D-Tap a BCT-8

[unpltd]

Alright I had a long post but my comp crashed, so here's the short and sweet version...


I'm looking to add a Discriminator Tap to my BCT-8


I tried Searching


And didn't get much as you can see...

And when I did find THIS even though it's totally lacking in info, I figured I'd open mine up and have a look.

and mine looks a little different.

MINE

THE WEB PIC

Shouldn't there be only be one tap point and a ground?

And they don't say anything about why there's two points tapped and which is which..

So ya that's me and I'm confused...

So anyone want to help me out?

 

[mtindor]

On the picture of the board i see on the web, LND07 is the discriminator data (data skip). There is also another point called just "data" - I question whether either one can be used.

At any rate, the other part of that connection is ground. Run one wire from LND7 to the center on your choice of phono jack, 1/8" (3.5 mm) or 3/32" (2.5 mm), whatever. Then run one from a ground point somewhere on the scanner to the sleeve (outside) on a jack. You only need a mono jack for application,no need for stereo.

Obviously the tip and sleeve I refer to are on the male plug. For the female jack I don't know the specific terminology. Just know that on a mono 1/8" or 3/32" jack, the part that would make contact with the center pin of the male plug is what I refer to as center and the portion of the jack that would make contact with the long shiny portion of the plug would be the ground.

See this link - the top graphic is a stereo plug with a tip, ring and sleeve. You'd have a mono jack with only tip/sleeve. Of course if a stereo jack is all you have, you can use it too - just connect to the applicable areas.

Also, read this thread regarding adding a resistor and/or capacitor of particular value, etc. for safety / best signal. That doesn't mean it won't work if you omit both, but each has their reason/application and you should consider that before omitting.

Mike

 

[mtindor]

Incidentally, on the WEB PIC the portion of the cable that is connected to LND7 is the center, with insulation around it - this is the actual audio signal. The other portion of cable is the shield of the cable and is soldered to a ground. You can pull the ground from any common chassis ground on it I would guess.... whatever is more obvious to you and easier to solder to. Just watch for cold solder joints.

Mike

 

[unpltd]

Awesome, That's mostly what I was wondering.. (which was the tap point)


I have a 3.5mm mono female jack sitting here waiting to go in..

I was just wondering why they had two points tapped and which was which..

Thanks for the quick reply and info

So I'm just going to tap the LD7 and use the chassis as the ground..

 

[torontokris]

THE BCT8 yahoo board suggested the DATA SKIP as well

http://groups.yahoo.com/group/UnidenBCT8/message/465

 

[N9JIG]

On my various scanners that I have tapped, including the BC780, 785, 796, 996 and BC15's, I just run a single wire from the discriminator tap point to an RCA jack on the back panel of the radio. Since the metal case is ground the jack mounting takes care of that.

I have never had any ill effects from not running a separate ground wire in these instances, and this avoids an extra solder point and the associated risk of trouble caused by soldering in close spaces when not really necessary.

The only time I ever use a separate ground wire on a discriminator tap is when I mount the jack on a plastic case.

 

[unpltd]

Thanks guys, I'll post up my results soon

 

[mancow]

Shouldn't LND 4 (FM Detect) be the proper one?

If I recall correctly that's what I did with my 433 which is basically the same radio.

 

[unpltd]

Well after a late dinner I got to work.

Unitrunker was giving me a slight headache and I didn't know what was going on hence why the ground wire is there, but it was not needed.

I figured that out after.

I get a steady 99 on the health meter.


All tapped and working beautifully

I know you like my output jack

Now if I could figure out how to get my other scanner to follow voice...