- Vibroplex Adjustment, Cleaning and Sending Technique - 
by David J. Ring, Jr., N1EA

GOOD BUG SENDING TECHNIQUE

Your wrist is "rocked" with the same motion that you use when opening a
door knob, the wrist and are lie on the desk and rock with that motion.
The position in which you assume to use the bug would be just like you
would grab a door knob or to receive a beverage bottle. You roll your
wrist on the fleshy part of your hand back and forth. No finger movements
at all!

Finger motions are not to be used as they give carpal tunnel syndrome
(glass arm) the idea is to rock the wrist with a bug and cootie key.
Unfortunately the paddle used with an electronic keyer must be tapped with
fingers at high speeds :(

I know it might be silly to say this, but it is much easier to send when
both feet are on the floor not angled to the left or right, but straight
and senders body is straight and not turned. It is much easier - try it
if you don't believe this.

BUG CLEANING

The following is time consuming but I find it always works and I do this
routinely and it takes time but it saves time because it eliminates
problems.

If your bug is old, take it completely apart and clean (especially) the
contacting surfaces, including the underneath connecting strips
(especially around the screws), the countersunk hole for the grounded
binding post, the silver contacts, the surface where the U shaped dot
spring contacts the vibrator, and the two beveled pins of the trunnion
assembly (the pins on which the main lever pivots in the frame), and make
sure that the cups into which the pins fit are clean of debris.

I use the cotton wadding with metal polish which is sold nationwide, and
a stick pencil type eraser to clean the more stubborn parts and then use
Flitz metal polish to finish the metal cleaning. If you have an
ultrasonic cleaner (jewelry cleaner) put some ammonia and water in it,
with a few drops of Dawn dish cleaner liquid and use for 15 minutes, then
repeat with clean water. I dry everything in a toaster oven for 1 hour
at 140 degrees F.

A bug has to swing far enough to compress the U spring - it doesn't send
like a paddle - you use your wrist - you shouldn't get tired with this
key - if you are, your probably doing it incorrectly. The dash spacing
and tension should be adjusted for reliable dashes.

See the "Art and Skill of Radiotelegraphy" by N0HFF available several
places and in several languages on the Internet for good advice on sending
and general tips.

CONTACT ALIGNMENT

Old bugs have a screw which holds the lever against the trunnion post.
This can be adjusted up and down. Later bugs do not, and the alignment
of the dot contact and the dash contact must be done by adjusting the top
and bottom trunnion screws. The bottom trunnion screw is held fast (and
will strip unless this screw is loosened) by a screw on the rear side of
the frame. You must use a long handled screw driver to get to this
screw! Loosen this screw and you will be able to loosen and tighten the
bottom trunnion screw and raise and lower the position of the lever.

The lever should be adjusted so that the height of the lever / mainspring
/ vibrator assembly is such that the contact on the U shaped dot spring is
vertically aligned with the dot post contact.

The alignment of the dash contact can be done (after the above is done)
by loosening the small contact plate and adjusting.

All final adjustments should be done so that the contacts are touching and
completely aligned so that the contacts meet as fully and directly as
possible.


DOT ADJUSTMENT

Bugs used for radiotelegraphy vs bugs used for landline telegraphy 
were set to approximately 60% of an analog VOM meter full-scale 
reading in resistance. Put the meter on OHMS, adjust for full scale, 
then start a series of dots, and adjust for about 60% full scale - 
there usually is a logging scale on the VOM meter. Digital won't 
work but an o'scope will work but adjust for more than 1:1 ratio to work 
well for radio work. Landline telegraph was 1:1 or a bit less.

If your power is 1500 watts key down, it will still be 1500 watts on each
dot closure - but the dots will give different meter ballistic movements
different results - but rest assured they are still full power.

That being said, dots with a dot/space ratio of about 100:60 OR 1.67:1
will give better copy than dots with a 1:1 ratio during radio conditions
on typical hf bands. Or instead of 1.00 to 1 - dots sound better about
1.5 to 1.67 to 1.

CONTACTS

If you buy some silver cleaner you can clean them. If you can find 1500
grit wet/dry sandpaper, you can smooth them out. You can also buy a
burnishing tool from GC Electronics for $1.57 which is an extremely fine
file that is about 1/4 inch wide and about 1/32 inch thick which was
designed especially for that purpose. I use 800 grit wet/dry sandpaper
(very lightly and with care) then 1500 grit wet/dry and finally I polish
with Flitz metal polish which is a very very low grit polish;. The
contacts if done this way will come out like mirrors.

Vibroplex sells a contact cleaner that is a narrow long strip of fine crocus 
cloth folded back on itself and glued together.  It works very nicely.  
You can make a bunch of them by taking a piece of contact paper, folding it 
in half, then putting rubber cement (from Office Supply store or bike shop) 
and putting a heavy large book on it until it dries.  Cut into 1/2 inch strips 
the narrow way.  To use hold the contacts together with your hands (be very 
careful of the fragile dot contact spring!) and rub in and out by drawing and 
pushing the strip through the held closed contacts.

Metal polishing the contacts.  Simachrome is nice, but Flitz is much better.  
I have a brass based Scotia paddle that I hand polished to a mirror finish 
with Flitz two (1998) years ago.  It is a mirror and it is as golden 
as the day I polished it - which is simply amazing.   
Flitz has an anti-corrosive in it.

You MUST clean the contact after using polish and it is recommended that you 
clean it after using a Vibroplex cleaning strip.  I use isopropal alcohol 91% 
for this as water around a Vibroplex is not nice as it can creep into where it 
will rust the base or screws.

I bought a 5% spray De-Oxit as an experiment as it was quite costly. It so 
impressed me that I bought the 100% pure product (even more costly but per 
"unit" of percent, much cheaper.  I swear by it.  The contasts last nearly 
*forever* but being near salt water (800 feet) they do go bad within six months.


BUG ADJUSTMENT

Old-timers insisted upon sizable gaps. In fact, a significant gap for the
dit lever moved against a significant spring resistance sets up a good
vibration of the mainspring for producing dits and avoiding scratchy and
bouncing dots.

The limit screw adjustment for the damper is adjusted just so the end of
the swinging pendulum contacts the damper. The bug is also quieter when
the damper doesn't move as dramatically.

The dot spring will have more tension than you might be accustomed to.
The spring tension returns the lever after sending dots quickly and it
also makes the lever move with more force which sets up a stronger impact
on the dot spring which results in much stronger and less problematic
dots. This is the cure for poor dots if the contacts and the other
connections are clean.

HARD TO FIND PROBLEMS

When you have bad dots, the hard to diagnose problems that I've routinely
found are: The terminal connectors are loose and the round cylinder
shaped nut is not holding the base tightly when the bug sends dots the
contact is intermittent. The dot spring is loose on the vibrating arm.
When the contacts crash, the spring conducts intermittently. Similar
happens for all the contact path on the connecting straps - if one is
loose or corroded, it will produce poor dots.

73

David J. Ring, Jr., N1EA
Former Commercial Radiotelegrapher