Terrestrial TV Reception in SE Reading, UK - C-H and TETRA Interference (LONG!)
Java Jive
improve terrestrial TV reception. I'm indebted to Bill Wright and other
professionals here for their advice, but should emphasise that any views
expressed and mistakes described below are my own, and that my area of
technical expertise lies elsewhere. I record problems and solutions
encountered hoping that I can save others the sometimes unnecessary expense,
time, and exasperation that I've undergone.
Useful general background on TV Interference can be found here:
http://www.ofcom.org.uk/static/archive/ra/publication/ra_info/ra323/ra323.htm
Local symptoms are:
1) Mains spikes &/or electromagnetic interference, which occur in winter
months to the extent that in practical terms it's impossible to make any
recording I'd want to keep. On analogue this appears as about 2 or 3
seconds of snow on picture and crackling on audio, and on digital at best
freezing on picture possibly with clicks on audio, at worst complete loss
and brief 'No signal' messages.
I believe this is interference from my own and neighbouring central-heating
systems. The area is mostly 80s housing estates, and presumably those
systems which have not since been replaced or at least well maintained are
wearing out. Useful background can be found here:
http://www.ofcom.org.uk/static/archive/ra/publication/ra_info/ra272.htm
2) Continuous faint patterning on analogue channels.
As I now watch almost exclusively digital, I didn't realise the
significance of this until I tried to cure the more important spikes
problem. It's a type of interference called cross-modulation - an
interaction between UHF TV frequencies and others outside the UHF TV band
emanating from TETRA transmitters, used by local emergency services, and
possibly also from some or all of 4 nearby mobile phone masts (note a).
Useful background can be found in the first link given, section 2.2 Masthead
Amplifiers, and here:
http://www.ofcom.org.uk/ind_groups/ind_info/broadcasting_br/tvi_tetra/?a=87101
FWTW My Conclusions/Advice:
Ensure that you have your aerial pointing at the optimum transmitter for
your location, but IME below don't just assume that even a reputable local
rigger will necessarily know which transmitter that is. Try and cross-check
for yourself. Remember that signal power and what lies along the line of
sight are important, and that the former is not always equi-directional from
the transmitter, and falls off sharply with distance (in another thread we
concluded that each doubling of distance quarters the signal power). Useful
sources are (note that clicking on the map in the first link seems to give
you analogue info, while the links at the end of the text give you digital
info):
http://www.bbc.co.uk/reception/tv_transmitters/index.shtml
http://www.megalithia.com/elect/terrain.html
In areas of high interference such as built-up areas, choose a
highly-directional aerial (with a central mount if long).
As far as possible, avoid a mounting site pointing out over other nearby
houses, and get the aerial as high as practicable.
Use double-screened components throughout.
Amplification won't cure interference glitches, because the interference
will be amplified as well. It may help - the ratio between the signal and
the glitches may be improved if the glitches are weaker than the signal
beforehand - but amplify primarily for other reasons such as to improve
overall reception or to distribute the signal, not solely in the expectation
that it will help with this problem.
Choosing to amplify your aerial system will probably require filtering
against TETRA and other sources of cross-modulation, especially in built-up
areas. For reasons such as in the next paragraph, this might have to be
specific channel-pass filtering, rather than general UHF TV band pass
filtering.
Amplification may degrade UHF signals from equipment such as VCRs as their
signal will be superimposed on whatever the aerial receives, and it may be
more difficult to find for them channels totally free of aerial signal.
This will be a significant problem if your only means of connecting
equipment is chaining the UHF aerial signal through various boxes to your
TV.
What I did:
My previous system was two aerials, pointing at Hannington and Crystal
Palace, combined through a masthead Triax TMC 3335 STP UHF diplexer, and a
circular FM aerial, TV & FM being diplexed in turn by a LabGear MSA241
distribution amp in the attic, with single downleads to twin TV/FM sockets.
Digital signal levels were about 48-50%.
