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K2 drift

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Bernie KF0QS

K2 drift

Dear OM's and YL's:

Twice, I've had people tell me my K2 (which I've had on the air for over 3 years) drifts a bit in frequency. Both times have occurred during long QSO's so it appears to be a slight drift.

This phenomenon may also explain something else that happens. Whenever I set up the filter settings, they work well for a while. After a while, the sweet spot (i.e., the point at which the heard signal is in the middle of the filter bandpass) seems to migrate eventually to about 1khz below wherever I set it (at least that's where I have to move the RIT to hear the signal when I switch in the filters).

Is there a common fix for both these problems, or am I experiencing two different things. Any help you can give would be appreciated.

73 de Bernie, KF0QS

Don Wilhelm-4

Re: K2 drift

Bernie,

I think there are possibly two different problems.
If you have to use RIT when you change filters, then your filters are
not set up properly. If you need information on setting the K2 filters,
refer to my website www.w3fpr.com article on K2 Dial Calibration. The
frequency shift between filters might be as high as 20 Hz, but that is
not audible in SSB but can be noticed in CW, but is still not enough to
require RIT for correction.

If you observe significant drift during a long QSO (and you have not
changed filters), then you have a problem with either the BFO frequency
changing or the PLL/VFO changing frequencies.
A K2 above SN3000 should have the new BFO inductor and the Temperature
Compensated PLL which normally produces a stable frequency. If your K2
is earlier than SN 3000, add those upgrade kits unless they have already
been added.

A bad solder connection can cause jumps in frequency as can bad BFO
crystals or a bad PLL crystal. The most common problem is a bad solder
connection - bad BFO or PLL crystals are low on the list of suspects.

73,
Don W3FPR

On 4/11/2015 12:13 PM, Bernie KF0QS wrote:

> Dear OM's and YL's:
>
> Twice, I've had people tell me my K2 (which I've had on the air for over 3
> years) drifts a bit in frequency. Both times have occurred during long
> QSO's so it appears to be a slight drift.
>
> This phenomenon may also explain something else that happens. Whenever I
> set up the filter settings, they work well for a while. After a while, the
> sweet spot (i.e., the point at which the heard signal is in the middle of
> the filter bandpass) seems to migrate eventually to about 1khz below
> wherever I set it (at least that's where I have to move the RIT to hear the
> signal when I switch in the filters).
>
> Is there a common fix for both these problems, or am I experiencing two
> different things. Any help you can give would be appreciated.
>
>

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Frank Krozel

Re: K2 drift

In reply to this post by Bernie KF0QS

Bernie,
What is your serial number?

Frank KG9H

> On Apr 11, 2015, at 11:13 AM, Bernie KF0QS <[hidden email]> wrote:
>
> Dear OM's and YL's:
>
> Twice, I've had people tell me my K2 (which I've had on the air for over 3
> years) drifts a bit in frequency. Both times have occurred during long
> QSO's so it appears to be a slight drift.
>
> This phenomenon may also explain something else that happens. Whenever I
> set up the filter settings, they work well for a while. After a while, the
> sweet spot (i.e., the point at which the heard signal is in the middle of
> the filter bandpass) seems to migrate eventually to about 1khz below
> wherever I set it (at least that's where I have to move the RIT to hear the
> signal when I switch in the filters).
>
> Is there a common fix for both these problems, or am I experiencing two
> different things. Any help you can give would be appreciated.
>
> 73 de Bernie, KF0QS
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
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> Please help support this email list: http://www.qsl.net/donate.html
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Bernie KF0QS

Re: K2 drift

Dear Frank and Don:

My K2 serial number is 6922.

With regard to Don's suggestion about improper filter setup, I have
redone the filters several times, always following the instructions
on Don's website. Always, I come out of that with the filters
working properly, and only after a long time, I find I have to adjust
the RIT in order to get the signal within the filter's bandpass.

