Thanks. It's not difficult at all if you take your time. I peeled up one corner and made sure I had the entire end peeled up before I started peeling down, slowly.
BCD436HP/BCD536HP: UHF Reception Issues due to Noise from Battery Compartment
- Thread starter bearcat
- Start date
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Thanks. It's not difficult at all if you take your time. I peeled up one corner and made sure I had the entire end peeled up before I started peeling down, slowly.
If you are referring to the foam block on the battery case, don't pull it up. Apply the copper foil over the foam block.
In my experience, placing the copper foil under the foam block has greatly improved reception.
Out of curiosity, this morning I placed a piece of copper foil tape over the foam... But it did not change anything, for better or worse.
Maybe it is related to the shielding properties of various tapes. As soon as i move my case even a 1/16th of an inch and the pressure from the foam on the batteries is gone. The noise comes back. Maybe it has to do with the condition of the foam. Mine is fairly squished as i change batteries up to three times a day
D
darunimal
Guest
No that poster is saying the exact opposite with what others are reporting, his is the only one reporting under the foam works best; other then the one poster saying it didn't work at all for high uhf and only today did he report he may try to listen to a lower UHF signal in the 460mhz range, as reported, where this works best, as per the first post. Guy's the fix is cheap and easy, the reading comprehension by many is limited to none by many respondents. Please read all post before replying, especially when it just adds nothing to nothing. give us some valid details of what what and what your using, to include
Antenna adapter,
Antenna Cable,
Antenna connection style,
Band your wanting this fix to fix
Batteries w or w/o conductive wrappers
Did you every have problems before with the 460ish mhz area.
With Batteries or without Batteries
DC power supply (computer, cupe, dual port 2.1a, whateva)
How many plys, which direction
To include fingers or not.
I've been messing around with mine.
Values are as follows.
No shield
173
Battery door shield
129
Piece over the SD card and back door
123
If I put a piece of copper out of the positive battery lead, (To make it act as an antenna) I get 213. The negative lead gets no difference.
Interesting issue here.
Values are as follows.
No shield
173
Battery door shield
129
Piece over the SD card and back door
123
If I put a piece of copper out of the positive battery lead, (To make it act as an antenna) I get 213. The negative lead gets no difference.
Interesting issue here.
deadvolvo1
Member
- Joined
- Mar 30, 2007
- Messages
- 8
Tried the fix with aluminum foil and had no improvement in the 450-470MHz range here in Center City Philadelphia.
Used the local stadiums as a test, which have a mix of DMR and analog signals for parking, security and staff. Also tried the airport. I could tell absolutely no difference. Without foil, the DMR signals from the stadiums come in perfectly fine, whereas the analog signals are a bit weak but readable.
The Custom Search method is kind of a joke here because of all the signals there are in downtown in the first place. You simply can't judge any improvement by the number of signals. It is like counting ripples in the Delaware River.
So I parked it on a weak NFM signal (sounds like some kind of school bus dispatch) on 452.250MHz and compared it with my BCD396XT to see if I could detect the difference that way. Both radios are using the stock antenna, both set to Squelch level 2.
My immediate observation is that the BCD436HP with or without foil is better at rejecting images from nearby strong signals, and thus the BCD396XT is actually worse at receiving this particular signal in this environment.
I heard no change to the BCD436HP with or without foil.
It doesn't seem like my crowded urban environment and testing confirms the observations here.
SN is 3726Z68001XXX.
Used the local stadiums as a test, which have a mix of DMR and analog signals for parking, security and staff. Also tried the airport. I could tell absolutely no difference. Without foil, the DMR signals from the stadiums come in perfectly fine, whereas the analog signals are a bit weak but readable.
The Custom Search method is kind of a joke here because of all the signals there are in downtown in the first place. You simply can't judge any improvement by the number of signals. It is like counting ripples in the Delaware River.
So I parked it on a weak NFM signal (sounds like some kind of school bus dispatch) on 452.250MHz and compared it with my BCD396XT to see if I could detect the difference that way. Both radios are using the stock antenna, both set to Squelch level 2.
My immediate observation is that the BCD436HP with or without foil is better at rejecting images from nearby strong signals, and thus the BCD396XT is actually worse at receiving this particular signal in this environment.
I heard no change to the BCD436HP with or without foil.
It doesn't seem like my crowded urban environment and testing confirms the observations here.
SN is 3726Z68001XXX.
Aluminum foil for cooking? If so we ruled out aluminum foil during the original tests. Aluminum shielding tape does work. Along with copper tape which is probably best
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D
darunimal
Guest
Pretty please with sugar on top!
I put a capacitor across the battery + and - to filter the higher frequencies and that reduced it down to about what I was seeing with the foil.
Can you be more specfic. Cap type and value. Picture of wiring? Great find
deadvolvo1
Member
- Joined
- Mar 30, 2007
- Messages
- 8
Sorry. Should have mentioned: 3M 1170.
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I've always been exceptional; both in success and in relation to the rule.
LOL!! :lol:
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darunimal
Guest
I'm thinking the center battery has the conductive resonance on it, you can dissipate or cancel that resonance, either by putting the tape over the foam touching the batteries, or for much weaker attenuation behind the foam. I mean, I'm all for aesthetics, but in the receiving world, especially when it comes to a battery door cover, I'd go with: over the foam, to further reduce the negative signal getting back to my receiver.
This is crazy especially since the offending signal is being picked up mostly at the center battery, which infers the speaker is at least is keeping the offending signal from coming out the front. My shunt and a penny on top of the SD card also attenuate but both aren't practical. Once again maybe the penny is touching both upper batteries and doing more good that way, than the original thinking, I had, which was: either it was helping to shield and/or ground the batteries cases to the chassis.
So by Monday or Tuesday, I will get the tape here, and put it over the foam. Even though, I have my Exacto knife ready with the spade blade; I think I can safely say that's getting put away and the heck with aesthetics. If I can garner an additional 10db of spurious-injection-rejection I will go for that. The first 10 is great but the next 10 might make all of the difference, you never know.
This is crazy especially since the offending signal is being picked up mostly at the center battery, which infers the speaker is at least is keeping the offending signal from coming out the front. My shunt and a penny on top of the SD card also attenuate but both aren't practical. Once again maybe the penny is touching both upper batteries and doing more good that way, than the original thinking, I had, which was: either it was helping to shield and/or ground the batteries cases to the chassis.
So by Monday or Tuesday, I will get the tape here, and put it over the foam. Even though, I have my Exacto knife ready with the spade blade; I think I can safely say that's getting put away and the heck with aesthetics. If I can garner an additional 10db of spurious-injection-rejection I will go for that. The first 10 is great but the next 10 might make all of the difference, you never know.
devicelab
Whacker Extraordinaire
Are the people with problems all using the stock rechargeable batteries that came with the scanner? From the videos I've seen it looks like it...
I recall someone saying that the issue reproduced with Alkaline batteries but has anyone else confirmed this..?
I recall someone saying that the issue reproduced with Alkaline batteries but has anyone else confirmed this..?
OK. Cross that capacitor out. I don't know what was going on, but when I first tested it I got a lower reading. After trying a few more times, it appears it isn't working as well as I originally though.
Still looking into this..
Still looking into this..
Yes, alkaline batteries do it also. At least on my radio anyway.
jeffm77
Member
yes, I can confirm, that no matter what batteries I use, I still have the problem. From the original ones that came with the radio, to eneloops, to regular alkaline batteries.
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