Wideband Interference - Oh my!

[WRMA547]

Lately I have been running into a persistent issue with Rx. When I set my radio to WB it seems I am getting constant (by appearance) Rx Interference.  However, if I set the same channel to NB, it goes away, but I deal with the limitations on NB.

 

I've done the basic logical troubleshooting and ruled out radio, cable, and power. Checked SWR, just to be safe (1.2), and also connections. The Interference seems to stay. I can still pickup others near me and transmit, but the static Interference remains as soon as the PTT is released. When transmitting in WB others mention I am choppy or unclear, then when in NB I "sound like a CB".

 

I am at a loss as I am rather new to this. Any thoughts on what I can test or try?

 

Equip:

Radio - Midlands MXT575

Antenna - MXAT05VP

[SteveShannon]

15 minutes ago, WRMA547 said:

Lately I have been running into a persistent issue with Rx. When I set my radio to WB it seems I am getting constant (by appearance) Rx Interference.  However, if I set the same channel to NB, it goes away, but I deal with the limitations on NB.

 

I've done the basic logical troubleshooting and ruled out radio, cable, and power. Checked SWR, just to be safe (1.2), and also connections. The Interference seems to stay. I can still pickup others near me and transmit, but the static Interference remains as soon as the PTT is released. When transmitting in WB others mention I am choppy or unclear, then when in NB I "sound like a CB".

 

I am at a loss as I am rather new to this. Any thoughts on what I can test or try?

 

Equip:

Radio - Midlands MXT575

Antenna - MXAT05VP

Are you operating from a vehicle or as a base station? You seem to be describing two different things: “static interference after releasing the PTT” and choppiness and poor quality audio while transmitting.  

Let’s take them one at a time. First, static interference.  Do you mean that you hear static immediately after letting go of the PTT?  How long does it continue? Static is always present to some extent. The squelch control turns off the audio when the signal strength is below a certain threshold. Turning up the squelch increases the threshold. Have you tried turning up the squelch?

[MarkInTampa]

Just on one channel or all of them?

 

[WRUU653]

My first thought was squelch as well. However I do have a question, is it on all channels or just one? I ask because I get interference on one frequency in one vehicle.

 Edit- @MarkInTampa beat me to it.

Edited January 13 by WRUU653
^^^

[WRMA547]

Ok, trying to reply to all. I SHOULD have mentioned that and I whiffed. 

Squelch has been adjusted to rule out out of range Tx. I've gone as high as 8 and 9 with the static present. It persists as soon as I release the PTT and doesn't seem to stop unless I get a clean TX coming in. Then, as soon as over, it starts again. 

At first, it was just channels 7 and 17, but seems to be present on most channel when I switch to wideband. 

 

This is set up in my Jeep. After installation it worked great, this is a new phenomenon that started a few weeks back. 

[SteveShannon]

58 minutes ago, WRMA547 said:

Ok, trying to reply to all. I SHOULD have mentioned that and I whiffed. 

Squelch has been adjusted to rule out out of range Tx. I've gone as high as 8 and 9 with the static present. It persists as soon as I release the PTT and doesn't seem to stop unless I get a clean TX coming in. Then, as soon as over, it starts again. 

At first, it was just channels 7 and 17, but seems to be present on most channel when I switch to wideband. 

 

This is set up in my Jeep. After installation it worked great, this is a new phenomenon that started a few weeks back. 

That helps. Does it only happen when the jeep is running or also when everything but the radio is turned off?

[WRMA547]

50 minutes ago, SteveShannon said:

That helps. Does it only happen when the jeep is running or also when everything but the radio is turned off?

Both. I at first thought power wires were too close, so I adjusted the ant cables and they're now not near any power wires AND I rewired to thicker power and ran direct to battery for power. I also used the ferrus insulators. 

[SteveShannon]

Send the radio back. Or at least try a different radio to see if the problem persists. 

[gortex2]

So it only happens when Jeep is on ? Alot of folks add aftermarket LED lights to jeeps that casue a ton of interfearance. If its only when key is on or running I'd check to see what turns on with the key. If its present regardless then its a radio issue. 

[WSGJ919]

I gave up trying to use my Radioditty DB-20G in wide band. I tried all the settings with squelch tail and other settings. I just set all my channels to narrow band 12.5 and the radio does not hang anymore with squelch wide open(set it back to 2 not the 8 I had it). I have two DB-20G's that do this. I wish they would come up with some new firmware and address the open squelch with wide band annoyance. Otherwise my family and the people I talk to do not hear a difference in narrow band or wide band. Problem solved IMO .