Since my serial number is above 3000, then that means that I have the
new BFO inductor and the Temperature
Compensated PLL Don refers to. Thus, I wonder if it is a bad solder
connection.

Where would I look for the bad solder connection? And also, is that
the possible cause of my periodic need to readjust the filter settings?

Thanks and 73 de Bernie, KF0QS

At 10:34 AM 4/11/2015, Frank Krozel wrote:

>Bernie,
>What is your serial number?
>
>Frank KG9H
>
> > On Apr 11, 2015, at 11:13 AM, Bernie KF0QS <[hidden email]> wrote:
> >
> > Dear OM's and YL's:
> >
> > Twice, I've had people tell me my K2 (which I've had on the air for over 3
> > years) drifts a bit in frequency. Both times have occurred during long
> > QSO's so it appears to be a slight drift.
> >
> > This phenomenon may also explain something else that happens. Whenever I
> > set up the filter settings, they work well for a while. After a while, the
> > sweet spot (i.e., the point at which the heard signal is in the middle of
> > the filter bandpass) seems to migrate eventually to about 1khz below
> > wherever I set it (at least that's where I have to move the RIT to hear the
> > signal when I switch in the filters).
> >
> > Is there a common fix for both these problems, or am I experiencing two
> > different things. Any help you can give would be appreciated.
> >
> > 73 de Bernie, KF0QS
> >
> >
> >
> > --
> > View this message in context:
> http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html
> > Sent from the Elecraft mailing list archive at Nabble.com.
> > ______________________________________________________________
> > 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-4

Re: K2 drift

Bernie,

My first suspicion is in the BFO area. Unfortunately, some of those
connections are under the L33 BFO inductor.
It is possible that you have a bad BFO crystal. But think about it a
bit before doing anything to decide if it is the BFO or the PLL/VFO
causing the problem.

Since you have a significant shift in frequency, if you use the most
narrow CW filter, has the audio pitch the same as you had set for the
filter center, or is the pitch substantially different. You can observe
the frequency at the center of the filter passband with Spectrogram.

What I am getting at is that if the BFO is changing frequency, the audio
pitch when the signal is tuned to the center of the narrow CW filter
will be different than you chosen center frequency.

OTOH, if the audio pitch stays the same, but you can retune (to that
same pitch) with the RIT or by moving the VFO, then the problem is in
the PLL/VFO area.

73,
Don W3FPR

On 4/11/2015 3:06 PM, Bernie and Cheryl wrote:

> Dear Frank and Don:
>
> My K2 serial number is 6922.
>
> With regard to Don's suggestion about improper filter setup, I have
> redone the filters several times, always following the instructions on
> Don's website. Always, I come out of that with the filters working
> properly, and only after a long time, I find I have to adjust the RIT
> in order to get the signal within the filter's bandpass.
>
> Since my serial number is above 3000, then that means that I have the
> new BFO inductor and the Temperature
> Compensated PLL Don refers to. Thus, I wonder if it is a bad solder
> connection.
>
> Where would I look for the bad solder connection? And also, is that
> the possible cause of my periodic need to readjust the filter settings?
>
> Thanks and 73 de Bernie, KF0QS
>
>
> At 10:34 AM 4/11/2015, Frank Krozel wrote:
>> Bernie,
>> What is your serial number?
>>
>> Frank KG9H
>>
>> > On Apr 11, 2015, at 11:13 AM, Bernie KF0QS <[hidden email]>
>> wrote:
>> >
>> > Dear OM's and YL's:
>> >
>> > Twice, I've had people tell me my K2 (which I've had on the air for
>> over 3
>> > years) drifts a bit in frequency. Both times have occurred during
>> long
>> > QSO's so it appears to be a slight drift.
>> >
>> > This phenomenon may also explain something else that happens.
>> Whenever I
>> > set up the filter settings, they work well for a while. After a
>> while, the
>> > sweet spot (i.e., the point at which the heard signal is in the
>> middle of
>> > the filter bandpass) seems to migrate eventually to about 1khz below
>> > wherever I set it (at least that's where I have to move the RIT to
>> hear the
>> > signal when I switch in the filters).
>> >
>> > Is there a common fix for both these problems, or am I experiencing
>> two
>> > different things. Any help you can give would be appreciated.
>> >
>> > 73 de Bernie, KF0QS
>> >
>> >
>> >
>> > --
>> > View this message in context:
>> http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html
>> > Sent from the Elecraft mailing list archive at Nabble.com.
>> > ______________________________________________________________
>> > 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]
>
> ______________________________________________________________
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vk2rq

