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SDS200 poor audio on analog

imd

Member
Joined
Jun 1, 2017
Messages
59
#1
Hi, I just received my SDS200 on Monday. I can clearly hear the 'tone' or 'buzzing' from the unit while sitting a few feet away. Anywho, that's not the point of this post. I'm hoping for some suggestions regarding the poor audio while scanning trunked systems with analog audio.

Here is the system I'm scanning:
https://www.radioreference.com/apps/db/?sid=330

I'm in good coverage, RSSI is -60, noise is 500 to 600. I've tried with and without attenuation, all the 'filter' settings, but it doesn't really help.

The issue:
Analog audio sounds raspy, distorted when dispatchers or other units that 'speak loud' while other units that must have the mic far way are 'quiet' but not distorted. Like the 'speak loud' users are over modulating the signal into distortion. It sounds so bad, my wife was asking me why my new scanner sounded so bad.

I don't think it's the system as I have other radios that this issue doesn't happen on (both Uniden and Whistler).

Another annoying issue is that quite often, to the point of being very annoying and not wanting to use the radio, in the middle of a transmission "LINK" will appear on the screen and the audio goes away. It probably misses a good 20% of the calls with this issue alone.

I want to be impressed by the radio, perhaps I'm missing something simple??
 
Joined
Sep 8, 2006
Messages
3,048
Location
Stockholm, Sweden
#2
Noise seems to be way too high, probably from interference. Try different filter settings HP and inverse and IFX and see which one will get the noise down below 25. As you have -60dBm you could use the attenutaor setting as well to bring it down to -80dBm which also should give a good signal without any background noise to speak of.

/Ubbe
 

imd

Member
Joined
Jun 1, 2017
Messages
59
#3
I've tried attenuation, all the different filters, no change. I don't think it's external noise from co-channel or adjacent channels. When someone keys up and doesn't speak, there is no noise, but when they start talking loudly, that gets distorted.
For example, the dispatchers turn 'the tone on' to indicate urgent traffic only. The channel is keyed for a long period of time with no talking but a tone every second. Even the tone comes out distorted but when no tone, no interference or noise. Then comes along a unit who's got the mic far away from his face and talks. The audio is low but very clear and no distortion.
 
Joined
Apr 3, 2018
Messages
70
#6
I think I know what you’re talking about and honestly I think it’s a problem we just have to put up with. There are some people that ‘eat the mic’ with naturally loud voices and those with very soft voices that hold the mic too far away. The loud mic-eaters’ voice is always distorted, regardless of system has been my experience. This is even true with actual radios on the system. I don’t think there will ever be a ‘fix’ unless the user that’s talking is offered some training.
 

N5XTC

Member
Premium Subscriber
Joined
Dec 24, 2012
Messages
817
Location
Hampton, Virginia
#8
I've monitored public safety comms since the late 1960s and this has always been an issue. Some agencies just don't supervise their dispatchers properly.
we have one here who talks so fast you can't copy her. i have made videos and posted. you would think there would be training for DSP. guess not.
 
Joined
Apr 3, 2018
Messages
70
#9
we have one here who talks so fast you can't copy her. i have made videos and posted. you would think there would be training for DSP. guess not.
Most never take the time to hear a replay of themselves and the others are too afraid of offending them by saying ‘you sound like you’re eating the mic.’
 

imd

Member
Joined
Jun 1, 2017
Messages
59
#10
Sorry, I shouldn't have used the analogy of "speak loud", I kind of thought it was poor choice to describe it and was hoping the other info I posted would highlight the problem better.

I don't think it's someone eating the mic, as I mentioned, the same station, the same time, on all my other scanners sound fine, it's only SDS200 that has this distortion. Also, the fire tone out and police emergency traffic tone is distorted and this isn't happening on my other radios. I would have to imagine the fire tone and police tone outs amplitude and deviation are set properly.
 

imd

Member
Joined
Jun 1, 2017
Messages
59
#11
Wondering if anyone else has listened to a similar analog trunked system on their SDS200 and can provide some feedback about audio quality? If they are experiencing the same distortion I am hearing? Preferably with the ability to compare the audio from another source (non SDS rig?) at the same time?

System Type: Motorola Type II SmartZoneSystem Voice: Analog and APCO-25 Common Air Interface
 
Joined
Dec 20, 2016
Messages
286
#12
I've tried attenuation, all the different filters, no change. I don't think it's external noise from co-channel or adjacent channels. When someone keys up and doesn't speak, there is no noise, but when they start talking loudly, that gets distorted.
For example, the dispatchers turn 'the tone on' to indicate urgent traffic only. The channel is keyed for a long period of time with no talking but a tone every second. Even the tone comes out distorted but when no tone, no interference or noise. Then comes along a unit who's got the mic far away from his face and talks. The audio is low but very clear and no distortion.
BlackTank-For the $699.95 price tag, I would send this back as fast as you can and notify your credit company to debit the merchant. How long have you had this product? This is why I never buy SOMETHING that first came out. I know there was just a firmware update on this SDS200 top of line base. I'm sure that other members can assist you more then me. Hope you have a nice Thursday and upcoming weekend sir.
 

UPMan

Uniden Representative
Premium Subscriber
Joined
Apr 19, 2004
Messages
13,287
Location
Arlington, TX
#14
It is possible that the system is transmitting slightly wider than the NFM filter expects. Try setting the system to FM and see if it helps.
 

imd

Member
Joined
Jun 1, 2017
Messages
59
#15
Thanks for the reply. I resolved the issue by changing the modulation type from "AUTO" to FM. It appears AUTO must have been NFM. The system isn't NFM.

I couldn't find the analog BW setting for the system in RR dB. I'm wondering if it's not there and when importing into Sentinel, it gets set to AUTO and AUTO didn't work right. The dB should have an attribute for FM bandwidth so it gets set correctly on the radio!

I'm sure others have the same issue. I was ready to return the radio until I did the switch last night. You should create a tech bulletin for people reporting bad / distorted audio on Analog systems, and or fix "AUTO". I'd imagine you are getting returns for this issue.
 
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