Sds200 humming noise

[timdevaney]

Hi all

So, I just bought a brand new sds200 from Amazon and have it shipped to New Zealand much to my disgust I plugged it in and there was an absolutely horrible humming noise coming from it. It was thickening absolutely sickening for a radio that cost me 1300 New Zealand dollars. For that type of money. I expect nothing, but the best my understanding was there had been issues with Scanners having the hum issue and then other people not having the issue, so I'm confused. Why are some having the issue and others are not? Is it just a bad batch of radios or am I missing something? Anyway, I've sent the radio back to Amazon And I requested a refund. And have ordered another brand new sds200 from a different supplier on Amazon what's the story with the hum have unidan implemented effects on this to all new scanners moving forward, or are they not doing anything about it? I thought that by buying a brand new. Sds200 the humming issue would have been fixed in it by now. Possibly I got an old unit. I don't know. So what I'm hoping is the unit I have ordered. To replace the defective unit has just been manufactured. And the hum issue is fixed. Am I getting this right or are you needing not doing anything about the issue at all and just leaving it. Sorry for all the questions. I'm kind of new So I'm learning the ropes. . Thanks kindly. Appreciate everyone's advice and help as always.

 

[StaticDischarge]

Sorry to hear you are just one more customer effected by this...

Yes, there was an oversight on Uniden's R&D concerning proper grounding of the front display board thus is the hum you experienced. Uniden did supply a "NMP200 mitigation part" that did in fact reduce the hum but later we discovered that there were dissimilar metals that oxidized/corroded and thus the hum returned. As of yet, other than the NMP200 part, we do not know what Uniden is doing about this...

Being one that was effected I decided to dig into it and try to figure out why, and I did. I have a sticky on this forum that explains what is needed to perform "My SDS200 HUM fix" and what is causing it. Click on that link and find out...

 

[hiegtx]

There is a very long, closed thread, that this topic generated:

SDS200 Hum Reports

We are aware of the reports of hum in the SDS200 and are working on a solution. At this time, we expect the solution to involve both hardware and software...but the hardware portion looks to be something anyone can do themselves. I don't have complete details, today, but hope to have a video...

forums.radioreference.com

You can read all the details buried in there. But basically, this seems to be an internal grounding problem in the scanner. There is one fix, posted by a different member, as how to end the issue. Uniden originally (in the U.S.) offered apart to be wedged in between the case & the chassis. That worked for some, but not for all. And, not everyone had a problem. I have one of the first SDS200s, and never had this issue.

Edit to add- I see StaticDischarge has provided a link to his fix, which, based on posts, is very effective, and not hard to do. I was about to include tha, but the author of the fix stepped in to provide it for you.

 

[timdevaney]

Sorry to hear you are just one more customer effected by this...

Yes, there was an oversight on Uniden's R&D concerning proper grounding of the front display board thus is the hum you experienced. Uniden did supply a "NMP200 mitigation part" that did in fact reduce the hum but later we discovered that there were dissimilar metals that oxidized/corroded and thus the hum returned. As of yet, other than the NMP200 part, we do not know what Uniden is doing about this...

Being one that was effected I decided to dig into it and try to figure out why, and I did. I have a sticky on this forum that explains what is needed to perform "My SDS200 HUM fix" and what is causing it. Click on that link and find out...

Hey

Thanks for the reply. Yes, that's a bit upsetting that are radio that cost so much money is not very well designed obviously. I did read your thread while I kind of understand it. There is no way I am confident enough to do anything like that at all. I have a brain injury. And a very unsteady hand and would probably end up causing More Damage if I tried to do it myself. So I'm not quite sure what to.do. I'm just hoping the replacement unit I received is not one that has this issue. Otherwise, I will just keep sending them back until I eventually get one that doesn't Humm I thought I could live with the hum. But after having it on last night and listening to it. The hum just about drove me mentally insane. And sadly I had to unplug the unit and put it back in its box.

