If you can solder at all ,you can buy the new pots and do it yourself. I did the mods to my IDX PRo and Classic II, III and III Plus. All you're doing is removing the PCB trimmers and replacing them with external potentiometers. There's a ton of info out there on the web. Pictures and all the parts plus instructions on making and then using the mods! It wasn't hard at all. Just be careful and follow the directions!
Here's the lowdown: (without pics) including the boost circuit mods!
Be very carefull unsoldering the componets. Destroying
the circuit traces is very easy to do.
Remove VR1 Trimmer off the board. Replace with a 50k
linear taper, single turn potentiometer.
Remove VR4 trimmer off the board replacing it with a
100k linear taper, single turn potentiometer.
Mount these potentiometer’s externally on the top of
the case.
Replace resistor R24 with a 2.2 Meg. You could have
either a 470k or a 1.5 Meg there depending on when the
unit was manufactured.
Check resistor R7. If it’s not a 51 ohm resistor,
replace it with one of that value. It’s most likely a
100 ohm from factory. Later manufactured units had 51
ohms.
For potentiometer wiring, I use flat multi wire such as
type used in computers for component connection to the
board. I cut a 2 wire, 7.5” piece for the 50k ground
balance pot, and a 3 wire 7.5” one for the 100k
threshold pot. I secure these wires with a wire tie to
the head phone & speaker wire near the connectors. I
used one other wire tie to secure the pot wires
together up near the pots.
Caution. Be sure that the pot closest to the end of the
case doesn’t short out against the installed board
components.
S.A.T changes. R32 220k resistor can be changed out.
Raising the value slows the SAT. I have been installing
a 375k running it through a toggle switch with the
220k. Giving a high & low setting of the SAT. One could
use a potentiometer for variable results.
If your detector uses a ID meter, open the meter case,
and replace resistor R28 (3.9 meg) with a 10 meg
resistor. This aids in increasing the meter response
depth. "
