Bcd536hp speaker pulsing noise issue

Does anybody know why when I spent 500.00 bucks for a brand new BCD536HP that I am getting a pulsing sound noise coming out of the speaker when a conversation ends and it happens from time to time even when in the scanning mode?

My BCD996P2 and other scanners do not have this issue. I went to HRO and heard the same thing happen on their floor model too. Its really annoying in a quiet radio shack when working.

Also, too I hear it alot when the volume is turned all the way down

try connecting a noise canceling speaker. I don't have that issue with my 536.

What kind of system being received?

UPMan said:

What kind of system being received?

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This happens on conventional and trunking talkgroups. P25 systems. This pulsing noise comes out of the speaker on scanning while its quiet and then it happens right after the talkgroup gets released.

What I am doing too is also connecting a Vertex MLS-100 speaker which sounds great on all of my radios like the BCD996P2 which I have two of them. I also have a BCT-15X and both of these models do not have that pulsing noise at all.

Only the BCD536HP. From what I am hearing and been searching the forums on when these radios that were released a couple of years ago this is a known issue.

I do not hear it out of the speaker jack with headphones plugged into the radio at all. Only the external speaker on the bottom of the radio and hear it from the external speaker plugged into the rear speaker port.

When I plug in BOSE noise cancelling headphones into the front speaker port all I get is faint conversations and alot of hissing noise. If I use 10 dollar pair of cheap ear buds I have no issues with the radio.

So there is some sort of hardware related issues with this radio because my other two uniden radios have none of these issues and my BOSE headphones have completely no issues.

What scary is that I just spent 500 dollars for this radio and there will probably be no fix to this issue

Honestly at the end of the day I really like the radio. It programs nicely and love the front display.

I would really love to keep the radio and see if there could be a fix at the repair shop for this pulsing noise.

However the 996P2 was constructed maybe the 536 can be fixed the same way.

I can hear it, it sounds like a double or triple beep, like it's writing to the SD card when I have replay or record feature on. I noticed it a while ago but never commented. It almost like an Alert with the Alert Volume set at 1 but at the end of the transmission.

Noise canceling headphones are far to high an ohm to use with the 32ohm 320mw output of the Headphone jack. The noise canceling are closer to 600ohms.

darunimal said:

Noise canceling headphones are far to high an ohm to use with the 32ohm 320mw output of the Headphone jack. The noise canceling are closer to 600ohms.

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But using noise cancelling headphones on the BCT15X and the BCD996P2 is a real enjoyable experience so I just don't understand why they do not work on this newer and greater BCD536HP radio scanner

The 536HP has an unusual amplifier section. You need to be careful what and how you hook up an external speaker to the unit. http://forums.radioreference.com/un...er-connection-considerations-precautions.html

Also noise cancelling headphones DO NOT play well with many of the newer scanners. So be careful what you choose, noise cancelling headphones can actually make the background noise much worse. I believe there are a number of threads on this as well.

Also there is R2D2 digtial noise that can be heard when the 536HP is scanning. Believe it or not I think some SD cards are more prone to cause the noise than others. Try a different SD card and see if the background noise changes.

Any amplified speaker will be a problem because it makes the digital artifacts more obvious over the background silence.

Changed the SD card on mine and the problems you speak of went away. Might be something to look at.

Sent from my Z750C using Tapatalk

I hear the same "warbly" noise on my 536 and it happens as soon as a transmission on a P25 trunked system talk group ends and the repeater drops. Or once the squelch closes after a transmission drops on a conventional channel. It's highly annoying and is more prominent with an external speaker. It sounds like a cheap, noisy amplifier circuit. And if that's the case there is no remedy unless Uniden sources another, better audio amplifier circuit. Bummer.
BG..

I think somehow the "mute" mode needed to be grounded or under a load of some sort?

Seems like something is "floating" or not fully isolated during a "mute" mode.

mule1075 said:

Changed the SD card on mine and the problems you speak of went away.

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That was going to be my suggestion before I saw your post - change the SD card.

mule1075 said:

Changed the SD card on mine and the problems you speak of went away. Might be something to look at.

Sent from my Z750C using Tapatalk

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So I am curious what kind of SD Card that you bought so I can try it?

But honestly I do not think changing out the SD CARD will fix this issue. Seems like everybody else might be having this problem only on this radio.

allend said:

So I am curious what kind of SD Card that you bought so I can try it?

But honestly I do not think changing out the SD CARD will fix this issue. Seems like everybody else might be having this problem only on this radio.

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Just a basic Sandisk card from Walmart.

Sent from my Z750C using Tapatalk

So for 15 bucks I bought a new SanDisk 32GB Ultra PLUS Card microSDHC UHS-I

micro SD card and it seems to be a little better. I do not hear it anymore through the scanner speaker since its buried under the radio. If I use an external speaker I still a little bit of hissing noise but no pulsing noise anymore.

Sounds like part of the problem is that Uniden is using really cheap parts. Radio seems to be a little bit snappier when navigating thru the menu too.

Lets just see how it all plays out.

So this was my final fix and I am pretty happy. I changed out my SD Card and got a better SanDisk.

Then I took my Vertex MLS-100 speaker and plugged the speaker into the front speaker port and I get NO pulsing or hissing noise.

The only thing is that I need to turn up the volume past 15 or above for it to sound good and loud enough.

allend said:

So I am curious what kind of SD Card that you bought so I can try it?

But honestly I do not think changing out the SD CARD will fix this issue. Seems like everybody else might be having this problem only on this radio.

Click to expand...

I prefer the upgraded SanDisk models rather than the basic ones (ultra, etc), and all scanners that use SD cards have the same issue (and same solution).