COI Light For Uniden Scanners-The low Down!
Ok, here we go!
First of all, I have to give credit where credit is due. Bob Parnass MUST take the credit for posting the original mod for a carrier-on-indicator light. Second, I have to credit RR member R1VINCE for his individual work and posts on this subject.
After reading Bob's original mod and Vince's posts and pictures, I decided to do a little experimenting of my own, keeping in mind the principles upon which the original mod was based on. Until now, all the mods discuss a COI light for Radio Shack scanners made by GRE. Well, I have discovered a way to modify Uniden made scanners either directly labeled or under the Radio Shack label made by Uniden.The idea is simple, find a chip that has a pin with 0 voltage when there is no signal present and some voltage where there IS signal present. That is the best way I can simplify it. I was experimenting with my basic no frills Pro-2018 scanner which is made by UNIDEN under the RS label. The IC- chip, which is common in some Uniden made scanners (NOT all), is the TDA-1905 16 pin chip. Pin # 4 has 0 voltage with no signal, and +/- 3 volts with signal present. I found this to be true in the Pro-2018, the BCT15, and 996 Digital scanner. I suspect that any Uniden made scanner with this same chip will allow you to do this mod.
The next issue to be tackled is where to find a 12V power source for the mod. That is something that will take some searching. I used my trusted Fluke meter to do my mod. For the BCT15 / 996, the source is the far left pin of IC-22. For other scanners, llike I said before, you will need to do some searching on your own. I have attached a Word document (see attachment below) to give everyone a basic reference on just how it all goes together. Here are some pictures taken from my 996 to give you visual reference:
Overall View
Overall View pictures from project spotlight photos on webshots
IC-17 Close View
IC-17 Close View pictures from project spotlight photos on webshots
IC-22 Close View
IC-22 Close View pictures from project spotlight photos on webshots
The above pictures are of the BEFORE not the finished product. I wanted to show an uninterupted look without all the wires and such. There really is not much to show. The whole thing was built on a tiny piece of perf board which I glued to the chassis. One connection to the Uniden IC (17), one to the power IC (22) and the LED connections, that is all. LED choice is up to you. I used a green 5mm LED:
5mm Green LED - RadioShack.com with this holder for a better more stable fit:
LED Holder - RadioShack.com
Now, as far as LED mounting, that I will leave up to the individual doing the mod. The BCT15/996 have VERY little real estate to work with. I was only able to find a decent opening on the right side near the head phone jack area. here is what it looks like from the rear:
Face Plate View pictures from project spotlight photos on webshots
VERY small opening to run wires through. It is a pain the the rump to take off the faceplate of the BCT15/996. besides the six screws (I think) you have to take off the rings that hold the volume/squelch and VFO knob in place. NOT a fun task trust me, but it's do-able!
I do not have access to a BCT15X/or a 996X so I can not tell you for sure if it has the same IC inside. But that is all in a nut shell. If anyone has any questions please feel free to ask.
Finally:
I will say this as sincere as I can, If you are NOT experienced with a soldering iron or tremble when using a drill, please, do yourself a favor, DO NOT attempt to do this mod.
Manny