[CW] Stuttering Dots on Vibroplex - Info from Two Experts, Frank W7IS and Jim W0EB

[Richard Knoppow]

    Its because the got contact buzzes. You can pinch it and see 
and hear it buzz. As the contact is opening the vibration of the 
spring may cause it not to break cleanly. Whether this happens in 
practice depends on many things so its quite possible all keys 
don't have noisy dots or that it depends on adjustment, perhaps 
the amount of swing of the pendulum, etc. It is observable. A 
damper will stop the buzzing but will have other effects.

On 7/8/2020 2:36 AM, Joe Pontek Sr wrote:
>
> I have to wonder why you are concerned about what a contact is
> doing in the open position?  When a contact swings to the closed
> position, you have to be concerned with two things.  Contact over
> travel and contact wiping.
>
> If there is no over travel, it is susceptible to light contact, 
> poor or
> no wiping and possible scratchiness.  When the contacts separate,
> it should wipe open.  Once clear, there is no effect on the next
> contact closure.
>
> The damper is just a soft stop which it easier on parts, all 
> the way
> to the pivot and bearing pins/screws.  If you have a wider dot bar
> swing, ie. slower speed ranges, you will have a stronger 
> contact with
> the damper, over travel.  It the steady state, the weight bar 
> should
> just contact the damper. The damper only effects to dot bar's stop,
> not the dot spring contact.
>
> Yes, I have tried all the dot spring tricks, dental floss, 
> sponge wedge,
> and the wire damper to hold the spring.  In technical field, we 
> call
> this pretensioning. Out of all the bugs I have worked on, I 
> have had
> to replace two actual contacts that were either burned or filed 
> beyond
> repair.  I had to replace one dot spring, I think it was 
> heated, maybe heavy
> current run through it.  The contact was fine, but?
>
> There are simple basic adjustments for bugs and if properly 
> used, they work
> without stuttering  They need to used vigorously, but with 
> proper good rubber
> feet will not move about on a smooth flat surface.
>
> 73, Joe, K8JP/K5--
>
> Regards, Joe, K8JP/V31JP, Ronnie, Martin & Sidney Pontek
> 175 Diamond Loch Rd., Apt. 5
> Gilmer, TX 75644-9374
> U.S.A.
> or
> P.O. Box 280, Dangriga, Stann Creek District
> (Hopkins Village) Belize
>
> 903-204-2318 (My TX cellular)
> 903-884-5990 (Skype telephone number, Belize & TX)
> Also, K8JP, member FOC-1743 Feb 2001, QCWA-LM21894, OOTC-4607, A1OP, SKCC-3171T, NAQCC-5798, Flying Pig-2819, FISTS-7625CC951, A1C-2299, SOC 1075, CFO, 10-10 22977, PG1915841, CW Rag chewers #21,
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> Skype: v31joepalooka
> LotW
>
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL