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BCD436HP/BCD536HP: UHF Reception Issues due to Noise from Battery Compartment
- Thread starter bearcat
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dcisive
Member
Let me just tell you this, which is in stark contrast to some folks results. I used about 6 layers (folded) of some commercial (thick) foil right over the pad on the inside of the door. It's a fairly tight fit, but oh man what a difference it makes. Just getting the treated door near the batteries helps but as I begin to push and pop it into place I then hear stations so much quieter its astounding. Like significant hiss to virtually NONE!. Not to mention a plethora of channels from 125mhz right up to the mid 800's that are otherwise not received and they when the door is in place with the foil they come in strong and quiet. So please don't make the statement foil won't work. It most certainly DOES!
Can someone please use a continuity meter to trace where the other side of the cap goes? One side is going to be ground but what are they routing the other side to?
The tab next to the resisitor measures continuity on both the top battery + and middle battery - . The other side of the cap goes to ground.
With the minimal measuring devices for something that size. The best I can give you is 1/16" long and 1/32" wide. It maybe 1/64 or 1/32 high. I really cannot get anything in there for height.
The problem is if you have not sent it back for the clock/display issue. We really do not know where the cap goes. That old board is different. Someone may figure it out, but I no longer have one to play with.
jeffm77
Member
so, this issue has been fixed? How do you know if you have the clock problem? My radio is serial numbered 376Z58003612. Not sure what year I have and not sure if the clock problem was corrected on model numbers before or at mine or after mine.
ChrisABQ
...
Has anyone verified that the new board is already installed in the 6800 series of radios?
k3fs
Member
Some 6800 series have the capacitor. Not all.
You really need to open it and look. There are several questions within your question:
Version # on display board white sticker
Does it have the cap or not?
Does it have an updated display?
I have a Z68 with the cap but it appears the display/backlight is still the old style. It is much darker than my other unit that went back for the the Clock/Display issue
It would be interesting to know your findings.
k3fs
Member
It would be interesting to know if units that are being sent in for the fading display / RTC repair, now have the capacitor.
The board V01.09.02 has been use since the repair campaign. There is a new resistor added, but the capacitor is missing in quite a few of them. The capacitor is what filters the noise.
Uniden either omitted these parts from early production, due to cost savings, or felt it was not needed. The R and C are marked on the boards, but no solder pads.
On the repair campaign boards, and new production, the resistor is in place, but the capacitor is missing I some. Uniden now recognized there was a problem, and placed the components that were omitted on the board. Again either due to cost savings, or poor quality control the capacitor is missing. Truly this is an issue they had the knowledge of, and means to fix with the dimming display / RTC board swap out.
Uniden has maintained they cannot tell by serial number which scanners have the bad display / RTC issue. This also shouts of poor record keeping and/or poor QC.
The board V01.09.02 has been use since the repair campaign. There is a new resistor added, but the capacitor is missing in quite a few of them. The capacitor is what filters the noise.
Uniden either omitted these parts from early production, due to cost savings, or felt it was not needed. The R and C are marked on the boards, but no solder pads.
On the repair campaign boards, and new production, the resistor is in place, but the capacitor is missing I some. Uniden now recognized there was a problem, and placed the components that were omitted on the board. Again either due to cost savings, or poor quality control the capacitor is missing. Truly this is an issue they had the knowledge of, and means to fix with the dimming display / RTC board swap out.
Uniden has maintained they cannot tell by serial number which scanners have the bad display / RTC issue. This also shouts of poor record keeping and/or poor QC.
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It costs $12 for a reel of 4000 capacitors, 0.01uF 50V X7R 0603, so cost is not likely the issue.
Making older BCD436's unsalable by publicizing a good/bad serial number cutoff would be bad for business. Ultimately Uniden will fix some percentage of these old production radios if the owner is aware of the issues and knows about the repair campaign. I don't think this is related to record keeping or QC. It is more likely intentional on Uniden's part in an attempt to minimize their losses. All the technical problems with the 436 suggest engineering design failures more than anything else.
And with the lack of interest this thread has generated, at least since the capacitor findings. Most folks will never know they have the problem. So why would Uniden acknowledge the issue. It is not like they are getting thousands of complaints. It is nice to know that my findings at least helped a few folks.
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I have a 436 in the 6800 range, and always thought the display wasn't very bright, but don't have another one to compare it to. Is there a way to see if it has the new display by opening it up?
From what I know the answer is no. I asked that question on a different thread and Upman said there is not. You just have to watch for the failure of the display or clock.
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Big thanks Bearcat. Your time and effort is appreciated!
I took a look at my board and see that I have the capacitor, so I probably have the newest board. I'll have to monitor the screen for any dimming going forward.
jeffm77
Member
my 436 is in the 5800 range, not sure if mine has the clock issue. Anyone??
jeffm77
Member
yes, and to make it right with everyone, they should fix all these radios. I would have never bought a TRX-1 if my 436 did not suffer so much on uhf.
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