Re: K2 drift

In reply to this post by Bernie KF0QS

You say it is shifting by as much as 1kHz? That is definitely not normal. My K2 built last year will only drift by around 20Hz or so as it warms up, it is pretty stable.

The BFO inductor is L33, the pre-wound one that sits on a rubber bumper. Wasn't there a thread some time last year where someone was having problems with BFO frequency stability, and it turned out there was some contaminant on the rubber bumper that was making it conductive?

73, Matt VK2RQ

> On 12 Apr 2015, at 1:13 am, Bernie KF0QS <[hidden email]> wrote:
>
> Dear OM's and YL's:
>
> Twice, I've had people tell me my K2 (which I've had on the air for over 3
> years) drifts a bit in frequency. Both times have occurred during long
> QSO's so it appears to be a slight drift.
>
> This phenomenon may also explain something else that happens. Whenever I
> set up the filter settings, they work well for a while. After a while, the
> sweet spot (i.e., the point at which the heard signal is in the middle of
> the filter bandpass) seems to migrate eventually to about 1khz below
> wherever I set it (at least that's where I have to move the RIT to hear the
> signal when I switch in the filters).
>
> Is there a common fix for both these problems, or am I experiencing two
> different things. Any help you can give would be appreciated.
>
> 73 de Bernie, KF0QS
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> 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]

Bernie KF0QS

Re: K2 drift

It only shifted that far with regard to the cw filters.

On QSO's, it's only noticeable on long QSO's apparently. I've never noticed it myself, but I've had two hams point it out to me, both during long QSO's.

At 04:59 PM 4/11/2015, vk2rq [via Elecraft] wrote:

You say it is shifting by as much as 1kHz? That is definitely not normal. My K2 built last year will only drift by around 20Hz or so as it warms up, it is pretty stable. The BFO inductor is L33, the pre-wound one that sits on a rubber bumper. Wasn't there a thread some time last year where someone was having problems with BFO frequency stability, and it turned out there was some contaminant on the rubber bumper that was making it conductive? 73, Matt VK2RQ
> On 12 Apr 2015, at 1:13 am, Bernie KF0QS <[hidden email]> wrote: > > Dear OM's and YL's: > > Twice, I've had people tell me my K2 (which I've had on the air for over 3 > years) drifts a bit in frequency. Both times have occurred during long > QSO's so it appears to be a slight drift. > > This phenomenon may also explain something else that happens. Whenever I > set up the filter settings, they work well for a while. After a while, the > sweet spot (i.e., the point at which the heard signal is in the middle of > the filter bandpass) seems to migrate eventually to about 1khz below > wherever I set it (at least that's where I have to move the RIT to hear the > signal when I switch in the filters). > > Is there a common fix for both these problems, or am I experiencing two > different things. Any help you can give would be appreciated. > > 73 de Bernie, KF0QS > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html> Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft> Help: http://mailman.qth.net/mmfaq.htm> Post: [hidden email] [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]
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Don Wilhelm-4

Re: K2 drift

Bernie,

Again, I ask - does the audio pitch change when the signal is centered
in the CW filter?
If that changes, then the problem is with the BFO.
If the audio pitch is the same at the filter center, the the shift is
due to the PLL/VCO.

73,
Don W3FPR

On 4/12/2015 12:46 AM, Bernie KF0QS wrote:

> It only shifted that far with regard to the cw filters.
>
> On QSO's, it's only noticeable on long QSO's apparently. I've never
> noticed it myself, but I've had two hams point it out to me, both
> during long QSO's.
>
> At 04:59 PM 4/11/2015, vk2rq [via Elecraft] wrote:
>> You say it is shifting by as much as 1kHz? That is definitely not
>> normal. My K2 built last year will only drift by around 20Hz or so
>> as it warms up, it is pretty stable. The BFO inductor is L33, the
>> pre-wound one that sits on a rubber bumper. Wasn't there a thread
>> some time last year where someone was having problems with BFO
>> frequency stability, and it turned out there was some contaminant on
>> the rubber bumper that was making it conductive? 73, Matt VK2RQ
>>> On 12 Apr 2015, at 1:13 am, Bernie KF0QS <[hidden email]>
>> wrote: > > Dear OM's and YL's: > > Twice, I've had people tell me
>> my K2 (which I've had on the air for over 3 > years) drifts a bit
>> in frequency. Both times have occurred during long > QSO's so it
>> appears to be a slight drift. > > This phenomenon may also explain
>> something else that happens. Whenever I > set up the filter
>> settings, they work well for a while. After a while, the > sweet
>> spot (i.e., the point at which the heard signal is in the middle
>> of > the filter bandpass) seems to migrate eventually to about 1khz
>> below > wherever I set it (at least that's where I have to move the
>> RIT to hear the > signal when I switch in the filters). > > Is
>> there a common fix for both these problems, or am I experiencing
>> two > different things. Any help you can give would be
>> appreciated. > > 73 de Bernie, KF0QS > > > > -- > View this message
>> in context:
>> <http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html>http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html>
>> Sent from the Elecraft mailing list archive at Nabble.com. >
>> ______________________________________________________________ >
>> Elecraft mailing list > Home:
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Bernie KF0QS

Re: K2 drift

Don:

When I switch to a filter, I can't hear the signal I had centered in the passband. I can only hear the signal if I tune about 1 khz down, and then I do hear the signal, albeit very low in pitch as opposed to the pitch I heard before I switched in the filter.

Given that, I suppose it sounds like the VFO is the problem?

Bernie

At 11:10 PM 4/11/2015, Don Wilhelm-4 [via Elecraft] wrote:

Bernie, Again, I ask - does the audio pitch change when the signal is centered in the CW filter? If that changes, then the problem is with the BFO. If the audio pitch is the same at the filter center, the the shift is due to the PLL/VCO. 73, Don W3FPR On 4/12/2015 12:46 AM, Bernie KF0QS wrote:
> It only shifted that far with regard to the cw filters. > > On QSO's, it's only noticeable on long QSO's apparently. I've never > noticed it myself, but I've had two hams point it out to me, both > during long QSO's. > > At 04:59 PM 4/11/2015, vk2rq [via Elecraft] wrote: >> You say it is shifting by as much as 1kHz? That is definitely not >> normal. My K2 built last year will only drift by around 20Hz or so >> as it warms up, it is pretty stable. The BFO inductor is L33, the >> pre-wound one that sits on a rubber bumper. Wasn't there a thread >> some time last year where someone was having problems with BFO >> frequency stability, and it turned out there was some contaminant on >> the rubber bumper that was making it conductive? 73, Matt VK2RQ >>> On 12 Apr 2015, at 1:13 am, Bernie KF0QS <[hidden email]> >> wrote: > > Dear OM's and YL's: > > Twice, I've had people tell me >> my K2 (which I've had on the air for over 3 > years) drifts a bit >> in frequency. Both times have occurred during long > QSO's so it >> appears to be a slight drift. > > This phenomenon may also explain >> something else that happens. Whenever I > set up the filter >> settings, they work well for a while. After a while, the > sweet >> spot (i.e., the point at which the heard signal is in the middle >> of > the filter bandpass) seems to migrate eventually to about 1khz >> below > wherever I set it (at least that's where I have to move the >> RIT to hear the > signal when I switch in the filters). > > Is >> there a common fix for both these problems, or am I experiencing >> two > different things. Any help you can give would be >> appreciated. > > 73 de Bernie, KF0QS > > > > -- > View this message >> in context: >> < http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html > http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html> >> Sent from the Elecraft mailing list archive at Nabble.com. > >> ______________________________________________________________ > >> Elecraft mailing list > Home: >> < http://mailman.qth.net/mailman/listinfo/elecraft > http://mailman.qth.net/mailman/listinfo/elecraft> >> Help: >> < http://mailman.qth.net/mmfaq.htm > http://mailman.qth.net/mmfaq.htm> >> Post: [hidden email] email] > > This list hosted by: >> <http://www.qsl.net >http://www.qsl.net > Please help support this >> email list: >> < http://www.qsl.net/donate.html > http://www.qsl.net/donate.html> >> Message delivered to [hidden email] >> ______________________________________________________________ >> Elecraft mailing list Home: >> < http://mailman.qth.net/mailman/listinfo/elecraft > http://mailman.qth.net/mailman/listinfo/elecraftHelp :>> < http://mailman.qth.net/mmfaq.htm > http://mailman.qth.net/mmfaq.htmPost : >> [hidden email] email] This list hosted by: >> <http://www.qsl.net ><a href="http://www.qsl.netplease help/" eudora="autourl"> http://www.qsl.netPlease help support this email >> list: >> < http://www.qsl.net/donate.html > http://www.qsl.net/donate.htmlMessage>> delivered to [hidden email] >> >> If you reply to this email, your message will be added to the >> discussion below: >> < http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236p7601249.html > http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236p7601249.html >> >> To unsubscribe from K2 drift, >> < >> here. >> < http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml >NAML >> > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236p7601268.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft> Help: http://mailman.qth.net/mmfaq.htm> Post: [hidden email] [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] >
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vk2rq

Re: K2 drift

The fact that the pitch sounds very low when you centre the signal in the passband filter indicates a BFO problem, not a VCO/PLL problem.

73,
Matt VK2RQ

> On 12 Apr 2015, at 3:15 pm, Bernie KF0QS <[hidden email]> wrote:
>
> Don:
>
> When I switch to a filter, I can't hear the signal I had centered in
> the passband. I can only hear the signal if I tune about 1 khz down,
> and then I do hear the signal, albeit very low in pitch as opposed to
> the pitch I heard before I switched in the filter.
>
> Given that, I suppose it sounds like the VFO is the problem?
>
> Bernie
>
> At 11:10 PM 4/11/2015, Don Wilhelm-4 [via Elecraft] wrote:
>> Bernie, Again, I ask - does the audio pitch change when the signal
>> is centered in the CW filter? If that changes, then the problem is
>> with the BFO. If the audio pitch is the same at the filter center,
>> the the shift is due to the PLL/VCO. 73, Don W3FPR On 4/12/2015
>> 12:46 AM, Bernie KF0QS wrote:
>>> It only shifted that far with regard to the cw filters. > > On
>> QSO's, it's only noticeable on long QSO's apparently. I've never >
>> noticed it myself, but I've had two hams point it out to me, both >
>> during long QSO's. > > At 04:59 PM 4/11/2015, vk2rq [via Elecraft]
>> wrote: >> You say it is shifting by as much as 1kHz? That is
>> definitely not >> normal. My K2 built last year will only drift by
>> around 20Hz or so >> as it warms up, it is pretty stable. The BFO
>> inductor is L33, the >> pre-wound one that sits on a rubber bumper.
>> Wasn't there a thread >> some time last year where someone was
>> having problems with BFO >> frequency stability, and it turned out
>> there was some contaminant on >> the rubber bumper that was making
>> it conductive? 73, Matt VK2RQ >>> On 12 Apr 2015, at 1:13 am,
>> Bernie KF0QS <[hidden email]> >> wrote: > > Dear OM's and YL's: > >
>> Twice, I've had people tell me >> my K2 (which I've had on the air
>> for over 3 > years) drifts a bit >> in frequency. Both times have
>> occurred during long > QSO's so it >> appears to be a slight
>> drift. > > This phenomenon may also explain >> something else that
>> happens. Whenever I > set up the filter >> settings, they work
>> well for a while. After a while, the > sweet >> spot (i.e., the
>> point at which the heard signal is in the middle >> of > the filter
>> bandpass) seems to migrate eventually to about 1khz >> below >
>> wherever I set it (at least that's where I have to move the >> RIT
>> to hear the > signal when I switch in the filters). > > Is >>
>> there a common fix for both these problems, or am I experiencing >>
>> two > different things. Any help you can give would be >>
>> appreciated. > > 73 de Bernie, KF0QS > > > > -- > View this
>> message >> in context: >>
>> <<http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html>http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html>http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236.html>
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John Oppenheimer

