[Techtoolslist] Sunday Project: Fluke 9010A Probe

[Jess Askey]

(I sent this on Sunday originally, but I think it didn't come through because I sent it from my non-subscribed email address, apologies if you got it twice)

Hey Folks... I thought I would share my Sunday project. I did cheat and pre-order all my parts for today(minus a couple things I wasn't aware of, more details below).

Since the Fluke 9010A probes are hard to come by these days, I figured I would make one... I bought the following..

Pictures are here... http://www.askey.org/fluke_probe/


-          15' DB9 Male to Male Serial Cable (I can cut this in two and make two probes I figure) - $5, free shipping

-          Old WaveTek slim Logic Probe (I had one, but I bought another one of these off ebay for $10)

-          Some old RadShack perf boards that I had laying around

-          About 4 hours of time

Then I did the following... (see pics above)


1.       Cut the perf board down to 5 rows wide, drilled the mounting holes. Make sure you have a nice row down the middle for the LED's to line up properly (centered)

2.       The break-away seam in the 'double' perf board was unfortunately right in the middle of where the LED's had to go. So if you can get solid perf board, it would probably work better. I had this laying around.

3.       Split the Logic Probe, took out the RED and GREEN LED's and the tip off the old Logic Probe PCB

4.       Assembled the circuit using page 142 of the 9010A Service Manual

a.       I had to sub in 1uf caps for the power supply filters (spec was .39uf). If you got smaller caps, they would fit better, I had to lie mine down.

b.      I didn't have a 205K 1% Metal Film Resistor, I used a 220K 5% CC resistor and I will sub after my next mouser order

c.       I also didn't have a 33pf cap, I used a 47pf from a scrap Firefox PCB (don't worry, it was in pretty rough shape anyway)

d.      I added 1.2K resistors on the Cathode side of the LED's since these were driven by transistors to 'maybe lamps??'... the schematic says they are lamps, but I have a hard time believing this. In hindsight, these may not be needed at all.

5.       I used an old clip lead for the ground clip out the back too... ironically, both cables seemed to fit pretty nicely out the back of the old Logic Probe case

6.       I fashioned a 'strain relief' by looping the nylon cable backer and crimping and epoxying it. I ended up doing it different from the pic as my loop had to be on the very back logic probe screw post, so it had to be much shorter and the yellow crimp was too big for the space. I just looped the nylon and wrapped it tight with a resistor lead, then dipped the whole thing in 5-minute epoxy and let it harden. Seems pretty solid.

Seems to work fine... the LED's are definitely dim but usable so I will pull those resistors out or lower them appropriately.

Let me know if you have any questions or suggestions... Im going to make another one with lessons learned.   :)

PS - I cleaned my bench spotless on Friday night after eating a bunch of edible pot (I live in Colorado :) so I can tell you this).... It didn't look right.. but... luckily, after this project,  it is now back to looking 'normal'...whew!!