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#1
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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 |
#2
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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 |
#3
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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 |
#4
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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~ |
#5
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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. |
#6
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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
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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~ |
#8
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I have low voltage lighting with switched mode transformers to 12V.
Wipes out the whole mw. Use torroidal transformers. -- ddwyer |
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