Tap question

[dbestfirefighter]

Any of my OK brethren have a pro-2046 discriminator tap location or pro-2055 location. I prefer to use the 2046.

 

[DanHenry]

Pin 9? on the discriminator chip and a 10K resistor

dbest,

I just tapped my PRO-2046 about a month ago.

Start here:
http://wiki.radioreference.com/index.php/SCANDATA.FAQ

Table 1 didn't list the tap point for the PRO-2046 so I opened the case to ID the discriminator chip. Then I used Table 2 to find the chip. From memory I believe it was a variation of the MC3361, and from memory I believe it was pin 9 but that might be wrong. Verify it when you open the case. The info from Table 2 for my chip was correct.

Now scroll down to Figure 1. That shows how the pins are numbered. The chip in the PRO-2042 gets tapped using the pin in the top right corner just like Figure 1.

This was my first ever tap and it's been working great with Universal Trunker, Trunker, and other decoder software. I had picked up some capacitors but didn't seem to need them. I attached a 10K resistor directly to pin 9? and fed that to a new jack on the back panel with some shielded wire.

Parts I used:
10K 1/4 resistor (Radio Shack 271-1335, $0.99 for 5 pack)
1/8" mono phone jack (Radio Shack 274-251, $3.99 for 3 pack)

I already had the shielded wire in the parts bin.

This last link is NOT for a PRO-2042, but it shows what the chip looks like the way I soldered the resistor directly to the chip.

http://www.discriminator.nl/pro-9200/index-en.html

Good luck,

-Dan

 

[fmon]

The Pro-2046 uses the same chip as listed for the 2040 in Bill Cheek's list (Dan's link). Scroll down and find IC MC3361BP in this parts list for the 2046. Pin 9 was what I used. http://support.radioshack.com/support_electronics/doc36/36055.htm BTW, I used a 1K 1/4 watt.

 

[dbestfirefighter]

Thank you, after an hour or two of googling i was almost ready to give up.