Discriminator tap help!!!!!!

[Sjinndoawi]

Can someone show me a picture of what the discriminator tap should look like? the finish product. I know where it is on my BCD996T but I think I did it wrong. I think i put the 10k cap in wrong or the resistor or hooked it up backwards,ground it wrong or something cuz.. I get NOTHING !!!

Any help would be great


Brian

 

[tonsoffun]

Hi Brian,
Have you checked the wiki for info. Here is the main page and scroll all the way to the bottom for the articles:
http://wiki.radioreference.com/index.php/Category:Modifications
Here is some good pics for the 898 but you will get the idea on what goes where.
http://wiki.radioreference.com/index.php/BC898T_Discriminator_Tap
Also for the 796:
http://wiki.radioreference.com/index.php/BC796D_Discriminator_Mod
Hope this helps

 

[Sjinndoawi]

Thank you but

That really doesnt help me but thank you...I need to know where does the resistor go..does it go inline (the same wire as the 10uf cap is on or does it go on the ground side? Also I see there is a (+) on the 10uf cap. Where does that go (is it solder to the discriminator tap point or on the wire side)? I am using a 3.5mm mono jack and there are 3 legs, does it matter where I solder this stuff?

Brian

 

[LordJ]

I didn't use the Cap on mine as it's not really needed (pro 2026) the resister goes in series with the cable, connected to the post of whatever connector you used..hth

 

[W4UVV]

It is not a resistor!

Can someone show me a picture of what the discriminator tap should look like? the finish product. I know where it is on my BCD996T but I think I did it wrong. I think i put the 10k cap in wrong or the resistor or hooked it up backwards,ground it wrong or something cuz.. I get NOTHING !!!

Any help would be great


IT IS NOT A RESISTOR! Use a .01 DISC CAPACITOR in line or at the end of the wire from the discriminator tap point identified as such on the PC board to a chassis mounted connector previously installed. I prefer using a female RCA chassis jack. Solder one leg of the capacitor to the discriminator tap point on the 996T and the other to the center conductor of the chassis mounted jack. Be careful in drilling through the rear chassis so as not to damage anything on the inside. Following are instructions but any modifications you make are at your own risk:

Here is a text description I copied and pasted from a previous RR forum post on locating the 996T discriminator tap point:

"OK, I dug around a little and it appears our friends at Uniden made it real easy!

Take off the outer case shell, and then the top inner case. Just about dead center on the
board look for the solder pad labled "DISC". Run a single insulated wire to this point to a jack
of your choice (I prefer RCA jacks) mounted on the rear of the radio. I also like to use a
tantalum capacitor in line with the jack as well. (Note: any .01 disc capacitor will work)

If you take the bottom inner cover off the radio you will see the best place to install the jack
appears to be the area of the bar code/serial number label. This is kind of thick double
walled metal so be carful drilling. You could also just run an audio cable into the radio thru
the threaded rear hole or even one of the holes on either side of the radio's rear".

 

[SCPD]

I need to know where does the resistor go..does it go inline (the same wire as the 10uf cap is on or does it go on the ground side?

You can use a resistor, a capacitor, or both. In all three cases - wire the components in series.

Also I see there is a (+) on the 10uf cap.

The positive lead goes to the radio. Most discriminator signals include a small DC voltage offset - which the capacitor removes. However, most PC hardware includes DC blocking capacitors already so this may be redundant.

I am using a 3.5mm mono jack and there are 3 legs, does it matter where I solder this stuff?

Plug your patch cable into the jack and use an ohm meter to figure out with lead is the tip (discriminator audio) and which lead is the ring (ground).