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K2 VFO encoder / control board close fit

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Mark Petrovic

K2 VFO encoder / control board close fit

While performing the initial power on tests on my K2 S/N 7809, I noticed
that the VFO knob/display tuning test produced a sluggish, intermittent, or
no change in display when I turned the knob in either direction.

I proceeded to remove the two chassis screws securing the control board to
the front panel board. This allowed the control board to relax and
slightly fall away from the front panel board, toward the back of the
radio, opening up the space between the front panel encoder board and the
control board. The display was at once responsive to knob turning on all
RATE settings.

Next, I slipped a piece of paper between the encoder board and the control
board, then reattached the control board to the front panel board with the
chassis screws. The display continued to be properly responsive to knob
movement. When I tugged on the paper to see how tight the fit was, it
resisted being slipped from its position. It was fairly pinned down.

Here is a photo of the control board backside taken at a glancing angle,
showing the joints for J1 in the foreground, and the pins of the U6 socket
behind that. The socket pins should probably be trimmed, which I did not
anticipate. The other joints, while not necessarily overly beautiful, I'll
also check for height. It's not clear to me which pins on the encoder
board are shorting to which pins on the control board, but it seems clear
that some are.

https://photos.app.goo.gl/KDzlAixNghg2tmhy1

If after trimming the U6 socket pins the problem persists, I'll leave the
paper slip in, but I don't feel great about it. The paper could fail on
these sharp solder joints given vibration over long periods of time.

Has anyone else had an experience like this where the front panel board
meets the control board? I believe the manual talks warns about this
condition.

Thank you.

Mark
AE6RT

--
Mark
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RobertG

Re: K2 VFO encoder / control board close fit

Mark...

All else aside, I'd suggest using good quality electrical tape, perhaps
even two layers. It won't slip and has a better half life than paper.

...robert

On 5/6/2018 02:58, Mark Petrovic wrote:

> While performing the initial power on tests on my K2 S/N 7809, I noticed
> that the VFO knob/display tuning test produced a sluggish, intermittent, or
> no change in display when I turned the knob in either direction.
>
> I proceeded to remove the two chassis screws securing the control board to
> the front panel board. This allowed the control board to relax and
> slightly fall away from the front panel board, toward the back of the
> radio, opening up the space between the front panel encoder board and the
> control board. The display was at once responsive to knob turning on all
> RATE settings.
>
> Next, I slipped a piece of paper between the encoder board and the control
> board, then reattached the control board to the front panel board with the
> chassis screws. The display continued to be properly responsive to knob
> movement. When I tugged on the paper to see how tight the fit was, it
> resisted being slipped from its position. It was fairly pinned down.
>
> Here is a photo of the control board backside taken at a glancing angle,
> showing the joints for J1 in the foreground, and the pins of the U6 socket
> behind that. The socket pins should probably be trimmed, which I did not
> anticipate. The other joints, while not necessarily overly beautiful, I'll
> also check for height. It's not clear to me which pins on the encoder
> board are shorting to which pins on the control board, but it seems clear
> that some are.
>
> https://photos.app.goo.gl/KDzlAixNghg2tmhy1
>
> If after trimming the U6 socket pins the problem persists, I'll leave the
> paper slip in, but I don't feel great about it. The paper could fail on
> these sharp solder joints given vibration over long periods of time.
>
> Has anyone else had an experience like this where the front panel board
> meets the control board? I believe the manual talks warns about this
> condition.
>
> Thank you.
>
> Mark
> AE6RT
>
>

--
Robert G Strickland, PhD ABPH - KE2WY
[hidden email]
Syracuse, New York, USA
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Don Wilhelm

Re: K2 VFO encoder / control board close fit

In reply to this post by Mark Petrovic

Mark,

The instructions packed in the encoder envelope tell you to flush cut
not only the pins on the encoder board, but also the leads on the
control board that might contact it.

If you do not have flush (or shear) cutters, and want inexpensive ones,
look for Xcelite (or Lufkin or Cooper) 170M shear cutters. They can
often be found in your local Home Depot.

In addition to flush cutting the boards, put something on the back of
the encoder board - fish paper would be best, but a piece of flat
plastic cut from one of the many plastic wrapped consumer products would
be good.
Paper or electrical tape will eventually puncture.

73,
Don W3FPR

On 5/5/2018 10:58 PM, Mark Petrovic wrote:

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Mark Petrovic

Re: K2 VFO encoder / control board close fit

Don, thank you.

With some copper braid solder wick to remove a bit of the fillets on the
joints on both boards, and after using my new Xcelite 170M shears, the
control board can be secured without an insulating sheet between it and the
front panel board. I may still use that sheet of plastic there, but the
new configuration is *much* better than when I first wrote.

Mark
AE6RT

On Sun, May 6, 2018 at 7:27 AM, Don Wilhelm <[hidden email]> wrote:

> Mark,
>
> The instructions packed in the encoder envelope tell you to flush cut not
> only the pins on the encoder board, but also the leads on the control board
> that might contact it.
>
> If you do not have flush (or shear) cutters, and want inexpensive ones,
> look for Xcelite (or Lufkin or Cooper) 170M shear cutters. They can often
> be found in your local Home Depot.
>
> In addition to flush cutting the boards, put something on the back of the
> encoder board - fish paper would be best, but a piece of flat plastic cut
> from one of the many plastic wrapped consumer products would be good.
> Paper or electrical tape will eventually puncture.
>
> 73,
> Don W3FPR
>
>
> On 5/5/2018 10:58 PM, Mark Petrovic wrote:
>
>> While performing the initial power on tests on my K2 S/N 7809, I noticed
>> that the VFO knob/display tuning test produced a sluggish, intermittent,
>> or
>> no change in display when I turned the knob in either direction.
>>
>> I proceeded to remove the two chassis screws securing the control board to
>> the front panel board. This allowed the control board to relax and
>> slightly fall away from the front panel board, toward the back of the
>> radio, opening up the space between the front panel encoder board and the
>> control board. The display was at once responsive to knob turning on all
>> RATE settings.
>>
>>

--
Mark
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
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Please help support this email list: http://www.qsl.net/donate.html
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Don Wilhelm

Re: K2 VFO encoder / control board close fit

Mark,

Put the plastic sheet in anyway. In your case, it may be overkill (good
job on flush cutting BTW).

73,
Don W3FPR

On 5/8/2018 10:26 PM, Mark Petrovic wrote:

> Don, thank you.
>
> With some copper braid solder wick to remove a bit of the fillets on
> the joints on both boards, and after using my new Xcelite 170M shears,
> the control board can be secured without an insulating sheet between
> it and the front panel board. I may still use that sheet of plastic
> there, but the new configuration is /much/ better than when I first wrote.
>
> Mark
> AE6RT
>
> On Sun, May 6, 2018 at 7:27 AM, Don Wilhelm <[hidden email]
> <mailto:[hidden email]>> wrote:
>
> Mark,
>
> The instructions packed in the encoder envelope tell you to flush
> cut not only the pins on the encoder board, but also the leads on
> the control board that might contact it.
>
> If you do not have flush (or shear) cutters, and want inexpensive
> ones, look for Xcelite (or Lufkin or Cooper) 170M shear cutters.
> They can often be found in your local Home Depot.
>
> In addition to flush cutting the boards, put something on the back
> of the encoder board - fish paper would be best, but a piece of
> flat plastic cut from one of the many plastic wrapped consumer
> products would be good.
> Paper or electrical tape will eventually puncture.
>
> 73,
> Don W3FPR
>
>
> On 5/5/2018 10:58 PM, Mark Petrovic wrote:
>
> While performing the initial power on tests on my K2 S/N 7809,
> I noticed
> that the VFO knob/display tuning test produced a sluggish,
> intermittent, or
> no change in display when I turned the knob in either direction.
>
> I proceeded to remove the two chassis screws securing the
> control board to
> the front panel board. This allowed the control board to
> relax and
> slightly fall away from the front panel board, toward the back
> of the
> radio, opening up the space between the front panel encoder
> board and the
> control board. The display was at once responsive to knob
> turning on all
> RATE settings.
>
>
>
>
> --
> Mark