I first unplugged the CP aerial - the one pointing out over other houses.
This resulted in significantly fewer spikes, though still too many.
Next I replaced the system with a single, more sensitive wideband pointing
at Hannington, amplified by an SLx2M masthead amp powered from the original
distribution amp via the downlead, with double-screened components
throughout. I put spike protection between the distribution amp and the
mains. Digital signal levels were then about 75-80%, yet the result was
*worse* than before. Cross-modulation was bad on some analogue channels,
and digital muxes 2, A, & C were unwatchable.
The masthead amp amplifies *everything* it receives, even frequencies
outside the UHF TV band, and it was being driven into overload by
cross-modulation from strong unwanted signals such as TETRA. I cured this
by adding a passive UHF TV band pass filter between the aerial and the
masthead amp.
I now have as near perfect analogue reception as I'm likely to get in this
location, and digital signal levels around the 80% mark.
However, I'm still getting glitches - my own c-h has not been nullified by
the spike protector on the amp system, and I still get them even with my own
c-h turned off.
So, unless anyone has any better ideas, I suppose the only thing left to try
would be to call in a c-h engineer to do the thermostat, and then the
airwave cops to find all the other offending systems - that'd be popular
with the neighbours! Can anyone here suggest how much that'd cost each
problem household? I wonder just how many would be involved?
A mistake I made: I bought a cheap aerial advertised for weak signal areas.
It was long (ie: had more elements), my recollection being that longer
aerials had a more directional response. and would therefore pick up more
signal and less noise. However, when I showed Bill a picture after
installation, he described it as 'not very directional'!
Historical Notes
In 1997, when I first moved in, TV was unwatchable. I noticed a cable
outlet in the house and some neighbouring satellite dishes. Not wishing to
pay subscription, I replaced a T-junction in the attic with a cheap aerial
amp from B&Q, which at least made life watchable.
Later, I wanted better FM reception. A local firm replaced my previous
aerial with the rig described above. At the time, not knowing better, their
work seemed reasonable to me, but now, as it cost £300-400 (GBP) and was
done by CAI-approved riggers, I think it should have been better (note b).
After a while, I began to notice interference on FM radio and TV. I
suspected mains spikes from my own fridge, c-h, or similar. Accordingly I
tried switching off the rest of my house, and was puzzled when it failed to
cure the problem.
Around 1999, NTL offered a deal on cable broadband, and I had their TV as
well. *Even* this was somehow affected by this interference! Either mains
spikes were still getting through the spike protection which everything was
plugged into, or the cable STB, leads, &/or old TV must have been picking it
up directly via electromagnetic spikes. NTL were such a painful firm to do
business with that I dumped them after three years.
Around 2001/2 I bought a Thomson DTT STB, then a Pace Twin in early 2003.
Surprisingly, digital reception was adequate, but its extra clarity on new
LCD TVs and its greater vulnerability to interference meant that the latter
could no longer be ignored.
I found its intermittent nature, and that I'd even got it with cable,
extremely confusing. I only became convinced it was c-h after:
1) My electricity supplier checked my mains and gave it a clean bill of
health.
2) I consciously noted the seasonal change in severity throughout a year.
I wonder, if I were to add up all the money I've spent over the years trying
directly to solve this problem or indirectly to get round it with cable or
sat systems, perhaps it would have been cheaper just to move house?
Foot Notes
(a) For locals: Official info on the location of TETRA masts is not freely
available, but the new police station on Rushey Way near Asda is a very
likely source. There is a mobile phone mast on Rushey Way near the junction
with Beeston Way, two others just across the M4 from the newly rebuilt
roundabout system at the western end of Lower Earley Way, and a new,
temporary one next to this roundabout itself - perhaps a test for a
proposed permanent mast.
(b) The CAI-approved installers ...
i) Tried to steer me towards Crystal Palace. In retrospect, I have no idea
why. They should have known or noticed that:
Hannington ...
+ Is the correct regional transmitter.
