SDS200 Hum repaired, but returned

[StaticDischarge]

This is great!
Also worth noting that staticdischarge does come from an electronics background. Am I right on this? Seems like you mentioned that previously? Im sure guys would feel more comfortable knowing this.
I would definitely offer my time also if I didn't travel so much for work.
Uniden owes you!!

- 15 years owned and operated an electronics repair shop and still have a multitude of test equipment.
- Amateur radio operator
- As for my job I am a machine repair technician (also known as OE repair.. OE being Operator Error).. Computers, PLC, hydraulic, pneumatic, high and low voltage on press brakes, plasma and fiber lasers, metal shears, etc...

 

[StaticDischarge]

I am curious to know better if others having experienced this undesirable residual noise/hum/ticking distortion, if it has been mainly observed when outputting via the rear ext speaker 3.5mm port? Has anyone set up an online feed via this port supplying the audio to PC as described in the broadcastify RR suggested setup FAQ and regarding the use of a ground loop isolator? Lastly I am curious what type of 3.5mm Male plug being used as in mono or stereo tip?

In playing around I have set up a feed so that my mom and dad can listen to my scanner as I live in Detoilét.. Oh wait, I mean Detroit.. and they live on the other side of the state. (Ha! do a DuckDuckGo search on Detoilét and see what comes up...)
Now this is after my "hum fix" which may have contributed to the fact that I did not experience noise, hum or ticking.
Using the rear speaker output to microphone input on the computer I noticed distortion at all but really low volume levels.
Using the front headphone output worked well but using either output jack I had to set up pass through on the computer to hear it here at my desk so I opted to use the audio through the LAN via ProScan. This way the volume setting on the scanner has no effect on the feed and I can control it for my personal listening pleasure at my desk.
Oh and I don't even own a ground loop isolator...
As far as I can tell, rear is mono and the front headphone can be either but is set up to match stereo type headphone plugs.

 

[frazpo]

@ StaticDischarge Very much appreciated and will certainly keep your offer in mind. First I will attempt a conversation with a Uniden Rep and specifically attempt to encourage them to acknowledge this particular thread and go from there.

I am curious to know better if others having experienced this undesirable residual noise/hum/ticking distortion, if it has been mainly observed when outputting via the rear ext speaker 3.5mm port? Has anyone set up an online feed via this port supplying the audio to PC as described in the broadcastify RR suggested setup FAQ and regarding the use of a ground loop isolator? Lastly I am curious what type of 3.5mm Male plug being used as in mono or stereo tip?

Also, is anyone electrically inclined familiar with the term "bridge tied load amplifier" in relation to what type of rear output Uniden has apparently went to with the last two base model scanners (536hp & sds200) ? The reason I ask this is a knowledgeable friend is beginning to believe my noise issues may not be related to this issue but rather no longer being recommended to use the rear output to supply audio to pc when setting up a feed.

I've read some other posts pertaining to feeds with a sds200. There are other complaints that I dont think have anything to do with the hum/crackling issue. I may be wrong but you might want to look into some other threads about it.

 

[Lazer9]

Thanks for the feedback and regarding the sds200 supplying a feed while fighting with this noise issue.

I also noticed a much more normal or expected sound if listening- supplying the audio through lan. I bought the sds200 to use for the digital and simulcast abilities and use the bct15x to listen to and supply the left channel of my feed, thus since having a L/R audio feed, the only way I know to set it up is via the audio cords to line in or mic in on the sound card.

Other combinations of scanners either say the *cough* TrX2 replacing the sds200 for the right channel or the Uniden 996P2 I don't experience the tick, hum, or hiss audio issues. I would use the Trx2 and call it a day at this point if it's simulcast p25 didn't generally suck when compared to the Uniden.

Now as I sit here and listen to my feed, I am hearing like a lead in and out "pop" everytime the sds200 comes on or off with audio using the front headphone port to supply audio to my [stereo] feed yet the background hiss, crack is gone. Yet using the more desirable rear port = back to the original problem that this discussion centers around.

 

[doctordialtone]

Now as I sit here and listen to my feed, I am hearing like a lead in and out "pop"

This can be eliminated with the use of an isolation transformer.


Lots of people here have reported this problem and fixed it with the use of the transformer.

It works great!

 

[doctordialtone]

Isolation Transformer fix

 

[Lazer9]

Thanks for the information regarding the isolator (transformer) fix, but after following that link, I already actually have two of these.....

1 at rear jack output on the bct15x

1 at (currently front headphone out) on the sds200

Yes, the mpows. Stupid question, but does it matter which way you aim them as in which side from the output to PC?

 

[kruser]

Thanks for the information regarding the isolator (transformer) fix, but after following that link, I already actually have two of these.....

1 at rear jack output on the bct15x

1 at (currently front headphone out) on the sds200

Yes, the mpows. Stupid question, but does it matter which way you aim them as in which side from the output to PC?

In the SDS200 Settings menu, Set Audio Off Time, is that set to Infinite so the audio amp stays powered on the entire time?
I've read reports that this attempt at helping with the hum issue can also cause the popping noise you describe.

edit: I meant to reply to your post about the audio pop sound question.
As far as the orientation of the mpows, I don't think it really matters. Someone did check the impedance on both sides and one side was a bit lower but not enough to make a difference so either way should be fine.

