[mythtv-users] Strange DVB-T Interference Any Ideas
charlie.mas at gmail.com
Mon Jan 12 12:59:54 UTC 2009
On Wed, Dec 17, 2008 at 11:06 AM, Mike Perkins
<mikep at randomtraveller.org.uk> wrote:
> David Brodbeck wrote:
>> Mike Perkins wrote:
>>> Have you considered birds? I get problems at certain times of year from the
>>> local flock of wood pigeons roosting on everyone's aerials. Not a lot you can do
>>> directly without getting up to the aerial and applying some kind of deterrent -
>>> like they use in town centres to keep pigeons off. (A shotgun may be a suitable
>>> alternative, I couldn't possibly comment.)
>> At small airports rubber snakes are used to discourage birds from
>> roosting on parked aircraft, with varying degrees of success.
>> I've heard an owl decoy is sometimes successful at discouraging pigeons,
>> but risks drawing attacks from crows.
>> Bird spikes are effective but not practical for an aerial, as they'd
>> detune it.
> Round here all the bird spikes are plastic, I wouldn't have thought they'd make
> too much difference to the signal.
> As for snakes, this is the UK, I doubt if most of the birds have ever seen a
> snake, so wouldn't consider one a danger.
Well according to some recent local reports Adders have been seen less
then half a mile away but I don't think I am about to draft them in to
help with this :)
I have seen various birds sitting on the antenna, I saw 3 crows which
actually made it wobble significantly has they all took flight at the
same time. Not sure if they really have that much effect though.
I am fairly sure its signal related. We are doing a barn conversion
and the electricians have installed what looks like a fairly decent 8
way distribution amp, so I liberated it temporally and tried it. Like
magic it worked fine, the dodgy recording issues stopped and I even
got the missing multiplex which carries Virgin 1 absolutely perfectly.
However the story does not have quite such a happy ending. I noticed a
few days later it was missing recordings from the USB tuner. I finally
resorted to using the command line scan utility. For some reason its
now only picking up 1 multiplex, the completely useless one with BBCi
and BBC parliament and all the BBC Radio stations. I tried it connect
to the areal with nothing but the mast head amp power supply
connected. I tried connecting its cable to the other tuner (which
No matter what I did I couldn't get it to pick up any other
multiplexes. Running the same command with the PCI tuner worked fine.
I even tried upgrading the firmware file to the latest version. I have
repeated this a several different days to discount the possibility of
So perhaps something has broken inside that USB tuner, perhaps that
was causing the intermittent problems which effect the other tuner as
well. The one thing I do see is lots (about 100 in an hour) of kernel
messages of the form:
cx88_wakeup: 2 buffers handled (should be 1)
After some Googling I found that, should be harmless and that it means
that the diver had to take more than one full buffer. According to the
messages on some occasions its found 4 filled buffers. I don't know if
this indicative of a problem with the system which could cause the
Thanks everyone for the previous suggestions they have been very useful.
Anyone got any more suggestions ?
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