Kevin I wanted to take it apart and see what mine looked like so I did the screw fix as it was only thing i saw that needed fixed so as to keep anything from popping up in the future.
SDS200 Hum repaired, but returned
- Thread starter Anderegg
- Start date
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I hear by officially name this procedure the "staticdischarge mod".
Uniden should be embarrassed. Now hopefully they'll modify future builds and identify them with a serial number sequence.
But why is it that not all the units exhibit the problem even though they are identical with insufficient grounding from the display pcb?
That may have not been the original intended grounding point in the design. There is likely another grounding point used that was marginal.
Yes I agree but I guess the marginal grounding was sufficient for some. Weird. I work in the technical field but no little on componetry like this. Good thing is there appears to be a fix for those that have tried it so far. Fingers crossed it works for everyone.
Great point, I was thinking this also. Maybe one with alot of problems should try sending it in to Uniden and "request/recommend" these "fixes" as to not potentially voiding a warranty if someone should fry their scanner? Would that be honored?
Now that would put them in the corner!
I'm thinking since there is a good chance this is a solid fix they may have to address it.
My thoughts on this hum issue frustrated me. It wasn't so much the hum due to the fact that it was fairly tolerable, but the fact that I paid the same amount for a flawed scanner that others paid the same amount for a flawless scanner. It wasn't like we all had the issue.
This is one of the "fixes" people have tried, so if someone sends it in and requests "all the suggested fixes" be tried before returning it? I'm hoping Uniden Support receives a response back from engineering soon before anyone damages their scanner.
TailGator911
Silent Key/KF4ANC
So, does this look like the result of a lazy day on the assembly line and someone not doing their job? If so, I would think that once the problem is isolated and found it would be easy enough to track the run on the production line to the culprit who shrugged this off thinking it wouldn't be noticed and not realizing that the consumers for this product are of above average intelligence, diligent, determined and technically proficient enough to locate and expose the faulty cause and repair it themselves. It would also explain why some scanners have it and others do not.
I am happy that there is a fix for people to get their scanners working as they should. I would hope this will lead to somewhat of a 'working relationship' between the technical guys here in the forums (beta engineers/quality control?) and the scanner radio electrical and mechanical engineers @ Uniden to come together in the name of quality and perfection to create the best scanners in the communications industry. Where this all leads to is anybody's guess, but where I hope it leads to is a better camaraderie here in the forums, a better attitude among the members, and a better format where good information, technical know-how, and product knowledge is once again the norm instead of all of the bitterness and bickering. The people who frequent these forums continue to amaze and impress me with their knowledge and intelligence, and they are the reason Radio Reference is the success that it is today and why I come here everyday. Man I love this place.
Keep up the good work, guys!
JD
kf4anc
I am happy that there is a fix for people to get their scanners working as they should. I would hope this will lead to somewhat of a 'working relationship' between the technical guys here in the forums (beta engineers/quality control?) and the scanner radio electrical and mechanical engineers @ Uniden to come together in the name of quality and perfection to create the best scanners in the communications industry. Where this all leads to is anybody's guess, but where I hope it leads to is a better camaraderie here in the forums, a better attitude among the members, and a better format where good information, technical know-how, and product knowledge is once again the norm instead of all of the bitterness and bickering. The people who frequent these forums continue to amaze and impress me with their knowledge and intelligence, and they are the reason Radio Reference is the success that it is today and why I come here everyday. Man I love this place.
Keep up the good work, guys!
JD
kf4anc
To me this would be oversight on the pcb design. Although I know nothing about pcb design or repair I have had to change alot of boards in my career. On those boards there is almost always grounding through the mounting screws. Maybe someone can comment if that is the norm or not.
If this fix and any of the others become the "authorized modification", I'm thinking those that have this issue would be better off sending it in to Uniden unless they're confident in their electronic skills.
I agree. Uniden should start offering this fix asap if they can confirm on their side. Taking apart a $700 radio isn't for everyone, and they shouldn't have too.
TailGator911
Silent Key/KF4ANC
Agreed, and as I posted before, it is almost a guarantee that someone somewhere will attempt this repair and damage their scanner. I would hope only the technically proficient would attempt this. Much better to finalize the remedy, initiate a repair campaign, and send in the scanner for the repair.
frazpo,
I agree this appears to be a PCB layout mistake. If the PCB layout engineer had intended to have these PCB "ground plane" mounting points have a good low impedance connection to the chassis they would have relieved the solder mask around the mounting holes to provide a clean plated/tinned surface for the screw head to make contact with the PCB ground. If they had not intended this these mounting holes to ground the board to the chassis, they would not have extended the ground plane to the mounting holes. As it is now, it is ambiguous. Some screw heads could scrape through the green solder mask while most would probably not.
StaticDischarge
Member
- Joined
- Mar 30, 2019
- Messages
- 295
I believe it was not a mistake and the engineer(s) purposely had it built just the way it is. What I also believe is that they did not know the consequences of their actions at that time. (Take the Raspberry Pi 4's USB-C power issue with a "smart cable" for example)...
Due to the thickness of the coating, which does vary, may indeed be the reason some SDS200's do not hum... Because the screw(s) are actually making contact with the ground plane.
Makes logical sense to me!...
Anyway...
Normal scanning may now resume...
Due to the thickness of the coating, which does vary, may indeed be the reason some SDS200's do not hum... Because the screw(s) are actually making contact with the ground plane.
Makes logical sense to me!...
Anyway...
Normal scanning may now resume...
Man, the coating on my pcb was very thick. I would even doubt that a spiked grounding washer would have made any contact to the board.
Mine had 2 gound wires
Ubbe
Member
For sure it is. But it is the other side of the pcb that is important, that the copper make contact with chassi ground and not neccesarily the head of the screw. But probably the same mistake there with thick laquer, or the intended grounding points in the chassi have been painted or threated so it doesn't make electrical contact.
/Ubbe
StaticDischarge
Member
- Joined
- Mar 30, 2019
- Messages
- 295
Seems I've started a jubilant movement (never done that before!) here on the RR threads with "my 2 cents on this hum issue.." as I see now that this grounding fiasco extends to the 536HP too!? Who knew?
Just had to share!... Enjoy!
Normal scanning may now resume...
Just had to share!... Enjoy!
Normal scanning may now resume...
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