Vibroplex Bug Adjustment and Technique
- This message is a recap of what I sent in the past.
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.
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
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.l
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.
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
Bugs used for radiotelegraphy vs bugs used for landline telegraphy
were set to approximately 60% of a VOM meter reading in resistance.
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
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.
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
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
David J. Ring, Jr., N1EA
Former Commercial Radiotelegrapher