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K3 in AM-Sync Mode Receiving WWV

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Kenneth Moorman

K3 in AM-Sync Mode Receiving WWV

I have been trying out the new AM-Sync mode by listening to WWV on its 5
frequencies and am seeing something that I wonder is a "problem" for my K3
(#1292) or is it being seen by others as well. I have observed that on the
10MHz WWV frequency only, that my K3 will momentarily "unlock" with the
frequency jumping either up or down by as much as 200 Hz. The frequency
quickly, less than a second, will be corrected, and all is well again. This
occurs at what appears to be entirely random timing, from several minutes,
to as often as a few seconds. I haven't noticed this happening on any of
the other WWV frequencies that I have observed, being all of the rest except
2.5MHz which is not open to me this morning. I did notice this yesterday on
10MHz, but did not check the other frequencies until today. I find it
difficult to believe that WWV is having "jumps" in its 10MHz transmission.
Has anyone else noticed this, or do I need to be giving Elecraft help desk a
call?

Ken, NU4I

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Jim Wiley-2

Re: K3 in AM-Sync Mode Receiving WWV

This problem may (or may not) be caused by selective fading, causing the
"real" WWV carrier to disappear for a moment, whereby the K3 then locks
up to one of the sidebands, perhaps from the 100 Hz time data, then
returns to the main carrier when it again is strong enough. Of course
it may be something else entirely, but that is one possibility.

Disclaimer: This opinion is worth exactly what you had to pay for it.

- Jim, KL7CC

Kenneth Moorman wrote:
> I have been trying out the new AM-Sync mode by listening to WWV on its 5
> frequencies and am seeing something that I wonder is a "problem" for my K3
> (#1292) or is it being seen by others as well. I have observed that on the
> 10MHz WWV frequency only, that my K3 will momentarily "unlock" with the
> frequency jumping either up or down by as much as 200 Hz
>
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KK7P

Re: K3 in AM-Sync Mode Receiving WWV

In reply to this post by Kenneth Moorman

> ... I find it
> difficult to believe that WWV is having "jumps" in its 10MHz transmission.
> Has anyone else noticed this, or do I need to be giving Elecraft help desk a
> call?

AM Synchronous receive is in its early stages. We are aware of the
behavior you describe and are improving the algorithms we are using.

Also, keep in mind that AM-S is a tool in your toolbox. There will be
times when regular AM envelope detection will work better, and times
when using the SSB demodulator will provide superior results.

73,

Lyle KK7P

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wayne burdick

Re: K3 in AM-Sync Mode Receiving WWV

Administrator

In reply to this post by Jim Wiley-2

This is exactly what's happening, and we're looking into a possible
change in the way we handle it.

For now, you can leave VFO auto-tracking turned off when listening to
WWV (tap CWT until the 'T' icon turns off). You can tune the signal in
manually until the PLL locks (+/- 10 Hz), or tap SPOT to have it track
the signal long enough to lock.

73,
Wayne
N6KR

On Nov 16, 2009, at 8:20 AM, Jim Wiley wrote:

> This problem may (or may not) be caused by selective fading, causing
> the
> "real" WWV carrier to disappear for a moment, whereby the K3 then
> locks
> up to one of the sidebands, perhaps from the 100 Hz time data, then
> returns to the main carrier when it again is strong enough. Of course
> it may be something else entirely, but that is one possibility.
>
>
> Disclaimer: This opinion is worth exactly what you had to pay for it.
>
>
> - Jim, KL7CC
>
>
>
> Kenneth Moorman wrote:
>> I have been trying out the new AM-Sync mode by listening to WWV on
>> its 5
>> frequencies and am seeing something that I wonder is a "problem"
>> for my K3
>> (#1292) or is it being seen by others as well. I have observed
>> that on the
>> 10MHz WWV frequency only, that my K3 will momentarily "unlock" with
>> the
>> frequency jumping either up or down by as much as 200 Hz

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Kenneth Moorman

Re: K3 in AM-Sync Mode Receiving WWV

Yes, I can clearly see this happening on my "panadaptor" lash-up using an
SDR and Rocky software from the IF output port of the K3. Thanks for
pointing this out. Obviously I shouldn't need to leave VFO Tracking on all
the time when receiving WWV.

Ken, NU4I

-----Original Message-----
From: Wayne Burdick [mailto:[hidden email]]
Sent: Monday, November 16, 2009 11:44 AM
To: Jim Wiley
Cc: Kenneth Moorman; [hidden email]
Subject: Re: K3 in AM-Sync Mode Receiving WWV

This is exactly what's happening, and we're looking into a possible
change in the way we handle it.

For now, you can leave VFO auto-tracking turned off when listening to
WWV (tap CWT until the 'T' icon turns off). You can tune the signal in
manually until the PLL locks (+/- 10 Hz), or tap SPOT to have it track
the signal long enough to lock.

73,
Wayne
N6KR

On Nov 16, 2009, at 8:20 AM, Jim Wiley wrote:

Joe Subich, W4TV-4

Re: K3 in AM-Sync Mode Receiving WWV

In reply to this post by Kenneth Moorman

> I have observed that on the 10MHz WWV frequency only, that my
> K3 will momentarily "unlock" with the frequency jumping either
> up or down by as much as 200 Hz. The frequency quickly, less
> than a second, will be corrected, and all is well again.
> This occurs at what appears to be entirely random timing,
> from several minutes, to as often as a few seconds.

The 10 MHz WWV may be the worst place to check the performance
of the K3 Sync-AM. I feel the 10 MHz WV transmitter has some
apparent frequency modulation and audio distortion not present
on any of the other frequencies (or on WWHV when I can hear it).

On the other hand, I also detect the momentary "unlock" on the
15 MHz WWV transmissions but those unlocks are associated with
audible fading.

73,

... Joe, W4TV

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Kenneth Moorman
> Sent: Monday, November 16, 2009 11:04 AM
> To: [hidden email]
> Subject: [Elecraft] K3 in AM-Sync Mode Receiving WWV
>
>
> I have been trying out the new AM-Sync mode by listening to
> WWV on its 5 frequencies and am seeing something that I
> wonder is a "problem" for my K3
> (#1292) or is it being seen by others as well. I have
> observed that on the 10MHz WWV frequency only, that my K3
> will momentarily "unlock" with the frequency jumping either
> up or down by as much as 200 Hz. The frequency quickly, less
> than a second, will be corrected, and all is well again.
> This occurs at what appears to be entirely random timing,
> from several minutes, to as often as a few seconds. I
> haven't noticed this happening on any of the other WWV
> frequencies that I have observed, being all of the rest
> except 2.5MHz which is not open to me this morning. I did
> notice this yesterday on 10MHz, but did not check the other
> frequencies until today. I find it difficult to believe that
> WWV is having "jumps" in its 10MHz transmission. Has anyone
> else noticed this, or do I need to be giving Elecraft help
> desk a call?
>
> Ken, NU4I
>
> ______________________________________________________________
> 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