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Flat Screen TV's and RF

Discussion in 'Discussions, Opinions & Editorials' started by N8QGC, May 5, 2012.

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  1. N8QGC

    N8QGC Ham Member QRZ Page

    Just wondering can anyone give me any insight into which brands of Flat Screen TV's are the least susceptable to RFI? I currently have a 36 inch Magnavox Tube type dinosaur that sits in our living room. Unfortuantly on my city lot I had to run my G5RV over the house and one leg runs over top of the living room.

    When I transmit on certain bands it shuts the TV off as it's poorly RF shielded.

    I've tried RF chokes common mode suppression and even tin foil. Nothing seems to help.

    My solution is to replace this TV with a 55 inch Flat Screen.

    So any feedback on best brands and RFI problems/concerns would be great.

    73 de John N8QGC
  2. WA6FX

    WA6FX Ham Member QRZ Page

    Plasma TV's can cause real problems, LCD's are usually quietest. I have a new Samsung edge lit 46" LED flat screen that replaced a Mitsubishi that was creating all kinds of RFI headaches.
    The new LED is in fairly close proximity to my antenna (ground mounted vertical on a small lot) and no problems RX or TX w/ 100W.
    Last edited: May 5, 2012
  3. NM5TF

    NM5TF Ham Member QRZ Page

    we had a 63 inch Samsung plasma that was not bothered by my Tx,
    but was a HORRIBLE RFI generator....thankfully it died...we replaced
    it with a Vizio LCD that neither generates or is bothered by RFI....

    seems like either LED or LCD models are immune.....stay away from
    Plasma models if RFI is a concern....

    hope this helps
  4. KB0VXN

    KB0VXN Ham Member QRZ Page

    We have two Vizio LED's....never had rfi problems either way.

  5. WA8LGM

    WA8LGM Ham Member QRZ Page

    I have a RCA 46 inch LED tv. I have no problems with it at all. Its located on the other side of the wall from my office where the ham gear is. I have never heard any noise out of it.
    Just a thought.
  6. KB1NXE

    KB1NXE Platinum Subscriber Platinum Subscriber QRZ Page

    I have an LG 47 LCD w/LED backlighting. You'll likely find the LCD TVs that have an RFI problem have cold cathode illuminated. LED backlighting is clearer and more energy efficient. Let alone low voltage without high voltage (cold cathodes run about 150V IIRC) switching and arcing issues.

    FWIW, I love my LG. It has one of the best pictures in the price range and looks great to boot.

    Amazon had great prices and blisteringly fast shipping:
  7. M0GVZ

    M0GVZ XML Subscriber QRZ Page

    I have a Panasonic TXP42G20 Plasma. Once you get more than 8ft away, there's no detectable RFI being emitted from it on the SW bands using an AM radio and it has no trouble with nearby transmitters - even a slinky dipole on 20m in the same room....
  8. N5AL

    N5AL Ham Member QRZ Page

    Buy from a store with a good return policy, so you can exchange the TV for another if it causes you RFI problems.

    I recently gave my plasma TV to my 11 year-old nephew/godson. He is thrilled to have a TV in his bedroom. The TV has a beautiful image: too bad it's a major RFI polluter.

    BTW, my nephew lives several miles miles from me, which is a safe distance away. I would have considered giving the RFI-polluting, plasma TV to my niece, but she lives next door to me!!!
  9. K0RGR

    K0RGR Premium Subscriber QRZ Page

    I have had a Westinghouse LCD and currently have a big LG LED. No RFI in either direction, and the TV antenna is only about 10 feet from one of my HF antennas. I do have other noise sources in the vicinity that may be masking lower level noise, however. Hunting that down is that the top of my to-do list today, too.
  10. N0WYO

    N0WYO Ham Member QRZ Page

    So do we. They seem to be a sturdy set. I've had one for 18 months and the other for 2 years. No problems at all. Not even a flinch on the display when I key up.
  11. N8QGC

    N8QGC Ham Member QRZ Page

    This is good information everyone thanks for your input. I'm not so much concerned about the TV giving me noise as I am about me disturbing the TV.

    My hobby is of course Ham Radiio. The XYL's is TV. Everytime I key down on 30,40, or 80 meters I shut the TV off. Obviously this means that I can't work those bands at crucial times if the XYL is watching a TV show.