Re: K2 drift

In reply to this post by Bernie KF0QS

Hi Bernie,

I had the same problem. After some time looking for the cause I replaced
the BFO crystals and L33. I ordered the Xtal Upgrade kit, BFOMDKT, and
replaced all of the parts supplied in the kit, including the new rubber
pad. Problem solved!

Additional information here:
http://marc.info/?l=elecraft&m=140086776221505&w=2

John KN5L
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Don Wilhelm-4

Re: K2 drift

In reply to this post by Bernie KF0QS

Bernie,

Since the pitch changed that says the BFO is the problem (not the VFO).
I repaired one recently where Q24 was the real culprit causing the BFO
to shift frequency.

73,
Don W3FPR

On 4/12/2015 2:15 AM, Bernie KF0QS wrote:

> Don:
>
> When I switch to a filter, I can't hear the signal I had centered in
> the passband. I can only hear the signal if I tune about 1 khz down,
> and then I do hear the signal, albeit very low in pitch as opposed to
> the pitch I heard before I switched in the filter.
>
> Given that, I suppose it sounds like the VFO is the problem?
>
>

Bernie KF0QS

Re: K2 drift

Don:

Would you suggest I replace Q24, or should I just check the solder?

Thanks for the help.

Bernie

At 05:41 AM 4/12/2015, you wrote:

Bernie, Since the pitch changed that says the BFO is the problem (not the VFO). I repaired one recently where Q24 was the real culprit causing the BFO to shift frequency. 73, Don W3FPR On 4/12/2015 2:15 AM, Bernie KF0QS wrote:
> Don: > > When I switch to a filter, I can't hear the signal I had centered in > the passband. I can only hear the signal if I tune about 1 khz down, > and then I do hear the signal, albeit very low in pitch as opposed to > the pitch I heard before I switched in the filter. > > Given that, I suppose it sounds like the VFO is the problem? > >
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Don Wilhelm-4

Re: K2 drift

Bernie,

I would first check the soldering - don't forget the thin wire leads of L33.
If that is not effective, I would order new BFO crystals, a new Q24, and
L33 - if you cannot salvage the 1/8 watt resistor and bumper stem, order
BFOMDKT instead of L33.
I would suggest replacing all of them to shorten the troubleshooting
work unless you are dead set on discovering the exact source of the
problem, which could take a substantial amount of time.

In rare cases, a capacitor could be changing value, so give thought to
also ordering a replacement C173, C174 and C169 unless you have a well
stocked junkbox.

