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K2/100 birdie at 28.020 MHz

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jeff martin-6

K2/100 birdie at 28.020 MHz

I have a loud birdie at 28.020 MHz on my K2/100. The KPA100 is integral to the K2. I thought it might be from the 4.0MHz oscillator on the KPA100, but the birdie does not respond to changes of C27. The birdie stops when the power is reduced to low power mode. The birdie is loud...can be heard when the 2nd antenna is selected with no antenna connected.

This may have been covered before, but I seem to recall that there was no firm resolution? I never reaaly worried about it for the past few years, but with the solar cycle waxing, I might miss some DX!

Thanks all for any insight.

Jeff Martin
N7KRT
K2/100 #5471

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K1FFX

Re: K2/100 birdie at 28.020 MHz

You might find some helpful information in this recent post.

- Bruce

Bruce Rosen
K1FFX
K2/100 6982 KSB2 KAT100-1 KAF2 KIO2

Geoffrey Mackenzie-Kennedy

Re: K2/100 birdie at 28.020 MHz

In reply to this post by jeff martin-6

Jeff,

I see that Bruce K1FFX has made you aware of Don's (W3FPR) and my comment on
the "birdie" that Bruce found on 21029 kHz, which also disappears when the
KPA100 is not active. However may I add a little more.

Don speculated that some of the oscillator energy (HV Bias oscillator) could
be picked up by the T/R switch when the KPA100 is in-line, and I can confirm
that this is fact. The fundamental and harmonics generated by this
oscillator and the assocated voltage multipliers are also found in many
other places in the KPA100.

It might be worthwhile to remove the audio leads from the KPA100 board, i.e.
those which connect to the K2 and to the speaker, to see if in your case
this affects this particular "birdie". The bundle of pcb traces in this area
(and other areas) of my KPA100 was quite hot with RF from the HV bias
oscillator/ voltage multiplier.

73,

Geoff
GM4ESD

Jeff Martin N7KRT wrote on Wednesday, February 02, 2011, at 12:26 AM:

>I have a loud birdie at 28.020 MHz on my K2/100. The KPA100 is integral to
>the K2. I thought it might be from the 4.0MHz oscillator on the KPA100, but
>the birdie does not respond to changes of C27. The birdie stops when the
>power is reduced to low power mode. The birdie is loud...can be heard when
>the 2nd antenna is selected with no antenna connected.
>
> This may have been covered before, but I seem to recall that there was no
> firm resolution? I never reaaly worried about it for the past few years,
> but with the solar cycle waxing, I might miss some DX!
>
> Thanks all for any insight.
>
> Jeff Martin
> N7KRT
> K2/100 #5471

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Don Wilhelm-4

Re: K2/100 birdie at 28.020 MHz

It may also be helpful to tuck the ribbon cable and speaker wire up
into the space above the control board. Remove the right side panel and
tuck the wires in front of the heat sink.
It may not help with this particular problem, but it will help with
other "noises and funny sounds" on SSB.

73,
Don W3FPR

On 2/2/2011 9:46 AM, Geoffrey Mackenzie-Kennedy wrote:

> Jeff,
>
> I see that Bruce K1FFX has made you aware of Don's (W3FPR) and my comment on
> the "birdie" that Bruce found on 21029 kHz, which also disappears when the
> KPA100 is not active. However may I add a little more.
>
> Don speculated that some of the oscillator energy (HV Bias oscillator) could
> be picked up by the T/R switch when the KPA100 is in-line, and I can confirm
> that this is fact. The fundamental and harmonics generated by this
> oscillator and the assocated voltage multipliers are also found in many
> other places in the KPA100.
>
> It might be worthwhile to remove the audio leads from the KPA100 board, i.e.
> those which connect to the K2 and to the speaker, to see if in your case
> this affects this particular "birdie". The bundle of pcb traces in this area
> (and other areas) of my KPA100 was quite hot with RF from the HV bias
> oscillator/ voltage multiplier.
>
> 73,
>
> Geoff
> GM4ESD
>
>
> Jeff Martin N7KRT wrote on Wednesday, February 02, 2011, at 12:26 AM:
>
>
>> I have a loud birdie at 28.020 MHz on my K2/100. The KPA100 is integral to
>> the K2. I thought it might be from the 4.0MHz oscillator on the KPA100, but
>> the birdie does not respond to changes of C27. The birdie stops when the
>> power is reduced to low power mode. The birdie is loud...can be heard when
>> the 2nd antenna is selected with no antenna connected.
>>
>> This may have been covered before, but I seem to recall that there was no
>> firm resolution? I never reaaly worried about it for the past few years,
>> but with the solar cycle waxing, I might miss some DX!
>>
>> Thanks all for any insight.
>>
>> Jeff Martin
>> N7KRT
>> K2/100 #5471
>
> ______________________________________________________________
> 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
>