    Looks like an LED or LCD will be the way to go for me.
  12. WY5V

    WY5V Ham Member QRZ Page

    Just switch of the TV and go outside. There's hardly anything useful on there anyway. :)

    The fact that it does it on certain bands/wavelengths is telling.

    Try to determine the source first. Disconnect antenna/cable/satellite/AV connections one at a time to see if the problem follows either individually or cumulatively.

    If you can, disconnect the set from the wall and run it of a UPS to determine if it is the power line.

    It is possible that the problem is direct incursion. If this turns out to be the case, some sort of shielding may be called for.

    If all else fails, try another set in the interest of marital bliss.
  13. WA4OTD

    WA4OTD XML Subscriber QRZ Page

    You may still have some problem of shutting off the TV when you transmit.
  14. KJ4VTH

    KJ4VTH Subscriber QRZ Page

    Here we go again. There have been numerous threads that claim TVs, plasma in particular, are bad news. We have a plasma TV in the next room. It never seems to bother my radio in the least and my wife never hears me when I key up unless she comes into "the shack". Maybe I'm just lucky but see no absolute correlation between plasma TV and radio interference, or vice versa.
  15. AC0FP

    AC0FP Ham Member QRZ Page

    I agree, their maybe be a minority who have gotten "lemons" and fixed it by buying another TV. As to N8QGC, it is not unusual for modern appliances to be turned off/on by an antenna installation such as yours, a strategically placed ferrite clip-on bead might help. Modern TV's, with a testing label such as the CE mark, are supposed to be tested for resistance to strong RF fields.

  16. N5AL

    N5AL Ham Member QRZ Page

    Possibly, the newest plasma TVs are better shielded that the older models and produce less RFI -- I don't have experience with them. Of course, it is possible to design a low RFI emission plasma set, but which manufacturers are adding this incremental expense to their already cost-sensitive consumer products?

    Another big consideration is antenna location. If a ham is fortunate enough to have his antenna high in the air, and far enough away from the plasma TV set, he might not hear much of the RFI. Conversely, if a ham has a neighborhood-friendly stealth antenna in his attic, this antenna might be located just meters from the offending TV set. A device that meets FCC Part 15 emissions requirements can still trash a sensitive receiver at close range.
    Last edited: May 6, 2012
  17. KJ4VTH

    KJ4VTH Subscriber QRZ Page

    Ah! You raise a good point about 'cost-sensitive consumer products'. Perhaps the offending TVs are lower priced models from big box stores? That would explain why some people insist their TVs are RFI generators while my mid-grade model from a specialty store is relatively clean.
  18. AC0FP

    AC0FP Ham Member QRZ Page

    A good point. I have a 45' 40 meter inverted V outside but one end of the antenna is tied to the house less than 10' from a HP 50" plasma TV. I tested the TV originally with a IFR-500 test set on 7 & 14 MHz 4' in front of the TV and could not tell whether the TV was on or off! The TV operates on cable.

  19. N0AZZ

    N0AZZ Ham Member QRZ Page

    I have a 27" Samsung LED/LCD less than 60" away from my radios/amps and the coax for it runs with 8 runs of UHF-HF antennas of all kinds. They are in the same bundle my direct TV receiver sits on the Power Supply Of mt Yaesu YL-1000 amp amd never a single blip. I have digital TV antennas mounted @ 35' 2 pointed at different cities and they are near 9 antennas from 25'-75' verticals and yagis most all running 1K no problems.

    The only problem I have sometimes is on our 65" Sony LED/LCD in the living room running on a 270' OCFD @ 55' on 80/160m will cause a menu to come up on the TV it does run over the house. None of my other antennas do that and I do have wires and verticals for 80/160m also. I never had any luck using ferrite beads on newer TVs but have used them on my home theater system on all 7 speakers and the sub-woofer. The sub-woofer is self powered 500w and it was the worst offender and then the 2 in-wall speakers between the living room and my shack/office. I mounted the beads on the speaker wires at the receiver and the AC power lines as well problem solved.
  20. K1FBI

    K1FBI XML Subscriber QRZ Page

    Big Box Store TV

    I have a Phillips 50" Plasma that's 3 years old and was purchased at Walmart; no RFI.
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