devicelab
Whacker Extraordinaire
This is pretty revealing. My Z4 model has V1.02 mainboard installed... with no C1 obviously.
BCD436HP/BCD536HP: UHF Reception Issues due to Noise from Battery Compartment
- Thread starter bearcat
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This is pretty revealing. My Z4 model has V1.02 mainboard installed... with no C1 obviously.
troymail
Silent Key
I think this is, in part, at least one of the reasons I have not yet sent my unit in. I have no idea what their process would be once the get the radio and decide to tell me it's my fault and not theirs and demand money for the repair. If I refuse, do they just send it back (at my cost both ways for shipping?) or hold my radio for ransom....
Great customer support.... not.
My very early (i.e. 2 months after the initial release) 436 CLEARLY suffers from this interference (proven long ago) but Uniden offers no plan or assurance that they will correct their mistake.
It's sad - as I have stated before, my last 3 Uniden radios were a BCD396T, a 436 and a 536 - and all three had to be returned after purchase for manufacturing flaws. Now, we have this obviously new flaw and they won't take clear responsibility for it. I honestly don't know which is worse for consumers - the multiple "repair campaigns" that each of these 3 units has undergone or the lack of taking responsibility for additional flaws that are found.
k3fs
Member
What makes that even more interesting are these two posts on the dfwscan Yahoo group. direct link :
https://groups.yahoo.com/neo/groups/dfwscan/conversations/messages/37218
Copy and pasted bellow :
Paul Opitz
Oct 15
That is a stopgap and really adding C1 is the best fix. It eliminates the source of the noise rather than trying to block the noise with foil tape.
From: "'Russell Adams' r7@... [dfwscan]" <dfwscan@yahoogroups.com>
To: dfwscan@yahoogroups.com
Sent: Sunday, October 15, 2017 11:28 AM
Subject: RE: [dfwscan] Older firmware
There is also the fix of sticking a copper tape shield under the batteries to reduce interference from the battery compartment. BTW the last firmware release I see is 1.11.31; mostly DMR I am sure but also contains other fixes.
Russell
End of copy and paste.
Add to this the false advertising for features that were promised and never delivered. Nor have there been any further updates on the progress of these features as was promised.
This is why consumers need protection.
When there is a problem, admit it as soon as possible.
Customers are not stupid. Ignoring or denying a legitimate problem is not the way to handle it.
https://groups.yahoo.com/neo/groups/dfwscan/conversations/messages/37218
Copy and pasted bellow :
Paul Opitz
Oct 15
That is a stopgap and really adding C1 is the best fix. It eliminates the source of the noise rather than trying to block the noise with foil tape.
From: "'Russell Adams' r7@... [dfwscan]" <dfwscan@yahoogroups.com>
To: dfwscan@yahoogroups.com
Sent: Sunday, October 15, 2017 11:28 AM
Subject: RE: [dfwscan] Older firmware
There is also the fix of sticking a copper tape shield under the batteries to reduce interference from the battery compartment. BTW the last firmware release I see is 1.11.31; mostly DMR I am sure but also contains other fixes.
Russell
End of copy and paste.
Add to this the false advertising for features that were promised and never delivered. Nor have there been any further updates on the progress of these features as was promised.
This is why consumers need protection.
When there is a problem, admit it as soon as possible.
Customers are not stupid. Ignoring or denying a legitimate problem is not the way to handle it.
Last edited:
I bought mine from scanner master in late 2016 early 2017 I can't remember but it was between Xmas and my birthday which is in Feb. I bought the 436 and 536 at the same time and had exchange both for display issues and reception issues w/436. While the 536 was good the second time around I still have a bad display on my 436 and it suffers from reception issues. I may pay the 90 dollars to get it fixed but it will be the last dollar I ever give uniden if I have to go down the road of paying to fix a known defect. I was really hoping the 436 would've been fixed by the time I bought it but no.
Sent from my SM-N910V using Tapatalk
I'd like to purchase a bcd436hp since most of the business around me have also updated their systems. I also do a a lot of traveling and the GPS option I know will come in handy.
Is it pretty much a crap shoot when it comes to a used radios? What about refurbished? Any recommended sellers?
