Slighty off topic - 80 meter second harmnic how to stop

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Slighty off topic - 80 meter second harmnic how to stop

paulb
Hi folks

slightly off topic

running 2 x K3 80 and 40 meter cw. Separate antenna
about 50 meters apart. 100 watts.

Power supply 14 volt dc via batterys + dc charge.

The 80 meter second harmonic is very strong. No surprise so have done
the usual 80 meter band pass filter and quarter wave stub

For what ever reason the harmonic is still very present..darn..
oddly has a rasping note not pure carrier.

A close ham about 400 meters away can also hear the 2nd hamonnic,
band pass in or out makes little change.

Possible is related to coax feedlines running close for some distance ?
Both are very well choked at feeder and TX

Happy to respond off topic


cheers from ZL

Paul
zl1ajy

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Re: Slighty off topic - 80 meter second harmnic how to stop

Jim Brown-10
When I posted on this issue to another list, W3LPL responded that it's
fairly common for harmonics with this sort of characteristic to be
generated in active electronics like switching power supplies.  Sort of
identifying which is the culprit and choking every cable connected to
it, there's no solution.

73, Jim K9YC

On Mon,2/22/2016 8:34 PM, paulb wrote:
> For what ever reason the harmonic is still very present..darn..
> oddly has a rasping note not pure carrier.
>
> A close ham about 400 meters away can also hear the 2nd hamonnic,
> band pass in or out makes little change.

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Re: Slighty off topic - 80 meter second harmnic how to stop

David Cutter
I understand that small ferrites are easily overloaded and become non-linear
generating harmonics and injecting a signal back into the wire from whence
they came.  You might have sleeve chokes on all sorts of wires, keying
lines, keyboard cables, video cables, the wall clock, lighting, etc.

David, G3UNA

----- Original Message -----
From: "Jim Brown" <[hidden email]>
To: <[hidden email]>
Sent: Tuesday, February 23, 2016 4:42 AM
Subject: Re: [Elecraft] Slighty off topic - 80 meter second harmnic how to
stop


> When I posted on this issue to another list, W3LPL responded that it's
> fairly common for harmonics with this sort of characteristic to be
> generated in active electronics like switching power supplies.  Sort of
> identifying which is the culprit and choking every cable connected to it,
> there's no solution.
>
> 73, Jim K9YC

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Re: Slighty off topic - 80 meter second harmnic how to stop

gm3sek
In reply to this post by Jim Brown-10
I feel sure that Jim and W3LPL are right. That rasping note is a big,
big clue that some *other* electronic device is also involved -
something else, in addition to your two K3s.

That "unknown third party" device is what you need to find. Begin by
switching off power to whole sections of the house,  and then go around
methodically unplugging individual devices. Murphy says: it's something
of yours, and it's right there in the shack.


73 from Ian GM3SEK

>-----Original Message-----
>From: Elecraft [mailto:[hidden email]] On Behalf Of
>Jim Brown
>Sent: 23 February 2016 04:42
>To: [hidden email]
>Subject: Re: [Elecraft] Slighty off topic - 80 meter second harmnic how
to

>stop
>
>When I posted on this issue to another list, W3LPL responded that it's
>fairly common for harmonics with this sort of characteristic to be
>generated in active electronics like switching power supplies.  Sort of
>identifying which is the culprit and choking every cable connected to
>it, there's no solution.
>
>73, Jim K9YC
>
>On Mon,2/22/2016 8:34 PM, paulb wrote:
>> For what ever reason the harmonic is still very present..darn..
>> oddly has a rasping note not pure carrier.
>>
>> A close ham about 400 meters away can also hear the 2nd hamonnic,
>> band pass in or out makes little change.
>
>______________________________________________________________
>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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Re: Slighty off topic - 80 meter second harmnic how to stop

John Severyn
Don't forget rain gutters and downspouts that may be slightly corroded
at the joints, forming a diode.
They make nice frequency doublers due to the non-linear element.
John  AF6QO

On 2/22/2016 11:58 PM, Ian White wrote:

