Noise with KX1 and Powerwerx supply

[NH7RO]

John, KK4BOB; the whooshing dishwasher noise you describe is coming from your switching power supply---that's exactly what was driving me nuts until I got a linear supply into my system.  The culprit was an Astron switcher but it was almost 15 years old when it started acting up in such a noisy fashion.
 
This is my first posting/email to the digest; hope it gets through properly!

Best regards,
 
Jeff,  NH7RO
 
[hidden email]
     
______________________________________________________________
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

[Dennis Moore]

I'm using a Powerwerx switching supply I picked up last week, testing it
out in place of my regular Astron RS-35M to run my K3/P3. So far I
haven't run into any noise issues with it, seems to be working as well
as the Astron.

73, Dennis NJ6G

On 11/16/2011 2:38 AM, Jeff Cathrow wrote:
> John, KK4BOB; the whooshing dishwasher noise you describe is coming from your switching power supply---that's exactly what was driving me nuts until I got a linear supply into my system.  The culprit was an Astron switcher but it was almost 15 years old when it started acting up in such a noisy fashion.
>
> This is my first posting/email to the digest; hope it gets through properly!
>
> Best regards,
>
> Jeff,  NH7RO

______________________________________________________________
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

[Chip Stratton]

If you start looking for an alternative, try the TDK Lambda LS25-15 (for
1.7A), LS35-15 (2.4A) or LS50-15 (3.4A). These are switch mode power
supplies that I've found to be fairly well shielded, light weight,
conservatively rated, and not expensive from Newark Electronics. They are
nominal fixed 15V supplies, but their output can be set from 13.5V to
16.5V. The supply is contained within a metal cage, but you will probably
want to mount it in another enclosure with an on/off switch and banana or
Powerpole terminals, and to protect the 120v input terminals.

These are especially good for the KX1, since maximum output comes with a
14V power input, which most small 12V supplies can't quite deliver. Is the
K1 the same way? They are also good for the K2 with internal battery, since
you need 14V for proper charging.

It might be hard to find any switch mode power supply that won't put some
noise into an antenna that is sitting right next to, though. If you can
move the antenna feed point 5 or 6 feet away from the PS with some coax you
might have better luck. You might also get a copy of the current issue of
QEX. There is an article in which the author details his quest to turn a RF
noisy switch mode PS into a very quiet one.

73
Chip
______________________________________________________________
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

[Gio]

Tnx for the responses. I'm going to try the isolation approach suggested
below. Once again, I'm amazed at the depth of my ignorance (well, not THAT
amazed).

Tnx es 73

John KK4BOB

On Wed, Nov 16, 2011 at 10:57 AM, Chip Stratton <[hidden email]>wrote:

> If you start looking for an alternative, try the TDK Lambda LS25-15 (for
> 1.7A), LS35-15 (2.4A) or LS50-15 (3.4A). These are switch mode power
> supplies that I've found to be fairly well shielded, light weight,
> conservatively rated, and not expensive from Newark Electronics. They are
> nominal fixed 15V supplies, but their output can be set from 13.5V to
> 16.5V. The supply is contained within a metal cage, but you will probably
> want to mount it in another enclosure with an on/off switch and banana or
> Powerpole terminals, and to protect the 120v input terminals.
>
> These are especially good for the KX1, since maximum output comes with a
> 14V power input, which most small 12V supplies can't quite deliver. Is the
> K1 the same way? They are also good for the K2 with internal battery, since
> you need 14V for proper charging.
>
> It might be hard to find any switch mode power supply that won't put some
> noise into an antenna that is sitting right next to, though. If you can
> move the antenna feed point 5 or 6 feet away from the PS with some coax you
> might have better luck. You might also get a copy of the current issue of
> QEX. There is an article in which the author details his quest to turn a RF
> noisy switch mode PS into a very quiet one.
>
> 73
> Chip
> ______________________________________________________________
> 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
>

--
John Flynn
Tallahassee, Florida
USA
______________________________________________________________
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