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  1. Is the attached video and sound an example of ground loop hum noise? I wonder if the ground loop is also causing this problem I have. https://forum.videohelp.com/threads/379470-Low-frequency-pulsing-noising-on-VHS-capture

    I'm thinking of getting this voltage hum filter. https://www.amazon.com/gp/product/B0002E4YI8/ref=s9_acsd_hps_bw_c_x_1_w
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  2. Member
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    Sounds like head-switch noise. Try adjusting the manual fine tracking in one direction or the other and see if it goes away.
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  3. I connected to a UPS power supply, running off battery only and it solved the problem but it's not a long term solution.
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  4. I'm a Super Moderator johns0's Avatar
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    Try connecting to a filtered ac power bar.
    I think,therefore i am a hamster.
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  5. I'm a Super Moderator johns0's Avatar
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    Not sure about that since there a ton of similar ones,just a regular filtered one sold in a home hardware store.
    I think,therefore i am a hamster.
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  6. You want me to go into a brick and mortar store and buy overpriced hardware?

    I'm going to buy that one on Amazon.

    Or maybe this one. https://www.amazon.com/Tripp-Lite-Protector-INSURANCE-ISOBAR4ULTRA/dp/B0000511U7?th=1

    Help me decide.

    Edit: I purchased the Tripp Lite since it has 1600 reviews.
    Last edited by digicube; 9th Jun 2017 at 01:50.
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  7. Power all equipment from one power strip or UPS (appropriately rated of course). Cable TV lines should get isolation transformers. Don't run long unbalanced analog signal lines (2M is OK, >10M not OK) and again, don't connect electronics together that are powered from different AC outlets or grounded through different paths. Sometimes it helps to use ground lifters on all boxes except one. The A/V signal shields act as ground return for the others.
    Last edited by raffriff42; 9th Jun 2017 at 03:29.
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  8. Member Cornucopia's Avatar
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    +1
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  9. raffriff42 provided correct approach to solve this problem - one remark - sometimes issue is related to bad home wiring - using single power bar with properly aligned power plugs (you may verify where is L and N by using some neon probe like this https://www.ebay.com/p/100-500v-Screwdriver-With-Voltage-Test-Neon-Bulb-Electric-Teste...38mm/672684360 ), if your equipment use 3 pin plug (is equipped with earth connection) it must be connected to earthed wiring (so you should verify if you use TN-C, TN-S or TN-C+S wiring in home) - sometimes there is issue with home wiring (earthing not work correctly - can be dangerous for life).

    AFAIR US power plug should prevent such issues but in Europe it is very common issue.
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  10. All my AV equipment are 2 prong and on one power strip, so ground lifters are not applicable in my case. My AV cables are 10-15 ft, hope this is not too long.
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    So you can't have a ground loop. You have noise coming in on the electric line.
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  12. So any 2 prong device can't have ground loop? Hopefully the filter ac power bar I just ordered will solve this problem.
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    Ground loop is unlikely because you have everything plugged in very close together and they will see the same ground potential.
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  14. Correct. So it must be interference between devices on the same power strip.
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  15. You may have one defective device that is leaking power-line AC into the signal. Try to test each device, one at a time, then in pairs etc.
    A trick I used to use (for my semi-pro recording studio back in the 80s) was to check each devices' case & signal shields with an AC voltmeter, while unconnected to anything else, switching the plug around for the lowest voltage. 60V was not uncommon!
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