> I feel sure that Jim and W3LPL are right. That rasping note is a big,
> big clue that some *other* electronic device is also involved -
> something else, in addition to your two K3s.
>
> That "unknown third party" device is what you need to find. Begin by
> switching off power to whole sections of the house,  and then go around
> methodically unplugging individual devices. Murphy says: it's something
> of yours, and it's right there in the shack.
>
>
> 73 from Ian GM3SEK
>
>> -----Original Message-----
>> From: Elecraft [mailto:[hidden email]] On Behalf Of
>> Jim Brown
>> Sent: 23 February 2016 04:42
>> To: [hidden email]
>> Subject: Re: [Elecraft] Slighty off topic - 80 meter second harmnic how
> to
>> stop
>>
>> When I posted on this issue to another list, W3LPL responded that it's
>> fairly common for harmonics with this sort of characteristic to be
>> generated in active electronics like switching power supplies.  Sort of
>> identifying which is the culprit and choking every cable connected to
>> it, there's no solution.
>>
>> 73, Jim K9YC
>>
>> On Mon,2/22/2016 8:34 PM, paulb wrote:
>>> For what ever reason the harmonic is still very present..darn..
>>> oddly has a rasping note not pure carrier.
>>>
>>> A close ham about 400 meters away can also hear the 2nd hamonnic,
>>> band pass in or out makes little change.
>> ______________________________________________________________
>> 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
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>
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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Re: Slighty off topic - 80 meter second harmnic how to stop

Jim Brown-10
In reply to this post by David Cutter
On Mon,2/22/2016 11:31 PM, David Cutter wrote:
> I understand that small ferrites are easily overloaded and become
> non-linear generating harmonics and injecting a signal back into the
> wire from whence they came.

That's theoretically possible, but VERY VERY VERY unlikely.

73, Jim K9YC
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Re: Slighty off topic - 80 meter second harmnic how to stop

Charlie T, K3ICH
In reply to this post by John Severyn
Please be sure to tell us all what your final
solution turns out to be.  It may help many of us
with related problems.

73, Charlie k3ICH



-----Original Message-----
From: Elecraft
[mailto:[hidden email]] On
Behalf Of John Severyn
Sent: Tuesday, February 23, 2016 3:47 AM
To: [hidden email]
Subject: Re: [Elecraft] Slighty off topic - 80
meter second harmnic how to stop


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Re: Slighty off topic - 80 meter second harmnic how to stop

paulb

Hello again folks

Thanks to all for the suggestions and hints to  what this problem could be.

Tests have been done at 2 locations; my own home station and here at another property  ( work in progress as we
politely say..) about 125km south of Auckland.

The same second harmonic garbage is heard at both places. Over the last day I have completely swapped out
all the 80m and 40m antenna and feeder components here in the provinces. No change.

What I now strongly suspect is the only common point at both locales;

both properties have burglar alarms installed.  Both are almost identical well known European name brand units.
There is no detectable RF radiation from the processors or wiring.
The clincher now that I think about the last time we ran 2 stations here without any drama
was before the alarm was commissioned here.

I have dropped the supply and backup DC to the alarm here without any change,
Likely 3.5 meg RF is simply hammering the PIR's, cable runs are in the roof cavity.
Can't %100 prove this without fairly major re-wiring, will leave it as is for the meantime,

thanks again guys

cheers from ZL

Paul
zl1ajy


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Re: Slighty off topic - 80 meter second harmnic how to stop

Mark Goldberg
I would expect that if it was getting into an alarm system, the alarm would
fail in some way. I had a bad problem with mine, cured by a 5th order 200
kHz lowpass filter where simple ferrites and caps did not work. The alarm
system has low frequency digital data. I built it with some caps and a few
turns on mix 31 cores I had. Since it is not a 50 ohm system, the filter is
not exactly as designed, but it worked well enough to completely eliminate
the problem. I put it at the alarm controller that was getting affected.