Sent from my SM-G950U using Tapatalk
Is it pretty much a crap shoot when it comes to a used radios? What about refurbished? Any recommended sellers?
Sent from my SM-G950U using Tapatalk
Last edited:
It is a crapshoot, especially if the seller can't or won't tell you the serial number of the unit you're buying.
FYI, I install internal GPS units in Uniden scanners (look ma, no wires!) and install C1 (which fixes the problem) if the board has the pads but it is not installed, while I have the unit apart.
FYI, I install internal GPS units in Uniden scanners (look ma, no wires!) and install C1 (which fixes the problem) if the board has the pads but it is not installed, while I have the unit apart.
JamesO
Member
Assuming there is no display problem, you would be better off spending the money to have jonwienke to install the GPS and resistor assuming the board has the circuit traces for the capacitor.
Around $90-$95 for Uniden to repair with shipping, do not know what jonwienke is currently charging, but it is probably no more than $95 with shipping both ways?
That includes the GPS module?
Agree...thinking this is the way to go. I'd rather keep the $$$ here.
Will PM and make arrangements.
Scott
royldean
Member
FYI, I was doing some satellite telemetry stuff with one of my RTL-SDR's, and decided to see if I could find this noise. I'm pretty sure somebody has already posted this, but this is a UHF noise I found after about 5 minutes of looking:
https://youtu.be/i681oOgHoZc
Noise is a spike at 369.950MHz. I apologize for the potato footage - I'm going to toss that old cell phone.
https://youtu.be/i681oOgHoZc
Noise is a spike at 369.950MHz. I apologize for the potato footage - I'm going to toss that old cell phone.
Yes, the quoted price includes the GPS module.
k3fs
Member
It is a broadband noise that affects UHF and to some extent VHF. There are or were some others who posted tests using similar set ups and some more elaborate. A video and some spectrum pictures posted.
https://youtu.be/hJWp3FsnwPg
http://forums.radioreference.com/un...-noise-battery-compartment-7.html#post2615972
http://forums.radioreference.com/un...noise-battery-compartment-34.html#post2740918
I don't know why this has not received a sticky yet.
The Capacitor is the fix for VHF and UHF.
When there is a problem, admit it as soon as possible.
Customers are not stupid. Ignoring or denying a legitimate problem is not the way to handle it.
The customers were able to figure out the problem, but Uniden still acts as if they are stupid.They continue to ignore this problem.
https://youtu.be/hJWp3FsnwPg
http://forums.radioreference.com/un...-noise-battery-compartment-7.html#post2615972
http://forums.radioreference.com/un...noise-battery-compartment-34.html#post2740918
I don't know why this has not received a sticky yet.
The Capacitor is the fix for VHF and UHF.
When there is a problem, admit it as soon as possible.
Customers are not stupid. Ignoring or denying a legitimate problem is not the way to handle it.
The customers were able to figure out the problem, but Uniden still acts as if they are stupid.They continue to ignore this problem.
Fidgety9996
Member
If you dont know what is it about it is clear what it is about.
bako88fan
Member
I'm having issues receiving UHF on my 436hp. I have a z5 serial so I'm assuming mine was built in 2015.i bought the scanner on eBay from a private seller. I'm guessing he knew what was up since I got a deal too good to be true. I'm still using the factory antenna.
I shielded the battery area with foil once I found this thread. There's a lot of interference on UHF frequencies, which is problematic because that's where out County fire and Sheriff's broadcast. The foil really hasn't helped. The weird thing is, I've played around with holding the scanner and pointing the antenna in different directions. Whenever I hold the scanner upside down, with the antenna pointed towards the ground, the UHF reception improves dramatically. I can't figure out why. It doesn't matter how far from the ground the antenna is.
Can anyone explain why a downward facing antenna would actually receive signals better?
I shielded the battery area with foil once I found this thread. There's a lot of interference on UHF frequencies, which is problematic because that's where out County fire and Sheriff's broadcast. The foil really hasn't helped. The weird thing is, I've played around with holding the scanner and pointing the antenna in different directions. Whenever I hold the scanner upside down, with the antenna pointed towards the ground, the UHF reception improves dramatically. I can't figure out why. It doesn't matter how far from the ground the antenna is.
