[Elecraft] K2 encoder installation 2018

Scott netbsd21 at gmail.com
Sun Sep 2 14:36:53 EDT 2018


Ted,

1.  The nut and washer go on the "outside", that is, the front facing 
side of the front panel behind the main VFO knob.  The encoder shaft has 
to be fully seated on the inside of the front panel with the encoder 
shaft extending a good distance out, then tighten the nut and washer on 
the outside of the front panel.  To my knowledge there should be nothing 
on the encoder shaft on the inside of the front panel.  My encoder shaft 
appeared to be too large for the hole, and I was about to "clean" the 
hole when I gave it one last push and it popped in.  Very tight fit but 
the encoder shaft base was flush on the inside of the front panel. 
After the lock washer, nut, 3 felt washers and the Main VFO knob were 
installed on the shaft, the backside of the main VFO knob was parallel 
to the front panel with nice friction.

2.  My kit came with 3 felt washers and I had to use all three to get 
the right friction that is close to that of my K3.  Look in one of the 
other envelopes there should be another felt washer.  IIRC, it was in 
one of the misc envelopes and not in the Main VFO board assembly bag 
with the other two washers.

3.  My Main VFO board assembly bag came with a 4 pin male header that 
actually fit the holes in BOTH the encoder PCB and the Front Panel 
Board.  If that male header is installed you may have found the problem 
as the directions for installation say to use stripped wire.  I asked 
Don about the extra 4 pin male header in my bag and he said follow the 
wire directions.

4.  The bottom side of the encoder PCB will have to have ALL the joints 
cut as flush as possible because when the Control Board is installed, 
there is very very little room between the two PCBs.  The Main VFO board 
assembly instructions say you can you use thin paper as an insulator 
between the two boards.

That's about all I know.  If I have any of that wrong I'm sure Don will 
chime in soon and correct me.

I'm still working on K2 #7815, just a bit further along than you.  Good 
Luck.

Scott
AD5HS

On 9/2/2018 6:30 AM, Ted Salmon wrote:
> The encoder plus attached PC board is attached to the Front Panel with a lock
> washer and 1/2" hex nut on the encoder shaft. The diameter of the hole on my
> Front Panel was 10 mm as measured with my calipers. The diameter of the
> threaded mount on the encoder is ~ 9 mm while the diameter of the ring at
> the base of the threaded mount is ~ 10 mm. How is the encoder correctly
> mounted by hardware to the inside face of the Front Panel?
> 
> I tried 3 methods without success.
> 
> 1) First was to just add the washer and nut to the shaft and try and tighten
> it down with a wrench, but the encoder kept tilting.
> 
> 2) So, I thought perhaps the inner diameter of the hole in the Front Panel
> was too narrow because of paint thickness.  I scrapped off the paint from
> the inside of the hole and a bit of aluminum, then the 10 mm ring at the
> base of the encoder shaft fit in the hole nicely. I could then barely
> tighten down the shaft with the nut and washer because this ring at the base
> of the encoder is slightly thicker than the thickness of the front pannel.
> When I put on the large knob, 2 felt washers were not thick enough to
> provide resistance to knob turning, so I thought I made a mistake in
> enlarging the hole. However, the position of the PC board on the back of the
> encoder was close enough to the Front Panel to allow the attachment of the
> Control board to the 1/2' posts attached to the back of the Front Panel
> Board.
> 
> 3) To solve the felt thickness problem, I put a very thin (0.2-0.3 mm)
> washer, ~9mm ID, on the threaded shaft of the encoder before inserting it
> into the hole in the Front Panel to stabilize the tilting problem. I
> attached the washer and nut to the threaded shaft and now the double felt
> washers work as described to provide friction against the inner surface of
> the large knob.  However, now the PC board on the back of the encoder
> extends too far away from the the back of the Front Panel Board to allow
> attachment of the Control Board to the two posts.
> 
> So, how to solve this problem?
> 
> Thanks, Ted Salmon WD4CAV


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