Topics

K3 rotary encoder replacement fun-again


M Gerber
 

I am about to start replacement of the group of 4 rotary encoders/PB switches on my K3 SN6000+ for the second time.

I first replaced them in March 2015, so they lasted about 5 yrs. First time, only 2 of the 4 were acting up, but I replaced all of them in anticipation of more troubles. Problem was solved. Now, the entire group of 4 are acting up. For example, turn the POWER up and it goes down--sometimes---and sometime acts properly. Same with both FILTER and MIC. I also noticed that when I clearly pressed the BAND switch, the MODE will change and the MODE switch itself is occasionally less responsive. The unusual behavior with the BAND and MODE switches is not nearly as consistently broken as the rotary encoder group.

I thought it might be J31, which is the primary MUX signal connector between front panel boards as the male pins only partially engage the female socket. I gently cleaned the gold pins with Deoxit and that didn't solve the problem. 

Replacements encoders were sourced from Elecraft first repair. This time, I got them from Mouser, PEC11R4015FS0018.
 
Anyone else with similar experience before I start the removal/replacement? It is surgery that is somewhat painful. From what I recall, it took mildly forceful TLC and patience to remove the old encoders without damaging the circuit board.

Thanks

Mark WH7W


Dave Cole
 

Hi Mike,

I had the exact same issues with my encoders... About 5 years in... I sent the K3 into Elecraft, and had them do it, and update the radio as well, there were a few things they did to bring it up to current specs.

It is interesting that your failure is the same as mine... I wonder if others have had this failure?

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 5/13/20 9:42 PM, M Gerber wrote:
I am about to start replacement of the group of 4 rotary encoders/PB switches on my K3 SN6000+ for the second time.
I first replaced them in March 2015, so they lasted about 5 yrs. First time, only 2 of the 4 were acting up, but I replaced all of them in anticipation of more troubles. Problem was solved. Now, the entire group of 4 are acting up. For example, turn the POWER up and it goes down--sometimes---and sometime acts properly. Same with both FILTER and MIC. I also noticed that when I clearly pressed the BAND switch, the MODE will change and the MODE switch itself is occasionally less responsive. The unusual behavior with the BAND and MODE switches is not nearly as consistently broken as the rotary encoder group.
I thought it might be J31, which is the primary MUX signal connector between front panel boards as the male pins only partially engage the female socket. I gently cleaned the gold pins with Deoxit and that didn't solve the problem.
Replacements encoders were sourced from Elecraft first repair. This time, I got them from Mouser, PEC11R4015FS0018.
Anyone else with similar experience before I start the removal/replacement? It is surgery that is somewhat painful. From what I recall, it took mildly forceful TLC and patience to remove the old encoders without damaging the circuit board.
Thanks
Mark WH7W


redarlington
 

The only issue on my K3S is the power setting knob feels like it skips counts.  If I turn it fast it doesn't budge.  Slowly turning allows me to set the power reliably.  Reliably and slowly.    I may pick up a set of encoders for the parts collection  Cutting pins and desoldering them seems like an easy way to go to remove the old, but am saying this without having actually looked at this stuff since building the rig several years ago.  The assembly manual shows an "H" shaped LED board that wraps around the top two (shift/width) leaving the speed and power knobs accessible enough without removing it.  Looks like a major tear down, but labor is skilled and very cheap at my place.   Till I actually do it, I do have macro buttons setup (external keypad) with various power levels to get me close to where I want to be.

-Bob N3XKB


On Thu, May 14, 2020 at 4:24 AM Dave Cole <dave@...> wrote:
Hi Mike,

I had the exact same issues with my encoders...  About 5 years in...  I
sent the K3 into Elecraft, and had them do it, and update the radio as
well, there were a few things they did to bring it up to current specs.

It is interesting that your failure is the same as mine...  I wonder if
others have had this failure?
<snip>


Dave Cole
 

Bob,
Are you using a Genovation pad?

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 5/14/20 9:09 AM, redarlington wrote:
The only issue on my K3S is the power setting knob feels like it skips counts.  If I turn it fast it doesn't budge.  Slowly turning allows me to set the power reliably.  Reliably and slowly.    I may pick up a set of encoders for the parts collection  Cutting pins and desoldering them seems like an easy way to go to remove the old, but am saying this without having actually looked at this stuff since building the rig several years ago.  The assembly manual shows an "H" shaped LED board that wraps around the top two (shift/width) leaving the speed and power knobs accessible enough without removing it.  Looks like a major tear down, but labor is skilled and very cheap at my place.   Till I actually do it, I do have macro buttons setup (external keypad) with various power levels to get me close to where I want to be.
-Bob N3XKB
On Thu, May 14, 2020 at 4:24 AM Dave Cole <dave@... <mailto:dave@...>> wrote:
Hi Mike,
I had the exact same issues with my encoders...  About 5 years in...  I
sent the K3 into Elecraft, and had them do it, and update the radio as
well, there were a few things they did to bring it up to current specs.
It is interesting that your failure is the same as mine...  I wonder if
others have had this failure?
<snip>


redarlington
 

Yes, specifically for things like changing power levels, bands, mixer settings, and the like.   5w, 25w, 75w and full power buttons are programmed in.  That lets me get close to where I want to be before spinning the power knob.