+ Is half the distance.
+ Has a clear path from Lower Earley.
+ Lies beyond immediate open ground.
Crystal Palace ...
- Is the wrong regional transmitter.
- Is twice as far away.
- Has no clear path from Lower Earley.
- Lies beyond neighbouring houses on higher ground.
I insisted on having the correct regional news and weather. Also, unwisely
with 20-20 hindsight, I favoured being able to receive other areas (note c),
but IIRC they mentioned that this wasn't a good idea. Nevertheless, having
gained the impression that it was either CP alone, or CP & Hannington, I
chose the latter. Only recently, when I disconnected the CP aerial, did I
discover it was the one picking up most of the interference spikes!
ii) Misaligned the Hannington aerial by 11 degrees to the north.
iii) Mounted the FM and Hannington aerials too close together.
iv) I don't know if they reused an existing aerial entry hole, but it:
- Comes in behind a roof truss timber.
- Does not slope upwards and inwards (to prevent water ingress).
- Was without an exterior loop of cable hanging downwards (ditto).
- Was unsealed (ditto).
v) Used the giant rawlplug type of fixing for the mast mount. When I tried
to set the mast truly vertical, the screws just rode round in the rawlplugs.
vi) Over crimped the downleads with a staple gun.
vii) Used one double-screened outlet and one not, and not double-screened
cable.
viii) Didn't mention anything about interference or a need to guard against
it. It took me a long time to wise up, but I'm in IT and have no relevant
training or professional experience here. Had they really *never*
encountered it before, when the whole area seems to be *riddled* with it?
(c) It's totally unimportant now, and may already have been then, but
historically there were many more differences in ITV regional programming,
so that, for example, I remember being utterly exasperated at missing the
last episode of 'The Prisoner' through being in a neighbouring region the
night it was broadcast.
Ben
If its lasting for 2 or 3 seconds on analogue, that sounds like a faulty
relay to me, probably in a CH thermostat.
GSM, UMTS, and TETRA are all listed on the ofcom sitefinder map,
unfortunately a lot of new TETRA masts are appearing due to the rollout
of Airwave and it takes a few months for them to appear on the site.
http://www.sitefinder.radio.gov.uk/
You talk about interference in the mains, but I'm not so sure about
this. I've been doing some measurements recently on RF propagation
through the mains, and by the time you get up to VHF frequencies the
attenuation is massive. I think it may be more likely that interference
from things like CH thermostats is being radiated rather than conducted
along the mains wiring (or maybe a bit of both). I'm going to get some
clip-on ferrites to put round my mains and coax cables to try and cure
occasional glitches - I'll report back on how it works.
Java Jive
have not received the first one back from the news server after several
hours.
tony sayer
What a sad tale of woe;( makes you wonder what the industry's coming to.
Perhaps after all that a Sky dish wouldn't have been such a bad
thing;)...
--
Tony Sayer
mike ring
news:Fij%d.32178$3A6....@newsfe1-gui.ntli.net:
<snip the story - you've prolly got it above!>
>
>
> viii) Didn't mention anything about interference or a need to guard
> against it. It took me a long time to wise up, but I'm in IT and have
> no relevant training or professional experience here. Had they really
> *never* encountered it before, when the whole area seems to be
> *riddled* with it?
>
Tell me about it- I've got the same, though not I think as bad, and I
can't identify the main culprits.
I like the filter before the masthead amp - I'll try that.
As regards the CH, I replaced my old room stat; it was really well
clapped anyhow, with a programmable digital.
This is well worth doing anyhow for the much superior control.
Have you tried dealing with mains spikes? Ferrite beads on the mains
leads.
You should try to eliminate interference at source, ie on the room stat,
on the fridge, freezer, etc, But spikes beyond your control can only be
dealt with on the lead to your apparatus. You may also have trouble with
these spikes being put on to the masthead amp by the power supply mains.
You can try Ferrite suppressors in all these spots.
