SDS-200 Speaker Noise Again like the 536HP

[trentbob]

I’ve only had mine since Tuesday and I can’t hear anything from mine. Even since this thread started I got my ear as close as I could to the speaker without touching it and still can’t hear anything like described in this thread.


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The first thing I would say is would you like to sell your radio? PM me, I think you'll like what I offer as it will be quite a premium and you can always just order another one, they're all the same right?

I think it's been established here ad nauseam that there are different degrees of the problem and it is potluck. I have seen a few posts here like yours and you are just a lucky guy.

This purchase should not be based on luck, it should be based on product quality and dependability.

Don't sell me your radio of course because you may not be able to duplicate what you have. I would love to have the radio that you have.

Congratulations and enjoy.

 

[tkowalik]

We, collectively as a scanning community, are going to solve this. I am no Uniden cheerleader but the products (100/200) are good. The 200 has an issue; I am certain Uniden is actively working on finding the root cause as are amateurs like myself. We are narrowing it down. Once resolved, I think all purchasers are going to be very happy.

“Always stay humble and kind” and work together to solve a problem.

 

[markjrenna]

I have yet to drop my 700 since I believe there are problems as they are clearly presented in this forum. What is frustrating to me is it seems there is a good batch and a bad batch. I don't feel lucky. But now I may just order from scannermaster as they seem to understand what customer service is while others clearly don't. And also frustrating is I am a Uniden scanner fan... Have now and have had a bunch. Never thought twice about ordering any of them. But I am guessing there is an issue but it may not come across in these videos all that well (for me) but Uniden playing like "what problem?" is rather disturbing too. Dice... roll... I'll try in March... maybe.

 

[ColdnFrosty]

We, collectively as a scanning community, are going to solve this. I am no Uniden cheerleader but the products (100/200) are good. The 200 has an issue; I am certain Uniden is actively working on finding the root cause as are amateurs like myself. We are narrowing it down. Once resolved, I think all purchasers are going to be very happy.

“Always stay humble and kind” and work together to solve a problem.

Have you found that there seems to be some relationship to how the top inner cover makes contact with the top of the display?

 

[Tramagod]

The first thing I would say is would you like to sell your radio? PM me, I think you'll like what I offer as it will be quite a premium and you can always just order another one, they're all the same right?

I think it's been established here ad nauseam that there are different degrees of the problem and it is potluck. I have seen a few posts here like yours and you are just a lucky guy.

This purchase should not be based on luck, it should be based on product quality and dependability.

Don't sell me your radio of course because you may not be able to duplicate what you have. I would love to have the radio that you have.

Congratulations and enjoy.

So sell yours and get another or just return it, problem solved. And for the record, I never said these problems are non existent, I’m just saying my radio doesn’t have them.


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[trentbob]

So sell yours and get another or just return it, problem solved. And for the record, I never said these problems are non existent, I’m just saying my radio doesn’t have them.


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Yes I see now how you got that impression, the comments about the radio problems were actually not meant to be directed to you, sorry about that. I have seen a few posts of people that have a problem free radio and that was my comment about you. Sorry about the rest I really didn't mean that directed towards you but I guess to the whole community. I didn't mean that you said there was no problems with the radios.

I was half kidding about buying your radio and being sarcastic.

The last part was sincere. I would love to have one of these radios without issues. It seems like getting one from a dealer at this point may be a problem so I'm going to wait and maybe down the line I will be able to get one.

The part about congratulations and enjoy your radio are very sincere. You are a lucky guy.

 

[cxgy2]

Got my SDS200 yesterday. Yes, I can hear the CPU noise within 13" of my external speaker. But it's quiet and since I don't sit right in front of the speaker, I don't hear it at all. And if the RR forums didn't exist, I wouldn't even think it was an issue. Zero noise with headphones. I'm getting used to the clicks between transmissions that are absent on my Icom R-8600 when it scans. It's definitely a keeper!

 

[escortz28]

Have you found that there seems to be some relationship to how the top inner cover makes contact with the top of the display?

Yes, there is definitely a relationship - when pressure is applied to the top inner cover near the display, the digital noise is greatly attenuated from both the internal speaker as well as external speaker output. A solution developed from work by tkowalik and myself: https://forums.radioreference.com/t...ified-for-sds-200-speaker-noise-issue.383622/

This does not address the root cause, it addresses the observable symptoms.

 

[BigC801]

We, collectively as a scanning community, are going to solve this. I am no Uniden cheerleader but the products (100/200) are good. The 200 has an issue; I am certain Uniden is actively working on finding the root cause as are amateurs like myself. We are narrowing it down. Once resolved, I think all purchasers are going to be very happy.

“Always stay humble and kind” and work together to solve a problem.

Uniden said the noise was normal so I doubt they are "Working On It"

 

[bob550]

With no luck. Did it have any effect on lowering the hum.