 

[timdevaney]

Hey

Thanks heaps to everyone that's replied. I know there's people from Uniden on this Forum it's a damn shame. They haven't picked up on this and have made a permanent fix to any units produced from when this problem was discovered. Obviously they don't care. I don't know. But I will wait till my replacement arrives and pray that it does not hum if it does. I will deal with that when the time comes. I'm just not confident at opening it up and missing with the inside of it. Due to my brain injury causing a severely unsteady shaky hand. Thank you to everyone that's replied. It's greatly appreciated. And I kind of have a better understanding of the issue now. Here's hoping my new replacement. Is ok. Cheers Tim

 

[Ishmole]

I am so sorry that you are having this problem. I ordered my SDS200 on Amazon also last week and was also concerned that I would get a radio that has that problem. The radio arrived and has absolutely no hum.
Hopefully your replacement will work quietly! I think your chances are good. Let us know how it turns out.

 

[timdevaney]

I am so sorry that you are having this problem. I ordered my SDS200 on Amazon also last week and was also concerned that I would get a radio that has that problem. The radio arrived and has absolutely no hum.
Hopefully your replacement will work quietly! I think your chances are good. Let us know how it turns out.

Hey

Do you know which store you bought it from? There are only a few that sell them I bought my replacement from CE STORE fulfilled by Amazon So, hopefully I get a decent unit. I promise I will let you guys know as I really love the unit just cannot stand the humming noise.

 

[Ishmole]

I believe the supplier was called iSave

 

[Ishmole]

What I love about this radio is the great performance on simulcast P25. I am hearing systems that were deaf on my BCD 536.

 

[timdevaney]

I believe the supplier was called iSave

That's where I got my first unit from. The defective one weird oh well, who knows we'll see what happens when you got yours. Was your box completely sealed? Like you know how when you buy something new quite often they put that clear security seal tape over. The sides of the boxes so you know if it's been opened or not? The reason I ask is mine was not sealed. Like edit being sent to someone else. They obviously noticed the squealing problem. Sent it back to Amazon and then it was sold to me as a new product. I don't know just seems weird as normally. You needed products are sealed.

 

[hiegtx]

That's where I got my first unit from. The defective one weird oh well, who knows we'll see what happens when you got yours. Was your box completely sealed? Like you know how when you buy something new quite often they put that clear security seal tape over. The sides of the boxes so you know if it's been opened or not? The reason I ask is mine was not sealed. Like edit being sent to someone else. They obviously noticed the squealing problem. Sent it back to Amazon and then it was sold to me as a new product. I don't know just seems weird as normally. You needed products are sealed.

Don't forget that, for the "Fulfilled by Amazon" orders, Amazon is just pulling one out of a bin. The stock in that bin could have come from anyone of several different sources, so you won't get one that comes 'directly from iSave' or any other vendor, Just the first one they grab & ship to you.

 

[VK3RX]

Bought a SDS200 from Scannermaster last month, it seems to be a late serial (834Z980009nn) so presumably has a factory "fix" of some sort, but it does have the hum/digital noise issue.

However to me its not intrusive, noticeable if within 300-400mm but not outside that. Lower level with the internal speaker, but that's probably because it faces down.

I can imagine it might be a PITA if the SDS200 is on a desk you sit in front of.

 

[Ubbe]

The SDS100/200 scanners are directed to people that have problems to receive systems that use simulcast technique. The receiver section in these scanners do not have the same dynamic range as Unidens other scanners. They have problem to receive both weak signals and strong signals at the same time.

They use a receiver chip that are designed for television sets and satellite boxes and doesn't have the sensitivity required for scanner use. So Uniden added a pre-amp to boost sensitivity but that makes it prone to overload issues from strong signals, that either creates interferencies or reduce the receivers sensitivity. To improve reception Uniden added filter settings that tries to reduce the offending frequencies either above or below the monitored frequency, but not both at the same time, and at the other side of the filter it will be wide open for interferencies. Uniden then added the Wide setting of the filters to go half way in filter effectiveness and only open the door half way on the other side.

