Scratchy dits are usually caused by dirty dit contacts or improper
adjustment on bugs.
A piece of paper pulled through the closed DIt contact can clean those
contacts - repeat until no further color appears on the paper.
Adjustment of the damper to properly time the length of the dits with
your dash sending speed is also important - the normal ratio is 3:1.
Many (most) bug users I have heard make the dits too short in comparison
to the dashes.
73,
Don W3FPR
On 6/3/2014 8:48 PM, Jim's Desktop wrote:
This is kind of a feeler email to see if there's any interest for a
product I've sort of resurrected. I don't know how many list
subscribers use a Semi-Automatic "Bug" key for CW when most rigs have
built in keyers now, but I have been hearing more bugs on the air
lately, mainly amongst the QRO operators and I've heard some really
excellent sounding ones and some really horrible sounding ones. Not
talking about the operator's "fists", but the really scratchy dots
inherent in the mechanical contact on the vibrating "Dit" generator.
This contact is usually a bent, flat spring and the cause of the
"scratchies" is extra contact bounce on contact break as the spring
becomes free to vibrate on it's own as the contacts separate.
Ted McElroy, who held the CW receiving record for many years and some
say that record hasn't been officially broken yet, came up with a
mechanical device that he incorporated into the contacts on the bugs
he marketed back in the 1920's and 30's. I've come up with a hand
made version of this "dot contact stabilizer" that eliminates the need
for a capacitor across the terminals of most bugs and almost
completely eliminates the scratchy dot syndrome when it's properly
adjusted.
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