On Fri, 19 Jun 2015 05:46:13 -0700 (PDT), Matthew Connor
wrote:

Good morning, Jeff! Thank you so much for your insight.
My counter is a Lionel CD V-700 Model 6b, manufacture date 1962.

That's the same as what I have. Watch out for leaky D cell batteries.
I nearly destroyed mine when Duracell's leaked.

On one hand, I'm a little confused. You mentioned several times
different variations of me having likely "trashed" my counter by
doing what I did. At the very end however, when I asked if I
had done any harm, you said, "No. They're fine. After all,
the counter was probably designed to survive a nuclear attack."
So I'm not quite sure that I'm understanding if what I did was
bad or not.

I would say it was a bad thing to tear it apart. You didn't mention
if it was working before you attacked, so I question whether any of
the work you've done was worthwhile or productive. If it was dirty,
just clean the board. There's no reason to clean the component leads,
or make it pretty unless you're installing a clear case and using it
for show and tell.

The detrimental parts a
1. The phenolic PCB is very sensitive to handling, soldering, and
"cleaning". You could easily have ruined it.
2. The coatings that you removed are there to prevent the high
voltage power supply from being shorted by water condensation and high
humidity. By removing the coating (probably some type of conformal
coating), you have removed that protection. However, not all C
V-700-6b counters had coated PCB's. One of mine does, while the other
does not.
3. Some of the old components are difficult to find, such as the neon
regulator tube, but are at least available. Unsoldering these and is
a bit of a risk.
http://www.surplustuff.com/radiolog.htm
4. The rotary switch is a big of a reliability problem. If you bend
the contacts more than once, they'll break.

The good news is that the device is very simple and has few
components. It's made for easy repair, which is fairly easy. That's
the origin of my bad joke about the counter surviving a nuclear
attack.

Drivel: It's not really a counter, because it doesn't count, but I
can't get out of the habit of calling it a counter.

On the other hand, you have given me lots of details to consider and
suggestions in areas I haven't even started to think about. You've
obviously got a great deal of experience and I'll be taking all of
your suggestions into account as I move forward with my project.
I'll be trying the breath moisture thing right away. Thanks for
taking the time to educate an east coast newbie! -Matthew

The breath test is fairly simple and will usually indicate immediately
if you have a problem. I haven't tried it on mine for a long time,
but as I recall, one counter consistently failed when I took it out a
cold garage, and brought it into a warm house. With moisture all over
the counter, it didn't work until it warmed up. This is a rather
severe test and I would not expect even a conformally coated PCB to
survive a condensed moisture test. However, a simple breath test
should give you a clue as to how sensitive the counter is to moisture.
If you want to fix that, some wax based conformal coating around where
the GM tube cable connects to the PCB should be a good start. The wax
coatings are nice because they come off easily if you need to do some
rework. Make sure the PCB is clean and degreased before coating or
you will trap the moisture under the wax.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558