent issue with others on multiple types of radios not being able to understand my transmissions. My radio is used almost exclusively during convoy driving, so very close proximity. When I switch over to my midland walkie talkie I'm told my voice is then much clearer. Repeating myself has gotten old very fast and I'd like to try to figure this out.

For context, I can hear everyone else crystal clear. The 6DB antenna has been great and at high elevations (bridges, elevated highways, etc.) I can almost always pick up signals that nobody else in my group is hearing. My antenna is mounted near the bottom left corner of my windshield, however there is no difference in quality based on whether the recipient is in front of or behind me so I don't think placement is the issue. Any feedback is appreciated.

[MXT400 scan always stops on channel 5]

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?

[MXT400 scan always stops on channel 5]

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

[MXT400 scan always stops on channel 5]

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.

[MXT400 scan always stops on channel 5]

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.

[MXT400 scan always stops on channel 5]

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?

[Need help with new setup - MXT400]

2 hours ago, mbrun said:

Your results sound completely normal for two radios operating simplex, antennas at 4-7’ AGL, and with loads of obstructions.

Midland’s lure of “38-Mile Range” is worse that saying “You too could win the lottery”. In the real world you are more likely to win the power-ball lottery 6 times before you would ever experience 38-mile range with their walkie talkies.

Obstructions are the enemy of range in radio communications. Never underestimate how much they negatively effect range and don’t accept any statements to the contrary.

Two GMRS handhelds will have a range of 6-miles if used on row boats over smooth water until the earth (water) becomes the obstruction and the signal is lost. That assumes both people are standing in the boat and holding radios at 6 feet AWL. If both people now sit in the boat, range will drop to about 3 miles until the earth becomes the obstacle again. Do an internet search on ‘Radio Horizon’ to see how this works. Also, here is a simple calculator to see what your best case scenario is: https://www.everythingrf.com/rf-calculators/line-of-sight-calculator.

As you will learn, the earth is an obstacle that blocks your signal quite dramatically. If there are hills between the two antennas, same thing. Hills are an earth obstacle. Now, if you go into a heavily treed area, or an urban area with lots of buildings everyone of these attenuates your signal to some degree too. All of these add up to reduce your range further. Mix distance, hills and other obstacles and range is squashed.

You will hear over and over phrases such as “Height is might”, “Height is King” and “Height is everything”. This is true for a couple of reasons. First, as each antenna goes up in elevation the radio horizon gets further and further way, so your theoretical maximum range on earth increases. Second, when you raise the antennas up, often the number and density of obstacles between the antennas drops too so your real-world range increases.

My simplex HT to HT range and HT to Mobile ranges mimics yours. However, when I use mobile to base communications with base antenna at 40’ I loose communications at around 4 miles. When I raise it to 56’ I loose all communications around 8 miles. Yet with both my base and mobile rights I can communicate with repeaters 22-50 miles away because the repeater antennas are so much higher than mine are. Higher antennas mean fewer obstacles, thus increased range.

Hope this helps


Michael
WRHS965
KE8PLM

Michael,

 

Thanks so much for such a clear explanation. I feel much better knowing this, I was worried there was something wrong with my setup. 

I quickly learned yesterday what you were saying about height, I had my radio on scan and finally started to pick up some noise so started driving around hoping to get a clearer signal. Only once I drove up a pretty significant hill in my area did I finally get a clear signal and could listen in. It was a few guys chatting on a repeater, but I have no idea which or where they were located so I could not talk back. There's only a handful of repeaters near me and most of them are part of the same system, I've reached out to get PL tones but havent heard back yet. Hopefully I can get on and make contact eventually. For now I will just be a listener.

[Need help with new setup - MXT400]

24 minutes ago, n4gix said:

The so-called "38-mile" range is nothing more than sheer fantasy. It assumes one on top of a 4,000' mountain talking with someone else down in the valley. Seriously! The best one can expect is nearly always less than 1 mile.

Absolutely agree, just wanted to give some context on the model of walkie used. I was expecting that I would stop hearing him way before he stopped hearing me 

[Need help with new setup - MXT400]

Hello all,

 

New operator here, WRMW445. Finally got my radio set up in my jeep, midland MXT400 with midland 6db gain antenna. Operating in Staten Island. Just performed first range test and am confused by the results.

 

I had my dad stay at home with a walkie, Midland X talker ("38-mile" version).

I figured I'd begin to drive away until he could no longer hear me, and then bump the power to medium, high and so forth until he could no longer hear me to get an idea of the range at each power level. I only made it about half a mile away before he could no longer hear me on low power. At this point he began to break up as well. I switched to medium and was able to travel a couple more blocks before he could no longer hear me. Then switched to full 40w power, and it didn't make a difference. We were using channel 19 so I know the radio was not limiting my output. The radio was also quite hot at this point. All told I made it about .8 miles from my house before I was out of range, hardly farther than the walkie talkies range. So something isn't right.

 

I know there are plenty of line of site obstructions in a suburban environment but this doesn't seem right to me. I'm using midlands NMO cable as between the radio and antenna as well. Any thoughts? I have no means to test SWR or even the knowledge to understand the readings, is there anyone local to me that might? Or is there anything obvious I can look for with with this setup?

 

Thanks in advance for feedback and suggestions.