K3 Freq jumpnig when cold (50F or so)

[Bill N2BC]

Have our club's K3/100, serial # 67xx.   When it is cold (FP=11C  52F ),
increasing the frequency using  VFO A or VFO B causes a 1MHz jump DOWN in
frequency.  When reducing frequency the failure is much less frequent and it
will also jump down 1 MHz.  At times while tuning up in freq there are some
relay clicks - usually 2 -  but no frequency jumps.

 

BOLD = actions / changed made

 

More observations:  

.          I picked up the radio, we are having an unusually warm spell here
in NY.  The rig seemed to work perfectly.  

.          I put it in my fridge.   FP temp = 11C (52F)  Fails frequently.
Always a 1 MHz jump down.   i.e on 7.125 the fail sets the freq to 6.125.

.          With the rig on 80M, band down press yields 100.00MHz.   If I
manually enter 1.80 it is on 160M, band up = 80M, band down is back to
100MHz.  Per the setup, 160M and 6M are excluded from up/down sequence.

.         Rig warming up, FP = 21C   Operates normally

.         Back to the fridge, FP=12

.         Starting on 40M, increasing VFO A will cause switch to 6MHz.
Pressing Band UP gives 80M not return to 40M.

.         Similar to above, starting on 30M the rig jumps to 9MHz, band UP
gives 80M

.         Again similar, starting on 20M, jumps to 13MHz, band UP gives 80M

.         Occasional jumps to 3xxMHz - difficult to see pattern

.         Rig up to FP=19C  working normally

.         Backed up the CONFIG, performed EE INIT, restored CONFIG

.         Cooled off the rig FP = 12

.         Not seeing the 80M band DN going to 100MHz.   Not seeing random
3xxMHz

.         Still have frequent jump down 1MHz

.         Removed Front panel, removed DSP board. Reseated both twice.

.         Working normally at room temp

.         Cooled off the K3  FP = 13

.         Failing as above, 1MHz down shifts

.         FP = 15+ seems to be working OK

.         Cooled off the rig

.         Exercised frequency control and band changes via RS232 - this rig
is also operated remotely - no failures noted

.         Other freq jumping as above occurring via manual tuning.

 

Net:  EE INIT seems to have "cured" the 80M band DN to 100mHz & random shift
to 300MHz.

 

Sorry for the loooong post.  What y'all think?   Trip to California - or
poor man's fix: turn up the heat in the club's shack (it is unheated!)

 

I'm a tiny bit tempted to swap front panels with my personal K3 - very tiny.

 

THX for reading,   73  Bill N2BC

 

 

 

 

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Don Wilhelm]

Bill,

Try loading beta firmware 5.54 to that K3 and see if that behavior
continues.
That firmware improves the flash memory interface.
I can't say for sure if it will fix that K3, but is worth a try.

73,
Don W3FPR

On 10/20/2016 10:16 AM, Bill Coleman wrote:
> Have our club's K3/100, serial # 67xx.   When it is cold (FP=11C  52F ),
> increasing the frequency using  VFO A or VFO B causes a 1MHz jump DOWN in
> frequency.  When reducing frequency the failure is much less frequent and it
> will also jump down 1 MHz.  At times while tuning up in freq there are some
> relay clicks - usually 2 -  but no frequency jumps.
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Bill N2BC]

Thanks Don.    I put on 5.54.... The K3 is behaving differently....   No
more jumping down 1MHz.

What it is doing now:  there's still a relay clicking once in a while as I
tune VFO A - this is within any given ham band.
Now, while tuning VFO A, VFO B will jump frequency.

Example:
VFO A = 3.853, press A>B, tune A up frequency less than a kHz, B jumps, now
A = 3.853 B = 3.994

Somewhat similar but stranger behavior on 40M
VFO A = 7.274, press A>B, tune A up freq, B jumps a LOT, now A=7.275 B =
8.600

In the time it has taken to test and scribble the results, the rig has
warmed up from 50F to 66F and it works fine  No freq jumps, no relay
clatter.

OK, I went back to Firmware  5.52 & chilled the rig (53F).   The jumping
1MHz down is back.   Hmmm...  Next step?  I'm thing the FP flash memory has
a problem with low temps.

THX,  Bill  N2BC

-----Original Message-----
From: Don Wilhelm [mailto:[hidden email]]
Sent: Thursday, October 20, 2016 10:51 AM
To: Bill Coleman; [hidden email]
Subject: Re: [Elecraft] K3 Freq jumpnig when cold (50F or so)

Bill,

Try loading beta firmware 5.54 to that K3 and see if that behavior
continues.
That firmware improves the flash memory interface.
I can't say for sure if it will fix that K3, but is worth a try.

73,
Don W3FPR

On 10/20/2016 10:16 AM, Bill Coleman wrote:
> Have our club's K3/100, serial # 67xx.   When it is cold (FP=11C  52F ),
> increasing the frequency using  VFO A or VFO B causes a 1MHz jump DOWN
> in frequency.  When reducing frequency the failure is much less
> frequent and it will also jump down 1 MHz.  At times while tuning up
> in freq there are some relay clicks - usually 2 -  but no frequency jumps.
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Arie Kleingeld PA3A-2]

Bill,

Maybe it's a hardware problem:
The connector from frontpanel to main rf board for example?

When the temp is low, maybe there are some bad contacts. Take off the
front panel and  clean all pins of the connections. Do this thouroughly,
polish all four sides of each connector-pin.

73
Arie PA3A
K3 #1255

Op 21-10-2016 om 1:50 schreef Bill Coleman:

> Thanks Don.    I put on 5.54.... The K3 is behaving differently....   No
> more jumping down 1MHz.
>
> What it is doing now:  there's still a relay clicking once in a while as I
> tune VFO A - this is within any given ham band.
> Now, while tuning VFO A, VFO B will jump frequency.
>
> Example:
> VFO A = 3.853, press A>B, tune A up frequency less than a kHz, B jumps, now
> A = 3.853 B = 3.994
>
> Somewhat similar but stranger behavior on 40M
> VFO A = 7.274, press A>B, tune A up freq, B jumps a LOT, now A=7.275 B =
> 8.600
>
> In the time it has taken to test and scribble the results, the rig has
> warmed up from 50F to 66F and it works fine  No freq jumps, no relay
> clatter.
>
> OK, I went back to Firmware  5.52 & chilled the rig (53F).   The jumping
> 1MHz down is back.   Hmmm...  Next step?  I'm thing the FP flash memory has
> a problem with low temps.
>
> THX,  Bill  N2BC
>
> -----Original Message-----
> From: Don Wilhelm [mailto:[hidden email]]
> Sent: Thursday, October 20, 2016 10:51 AM
> To: Bill Coleman; [hidden email]
> Subject: Re: [Elecraft] K3 Freq jumpnig when cold (50F or so)
>
> Bill,
>
> Try loading beta firmware 5.54 to that K3 and see if that behavior
> continues.
> That firmware improves the flash memory interface.
> I can't say for sure if it will fix that K3, but is worth a try.
>
> 73,
> Don W3FPR
>
> On 10/20/2016 10:16 AM, Bill Coleman wrote:
>> Have our club's K3/100, serial # 67xx.   When it is cold (FP=11C  52F ),
>> increasing the frequency using  VFO A or VFO B causes a 1MHz jump DOWN
>> in frequency.  When reducing frequency the failure is much less
>> frequent and it will also jump down 1 MHz.  At times while tuning up
>> in freq there are some relay clicks - usually 2 -  but no frequency jumps.
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]