Amplidan Morse Key Copies

Ham4CW

Administrator
Before I managed to obtain a genuine Amplidan Marine key I purchased some clones or copies from G3YUH.

After he made the two full size clones he found he had just enough material left over to create a miniature model too.

 

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Is the helical spring just aft of the pivot a tension or compression spring? I'd say it's probably a tension spring but I'm struggling a little to see how this key operates. On key down, does the end of the arm touch a contact which floats above it? What is the S-shaped piece of metal doing, forming some sort of spring which allows the contact to be adjusted up and down above the arm?
 
MI0PYN said:
Is the helical spring just aft of the pivot a tension or compression spring? I'd say it's probably a tension spring but I'm struggling a little to see how this key operates. On key down, does the end of the arm touch a contact which floats above it? What is the S-shaped piece of metal doing, forming some sort of spring which allows the contact to be adjusted up and down above the arm?

Yup, the contact is above the end of the arm, and a 'tongue' of metal makes contact with it when the key is pressed. There is a spring just behind the pivot that is for tension (that's the coiled one), and the S-shaped piece of metal is actually a wide flat earthing strap (instead of the more usual braided copper ones used on a lot of keys).

The feel of the copies is exactly the same as genuine ones, though the prices are much better! Having said that the finish on genuine Amplidan keys are superb, whereas the copies though good still have a handmade look about them.

73, Mark...
 
MI0PYN said:
Is the helical spring just aft of the pivot a tension or compression spring? I'd say it's probably a tension spring but I'm struggling a little to see how this key operates. On key down, does the end of the arm touch a contact which floats above it? What is the S-shaped piece of metal doing, forming some sort of spring which allows the contact to be adjusted up and down above the arm?

Just thought I would add a photo of the contact/tension spring/grounding "S" strap.

This is a clone by G3YUH (sn-120), not an Amplidan original.

Hopefully the photo says more than my previous narration :)

73, Mark...
 

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Excellent photo. It really does illustrate what you were saying about how this key works.

Also
"...the copies though good still have a handmade look about them."
That's very apparent from this photo too.

The bent metal plate on the end of the rocker arm seems to hold the contact at a very odd angle...
 
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