Theoretically, the ground loop isolator should have no effect on eliminating the hum when using an unpowered external speaker. Since the speaker is not plugged into an electrical circuit, there would be no ground loop established.

Years ago, I had a situation for which a ground loop isolator was effective. I had a scanner connected to a tape recorder with both electrically connected to a common power strip. Because the scanner and recorder also had a common audio connection, I'd get a bad hum on all recordings. Placing the isolator in line with the connecting audio cable eliminated the hum with no adverse effect on volume. In this case, the problem was accidentally caused by establishing two grounding points for the both the scanner and recorder.

 

[cxgy2]

Even though I have no noise at my normal listening distance, I found myself instinctively getting closer to the external speaker this morning when listening to a weak airband SAR signal. So rather than take the cover off and risk making the noise worse (since it's "ok" right now), I put a 4.7 ohm resistor in series with the speaker. This lowered the range of detectable noise from 13" down to 8". i.e.- I can't hear any noise beyond 8". (Speaker is an old Radio Shack mini-bookshelf.)

 

[RF23]

Uniden said the noise was normal so I doubt they are "Working On It"

You might wish to look at post #375 by UPMan.

 

[maus92]

Interestingly, removing the SD card makes the noise go away. Replacing it doesn't do anything. Now I'm eyeing the processor and how it ties to the screen. Closing in on the problem.

Data point: Removing the SD card makes no difference in the noise emanating from my radio (and the radio won't function without it.)

 

[trentbob]

Yes, there is definitely a relationship - when pressure is applied to the top inner cover near the display, the digital noise is greatly attenuated from both the internal speaker as well as external speaker output. A solution developed from work by tkowalik and myself: https://forums.radioreference.com/t...ified-for-sds-200-speaker-noise-issue.383622/

This does not address the root cause, it addresses the observable symptoms.

I just want to say again thank you to you and tkowalik. When I saw his videos the wheels in my head started turning and I was thinking of everything I could including felt and cloth, the whole time I had a roll of 3m double-sided tape on my desk in front of me and it just never hit me. I've been using that stuff for years just like a lot of us here and I just didn't see it.

Kudos to both of you.

 

[Ubbe]

I put a 4.7 ohm resistor in series with the speaker.

A speaker are a huge coil, a lot of impedance that needs to be kept under control from the very low impedance from the amplifier. Put a 2.2 ohm resistor over the speaker to have better control over it or it will have a less distinct sound and are more difficult to hear what's actually being said. Always try to use as low resistor value as possible in series with a speaker and add a lower values in parallell with the speaker to reduce its volume.

/Ubbe

 

[m42duster]

When I set my avoid list and have it scanning just my local area, the noise is even more intense with a rapid repeating sequence. Hope that makes sense, but I'm only scanning 4 departments. Of course, it scans that rapidly and there is like a little tempo going on. The headphone jack is quiet as a mouse.

beep beep beep... boop boop... beep beep beep... boop boop....lol, get the point? Make a good electronic warfare broadcast.

 

[tvengr]

I didn't notice the noise until I connected the scanner to an audio mixer and listened with a good pair of headphones. At first, I thought it sounded like noise generated by a switching power supply, but that wasn't the case. I substituted an old transformer supply, but still had the same digital noise. I have used many other scanners for feeding sound systems at fire department events and had no problems. The headphone jack of the SDS100 sounds clean into my mixer, even running on an AC supply. The problem seems to be only SDS200 related. It isn't caused by a hum loop since the problem is there in the scanner speaker with nothing else connected to the scanner. The noise is being inserted after the volume control. It remains constant at all volume settings. My guess is that we are either getting crosstalk into the audio output stages from radiated signals or that there is insufficient decoupling on the audio output power supply bus. In either case, the SDS200 is useless for feeding sound systems.

 

[m42duster]

Yeah, I had to remove it from my feed. Terrible

 

[maus92]

I didn't notice the noise until I connected the scanner to an audio mixer and listened with a good pair of headphones. At first, I thought it sounded like noise generated by a switching power supply, but that wasn't the case. I substituted an old transformer supply, but still had the same digital noise. I have used many other scanners for feeding sound systems at fire department events and had no problems. The headphone jack of the SDS100 sounds clean into my mixer, even running on an AC supply. The problem seems to be only SDS200 related. It isn't caused by a hum loop since the problem is there in the scanner speaker with nothing else connected to the scanner. The noise is being inserted after the volume control. It remains constant at all volume settings. My guess is that we are either getting crosstalk into the audio output stages from radiated signals or that there is insufficient decoupling on the audio output power supply bus. In either case, the SDS200 is useless for feeding sound systems.

Data point: The audio output via LAN is pristine.

 

[m42duster]

That's my next step.