jeff martin-6

Re: K2/100 birdie at 28.020 MHz

Bruce, Geoff and Don,
Sorry I am late in replying and thanking all for their help. The little power plant I work at here in South Texas has been demanding my attention with the cold weather here! They didn't build these plants with this kind of cold in mind!

I will give the ideas a try this weekend, and let you all know how it worked out.

73,
Jeff N7KRT
--- On Wed, 2/2/11, Don Wilhelm <[hidden email]> wrote:

> From: Don Wilhelm <[hidden email]>
> Subject: Re: [Elecraft] K2/100 birdie at 28.020 MHz
> To: "jeff martin" <[hidden email]>
> Cc: "Elecraft Discussion List" <[hidden email]>
> Date: Wednesday, February 2, 2011, 7:54 AM
> It may also be helpful to tuck
> the ribbon cable and speaker wire up
> into the space above the control board. Remove the
> right side panel and
> tuck the wires in front of the heat sink.
> It may not help with this particular problem, but it will
> help with
> other "noises and funny sounds" on SSB.
>
> 73,
> Don W3FPR
>
> On 2/2/2011 9:46 AM, Geoffrey Mackenzie-Kennedy wrote:
> > Jeff,
> >
> > I see that Bruce K1FFX has made you aware of Don's
> (W3FPR) and my comment on
> > the "birdie" that Bruce found on 21029 kHz, which also
> disappears when the
> > KPA100 is not active. However may I add a little
> more.
> >
> > Don speculated that some of the oscillator energy (HV
> Bias oscillator) could
> > be picked up by the T/R switch when the KPA100 is
> in-line, and I can confirm
> > that this is fact. The fundamental and harmonics
> generated by this
> > oscillator and the assocated voltage multipliers are
> also found in many
> > other places in the KPA100.
> >
> > It might be worthwhile to remove the audio leads from
> the KPA100 board, i.e.
> > those which connect to the K2 and to the speaker, to
> see if in your case
> > this affects this particular "birdie". The bundle of
> pcb traces in this area
> > (and other areas) of my KPA100 was quite hot with RF
> from the HV bias
> > oscillator/ voltage multiplier.
> >
> > 73,
> >
> > Geoff
> > GM4ESD
> >
> >
> > Jeff Martin N7KRT wrote on Wednesday, February 02,
> 2011, at 12:26 AM:
> >
> >
> >> I have a loud birdie at 28.020 MHz on my K2/100.
> The KPA100 is integral to
> >> the K2. I thought it might be from the 4.0MHz
> oscillator on the KPA100, but
> >> the birdie does not respond to changes of C27. The
> birdie stops when the
> >> power is reduced to low power mode. The birdie is
> loud...can be heard when
> >> the 2nd antenna is selected with no antenna
> connected.
> >>
> >> This may have been covered before, but I seem to
> recall that there was no
> >> firm resolution? I never reaaly worried about it
> for the past few years,
> >> but with the solar cycle waxing, I might miss some
> DX!
> >>
> >> Thanks all for any insight.
> >>
> >> Jeff Martin
> >> N7KRT
> >> K2/100 #5471
> >
> >
> ______________________________________________________________
> > 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
> >
>