New SDS200 has slight hum

[Darren418]

I just got an SDS200 this week from HRO and it too has the hum. Pressing lightly on the case does make the hum go away, so I guess it's the grounding issue like the others have reported. I think mine's a 2021 build also, and apparently before Uniden implemented the fix.

However, mine also has a bad USB connection. It will not recognize the scanner in Mass Storage mode no matter what I've tried (4 different computers, 3 USB cables and none will recognize the scanner). So the unit is going back as defective for the USB problem. I think I may ask for a refund and not an exchange since it looks like others have had problems with HRO, possibly old stock, who knows, and just order from another seller. I like the scanner just not the hassle of problems out of the box.

 

[N9JIG]

However, mine also has a bad USB connection. It will not recognize the scanner in Mass Storage mode no matter what I've tried (4 different computers, 3 USB cables and none will recognize the scanner). So the unit is going back as defective for the USB problem. I think I may ask for a refund and not an exchange since it looks like others have had problems with HRO, possibly old stock, who knows, and just order from another seller. I like the scanner just not the hassle of problems out of the box.

Are you using the Micro USB port on the front of the radio? The rear port does not function so it will not recognize the card.

 

[MStep]

I just got an SDS200 this week from HRO and it too has the hum. Pressing lightly on the case does make the hum go away, so I guess it's the grounding issue like the others have reported. I think mine's a 2021 build also, and apparently before Uniden implemented the fix.

However, mine also has a bad USB connection. It will not recognize the scanner in Mass Storage mode no matter what I've tried (4 different computers, 3 USB cables and none will recognize the scanner). So the unit is going back as defective for the USB problem. I think I may ask for a refund and not an exchange since it looks like others have had problems with HRO, possibly old stock, who knows, and just order from another seller. I like the scanner just not the hassle of problems out of the box.

If you read through this thread, you will find that Ham Radio Outlet (HRO) does not accept the "hum" as an issue. So if you are going to return it, definitely make sure there is something else demonstrably wrong with it and request a refund, not a replacement.

 

[Darren418]

Are you using the Micro USB port on the front of the radio? The rear port does not function so it will not recognize the card.

Bingo! That was it! Boy I feel like a real dummy. I’ve only been scanning for 40 years and every scanner has had the port on the back. Didn’t even think to use the one on the front. The manual isn’t clear on this either.

Well, chalk another one up to operator error.

I’ve now got the scanner firmware updated, database updated, and am on my way. It’s actually pretty intuitive and easy to figure out.

It still has the hum however. It’s quite noticeable when in a quiet environment. It changes tone as it scans. The hum changes to a constant tone when it is not scanning. I could see how in a vehicle you’d probably never notice it, but it’s clearly noticeable otherwise. Since this is going to be used bedside, the hum is unacceptable. I guess I’ll need to decide to send it to Uniden for the fix or attempt to fix it myself.

I thought the hum was resolved a year or two ago with a factory fix? Guess not.

 

[Ubbe]

I thought the hum was resolved a year or two ago with a factory fix? Guess not.

It's fixed by an added function in the firmware. A mute timer that silence the audio after a call ends. You can set how long time after a call when it will engage the audio mute.

That's probably the most suitable solution to use in your situation, without taking the scanner apart and modify it, but then there's a risk that you discharge static electricity on all components while you work on it, and it will start to fail and show all kinds of strange anomalies after several months. Use antistatic wrist straps and other precautions if you choose to handle electronic components.

/Ubbe

 

[JoeBearcat]

If this is the hum issue that was discussed in the past, it should have been squashed over a year ago.

Hum can still be caused by other things such as ground loops and bad power supplies.

 

[mikec10]

As an alternative to opening up your unit, you might consider setting the Audio Off Time in the Sentinel profile to a smaller number, which effectively silences the hum after any audio. Mine is set at 100ms. I still hear a slight hum when people are talking, but it's very tolerable. It's also important to mention that I also keep the volume level down around 2-3 most of the time. Your mileage may vary.

I received my SDS200 from Main Trading Co on 10/1/2022. Easy setup. I just loaded the SDS200 with the same favorite lists as my SDS100. After a couple of days I noticed there was a hum. After reading some info on the forums I was all set to open the unit up to see if there was the noise mitigation piece installed. I then saw your suggestion and gave it a try. I set the Audio Off at 100ms and it did the trick. I did not open the unit up and am very satisfied with the results. Thank you sir......