I still have one source of interference causing sound dropout on my STB
that I can't identify <sigh>
mike
mike ring
<snip the story - you've prolly got it above!>
>
>
> viii) Didn't mention anything about interference or a need to guard
> against it. It took me a long time to wise up, but I'm in IT and have
> no relevant training or professional experience here. Had they really
> *never* encountered it before, when the whole area seems to be
> *riddled* with it?
>
Java Jive
"mike ring" <mike...@MICHAELbtinternet.com> wrote in message
news:Xns961FCB5FD44B1mi...@130.133.1.4...
> You should try to eliminate interference at source, ie on the room stat,
> on the fridge, freezer, etc,
Yes, I entirely agree with that. It's just that before, when I was picking
up so many more spikes from the CP aerial, to spend that much money on c-h
'repair' of a working system seemed a bit pointless! The next thing though,
definitely.
> But spikes beyond your control can only be
> dealt with on the lead to your apparatus. You may also have trouble with
> these spikes being put on to the masthead amp by the power supply mains.
> You can try Ferrite suppressors in all these spots.
I've got everything plugged into spike protected extension leads. Do you
think it would be worth trying ferrites as well (my midi system came with
one, and I'm not convinced as to how much good it's doing)?
Java Jive
"Ben" <nos...@nospam.com> wrote in message
news:423d5ce7$0$57162$ed26...@ptn-nntp-reader01.plus.net...
> Just a few points;
>
> If its lasting for 2 or 3 seconds on analogue, that sounds like a faulty
> relay to me, probably in a CH thermostat.
Yes, the link I gave goes into this in more detail ...
> GSM, UMTS, and TETRA are all listed on the ofcom sitefinder map,
> unfortunately a lot of new TETRA masts are appearing due to the rollout
> of Airwave and it takes a few months for them to appear on the site.
> http://www.sitefinder.radio.gov.uk/
Yes and no. My info on mobile masts came from that source, but when
searching for TETRA sources there were definite suggestions on the web both
as you suggest but also that the info was deliberately, officially being
kept under wraps. In support of the latter point of view, the new police
station I mentioned has been open at least a couple of years now, but still
doesn't appear on the map.
> You talk about interference in the mains, but I'm not so sure about
> this. I've been doing some measurements recently on RF propagation
> through the mains, and by the time you get up to VHF frequencies the
> attenuation is massive.
I just meant the surges and arcing that accompany 'dirty' switching.
> I think it may be more likely that interference
> from things like CH thermostats is being radiated rather than conducted
> along the mains wiring (or maybe a bit of both).
Yes, as per the link ...
> I'm going to get some
> clip-on ferrites to put round my mains and coax cables to try and cure
> occasional glitches - I'll report back on how it works.
Er, I have only general rather than specific knowledge here, but won't
ferrites on coax degrade the signal it carries?
mike ring
> Er, I have only general rather than specific knowledge here, but won't
> ferrites on coax degrade the signal it carries?
>
I would think so, though I'm not an expert, too.
I use an inline coax filter for the aerial.
Java Jive
> Camouflage wrote:
> > Apologies if multiple copies arrive
>
> I should think so, its confusing the hell out of me!
I can only apologise again. Having thought the problem was solved, I've
just had two posts fail on DialUp - they haven't sorted out my ADSL yet -
with the new ISP's news server (groan) but as before I'll wait awhile before
reposting them!
> Typical - they come up with something that on the face of it has the
> potential to be useful, then they make sure it isn't. What exactly do
> you mean by 'under wraps'?
Perhaps the wrong expression, but this site ...
http://www.tetrawatch.net/links/links.php?id=find
... is saying TETRA will not be put in the mast finder site until the
network is complete. Not much help meanwhile in finding your local source
of TV interference, or to planning democracy!
> Are we talking 'never to be revealed' here,
> or just 'keep quiet about it until Airwave rollout is complete'?
The latter
> > Er, I have only general rather than specific knowledge here, but won't
> > ferrites on coax degrade the signal it carries?
