With the introduction of the P-500 keys, McElroy's keys started to be very similar to Vibroplex's keys. The shorter left hand screw adjusted a cone shaped compression spring. David Ballentine, KK4DW, has a good picture of such a bug showing the spring: http://www.goofus.org/MACP500.jpg
With the old style Mac Bugs - and also the S600 Stream Key (which I believe is one of the most beautiful keys ever made) the pendulum return spring is configured differently - probably to avoid patent infringement with Vibroplex.
On the S600: On the left-hand side of the instrument, the screw you call a "centering screw" has a knurled adjusting screw threaded on it which holds in place and adjusts by it's position on the screw, a long coiled compression spring through which this machine screw passes and which at the end nearest the lever, fits into a hole of the same diameter which was bored into the lever to fix the spring.
On Sat, Mar 13, 2010 at 10:05 AM, TJRachwal <tjrachwal@...>
I just recently required a McElroy P-500 bug. I have a question
about the mechanics of the bug. It seems it doesn't center after
sending dits, I believe there is a spring missing.. I have checked all
the sights for a clear close-up picture and can not tell if there is a
spring missing or not. There are two longer centering screws and then
there is a shorter screw that appears to do "nothing." I believe there
should be some sort of spring (maybe a cone spring) that would center
the arm after making a dit. If anyone has a P-500 or knows the answer
to my question I sure would appreciate knowing. A picture of their P
500 would help if it shows what that short post does. Of course if I am
correct then I need to track down a spring that would work as I am sure
a correct part won't be available.
Any advice or help sure would be appreciated.
Tnx es 73,
Yahoo! Groups Links
<*> To visit your group on the web, go to:
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to: