Recently purchased a "new" BCT15X and have noticed that the volume and squelch knobs don't do anything until they are turned about a quarter clockwise. Is this normal? I would have expected the volume/squelch to start increasing (from 0) much earlier from the full counterclockwise position.
BCT15X: BCT15X knob dead zone
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Don't know about the 15X but many of Uniden's volume and/or squelch knows use "encoder controls" rather than potentiometer type controls.
You can tell if it's an encoder if as you turn it you feel "little bumps or clicks" rather than smooth turns. If the 15x uses encoders, then what is occurring with yours is normal.
You can tell if it's an encoder if as you turn it you feel "little bumps or clicks" rather than smooth turns. If the 15x uses encoders, then what is occurring with yours is normal.
Thanks for the response. There are bumps/clicks as you turn, so they must be encoders. Do you know if there's a particular reason why they function in that way?
Ubbe
Member
Squelch and volume are resistor potentiometers and a voltage are feed to them and then the vipers voltage are sensed to determine how much the control have been turned. I don't know why there's a dead zone at the beginning, but can guess that the pot are feed 3,3volt and the lowest setting of the squelch or volume are 0 volt but the processor only detects voltages that begin at 0,5volt, so the first 15% are then not sensed.
Those are 10k pots and Uniden have set a 100 ohm resistor between pot and ground to raise their lowest setting a bit, 0,03V higher, but it probably needs to be replaced by a 1k resistor.
/Ubbe
Those are 10k pots and Uniden have set a 100 ohm resistor between pot and ground to raise their lowest setting a bit, 0,03V higher, but it probably needs to be replaced by a 1k resistor.
/Ubbe
fxdscon
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There are many posts about Uniden using rotary encoders and not resistive pots for volume and squelch. Some folks have sent units in for repair and the repair slip noted replacing the encoder:
Search results for query: sds100 encoder
Does the BCT15X actually use pots instead of encoders?
BCD396T - Control Knob Hack?
BCD396T - Rotary Encoder Hack Has anyone attempted to hack the existing rotary encoder on a BCD396T with one that is like the BCT-15's? I ask this because the clicking seems way too loud and rough. The BCT-15's control knob is much smoother. Thanks, nebj00la
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Yes, every base/mobile from the BC15x to the SDS200 has these type controls on both volume and squelch... they go about 5 "clicks" until they show the level changing on the display.
Ubbe
Member
It's only the rotary selector that are encoded, the big metallic wheel at the mobile models. The 436/SDS100 only has one common controller for all functions and that are digitally encoded. The separate volume and squelch controls are normal variable resistor potentiometers but there's no audio going thru them as in the older models. It's only a DC voltage that the CPU senses that then controls a stepped attenuator so it's impossible to get any pot scratch or erratic behavior as the DC signal are filtered by a big capacitor.
It's easy to tell if a controller are digital, if you don't have a schematic, that only tells a CPU that the controller are turned clockwise or anticlockwise, and that are if it has no end stop, it can be turned freely turn after turn. This is the schematic for BCT15X:
/Ubbe
It's easy to tell if a controller are digital, if you don't have a schematic, that only tells a CPU that the controller are turned clockwise or anticlockwise, and that are if it has no end stop, it can be turned freely turn after turn. This is the schematic for BCT15X:
/Ubbe
In answer to the the original question, that is typical behavior for the Uniden scanners.. On all my 996P2s, 996XTs, & 15Xs, the squelch control doesn't change to S=01 until the 8th click/bump.
chris
chris
Remon
Newbie
You might also notice the volume encoder skips some values in one or both directions.
I have tested about 6 BCT15X's and they all behave the same (including what you described).
I have tested about 6 BCT15X's and they all behave the same (including what you described).
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