I don't have the pics but you can find them on the web if you search for them. What I do have is all the data. you should be able to do these mods without the pics since all the VR (variable resistor) numbers are there and are easy to locate. (look for the access holes directly above them hidden under the decals. They are for making adjustments to the VRs with a small screwdriver) They are small blue components that look like little boxes with a dial in the middle of them. They are removed, wires are soldered to the three places on the PCB to each VR that runs to the potentiometers that will be doing their jobs, accessible from the outside.
Here's the instructions:
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.