73,

Mark
W7MLG
On Feb 23, 2016 2:04 PM, "paulb" <[hidden email]> wrote:

>
> Hello again folks
>
> Thanks to all for the suggestions and hints to  what this problem could be.
>
> Tests have been done at 2 locations; my own home station and here at
> another
> property  ( work in progress as we
> politely say..) about 125km south of Auckland.
>
> The same second harmonic garbage is heard at both places. Over the last day
> I have completely swapped out
> all the 80m and 40m antenna and feeder components here in the provinces. No
> change.
>
> What I now strongly suspect is the only common point at both locales;
>
> both properties have burglar alarms installed.  Both are almost identical
> well known European name brand units.
> There is no detectable RF radiation from the processors or wiring.
> The clincher now that I think about the last time we ran 2 stations here
> without any drama
> was before the alarm was commissioned here.
>
> I have dropped the supply and backup DC to the alarm here without any
> change,
> Likely 3.5 meg RF is simply hammering the PIR's, cable runs are in the roof
> cavity.
> Can't %100 prove this without fairly major re-wiring, will leave it as is
> for the meantime,
>
> thanks again guys
>
> cheers from ZL
>
> Paul
> zl1ajy
>
>
>
>
>
>
> --
> View this message in context:
> http://elecraft.365791.n2.nabble.com/Slighty-off-topic-80-meter-second-harmnic-how-to-stop-tp7614506p7614534.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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Re: Slighty off topic - 80 meter second harmnic how to stop

Victor Rosenthal 4X6GP
In reply to this post by paulb
When I lived in California I had a 80/160m inverted L in which the horizontal part passed over the house. There were alarm wires running through the attic, and when I first tried it I actually vaporized a terminating resistor at one of the windows. Those wires were quite long and possibly resonant lengths.
I solved the problem by installing no. 31 ferrite toroids on the alarm wires and also the power supply wires at the alarm control box. I wrapped as many turns of wire as I could on them. That might fix your issue.

Vic 4X6GP

> On 23 Feb 2016, at 11:03 PM, paulb <[hidden email]> wrote:
>
>
> Hello again folks
>
> Thanks to all for the suggestions and hints to  what this problem could be.
>
> Tests have been done at 2 locations; my own home station and here at another
> property  ( work in progress as we
> politely say..) about 125km south of Auckland.
>
> The same second harmonic garbage is heard at both places. Over the last day
> I have completely swapped out
> all the 80m and 40m antenna and feeder components here in the provinces. No
> change.
>
> What I now strongly suspect is the only common point at both locales;
>
> both properties have burglar alarms installed.  Both are almost identical
> well known European name brand units.
> There is no detectable RF radiation from the processors or wiring.
> The clincher now that I think about the last time we ran 2 stations here
> without any drama
> was before the alarm was commissioned here.
>
> I have dropped the supply and backup DC to the alarm here without any
> change,
> Likely 3.5 meg RF is simply hammering the PIR's, cable runs are in the roof
> cavity.
> Can't %100 prove this without fairly major re-wiring, will leave it as is
> for the meantime,
>
> thanks again guys
>
> cheers from ZL
>
> Paul
> zl1ajy
>
>
>
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/Slighty-off-topic-80-meter-second-harmnic-how-to-stop-tp7614506p7614534.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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Re: Slighty off topic - 80 meter second harmnic how to stop

Jim Bolit
In reply to this post by Jim Brown-10
I would take an antenna analyzer and sweep the antenna system (coax with
stubs, connectors,  etc.) by connecting the analyzer at the xmitter "end" of
the antenna system.  Disconnect the coax that goes to the amplifier and take
that coax and plug it into the analyzer instead and sweep the antenna system
with start freq of 3.0 MHz and end point of 8 MHz  You should see a "short"
somewhere in the 40 meter band, but my guess is that it will not be where
you want it to be.  IT is important to do this on the antenna *SYSTEM*
(coax, connectors, switches, etc.).

Jim
W6AIM


.
 

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Jim
Brown
Sent: Monday, February 22, 2016 8:42 PM
To: [hidden email]
Subject: Re: [Elecraft] Slighty off topic - 80 meter second harmnic how to
stop

When I posted on this issue to another list, W3LPL responded that it's
fairly common for harmonics with this sort of characteristic to be generated
in active electronics like switching power supplies.  Sort of identifying
which is the culprit and choking every cable connected to it, there's no
solution.

73, Jim K9YC

On Mon,2/22/2016 8:34 PM, paulb wrote:
> For what ever reason the harmonic is still very present..darn..
> oddly has a rasping note not pure carrier.
>
> A close ham about 400 meters away can also hear the 2nd hamonnic, band
> pass in or out makes little change.

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
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Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]

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