-Bob


On Thu, May 14, 2020 at 11:01 AM Dave Cole <dave@...> wrote:
Bob,
Are you using a Genovation pad?

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 5/14/20 9:09 AM, redarlington wrote:
> The only issue on my K3S is the power setting knob feels like it skips
> counts.  If I turn it fast it doesn't budge.  Slowly turning allows me
> to set the power reliably.  Reliably and slowly.    I may pick up a set
> of encoders for the parts collection  Cutting pins and desoldering them
> seems like an easy way to go to remove the old, but am saying this
> without having actually looked at this stuff since building the rig
> several years ago.  The assembly manual shows an "H" shaped LED board
> that wraps around the top two (shift/width) leaving the speed and power
> knobs accessible enough without removing it.  Looks like a major tear
> down, but labor is skilled and very cheap at my place.   Till I actually
> do it, I do have macro buttons setup (external keypad) with various
> power levels to get me close to where I want to be.
>
> -Bob N3XKB
>
>
> On Thu, May 14, 2020 at 4:24 AM Dave Cole <dave@...
> <mailto:dave@...>> wrote:
>
>     Hi Mike,
>
>     I had the exact same issues with my encoders...  About 5 years in...  I
>     sent the K3 into Elecraft, and had them do it, and update the radio as
>     well, there were a few things they did to bring it up to current specs.
>
>     It is interesting that your failure is the same as mine...  I wonder if
>     others have had this failure?
>     <snip>
>
>




Keith_WE6R
 

I have done a lot of them. Make sure you solder suck and release all the pins so you don't rip any traces. (or you can cut the ones you can reach and remove individually).
Clean any fluid that has leaked out onto the board but don't touch the LCD with cleaner (learned the hard way). The fluid can disrupt the ohm-age of the Matrix! hi hi.
I am curious, does the sun ever shine on your radio? We see the same encoder fail in the KX series more often and I have a theory it could be from thermal cycles from sunshine on the black knobs wicking down the encoder shafts and causing the internal goo to leak out. Take one of your old ones apart and you will see.
Our part # E640018, washer spacer E700187 or E700035 to space them above the board evenly.
Keith WE6R, Elecraft K3 Tech.
FYI early K3 radios had a rough grainy feel to them, and they failed more often in that the pushbutton switch would disrupt the matrix. Then around 3,000 we had some viscous, thick turning ones that tended to skip, the ones after that (yours) are smooth and rarely fail.


Dave Cole
 

Cool, I also have one of those, and it almost replaces touching the front panel...

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 5/14/20 10:45 AM, redarlington wrote:
Yes, specifically for things like changing power levels, bands, mixer settings, and the like.   5w, 25w, 75w and full power buttons are programmed in.  That lets me get close to where I want to be before spinning the power knob.
-Bob
On Thu, May 14, 2020 at 11:01 AM Dave Cole <dave@... <mailto:dave@...>> wrote:
Bob,
Are you using a Genovation pad?
73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources
On 5/14/20 9:09 AM, redarlington wrote:
> The only issue on my K3S is the power setting knob feels like it
skips
> counts.  If I turn it fast it doesn't budge.  Slowly turning
allows me
> to set the power reliably.  Reliably and slowly.    I may pick up
a set
> of encoders for the parts collection  Cutting pins and
desoldering them
> seems like an easy way to go to remove the old, but am saying this
> without having actually looked at this stuff since building the rig
> several years ago.  The assembly manual shows an "H" shaped LED
board
> that wraps around the top two (shift/width) leaving the speed and
power
> knobs accessible enough without removing it.  Looks like a major
tear
> down, but labor is skilled and very cheap at my place.   Till I
actually
> do it, I do have macro buttons setup (external keypad) with various
> power levels to get me close to where I want to be.
>
> -Bob N3XKB
>
>
> On Thu, May 14, 2020 at 4:24 AM Dave Cole <dave@...
<mailto:dave@...>
> <mailto:dave@... <mailto:dave@...>>> wrote:
>
>     Hi Mike,
>
>     I had the exact same issues with my encoders...  About 5
years in...  I
>     sent the K3 into Elecraft, and had them do it, and update the
radio as
>     well, there were a few things they did to bring it up to
current specs.
>
>     It is interesting that your failure is the same as mine...  I
wonder if
>     others have had this failure?
>     <snip>
>
>


K9MA
 

I think the electronics and/or firmware associated with the recorders limits the rate. If you turn the knob too fast, the count doesn't change. I notice this particularly when trying to change the span on the P3 or the K3 power level. I don't think in necessarily means the encoder has failed.