>
> Its common practice to put ferrites around coax cable to stop
> common-mode currents on the outer.
Yes, I understand that now ...
mike ring
news:1111486715.515644ada2e67b8a30e211fbe8524b53@teranews:
>> But spikes beyond your control can only be
>> dealt with on the lead to your apparatus. You may also have trouble
>> with these spikes being put on to the masthead amp by the power
>> supply mains. You can try Ferrite suppressors in all these spots.
>
> I've got everything plugged into spike protected extension leads. Do
> you think it would be worth trying ferrites as well (my midi system
> came with one, and I'm not convinced as to how much good it's doing)?
I wish I knew - it's nigh impossible to know *exactly* what the problem is;
you just have to keep trying.
(I've got some useful ideas from this thread)
mike
Camouflage
and previous posts do not appear to have made it ...
"Ben" <nos...@nospam.com> wrote in message
news:423d5ce7$0$57162$ed26...@ptn-nntp-reader01.plus.net...
> Just a few points;
>
> If its lasting for 2 or 3 seconds on analogue, that sounds like a
faulty
> relay to me, probably in a CH thermostat.
Yes, the link I gave goes into this in more detail.
> GSM, UMTS, and TETRA are all listed on the ofcom sitefinder map,
> unfortunately a lot of new TETRA masts are appearing due to the rollout
> of Airwave and it takes a few months for them to appear on the site.
> http://www.sitefinder.radio.gov.uk/
Yes and no. My info on mobile masts came from that source, but when
searching for TETRA sources there were definite suggestions on the web
both as you suggest but also that the info was deliberately, officially
being kept under wraps. In support of the latter point of view, the new
police station I mentioned has been open at least a couple of years now,
but still doesn't appear on the map.
> You talk about interference in the mains, but I'm not so sure about
> this. I've been doing some measurements recently on RF propagation
> through the mains, and by the time you get up to VHF frequencies the
> attenuation is massive.
I just meant the surges and arcing that accompany 'dirty' switching.
> I think it may be more likely that interference
> from things like CH thermostats is being radiated rather than conducted
> along the mains wiring (or maybe a bit of both).
Yes, as per the link.
> I'm going to get some
> clip-on ferrites to put round my mains and coax cables to try and cure
> occasional glitches - I'll report back on how it works.
Er, I have only general rather than specific knowledge here, but won't
Johnny B Good
from mike ring <mike...@MICHAELbtinternet.com> contains these words:
The ferrite is meant to 'degrade' the signal carried on the outside of
the screen. It has no effect whatsoever on the signal carried by the
inner conductor.
The idea is to reduce injection of unwanted out of band interference
signals into the TV chassis The lengh of co-ax is effectively a long
wire antenna with a lump of alloywork (TV antenna) stuck on the end.
--
Regards, John.
To reply directly, please remove "buttplug" .Mail via the
"Reply Direct" button and Spam-bots will be rejected.
Ben
> Apologies if multiple copies arrive, I'm in the middle of swapping ISPs,
> and previous posts do not appear to have made it ...
>
> news:Xns961FCB5FD44B1mi...@130.133.1.4...
>
>
>>on the fridge, freezer, etc,
>
>
> up so many more spikes from the CP aerial, to spend that much money on c-h
> 'repair' of a working system seemed a bit pointless! The next thing though,
> definitely.
>
>
>>dealt with on the lead to your apparatus. You may also have trouble with
>>these spikes being put on to the masthead amp by the power supply mains.
>>You can try Ferrite suppressors in all these spots.
>
>
> think it would be worth trying ferrites as well (my midi system came with
> one, and I'm not convinced as to how much good it's doing)?
Generally speaking, spike protection means transient overvoltage
protection and will not help you here, you need EMI/RFI filter
protection. In principle ferrites should be useful, but I tend to agree
with you that they don't make much difference. Before coming home from
work today I bunged some ferrites on a bit of mains cable and measured
the RF attenuation. The effect can be briefly summarised as bugger all.
