BCT15X: Wanted

WB9YBM

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May 6, 2019
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Niles, IL
Hi all i am looking for a squelch potentiometer for my BCT15X if anyone has one.
Thanks.
If no one has a spare, you might have to go back to the manufacturer to make sure the replacement is not only the correct value but also the right size to physically fit into the radio. Alternately a few electronic parts suppliers I can recommend that I've had good luck with are Jameco electronics, Digi-Key, Mouser, and Newark (all have web sites).
 

iMONITOR

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Hi all i am looking for a squelch potentiometer for my BCT15X if anyone has one.
Thanks.
I seriously doubt anyone would have one laying around in a cigar box. It's odd yours went bad as they're hardly ever used. Did it get physically damaged? If not have you tried electronic cleaner spray? Have you tried Uniden?
 

geowhitt

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Apr 27, 2005
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Leigh Gt Manchester UK
Thanks for the quick reply.
The problem is i bought of a web site and i did not see that it had a fault.
So thats were my problem is.
I have sent emails,, messages,, joined web sites.
If i can find a pot i should be able tom sort the scanner.
I have sent emails to uniden and waitng for a reply.
The scanner is mint came boxed with all the bits looks a good scanner but does have this fault.
Would love to see it up and running.
Again many thanks for the quick replys.
George
 

wtp

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Port Charlotte FL
i am not sure, but, i think it is not a regular potentiometer.
sort of like a mouse wheel.

may you could use a computer to control it.
 

Ubbe

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Hi all i am looking for a squelch potentiometer for my BCT15X if anyone has one.Thanks.
What's the exact problem with it? Nothing happens when you turn it down and doesn't open up the audio? Or is it just the plastic knob that are broken?

Does the click function still work when you push the knob? Can you wiggle or remove and reinsert the J4 connector that goes to the squelch pot to see if that helps?

/Ubbe
 

geowhitt

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Apr 27, 2005
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Leigh Gt Manchester UK
Hi and thanks for your reply.
The squelch does not work but the bush button does when i turn the knob the screen shows the numbers going up and down when turning the knob.
I have emailed Uniden and no reply and when on the site i would be able to send the scanner back to them to fix as I dont live in the US.
So at a loss at the mo.
George 2E0GLW
 

wtp

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Port Charlotte FL
can you take the knob off and check that something is not keeping it from going all the way down ?
i just checked and see it is different than other squelch functions.
turn and set not push, oh well.
 
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Ubbe

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when i turn the knob the screen shows the numbers going up and down when turning the knob.
Then it's nothing wrong with the pot.

Do you get any kind of audio in the speaker, any beeps from key presses? It could be the speaker jack that's bad. The audio goes thru a switch in the jack that cuts off the audio to the internal speaker. Does an extenal speaker work, even headphones can be used to test in that jack.

The headphone jack at the front also has three switches, two that are in line with the external speaker jack and one signal switch that tells the audio circuit to mute the internal speaker when you use a headphone. Try fiddel around with that front jack as well and insert a plug halfway and wiggle it.

/Ubbe
 

geowhitt

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Yes i get audio and the bleep works.
I have checked the jack plugs and thet are ok.
The display shows the vol when turning the pot, the squlech also shows when the pot is turned but the squlech will not work and as squlech does not work the thing wont scan.
 

crippledchicken

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Butler County MO
I've had a couple of older model scanners that had an internal potentiometer that had became oxidized between the rotating contacts that caused that problem I used a tiny bit of Deoxit contact cleaner and never had another problem. I've got, a bct 15x I'll pop the top later and see if it also, has the Pot.
 

Ubbe

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Yes just static.The squelch is open and will not close when turning the pot from 1 to 20 just noise.
If the SQ knob makes the values on the display step both up and down in value then the SQ pot is fully working and has no problem. Instead it is a component failure on the circuit board if you get noise and the audio doesn't mute when the SQ it set to its highest value.

Either the noise level are not enough to activate the squelch, could be a crystal filter that are broken, or the SQ circuit doesn't decode the noise properly, could be a capacitor that's gone bad.

You probably need an oscillioscope to be able to pinpoint the exact component that needs to be replaced. The schematics that are on the web are not complete but there's a test point on the circuit board called "noise" which is a DC voltage you can measure with a digitial voltmeter. It should probably be something like 3 volt when there's no carrier and go to 0 volt when you listen to a carrier, like a FM broadcast station.

/Ubbe
 

WB9YBM

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Niles, IL
Yes just static.
The squelch is open and will not close when turning the pot from 1 to 20 just noise.
This is one reason I wish scanners would have a signal strength meter of some kind or another built-in (unless manufacturers started that on modern units?); without it, it's hard to tell if you've got a problem with the squelch, or some kind of localized noise source swamping your receiver!
 

crippledchicken

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If the SQ knob makes the values on the display step both up and down in value then the SQ pot is fully working and has no problem. Instead it is a component failure on the circuit board if you get noise and the audio doesn't mute when the SQ it set to its highest value.

Either the noise level are not enough to activate the squelch, could be a crystal filter that are broken, or the SQ circuit doesn't decode the noise properly, could be a capacitor that's gone bad.

You probably need an oscillioscope to be able to pinpoint the exact component that needs to be replaced. The schematics that are on the web are not complete but there's a test point on the circuit board called "noise" which is a DC voltage you can measure with a digitial voltmeter. It should probably be something like 3 volt when there's no carrier and go to 0 volt when you listen to a carrier, like a FM broadcast station.

/Ubbe
I've wished I still had my scope a few times but, due to health problems and eye sight I had to give up my electronics repairs/hobbies! :)
 

Bob132

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Feb 19, 2003
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Location
Mid MO. (transplant from So. Cal.)
Hi all i am looking for a squelch potentiometer for my BCT15X if anyone has one.
Thanks.

Sorry, somehow I thought you were referring to a BCD 436. Kindly disregard this post until I can figure out how to delete it, or not.
 
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Codar

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Nov 24, 2020
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Hi all, Hi Geoff.
Had a look at the said scanner, getting a varying DC voltage at pin 1 of J4 this is the green wire to the main board, so I guess the pot and board is OK, this then goes to IC32 an op-amp, then goes via R287 1K to pin 92 of the CPU the wire is marked 'SQ' and pin 92 if the cpu is marked SQL_POS (I understand this means squelch position)

I got no further at this moment, the screening can will ahve to come off..... and I will need to find where the squelch control comes out, I have a feeling it's done within the CPU - I could be wrong here.

Dare I try a factory reset in case there's a glitch? It is receiving OK just that there's no scan because the squelch is fully opened.

Dave
 
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