73,
Scott K9MA


On 5/14/2020 11:09, redarlington wrote:
The only issue on my K3S is the power setting knob feels like it skips counts.  If I turn it fast it doesn't budge.  Slowly turning allows me to set the power reliably.  Reliably and slowly.    I may pick up a set of encoders for the parts collection  Cutting pins and desoldering them seems like an easy way to go to remove the old, but am saying this without having actually looked at this stuff since building the rig several years ago.  The assembly manual shows an "H" shaped LED board that wraps around the top two (shift/width) leaving the speed and power knobs accessible enough without removing it.  Looks like a major tear down, but labor is skilled and very cheap at my place.   Till I actually do it, I do have macro buttons setup (external keypad) with various power levels to get me close to where I want to be.

-Bob N3XKB


On Thu, May 14, 2020 at 4:24 AM Dave Cole <dave@...> wrote:
Hi Mike,

I had the exact same issues with my encoders...  About 5 years in...  I
sent the K3 into Elecraft, and had them do it, and update the radio as
well, there were a few things they did to bring it up to current specs.

It is interesting that your failure is the same as mine...  I wonder if
others have had this failure?
<snip>


-- 
Scott  K9MA

k9ma@...


M Gerber
 

Thanks for the feedback/comments.

Bob's (N3XKB) report that rotating the encoders slower seems to improve their detection of the knob turning is spot on with my experience. When the encoders are working properly, the encoders can detect an increase in the speed of rotation and still seem to count properly. I do have another older K3 (SN1500) with encoders that have micro-detents. The encoders on that K3 work fine. The newer encoders have no detents.

To answer Keith's (WE6R) question, my K3 does not sit in the sun, however, it has been powered on close to continuously for the past 9-10 yrs. I wonder if that has something to do with it. I cannot tell from the spec sheet if these are mechanical/magnetic or optical encoders. From what i see in the Bourns catalog, these have the lowest rotation life of their offerings. For under $2/encoder, I can't imagine they are anything too fancy, so I suspect they are simple mechanical/Hall effect encoders. I do not recall seeing any fluid leaking out, but as suggested, I'll plan to take one apart.

As Keith commented, these encoders unfortunately seem prone to failure. I recall using a larger solder tip and solder sucker last time. I also recall the plastic spacing washers as well.

Thanks again

Mark WH7W





Mitch NW0M
 

Hi Mark,

I hope you resolve your encoder issue.

My question is why do you leave your K3 powered on 24X7 for the past 9-10 years?  What is your rationale?  I would never consider that but was curious as to why you do.  I'm not at all being critical just curious...

73, Mitch


M Gerber
 

Hi Mitch-

Some voodoo and witchcraft. My station used to be used remotely on a regular basis. It was easiest to leave the computer and radio on all the time as with each power cycle, there was a moderate amount of remoting into the computer required, just to get all the devices up and running. Additionally, there is a 105AH AGM battery backup for the station. If I recall the battery chemistry correctly, the battery stays healthier if there is some load on it as opposed to sitting topped off.  I have the K3 connected to the battery which is charged through a West Mountain PWRGate. The 12V output side of the PWRGate goes to the 12V accessories in the shack. Last reason, is more the voodoo. Many of us in Hawai'i have no air conditioning. Despite what most people might think, the humidity is incredibly variable depending on where you live on any of the islands. By keeping the radio on, it stays warm, thereby preventing condensation from settling on the circuit boards and surface mount components. I have lost several pieces of electronics over the years from this issue. Computer video cards are the worst. The fans accumulate dust, and then moisture does not mix well with circuit boards. Raspberry Pi's also have a tendency to die on me as well.

BTW, for cooling, we rely on ceiling and floor fans-----and the all important trade winds. As you might figure, the windows are open all the time as well.

73

Mark


Mitch NW0M
 

Hi Mark,

So there is ONE downside to living in Hawaii - condensation!!!  :-)  I hope to visit there someday... 

OK, thanks for the explanation and look forward to working you soon as I see we've only worked once this year.

73, Mitch
NWØM