Pro-164 Discriminator Tap

• The discriminator tap in the Pro-164 is found at TP4.

• However, unlike the Pro-97, there is no post installed at TP4, so the wire must be soldered directly to the copper solder pad. Soldering to the pad IS possible, but be very careful not to apply too much heat because the copper pad may lift from the board. Also, once a wire is soldered to the pad, do not let any movement of the wire put any strain on the pad because it will cause the pad to lift from the board. Hot-glue was used to secure the wire to the board to prevent movement of the wire.

• Although a 1/4watt, 10K resistor was soldered directly to the pad, if this were done a second time, a better solution might be to solder wire-wrap (or other very thin-gauge) wire to the board, then run the thin wire to the jack. Soldering a resistor to that small pad might be asking for trouble.

Click on the image to enlarge it

• 

  board showing TP4

• 

  tap installed

With thanks to edmk3000 for the photos and writeup