Jim

 

[WRYZ926]

@WSGJ919 I would still send it back for repair or replacement.  While you haven't seen much difference between being heard, you did not mention if that was on simplex or through a repeater. There can and will be a difference when using a repeater. We can always tell when someone talks on our repeater that is using narrow band because they are hard to hear and understand.

[GrouserPad]

Interesting, to to recap, have you determined if this is RX interference being caused by your vehicles electronics, or maybe a noisy power line transformer close to your operating area? Could be an old street sign flickering outside or a badly shielded electronic appliance that is running in your house. I’ve even seen alarm clocks that “blink” or flash cause significant interference to radios. Just throwing this all out there. Sometimes something as simple as just moving the mag mount to the other side of the cab front to back can make a difference. 

[SteveShannon]

I don’t think it’s interference (referring to the issue reported by @WSGJ919, not necessarily the OP’s issue).  There have been other reports of the db20g not returning to a squelched state after transmitting.  My friend Jack experiences that frequently, with squelch remaining open for four or more seconds until someone else transmits on the same channel. It’s interesting that it happens in wideband but not narrow, though. I’ll see if Jack’s radio has the same result when switched to narrow rather than wide..

[nokones]

If others are receiving you choppy and/or garbled on wideband emissions and clear not choppy or garbled on narrowband emissions than the other users more than likely are using FRS radio that have to be set for narrowband emissions or their non-FRS radios are programmed for narrowband emission operations, which means you should also have your radio set for narrowband emission operations so they can receive you clearly. And, that will resolve the interference you're receiving when operating with Wideband emissions on the affected channel.

Most inexpensive radios will definitely notice the difference in the audio tone quality because those radios do not have the quality filtering components as professional radios possess.

[nokones]

1 hour ago, SteveShannon said:

I don’t think it’s interference.  There have been other reports of the db20g not returning to a squelched state after transmitting.  My friend Jack experiences that frequently, with squelch remaining open for four or more seconds until someone else transmits on the same channel. It’s interesting that it happens in wideband but not narrow, though.

I guess you could call that "wideband noise"

[nokones]

3 hours ago, GrouserPad said:

Interesting, to to recap, have you determined if this is RX interference being caused by your vehicles electronics, or maybe a noisy power line transformer close to your operating area? Could be an old street sign flickering outside or a badly shielded electronic appliance that is running in your house. I’ve even seen alarm clocks that “blink” or flash cause significant interference to radios. Just throwing this all out there. Sometimes something as simple as just moving the mag mount to the other side of the cab front to back can make a difference. 

Make sure that your antenna system is grounded to the vehicle ground at the mount and not just through the coax connection.

Also, do not ground your radio negative power lead directly to the battery with the later model vehicles that are laden with LED lighting and various control modules connected to a CAN system. Connect your negative power lead to a factory chassis grounding point. There is one in the front passenger kick panel well.

[WRYZ926]

25 minutes ago, nokones said:

Also, do not ground your radio negative power lead directly to the battery with the later model vehicles that are laden with LED lighting and various control modules connected to a CAN system. Connect your negative power lead to a factory chassis grounding point. There is one in the front passenger kick panel well.

That can't be stated enough with newer vehicles AKA computers on wheels.

[GrouserPad]

My experience installing Cb radios in probably over 50 different dump trucks/haul trucks/dozers and excavators over the years (I work construction/trucking and am by no means a rf expert) is that if there was an rf interference issue caused by a machine or trucks electrical system then running the power AND ground straight to the battery was the best option and nearly always fixed the electrical interference. A lot of times tapping into spare fuses for power or auxiliary switches with supplied power nearly always resulted in rf getting into the radios receiver. And on a few occasions I’ve had to run flat braid copper straps to bond the chassis to the frame and this stopped a lot of interference for me too for some reason. 
 

I know this goes against what most of you have said above but for 27mhz with cb; to the battery IS the way to go far as I’m concerned. 

