- 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
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 eliminates
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 as
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 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.
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 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.
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
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.
The trunnion screws (they hold the lever and allow it to swing) should NOT be lubricated. Lubrication of such a small bearing causes more problems than help. It attracts dirt, dander and dust, and on some keys that have been "oiled" the lubricant had gotten between the main lever and the dash lever. This sticky residue causes the levers to stick when the dash lever is used. This problem is much more common than most people realize! Clean off the lubrication with ammonia then water and let dry for a few hours before reassembling. Moisture will weld your screws to the frame when the water turns iron to rust!
Also take a strand of stranded wire or a pin and clean out the trunnion screw cavity. I use a cheap ultrasonic cleaner with ammonia or Formula 409 to degrease and clean. I usually follow up with another 5 minutes of water and Dawn dish detergent then five more minutes with just water. Dry for a few hours and reassemble.
When tightening the trunnion screws, they should be adjusted with the key set wide so you can feel the drag. If the lever drags no matter what, it is rough and should be smoothed with 600 then 800 then 3000 grit wet/dry sandpaper (or other) and tried again. The correct adjustment is the best of "minimum up and down play with minimum drag" - when adjusted correctly, the lever will move slightly up and down as if it is tightened too much it will bind.
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.
David J. Ring, Jr., N1EA
Former Commercial Radiotelegrapher