[CW] GHD GH-GF501A

[Joe]

Hi, Stan.

I worked on minimizing that scratchy last few, or on any dits. It 
appears to be caused by various 'things'

Probably the two most effecting things are contact surfaces, ie. 
smoothness and the keyed circuit.  If the two mating surfaces are not 
mirror smooth,
the contacts will, you might say, bump along when the pressure is 
reduced.  The "U" spring's tension goes down as each dit is made to the 
steady
state of either on or off..  If the two contact surfaces are mirrored 
finished, at the lower tensions, the bumping will be barely noticed.

The other is the circuit being keyed.  Where is the thresh hold for on 
and off at?  Is it a wide range or a narrow range?  If it is a wide 
range, you may
have what appears to be scratchy sounding keying at the keying goes on & 
off over that transition range, not a clear on or off state.

As I get ready to use my Junior, I take a piece of paper wet with either 
alcohol or naphtha and draw it through the closed contacts.  No dirty ink
laden dollar bill.


On 2/25/2017 3:09 PM, stan levandowski wrote:
> Funny you should mention the 8 dit thing...I was messing around this 
> morning with my 70s era Vibroplex presentation and yes, after about 8 
> to 10 GOOD dits, it got sloppy.  Wish I'd seen your email comment 
> earlier.  Would have saved me a lot of frustration this a.m. trying to 
> "fix" the "problem."  I was trying to get it to go from the last good 
> dit to steady state without first going through a couple of fuzzy, bad 
> dits.  I even stuffed differing amounst of foam in the U spring 
> thinking that might be part of the problem with the scratchy dits, 
> I've tried a 1 uf cap  I have a "dot stabilizer" also but that doesn't 
> work either.  The contacts are like new.  It must be something 
> mechanical I don't understand that occurs near the end of the dit 
> string.  Probably not solvable.  Not really an operating issue; just 
> something that bothers me that I wish I could fix.
>
> 73, Stan WB2LQF

-- 
Regards, Joe, K8JP/V31JP, Ronnie, Marty & Sidney Pontek
2129 CR 1229
Pittsburg, TX 75686
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, QCWA-LM21894, OOTC-4607, A1OP, SKCC-3171T, NAQCC-5798, Flying Pig-2819, FISTS-7625CC951, A1C-2299, SOC 1075, 10-10 22977, PG1915841, CW Rag chewers #21,
Skype: v31joepalooka
Facebook: Joe Pontek
I am looking for Vibroplex Model X, Double lever and prefer basket cases to restore.
LotW

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