K3 VFO Tuning noise reduction

[John Lemay]

Hello all

Has anyone carried out the VFO tuning noise reduction modification yet ?

The photo is a little unclear (or maybe it's my eyes) - it looks as though
one resistor-diode combination has the anode connected to the resistor and
the other pair has the cathode connected to the resistor. Have I got this
right ?

Perhaps the folks at Aptos read this reflector .............

Thanks

John G4ZTR

 

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[John Lemay]

Aha

Question answered - I see that the application note has been updated since I
took a copy !!

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of John Lemay
Sent: 14 August 2009 08:38
To: 'Elecraft Reflector'
Subject: [Elecraft] K3 VFO Tuning noise reduction

Hello all

Has anyone carried out the VFO tuning noise reduction modification yet ?

The photo is a little unclear (or maybe it's my eyes) - it looks as though
one resistor-diode combination has the anode connected to the resistor and
the other pair has the cathode connected to the resistor. Have I got this
right ?

Perhaps the folks at Aptos read this reflector .............

Thanks

John G4ZTR

 

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4333 (20090813) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com
 

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database 4333 (20090813) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com


 

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[Bill W4ZV]

John Lemay wrote

Hello all

Has anyone carried out the VFO tuning noise reduction modification yet ?

The photo is a little unclear (or maybe it's my eyes) - it looks as though
one resistor-diode combination has the anode connected to the resistor and
the other pair has the cathode connected to the resistor. Have I got this
right ?

Yes that's correct...note the orientation of the black band on the diodes.  I first soldered the resistor-diode combination at approximately the same acute angles in the photographs.  Then align the ends so that they match the vias on the PC board.  After soldering I checked the resistance between pins 15 and 20 on the connectors.  I got ~800k one way and ~5.5M the other.

73,  Bill

[Stewart Baker]

I found it easier to solder the components directly to the connector pads.

End result is the same, no more VFO tuning noise on 6m.

73
Stewart G3RXQ
On Fri, 14 Aug 2009 05:20:12 -0500 (CDT), Bill W4ZV wrote:

>
>
> John Lemay wrote:
>>
>> Hello all
>>
>> Has anyone carried out the VFO tuning noise reduction modification yet ?
>>
>> The photo is a little unclear (or maybe it's my eyes) - it looks as though
>> one resistor-diode combination has the anode connected to the resistor and
>> the other pair has the cathode connected to the resistor. Have I got this
>> right ?
>>
>
> Yes that's correct...note the orientation of the black band on the diodes.
> I first soldered the resistor-diode combination at approximately the same
> acute angles in the photographs.  Then align the ends so that they match the
> vias on the PC board.  After soldering I checked the resistance between pins
> 15 and 20 on the connectors.  I got ~800k one way and ~5.5M the other.
>
> 73,  Bill

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[K2QI]

I had a tuning noise issue on 60m, but nothing noticeable anywhere else.  Is
the hardware mod really necessary if the firmware successfully suppresses
the encoder noise?  When I have SPI2 on in firmware, it totally eliminates
all ticking noise previously heard around 5MHz.  It would seem to me that
unless the firmware can't remove the noise alone, then the hardware mod is
unnecessary?

73 de James K2QI


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[K2QI]

Solder the components directly to the pads; you mean in parallel instead of
series???  I'm probably wrong, but I'm having a hard time visualizing this
for some reason. Please explain.

Thanks!
James K2QI

On Fri, Aug 14, 2009 at 6:29 AM, Stewart <[hidden email]>wrote:

> I found it easier to solder the components directly to the connector pads.
>
> End result is the same, no more VFO tuning noise on 6m.
>
> 73
> Stewart G3RXQ
> On Fri, 14 Aug 2009 05:20:12 -0500 (CDT), Bill W4ZV wrote:
> >
> >
> > John Lemay wrote:
> >>
> >> Hello all
> >>
> >> Has anyone carried out the VFO tuning noise reduction modification yet ?
> >>
> >> The photo is a little unclear (or maybe it's my eyes) - it looks as
> though
> >> one resistor-diode combination has the anode connected to the resistor
> and
> >> the other pair has the cathode connected to the resistor. Have I got
> this
> >> right ?
> >>
> >
> > Yes that's correct...note the orientation of the black band on the
> diodes.
> > I first soldered the resistor-diode combination at approximately the same
> > acute angles in the photographs.  Then align the ends so that they match
> the
> > vias on the PC board.  After soldering I checked the resistance between
> pins
> > 15 and 20 on the connectors.  I got ~800k one way and ~5.5M the other.
> >
> > 73,  Bill
>
>
>  ______________________________________________________________
> 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
>

--
73 de James K2QI
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[Stewart Baker]

No, you still have the diode and resistor in series.

However as the each of the vias go to pads 15 & 20 of the
connectors respectively, soldering to the pads is an alternative
to soldering to the vias.

You can check the continuity with a VOM just to make sure.

Hope that's OK ?

73
Stewart G3RXQ

 
On Fri, 14 Aug 2009 10:14:06 -0400, James Sarte wrote:
> Solder the components directly to the pads; you mean in parallel
instead of series???  I'm probably wrong, but I'm having a hard
time visualizing this for some reason. Please explain.
>  
> Thanks!
> James K2QI
>
> On Fri, Aug 14, 2009 at 6:29 AM, Stewart
<[hidden email]> wrote:
>> I found it easier to solder the components directly to the
connector pads.