[WRYZ926]

7 minutes ago, GrouserPad said:

My experience installing Cb radios in probably over 50 different dump trucks/haul trucks/dozers and excavators over the years (I work construction/trucking and am by no means a rf expert) is that if there was an rf interference issue caused by a machine or trucks electrical system then running the power AND ground straight to the battery was the best option and nearly always fixed the electrical interference. A lot of times tapping into spare fuses for power or auxiliary switches with supplied power nearly always resulted in rf getting into the radios receiver. And on a few occasions I’ve had to run flat braid copper straps to bond the chassis to the frame and this stopped a lot of interference for me too for some reason. 
 

I know this goes against what most of you have said above but for 27mhz with cb; to the battery IS the way to go far as I’m concerned. 

That use to be the best way to hook up radios but that doesn't work very well with modern vehicles with all of the computers and battery management system onboard.

I know battery chargers/maintainers are different than two way radios, but the manufacturers don't even want you to connect a charger to the negative terminal of the battery on newer vehicles. They will state to use a good chassis ground so you don't take any chances of messing up the battery monitoring system or computer modules.

[SteveShannon]

2 minutes ago, WRYZ926 said:

I know battery chargers/maintainers are different than two way radios, but the manufacturers don't even want you to connect a charger to the negative terminal of the battery on newer vehicles. They will state to use a good chassis ground so you don't take any chances of messing up the battery monitoring system or computer modules.

Although (as you pointed out about the BMS) there’s an even greater reason to do that now, it has been that way even before BMS.  You want the final connection to the battery (which almost always sparks) to be somewhere else other than near the vents of the battery so the hydrogen gas released by the battery doesn’t explode.
I knew of a guy who was blinded when a truck’s battery exploded with his face above it. I was 18 or 19 and working for the same oilfield roustabout company as he was.  I’ve taken it very seriously ever since.  The final connection is to a point on the chassis.

[WRYZ926]

Most vehicles with the Auto Stop Start systems all use sealed and spill proof AGM batteries. AGM batteries are a whole lot safer than a standard flooded lead acid battery. And the Auto Stop Start system is standard on most newer vehicles now days. I do agree that you should always be cautious when working around any type of battery.

[WSGJ919]

On 1/15/2025 at 5:45 PM, WRYZ926 said:

@WSGJ919 I would still send it back for repair or replacement.  While you haven't seen much difference between being heard, you did not mention if that was on simplex or through a repeater. There can and will be a difference when using a repeater. We can always tell when someone talks on our repeater that is using narrow band because they are hard to hear and understand.

I bought the radio and obtained the GMRS license so my family can keep in contact with me while I am mobile. There is a repeater or two in Roswell NM that is 40 miles  away. While it was fun to talk to some of those guys my primary reason to use this radio is for family coms. So I am satisfied. I have heard of other people sending in there units to only have the new radio doing the same. Simplex and the less than 20 watts the DB-20 provides is sufficient for me. Also the radio in my F-150 is not a Radioditty DB-20G so I have no problem talking to Roswell repeaters with it.

Jim

 

[WRYZ926]

52 minutes ago, WSGJ919 said:

I bought the radio and obtained the GMRS license so my family can keep in contact with me while I am mobile. There is a repeater or two in Roswell NM that is 40 miles  away. While it was fun to talk to some of those guys my primary reason to use this radio is for family coms. So I am satisfied. I have heard of other people sending in there units to only have the new radio doing the same. Simplex and the less than 20 watts the DB-20 provides is sufficient for me. Also the radio in my F-150 is not a Radioditty DB-20G so I have no problem talking to Roswell repeaters with it.

Jim

 

Go with what works for you.

That being said, it sounds like there are some issues with the DB-20G that need to be addressed. The radios should work fine when set to wide band without any interference. And it is obvious that there is a problem with the radio since people are having issues when transmitting on wide band. And the seller and/or manufacturer will not know about the issues if people don't let them know.

[WSGJ919]

4 hours ago, WRYZ926 said:

Go with what works for you.

That being said, it sounds like there are some issues with the DB-20G that need to be addressed. The radios should work fine when set to wide band without any interference. And it is obvious that there is a problem with the radio since people are having issues when transmitting on wide band. And the seller and/or manufacturer will not know about the issues if people don't let them know.

Radioditty DB20G in the junk box now. Tired of this crap with this radio. It is now hanging up with the channels set to narrow. I will just carry the Tidradio HT with me within a couple of miles in town. Just as good. Radioditty fix this crap! I can go with a radio not type excepted and be done with it. Thought I would be technically legal with the DB20G. jeesh...

Jim