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Old May 21st 04, 05:21 PM
Al Arduengo
 
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Default Noise on MW using mains

One of my portables which I like has a problem with noise. The odd thing is
that when using the mains input the noise appears only on the lower SW and
all MW frequencies. The lower I go the more it becomes a whistle. This
occurs whether I use the supplied AC adapter or a DC-DC converter. For the
veterans, does this imply that the input jack itself is somehow generating
lower frequency noise? Has anyone else ever experienced this sort of
thing? I would consider a ferrite bead on the cord at the adapter but
since it seems to be related more to the jack than the adapter, would a
bead on the adapter cord right next to the jack input make any sense? Any
other suggestions?

Thanks very much.
-Al
--
~/.signature
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Old May 22nd 04, 12:46 AM
Jeff Seale
 
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Default

Al Arduengo wrote:
One of my portables which I like has a problem with noise. The odd thing is
that when using the mains input the noise appears only on the lower SW and
all MW frequencies. The lower I go the more it becomes a whistle. This
occurs whether I use the supplied AC adapter or a DC-DC converter. For the
veterans, does this imply that the input jack itself is somehow generating
lower frequency noise? Has anyone else ever experienced this sort of
thing? I would consider a ferrite bead on the cord at the adapter but
since it seems to be related more to the jack than the adapter, would a
bead on the adapter cord right next to the jack input make any sense? Any
other suggestions?

Thanks very much.
-Al


Well, I have a Grundig Satellit 800 and on the HF bands it seems like
I'm hearing strong heterodynes quite frequently. I am running my
computer near the radio and I'm wondering if this is the culprit or is
this just 'normal' behavior for this particular radio.
As for noise from the power lines, I get that even when the radio is
off. I can't hear it, but I can SEE it in a spectrogram. My scanner has
that same issue with power line noise. I've tried jiggling my cords
around and moving my AC adapters to different places on my surge
protector but to no avail. Know how to fix these problems?

Jeff Seale
Satellit 800, YB550PE, DX440, BC780, Pro95
Louisville, KY
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Old May 22nd 04, 03:49 AM
J999w
 
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Default


One of my portables which I like has a problem with noise. The odd thing is
that when using the mains input the noise appears only on the lower SW and
all MW frequencies. The lower I go the more it becomes a whistle.


I dunno, but noise never becomes a 'whistle'.

Is it a buzz? crackle? hiss? or tones/notes?

jw
K9RZZ
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Old May 22nd 04, 09:20 AM
GO BEARCATS
 
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Default

One of my portables which I like has a problem with noise. The odd thing is
that when using the mains input the noise appears only on the lower SW and
all MW frequencies


****************rest snipped***************

Al,
Can you tell us a little more. What radio are you using by chance? What
adapter are you using? How many mA is it (the adapter?)

What kind of antenna? Location-country or city?

Thanks

~^Monitoring The Spectrum^~
Hammarlund HQ129X /Heathkit Q Multiplier
Hammarlund HQ140X
Multiple GE P-780's(GREAT BCB Radios)
RCA Victor *Strato- World*
RCA Victor RJC77W-K(Walnut Grain)
1942 Zenith Wave Magnet 6G 601M
Cathedral/ Ross#2311/Rhapsody-MultiBand
DX100/394/*SUPER*398/399/402
OMGS Transistor Eight/Realistic 12-1451
Henry Kloss Model One/Bell+HowellSW
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Alpha Delta DX Sloper 57ft.
500ft. 12AWG. (non-terminated)
120ft. 12 AWG Long-Wire
2 Radio Shack Loop Antennas
Radio Shack Amplified Antenna
30X30 DiamondLoop(six section 830pf Cap)
* Diamond Loop mounted to Lazy Susan TurnTable*
*21/2X2ft.FiveSpoked~Penta-Loop~PancakeLoop*
~OptimusCTR-111Cassettte Recorder~
~Radio Shack 2Speed VOX#43-476~
~Ramsey Speech Scrambler~



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Old May 22nd 04, 09:32 AM
 
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Default

Hello, Computers are very noisy, but I think monitors are worse, I read the
plasma screens are quite. I have to shield a lead to the PC for data
decoding, I have ferrite rings that the wire is wound round and some beads
the wire threads through. I also have the radio in a foil covered cardboard
box with holes for wires, the radio and the box have a good earth wire
to,,,, water pipe earth.

For the fellow with the whistling radio, If you could try another power
source. Wire a battery pack, or a car battery to see if the noise is still
there, get true DC. If it goes get a proper ham radio type shielded PSU a
good one will have filters to stop the noise rubbish. All the best.




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Old May 22nd 04, 09:40 AM
Zaphon B.
 
Posts: n/a
Default


wrote in message
...
Hello, Computers are very noisy, but I think monitors are worse, I read

the
plasma screens are quite. I have to shield a lead to the PC for data
decoding, I have ferrite rings that the wire is wound round and some beads
the wire threads through. I also have the radio in a foil covered

cardboard
box with holes for wires, the radio and the box have a good earth wire
to,,,, water pipe earth.

For the fellow with the whistling radio, If you could try another power
source. Wire a battery pack, or a car battery to see if the noise is still
there, get true DC. If it goes get a proper ham radio type shielded PSU a
good one will have filters to stop the noise rubbish. All the best.



Wow, sound more like to me you're just trying to build the worlds most
complex bong to smoke pot out of. :0)

Sorry I couldn't resist and I'm sure
you are not the sort of person to
allow any of that demon weed to
pass your lips.

My apologies sir.

Zaphod


  #7   Report Post  
Old May 23rd 04, 10:35 AM
GO BEARCATS
 
Posts: n/a
Default

Sorry I couldn't resist and I'm sure
you are not the sort of person to
allow any of that demon weed to
pass your lips.

My apologies sir.


I think this guy is that *Phil*-guy who had the ebay auction for the UFO
Antenna on the head.

Part of his website (if I remember right) had a 'group' of either the good
'ones' or the bad 'ones' called Zaphod --- -----something close.

Is this crazy Phil? ;-)

~^Monitoring The Spectrum^~
Hammarlund HQ129X /Heathkit Q Multiplier
Hammarlund HQ140X
Multiple GE P-780's(GREAT BCB Radios)
RCA Victor *Strato- World*
RCA Victor RJC77W-K(Walnut Grain)
1942 Zenith Wave Magnet 6G 601M
Cathedral/ Ross#2311/Rhapsody-MultiBand
DX100/394/*SUPER*398/399/402
OMGS Transistor Eight/Realistic 12-1451
Henry Kloss Model One/Bell+HowellSW
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Alpha Delta DX Sloper 57ft.
500ft. 12AWG. (non-terminated)
120ft. 12 AWG Long-Wire
2 Radio Shack Loop Antennas
Radio Shack Amplified Antenna
30X30 DiamondLoop(six section 830pf Cap)
* Diamond Loop mounted to Lazy Susan TurnTable*
*21/2X2ft.FiveSpoked~Penta-Loop~PancakeLoop*
~OptimusCTR-111Cassettte Recorder~
~Radio Shack 2Speed VOX#43-476~
~Ramsey Speech Scrambler~

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Old May 23rd 04, 10:47 PM
ddwyer
 
Posts: n/a
Default

I have low voltage lighting with switched mode transformers to 12V.
Wipes out the whole mw.
Use torroidal transformers.

--
ddwyer
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