>>
>> End result is the same, no more VFO tuning noise on 6m.
>
>> 73
>> Stewart G3RXQ
> On Fri, 14 Aug 2009 05:20:12 -0500 (CDT), Bill W4ZV wrote:
>> >
>> >
>> > John Lemay wrote:
>> >>
>> >> Hello all
>> >>
>> >> Has anyone carried out the VFO tuning noise reduction

modification yet ?
>>>
>> >> The photo is a little unclear (or maybe it's my eyes) - it
looks as though
>> >> one resistor-diode combination has the anode connected to
the resistor and
>> >> the other pair has the cathode connected to the resistor.
Have I got this
>>> right ?
>> >>
>> >
>> > Yes that's correct...note the orientation of the black band
on the diodes.
>> > I first soldered the resistor-diode combination at
approximately the same
>> > acute angles in the photographs.  Then align the ends so that
they match the
>> vias on the PC board.  After soldering I checked the resistance
between pins
>> > 15 and 20 on the connectors.  I got ~800k one way and ~5.5M
the other.

>> >
>> > 73,  Bill
>
>
>> ______________________________________________________________
>> 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


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[K2QI]

Yup, makes sense now.  Thanks for the clarification.

73 de James K2QI

On Fri, Aug 14, 2009 at 10:27 AM, Stewart <[hidden email]>wrote:

> No, you still have the diode and resistor in series.
>
> However as the each of the vias go to pads 15 & 20 of the
> connectors respectively, soldering to the pads is an alternative
> to soldering to the vias.
>
> You can check the continuity with a VOM just to make sure.
>
> Hope that's OK ?
>
> 73
> Stewart G3RXQ
>
>
> On Fri, 14 Aug 2009 10:14:06 -0400, James Sarte wrote:
> > Solder the components directly to the pads; you mean in parallel
> instead of series???  I'm probably wrong, but I'm having a hard
> time visualizing this for some reason. Please explain.
> >
> > Thanks!
> > James K2QI
> >
> > On Fri, Aug 14, 2009 at 6:29 AM, Stewart
> <[hidden email]> wrote:
> >> I found it easier to solder the components directly to the
> connector pads.
> >>
> >> End result is the same, no more VFO tuning noise on 6m.
> >
> >> 73
> >> Stewart G3RXQ
> > On Fri, 14 Aug 2009 05:20:12 -0500 (CDT), Bill W4ZV wrote:
> >> >
> >> >
> >> > John Lemay wrote:
> >> >>
> >> >> Hello all
> >> >>
> >> >> Has anyone carried out the VFO tuning noise reduction
> modification yet ?
> >>>
> >> >> The photo is a little unclear (or maybe it's my eyes) - it
> looks as though
> >> >> one resistor-diode combination has the anode connected to
> the resistor and
> >> >> the other pair has the cathode connected to the resistor.
> Have I got this
> >>> right ?
> >> >>
> >> >
> >> > Yes that's correct...note the orientation of the black band
> on the diodes.
> >> > I first soldered the resistor-diode combination at
> approximately the same
> >> > acute angles in the photographs.  Then align the ends so that
> they match the
> >> vias on the PC board.  After soldering I checked the resistance
> between pins
> >> > 15 and 20 on the connectors.  I got ~800k one way and ~5.5M
> the other.
> >> >
> >> > 73,  Bill
> >
> >
> >> ______________________________________________________________
> >> 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
>
>
>

--
73 de James K2QI
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[AC7AC]

CONTENTS DELETED

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[Eric Swartz - WA6HHQ]

Yes, you absolutely must make the h/w mod for the diode/resistor change
if you enable the tuning mod in the K3 menu. If you do not make the h/e
change, and then enable this feature in the menu, there may be
intermittent synthesizer communication failures in your radio (which
could be temperature dependent etc.)

73, Eric  WA6HHQ


James Sarte wrote:
> I had a tuning noise issue on 60m, but nothing noticeable anywhere else.  Is
> the hardware mod really necessary if the firmware successfully suppresses
> the encoder noise?  When I have SPI2 on in firmware, it totally eliminates
> all ticking noise previously heard around 5MHz.  It would seem to me that
> unless the firmware can't remove the noise alone, then the hardware mod is
> unnecessary?
>
> 73 de James K2QI
>  
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[K2QI]

Eric - I've switched the settings back to SPI1 until I have the parts to
perform the HW modification.  I'm curious however; SPI2 totally eliminated
the noise for me even without the hardware mod in place.  The communication
errors you mentioned, could those lead to permanent hardware failure if
someone where to use SPI2 without the resistor/diode combination?  Anyway,
when I was beta-testing this release, there wasn't any mention in the
release notes of a hardware change being required in order to use those
functions, hence my surprise.

James K2QI

-----Original Message-----
From: Eric Swartz - WA6HHQ, Elecraft [mailto:[hidden email]]
Sent: Friday, August 14, 2009 2:36 PM
To: James Sarte
Cc: [hidden email]
Subject: Re: [Elecraft] K3 VFO Tuning noise reduction

Yes, you absolutely must make the h/w mod for the diode/resistor change
if you enable the tuning mod in the K3 menu. If you do not make the h/e
change, and then enable this feature in the menu, there may be
intermittent synthesizer communication failures in your radio (which
could be temperature dependent etc.)

73, Eric  WA6HHQ


James Sarte wrote:
> I had a tuning noise issue on 60m, but nothing noticeable anywhere else.
Is
> the hardware mod really necessary if the firmware successfully suppresses
> the encoder noise?  When I have SPI2 on in firmware, it totally eliminates
> all ticking noise previously heard around 5MHz.  It would seem to me that
> unless the firmware can't remove the noise alone, then the hardware mod is
> unnecessary?
>
> 73 de James K2QI
>  

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