Television and sat-boxes receives signals mostly in the 500-2200Mhz band and the receiver chip in the SDS100/200 seems to be optimized to that frequency range and will perform less favourable below 500Mhz.

Even Uniden themselves recommended to use other scanners, BCD436/536HP have the same features, if you do not suffer from simulcast issues. It's a higher risk of getting into problems with these scanners than Unidens other models due to the receivers design.

I don't see any reason to sell, or buy, these SDS scanners outside of US/Canada except for increased profit.

I hope that Uniden by now have changed the circuit board manufacturing for the control head to mask off the area for the screws to make them ground the circuit board better, or at least added jagged washers that cut through the film that's on top of the copper foil.

/Ubbe

 

[buddrousa]

I and many more owners beg to differ with you UBBE I have a SDS200 sitting in a scanner rack with 4 15x's 6 996p2's and 5 536's all sharing the same antenna at the same time and the receiver in the SDS200 hears the same traffic at the same range in the same bands as the other 15 scanners ANALOG P25 DMR NXDN UHF VHF and 800. Again how well does the SDS200 you own work?

 

[phask]

I know you are unable to do the fix mentioned. Maybe you could find a Ham or someone through a Ham club that could do it.

I'll add that I did it, it was not that hard as I just took my time, followed the photos and was careful.

Honestly, any teenage computer/robotics savy builder could do it. Might check with local schools as well.

 

[W1KNE]

I and many more owners beg to differ with you UBBE I have a SDS200 sitting in a scanner rack with 4 15x's 6 996p2's and 5 536's all sharing the same antenna at the same time and the receiver in the SDS200 hears the same traffic at the same range in the same bands as the other 15 scanners ANALOG P25 DMR NXDN UHF VHF and 800. Again how well does the SDS200 you own work?

These are my results as well. Other than some overload from a repeater located a mile away from me. (Which causes troubles with my 785D also), it's a phenomenal performer for me. It picks up stuff the other stuff hasn't.

I too have the noise issue, and it came with the factory fix installed. I found the insert piece from Uniden didn't make good enough contact, so I wedged some tape in to make better contact, and it worked well for a while. I think it's worn some and needs to be re-wedged.

 

[VK3RX]

These are my results as well. Other than some overload from a repeater located a mile away from me. (Which causes troubles with my 785D also), it's a phenomenal performer for me. It picks up stuff the other stuff hasn't.

I also find that compared to a UBCD536 & UBCD436 there are less missed transmissions with my SDS100 & SDS200.

I too have the noise issue, and it came with the factory fix installed.

The fact that some units still have the noise and some don't suggests Uniden's final assembly check before packing needs investigation.

 

[maus92]

I just bought a second SDS200 last week, and it does not have to "hum" that some units seem to produce. The first one does have a very slight "hum," but it's a mobile unit so tire and wind noise produced by the vehicle is much louder. Even when the vehicle is turned off and stilling still, you cannot hear it - the ambient noise of the environment is louder.

 

[N8SHA]

I've had my SDS200 for a about a year and a half now. For most of that time, it sat on top of the desk and I never really noticed an issue. I recently mounted in in a rack with several other radios, connected an external speaker, and started experiencing the issue. The hum is there, but not super noticeable. What drives me crazy is a "pop" or "click" at the start of receiving a transmission.

I ordered the NMP200, only to discover that it had already been installed at the factory. I added the one I ordered for kicks to see if it would help. It's mildly better, but it is still difficult to listen to. Unplugging the external speaker isn't much of a help since now the audio is too muffled to listen to being mounted in the rack.

Anybody know if the fix posted by @StaticDischarge helps? Anyone have other suggestions?

-Matt

 

[fxdscon]

Anybody know if the fix posted by @StaticDischarge helps? Anyone have other suggestions?

-Matt

I don't think there have been any instances where that fix was applied, and the result was anything less than 100% .

All of the units I have encountered didn't have the hum, and I didn't open them up to check for the factory fix.

.