Can anyone explain why a downward facing antenna would actually receive signals better?
Probably because your body is making a better counterpoise to the antenna when you hold it in that position, or your hand is shielding the interference more.
Another factor that makes a big difference is getting the antenna farther away from the battery compartment. The effect of the interference is very localized, so just switching to a BNC antenna and using the SMA-BNC adapter will get rid of a lot of it. A physically longer antenna, such as the Diamonnd RH77CA, will improve reception in two ways, by picking up a lot more signal overall, and by reducing the impact of the interference because more of the antenna is farther away from the noise source than the factory antenna (which isn't that great to begin with).
The best solution is to install C1, because that eliminates the source of the noise. Your scanner may have one of the updated boards that has the fixes for the fading display backlight and RTC failure, but didn't have C1 installed, or it may have the original board that doesn't have the connections for C1. It's easy to check, if you don't mind opening up the scanner. I would suggest doing so, and sending the scanner back to Uniden if it has the old board version. If it has the newer board, but doesn't have C1 installed, it's not that hard to install it yourself if you know how to solder surface-mount devices.
Another factor that makes a big difference is getting the antenna farther away from the battery compartment. The effect of the interference is very localized, so just switching to a BNC antenna and using the SMA-BNC adapter will get rid of a lot of it. A physically longer antenna, such as the Diamonnd RH77CA, will improve reception in two ways, by picking up a lot more signal overall, and by reducing the impact of the interference because more of the antenna is farther away from the noise source than the factory antenna (which isn't that great to begin with).
The best solution is to install C1, because that eliminates the source of the noise. Your scanner may have one of the updated boards that has the fixes for the fading display backlight and RTC failure, but didn't have C1 installed, or it may have the original board that doesn't have the connections for C1. It's easy to check, if you don't mind opening up the scanner. I would suggest doing so, and sending the scanner back to Uniden if it has the old board version. If it has the newer board, but doesn't have C1 installed, it's not that hard to install it yourself if you know how to solder surface-mount devices.
bako88fan
Member
Thanks for the info. I got the Diamond antenna you suggested and reception has improved. I guess I'll use a copper tape to shield the battery compartment and see if that helps any more. Eventually, I'll send the scanner back to Uniden to install the C1 since I have no experience with surface soldering.
Before paying Uniden a flat rate $80 just to have a part installed that costs less than $1, open the unit up and see if you have the old front board that needs replacement. If so, Uniden will change it out for free under the RTC/display repair campaign. If you have the newer board, but C1 is missing, you could send the scanner to me and get an internal GPS installed along with C1 for pretty much the same money Uniden would charge you.
dcisive
Member
I must admit I've been quite surprised at some folks that have tried the aluminum foil mod and gotten no good results. I did it folding about 6 layers of it and it was like day and night regarding sensitivity. In the 400mhz band where I mainly tested it out, I went from getting solid reception on a number of channels when removing the foil it was either very weak or gone altogether. I certainly appreciate the changes to the board that were done making perhaps even MORE change, but this is fine for me. I'm not having any sensitivity issues nor noise. It's been like a new scanner since I did it, and it's NOT copper which really surprised me. it's just competent foil folded multiple times and cut to shape. It's become a literal part of the door fitting perfectly as now it's molded to the battery pressure shape. All is well
k3fs
Member
The foil or copper is a fairly decent solution to the UHF noise and reception issue.
C1 is even better at decreasing UHF noise and improving UHF reception. It also improves reception on VHF. Foil or copper does not improve VHF reception much. The omitted C1 actually repairs the defect.
Uniden should be fixing this defect.
This should receive a sticky as it was cited by Paul, and is still helpful and being used by people regarding this defect,
C1 is even better at decreasing UHF noise and improving UHF reception. It also improves reception on VHF. Foil or copper does not improve VHF reception much. The omitted C1 actually repairs the defect.
Uniden should be fixing this defect.
This should receive a sticky as it was cited by Paul, and is still helpful and being used by people regarding this defect,
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