73,
Don W3FPR

On 4/12/2015 5:25 PM, Bernie KF0QS wrote:

> Don:
>
> Would you suggest I replace Q24, or should I just check the solder?
>
> Thanks for the help.
>
> Bernie
>
> At 05:41 AM 4/12/2015, you wrote:
>> Bernie, Since the pitch changed that says the BFO is the problem
>> (not the VFO). I repaired one recently where Q24 was the real
>> culprit causing the BFO to shift frequency. 73, Don W3FPR On
>> 4/12/2015 2:15 AM, Bernie KF0QS wrote:
>>> Don: > > When I switch to a filter, I can't hear the signal I had
>> centered in > the passband. I can only hear the signal if I tune
>> about 1 khz down, > and then I do hear the signal, albeit very low
>> in pitch as opposed to > the pitch I heard before I switched in the
>> filter. > > Given that, I suppose it sounds like the VFO is the problem? > >
>> ______________________________________________________________
>> Elecraft mailing list Home:
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Bernie KF0QS

Re: K2 drift

Don:

I'm assuming I can order these from Elecraft, using the part numbers out of the manual?

I am curious about how Q24 would affect things on receive? Pg. 115 of the manual says it is only active on transmit.

Thanks.

Bernie

At 04:42 PM 4/12/2015, you wrote:

Bernie, I would first check the soldering - don't forget the thin wire leads of L33. If that is not effective, I would order new BFO crystals, a new Q24, and L33 - if you cannot salvage the 1/8 watt resistor and bumper stem, order BFOMDKT instead of L33. I would suggest replacing all of them to shorten the troubleshooting work unless you are dead set on discovering the exact source of the problem, which could take a substantial amount of time. In rare cases, a capacitor could be changing value, so give thought to also ordering a replacement C173, C174 and C169 unless you have a well stocked junkbox. 73, Don W3FPR On 4/12/2015 5:25 PM, Bernie KF0QS wrote:
> Don: > > Would you suggest I replace Q24, or should I just check the solder? > > Thanks for the help. > > Bernie > > At 05:41 AM 4/12/2015, you wrote: >> Bernie, Since the pitch changed that says the BFO is the problem >> (not the VFO). I repaired one recently where Q24 was the real >> culprit causing the BFO to shift frequency. 73, Don W3FPR On >> 4/12/2015 2:15 AM, Bernie KF0QS wrote: >>> Don: > > When I switch to a filter, I can't hear the signal I had >> centered in > the passband. I can only hear the signal if I tune >> about 1 khz down, > and then I do hear the signal, albeit very low >> in pitch as opposed to > the pitch I heard before I switched in the >> filter. > > Given that, I suppose it sounds like the VFO is the problem? > > >> ______________________________________________________________ >> Elecraft mailing list Home: >> < http://mailman.qth.net/mailman/listinfo/elecraft > http://mailman.qth.net/mailman/listinfo/elecraftHelp :>> < http://mailman.qth.net/mmfaq.htm > http://mailman.qth.net/mmfaq.htmPost : >> [hidden email] email] This list hosted by: >> <http://www.qsl.net ><a href="http://www.qsl.netplease help/" eudora="autourl"> http://www.qsl.netPlease help support this email >> list: >> < http://www.qsl.net/donate.html > http://www.qsl.net/donate.htmlMessage>> delivered to [hidden email] >> >> If you reply to this email, your message will be added to the >> discussion below: >> < http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236p7601277.html > http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236p7601277.html >> >> To unsubscribe from K2 drift, >> < >> here. >> < http://elecraft.365791.n2.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml >NAML >> > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/K2-drift-tp7601236p7601289.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft> Help: http://mailman.qth.net/mmfaq.htm> Post: [hidden email] [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] >
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Don Wilhelm-4

Re: K2 drift

Bernie,

Yes, use the part numbers from the manual to order them.
Q24 is only active on TX, but is still in the circuit during RX. So
during RX it can add capacity to the BFO circuit.

73,
Don W3FPR

On 4/12/2015 11:58 PM, Bernie KF0QS wrote:

> Don:
>
> I'm assuming I can order these from Elecraft, using the part numbers
> out of the manual?
>
> I am curious about how Q24 would affect things on receive? Pg. 115
> of the manual says it is only active on transmit.
>
> Thanks.
>
> Bernie
>
> At 04:42 PM 4/12/2015, you wrote:
>