KXPD3 Paddle Intermittent - At the hinge-posts ?

[AB3SX]

Good afternoon, Gentlemen -

I have been experiencing intermittent contact problems on my KX3 paddle for weeks now. ( I have read all the experiences on the group, and tried those suggestions.) Sometimes I would gain temporary relief from dis-assembly, cleaning, reassembly, but the problem always returned.

The main symptoms are "missing dit"; with easy wrist-rolling from side to side, I suddenly come up with no dit where one should be. I learned I could minimize this problem by "man-handling" the levers, but this was tiring ( that is, forceful lever movements seemed to solve the problem of intermittent contact ). This seemed strange, since I could clearly "feel" the movable contact stop on the post, even though no electrical contact was completed.

Well, something FORCED me to have a better look into what was happening, and I thought I would see if any of you have been experiencing this same problem. I have recently been operating the KX3 set up as "hand-key" and the automatic creation of proper length dots and dashes is no longer present to cover up the frequently intermittent contact. So today, I followed a hunch and connected two clip leads to provide ground from the chassis to each of the movable levers. Sure enough, this put an end to the intermittent operation. I repeated the test several times, and each time the intermittent would appear without the clip leads, and disappear once the clip leads were reattached.

I followed this up with a power-off resistance measurement from each of the movable levers to the chassis and, sure enough, LARGE resistances were found. Depending on the amount of pressure exerted on the lever ( to load the swing-lever/pin joint, the resistance could be varied from 8000 ohms to 1200, 800, all the way down to 1.3 ohms ). I went further to check the resistance to chassis from the knurled-bolt KXPD3 fasteners ( 1.0 ohm ) and the resistance to chassis from the top-place of the KXPD3 ( 1.2 ohms ). Only the last part of the path to each lever seems to be involved in the high-resistance problem ( the vertical hinge that supports and grounds each lever ).

So, AT-LAST, my problem has been located. I am wondering if this has happened to anyone else with the KXPD3? ( It looks like most of such discussion peaked and went away in year 2012, so I am guessing I am the only one with the problem ).

Love my KX3, and can't wait to get this one little quibble quashed :)

Jerry AB3SX

[vk2rq]

Yes, this has been discussed in both this reflector, and the KX3 yahoo group. Here is a blog posting from one of the guys who did this mod:
http://wv0h.blogspot.com.au/2013/09/kxpd3-mod.html

I did pretty much the same thing, and it has proven effective.

73,
Matt VK2RQ

> On 26 Jul 2014, at 5:23 am, AB3SX <[hidden email]> wrote:
>
> Good afternoon, Gentlemen -
>
> I have been experiencing intermittent contact problems on my KX3 paddle for
> weeks now. ( I have read all the experiences on the group, and tried those
> suggestions.) Sometimes I would gain temporary relief from dis-assembly,
> cleaning, reassembly, but the problem always returned.
>
> The main symptoms are "missing dit"; with easy wrist-rolling from side to
> side, I suddenly come up with no dit where one should be. I learned I could
> minimize this problem by "man-handling" the levers, but this was tiring (
> that is, forceful lever movements seemed to solve the problem of
> intermittent contact ). This seemed strange, since I could clearly "feel"
> the movable contact stop on the post, even though no electrical contact was
> completed.
>
> Well, something FORCED me to have a better look into what was happening, and
> I thought I would see if any of you have been experiencing this same
> problem. I have recently been operating the KX3 set up as "hand-key" and the
> automatic creation of proper length dots and dashes is no longer present to
> cover up the frequently intermittent contact. So today, I followed a hunch
> and connected two clip leads to provide ground from the chassis to each of
> the movable levers. Sure enough, this put an end to the intermittent
> operation. I repeated the test several times, and each time the intermittent
> would appear without the clip leads, and disappear once the clip leads were
> reattached.
>
> I followed this up with a power-off resistance measurement from each of the
> movable levers to the chassis and, sure enough, LARGE resistances were
> found. Depending on the amount of pressure exerted on the lever ( to load
> the swing-lever/pin joint, the resistance could be varied from 8000 ohms to
> 1200, 800, all the way down to 1.3 ohms ). I went further to check the
> resistance to chassis from the knurled-bolt KXPD3 fasteners ( 1.0 ohm ) and
> the resistance to chassis from the top-place of the KXPD3 ( 1.2 ohms ). Only
> the last part of the path to each lever seems to be involved in the
> high-resistance problem ( the vertical hinge that supports and grounds each
> lever ).
>
> So, AT-LAST, my problem has been located. I am wondering if this has
> happened to anyone else with the KXPD3? ( It looks like most of such
> discussion peaked and went away in year 2012, so I am guessing I am the only
> one with the problem ).
>
> Love my KX3, and can't wait to get this one little quibble quashed :)
>
> Jerry AB3SX
>
>
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/KXPD3-Paddle-Intermittent-At-the-hinge-posts-tp7591582.html
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[AB3SX]

Thanks for the assist. I installed a #30 gage wire-wrap wire to ground each arm: perfect operation now.