 

[Lazer9]

In the SDS200 Settings menu, Set Audio Off Time, is that set to Infinite so the audio amp stays powered on the entire time?
I've read reports that this attempt at helping with the hum issue can also cause the popping noise you describe.

edit: I meant to reply to your post about the audio pop sound question.
As far as the orientation of the mpows, I don't think it really matters. Someone did check the impedance on both sides and one side was a bit lower but not enough to make a difference so either way should be fine.

Yea, I had not thought the direction of the isolators mattered since their was no indication. Was just making certain I did not miss something obvious.

Just looked and the Audio Off time is set to 100ms and not sure I ever touched it on either unit. When you say about it set to the "Infinite" , does that remove the pops or make them worse?

 

[StaticDischarge]

In theory if you set it to "infinite" the audio amp should never turn off. Which would leave you to believe that the pops would be gone. Try it and see...

 

[bravo14]

I have changed Audio Off Time from Infinite to 100ms & 200ms. Infinite hum or static or what ever you want to call it it stayed even with no audio. Only time the hum would show up when there is audio in analog or digital.

 

[frazpo]

The number indicates how long the amp stays on after a transmission. The hum should not be heard after the amp is off. So while you hear a transmission you may hear it in the background. They created this option so the hum would not be heard while the scanner was scanning idol with no radio traffic.

 

[kruser]

The number indicates how long the amp stays on after a transmission. The hum should not be heard after the amp is off. So while you hear a transmission you may hear it in the background. They created this option so the hum would not be heard while the scanner was scanning idol with no radio traffic.

Yep, that was what they did but little did they know, doing so may have created the pops some hear now when the amp turns on and off!

 

[kruser]

Just looked and the Audio Off time is set to 100ms and not sure I ever touched it on either unit. When you say about it set to the "Infinite" , does that remove the pops or make them worse?

Maybe.
Setting it to Infinite will allow the audio amp to remain powered on instead of powering down 100ms after audio cuts out. I'm not certain but this may remove the pops you hear if they are from the radios audio amp powering on/off all the time.
That's what I gathered from others who complained about the same popping in another thread.

Hope it works!

 

[Lazer9]

In theory if you set it to "infinite" the audio amp should never turn off. Which would leave you to believe that the pops would be gone. Try it and see...

With a day of testing on the Infinite setting and even powering down and back on after applying the setting, I still get the "pop" - this is with the output from the headphone jack. Rear ext spkr out gives the original static, hiss background noise.

Either method while the simulcast and trunking is superior to the TRX2 on the sds200, the overall audio quality of the TRX2 is crystal clear and free of both issues using same outputs and cables to supply pc feed.

If I could have the actual simulcast performance of the sds200 with the audio output quality of the TRX2, I would be very pleased.

 

[radio3353]

... does it matter which way you aim them as in which side from the output to PC?

I have a REIIE ground loop isolator. The directions state: "Input and output devices are connected to either port of the Noise Isolator." The same would hold true for the MPOW device.

 

[allend]

With the perm HUM fix there is no reason to turn the audio amp off anymore. It can stay on at all times with the fix. No more HUM

 

[Lazer9]

Just to update, a Uniden Rep has reached out to me regarding this issue via PM. A paid return label has been furnished this time. I made extensive notes both printed out and included along with links to this and another thread on this board making special attention to StaticDischarge's method and resolve repair presented here.

The TRX2 is back up for my (R) channel digital portion of my BroadCastify feed meanwhile while the Uniden BCT15X continues to handle the Analog (L) channel: Mercer County Fire / EMS, Trumbull and Mahoning Counties Fire, EMS / Police Live Audio Feed

I will look forward to following up here and hope to have proper fix and resolve this time.

 

[citiot]

Whine was slowly increasing over time. Serial number is in low 500s.

Was going to do the @StaticDischarge method. Decided to try something first.

Opened up. Found ground bar part was fitted by factory. Removed. Sprayed a wee bit of Deoxit on cotton swab. Rubbed all surfaces where metal to metal contact would occur including copper side of bar. Swab showed that the cleaning did remove something because cotton became darkened a little bit.
Reassembled and whine is way lower. I would say 75% lower. Have to put ear right on speaker to hear it now.

Possible conclusions:
1) Original bar from factor was not aligned and my reassembly fixed that.
2) OR Copper to chassis metal is dissimilar enough to cause slight current and oxidation occurs. Deoxit removed oxidation and lowered resistance.
3) OR Combination of 1 and 2 above.

I will report if whine comes back over time.

--Citiot

 

[StaticDischarge]

There are other possible contributions to this:

There may be DC present from the origination of the hum itself
Humidity in your air
Contact tension of the NM200 part
Along with your suggestion of dissimilar metals

One or a combination there of will surely produce the oxidation you witnessed and bring you back to report your findings... again!

Which leads to the truth of the matter... The NM200 was a "cheap fix", a band-aid if you will, and cheap band-aids fall off with just the slightest bit of water...