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Ham radio transmission causes a reboot

Discussion in 'TiVo Roamio DVRs' started by TimeShifter2009, May 13, 2018.

  1. TimeShifter2009

    TimeShifter2009 New Member

    Jun 27, 2009
    I’m a ham radio operator and recently became active on the high freq bands especially 40 meters (7mhz).
    I’ve installed a wire antenna (inverted V) on my roof. When I key up my radio at low (10w)or higher (100w) ( fully licensed) power, my roamio ota reboots. I’ve disconnected the cat5 and antenna connection but it still suffers from the RF causing a reboot.
    It’s I’m sure a case of not enough RF shielding in the tivo and as is quite common. RF bypassing isn’t considered at the design level due to the thinking ham radio and CB radio is a thing of the past. Not so and in a true weather disaster as we’ve seen recently, cell and land lines will be unusable. So let’s not go there please.
    I’m going to try and get help from tivo to solve this but my guess is I’m on my own.
    My temp solution is to not operate during peak recording times for shows I watch. Mainly prime time evenings. Probably best to unplug the tivo to prevent any constant reboot damage.
    The next issue will be my neighbors if they own a tivo.
    Good news would be if it’s the one that owns the barking dog that barks all day and weekend nights when they are away.

    If any ham radio operators with solutions reads this and has some fix suggestions, thank you in advance.
  2. Worf

    Worf Well-Known Member

    Sep 15, 2000
    Actually, you have to remember what Part 15 licensing means - no one tests for RF ingress because Part 15 doesn't require it. Part 15 is only concerned with emissions by the device - and basically a spectrum analysis of your device's emissions must match a predefined envelope. (Yes, you can fail this quite easily - in fact during analysis, we failed because of emissions by attachment cables (the rules state it's by the device itself).

    We had to shield our cables in order to actually get proper emissions results for certification.

    Anyhow, for FCC certification, RF ingress is not a criterion that's tested - so no one designs for it. The second part of the FCC statement after all states that the device must accept all interference presented to it, even if it results in abnormal operation.

    So no, no one actually tests for it because no one cares - certification requirements don't require that level of testing so no one will test for it. All the shielding inside exists to control emissions from the device to the world, not from the world to the device.

    Your best bet is to follow your standard "good neighbour" policies that come up when a neighbor complains you're causing his TV to go wonky when you key up. Chances are you need to shield your TiVo - remember the TiVo's emissions are generally weak so the limited amount of shielding is adequate, but it's not designed to withstand watts of RF power.
  3. TimeShifter2009

    TimeShifter2009 New Member

    Jun 27, 2009
    Thanks, I ran a few more tests.
    I have a vertical antenna I haven’t used in years at a corner of my small lot that’s at the opposite side of where the tivo resides. Using that antenna doesn’t seem to cause a reboot at 100w.
    More receive noise on the vertical but if it solves this issue I can listen on the wire antenna that’s less noise and transmit on the vertical. Better than nothing for now. I may try some shielding of the tivo but can’t do too much being the case is plastic.
    The digital radio mode I’m hoping to use actually wants low power to be used 25 w or less, so that’s good news for everyone.
  4. rpj22

    rpj22 New Member

    Mar 26, 2016
    At 40 Meters, wouldn't a simple, chicken wire Faraday cage do the job? It wouldn't look great, but it wouldn't interfere with cooling, remote use, etc.
  5. murgatroyd

    murgatroyd Don't stop believin'

    Jan 5, 2002
    Berkeley CA
    My in-house physicist says the interference is coming into your TiVo through the power leads.
  6. TimeShifter2009

    TimeShifter2009 New Member

    Jun 27, 2009
    I moved the downward legs of my inverted V antenna to avoid the tv room. So far at 100W no reboots. I did do a test prior with only power and the hdmi connected and it still rebooted. Short run hdmi to the tv and the power is a wall wart that may not carry any direct connection thru?
    Maybe if it’s a switcher type, didn’t check.
    It’s sugested I use some toriod choked around the hdmi and power cables.
    Always a good idea with high RF around.
    It would seem that if I stay with the new antenna arrangement and 100W it work.
    Not sure if the antenna direction is best for contacts but got to go with what works for now.
    Not begitive, but if tivo decides to bail or I decide to go all streaming in the future or we have no choice, all this could change antenna wise.
    That or possibly a bolt or other model give may be more forgiving.
    This for now is a bandaid to keep the wife and me happy.
    I haven’t tried my Roku streaming stand alone or LG tv with streaming to see how that hold up as well as my modem and router when I try 100-800w.
    That’s next as time permits. Then I’ll know my options.
    Turn off the tivo when running higher power and let her watch streaming something maybe?
    Work in progress.
    Actually many ham radio contacts are migrating to a internet based connection. Either directly or via low power vhf or uhf transmission (5w).
    If recognized for points and contacts, high power HF may be less popular. Technogly keeps moving forward even in ham radio.
    I’ll try and update my progress with my tivo if I make improvements.
  7. GaryD9

    GaryD9 Member

    Mar 1, 2002
    Many years ago, I had an issue with a TiVo Premiere when I transmitted at any power over 5w on 20m and 40m with an antenna over my roof. In my case, it caused audio and video issues (but no rebooting.) The solution form me was to wrap (2 turns) the coax going into the tivo around a pair of snap-on ferrites. I also wrapped the power cord, as there's no shielding at all in the switching power supply inside the tivo. As I'm sure you're already aware, any wire sticking out of the tivo can act as an antenna.

    Good luck, and please keep us informed on your progress.
  8. mattyro7878

    mattyro7878 Active Member

    Nov 27, 2014
    The RF affects nothing else? Tv, microwave, laptops,phones, tablets?? How odd!
  9. ncjohn

    ncjohn Member

    Apr 9, 2015
    Late to the party but is what I did with a similar situation. Transmit was causing problems with my TiVo 6 feet away and my computer next to rig. I am using a 160 meter horizontal loop with a tuner and a 6:1 balun. Have a 1KW amp and run it thru an in line coax choke balun after about 6 feet from the tuner. then another 6 feet to the 6:1; then ladder line to the antenna. It still will cause interference but no reboot with the TiVo on 40, 80 &160 at power but not the Computer. At 100W no problems. Hoping a choke balun might also help you get the rf off the ground side and out of the AC. Also note that rig is on second floor which is usually a problem.
    John, N4ZX

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