[Boatanchors] HP 8640B RF Signal Gen has broken gear on Freq Change

[Bob Hardie- W5UQ]

Sounds similar to what I was wanting to do. 

I had already put two wire ties on it and it worked some...for a while.  
Still would slip some.  The switch shaft/gears have too much to turn for 
this injured little feller.  I'll leave it on the 2 meter range and use 
my other signal generator for all lower freqs. as it's a good digital 
high quality generator, just doesn't go above 140 mHz. 

Since the 8640B is at my other QTH, 15 hours drive from here, it will be 
a while before I can get to it.  Thought I'd give it a try to locate the 
part.  Since part is "unobtainium" ........then I'll save any further 
research until later when I'm at the other QTH.

thanks guys.
Bob

J. Forster wrote:
> This has been discussed at great length many times on the HP-Agilent Group
> on Yahoo. There are fixes that apparently work.
>
> The root problem is that, over time, the Nylon looses water and shrinks
> and splits. Someone tried to make replacements, but there were few takers
> and AFAIK the project died stillborn.
>
> The fixes in the archive seem to involve some opening of the center hole
> to reduce the hoop stress in the gear and gluing the gear back together,
> sometimes with a wire serving.
>
> -John
>
> ================
>
>
>
>   
>> More info... the set of gears behind the Range Switch, aka #13 control.
>> These are the milky white gears.  I've put wire ties on the broken one
>> and it seems to work, however it can still slip ranges.
>>
>> These gears appear to be cracked due to age and having stress put on
>> them...  Actually only one gear is stressed/cracked.
>>
>> Maybe the full assembly could be found in an old 8640 that has been
>> parted out.  I could use a couple of other parts if someone answers and
>> has the parts.
>>
>> Thanks... know it's a long shot... but here goes.
>> Bob
>>
>> Bob Hardie- W5UQ wrote:
>>     
>>> The broken gear is the round one like shark's teeth, kinda.  I'm trying
>>> to find my manual to locate the part.
>>>
>>> Anyone know where to get these gears?  Otherwise the unit is fine.
>>>
>>> Bob
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