Its worth bearing in mind that the RF attenuation on reasonable lengths
of mains cable is pretty high anyway.
Ben
> http://www.tetrawatch.net/links/links.php?id=find
Grrrr!!!
So the Telecommunications Masts (Registration) Bill (2004) says that the
operators must inform ofcom within one month of their erection <snigger>
and ofcom must publish this information on its website within one month
of receiving it, but the home office thinks its above the law. Thats
what really pisses me off about this fucking government. They keep
trying to push laws through that are so general and sweeping it'll make
you a criminal if you so much as set foot out of your front door, but
they don't think the law applies to them. I would say roll on May 5th,
except I can still remember Michael "I know there are children here, I
can smell them" Howard when he was home secretary, and I don't think any
of us want to go back to that.
Ben
> Apologies if multiple copies arrive
I should think so, its confusing the hell out of me!
>>GSM, UMTS, and TETRA are all listed on the ofcom sitefinder map,
>>unfortunately a lot of new TETRA masts are appearing due to the rollout
>>of Airwave and it takes a few months for them to appear on the site.
>>http://www.sitefinder.radio.gov.uk/
>
>
> Yes and no. My info on mobile masts came from that source, but when
> searching for TETRA sources there were definite suggestions on the web
> both as you suggest but also that the info was deliberately, officially
> being kept under wraps. In support of the latter point of view, the new
> police station I mentioned has been open at least a couple of years now,
> but still doesn't appear on the map.
Typical - they come up with something that on the face of it has the
potential to be useful, then they make sure it isn't. What exactly do
you mean by 'under wraps'? Are we talking 'never to be revealed' here,
or just 'keep quiet about it until Airwave rollout is complete'? I've
had my eye on a new mast for a while now that they've been building half
way up a mountain. First a big trench appeared taking mains cables all
the way up, then a hut and a concrete base, then finally the mast and
antennas. When they finished it all off they put various signs on it,
one of them announcing that the only people allowed to climb up it were
Airwave employees, which kind of gives away what it is. The funny thing
is that halfway up the hill, alongside their new trench, there's a metal
cabinet with mains switchgear in it and no lock on the door, so you can
just switch it off if you like :-)
>>You talk about interference in the mains, but I'm not so sure about
>>this. I've been doing some measurements recently on RF propagation
>>through the mains, and by the time you get up to VHF frequencies the
>>attenuation is massive.
>
>
> I just meant the surges and arcing that accompany 'dirty' switching.
Yes, switching and arcing produce RF interference with a wide frequency
spectrum, which either propagates along the mains wiring (lower
frequencies) or radiates (higher frequencies).
>>I'm going to get some
>>clip-on ferrites to put round my mains and coax cables to try and cure
>>occasional glitches - I'll report back on how it works.
>
>
> Er, I have only general rather than specific knowledge here, but won't
> ferrites on coax degrade the signal it carries?
Its common practice to put ferrites around coax cable to stop
common-mode currents on the outer. I tried to measure the effect of this
on the signal today, but the ferrites didn't seem to be having any
discernible effect on anything.
Ben
http://www.mindcontrolforums.com/tetra.htm
I thought these mast campaigners where a load of paranoid hysterical
nutters, but thats a really good introductory article.
Camouflage
and previous posts do not appear to have made it ...
"mike ring" <mike...@MICHAELbtinternet.com> wrote in message
news:Xns961FCB5FD44B1mi...@130.133.1.4...
> You should try to eliminate interference at source, ie on the room stat,
> on the fridge, freezer, etc,
Yes, I entirely agree with that. It's just that before, when I was picking
up so many more spikes from the CP aerial, to spend that much money on c-h
'repair' of a working system seemed a bit pointless! The next thing though,
definitely.
> But spikes beyond your control can only be
> dealt with on the lead to your apparatus. You may also have trouble with
> these spikes being put on to the masthead amp by the power supply mains.
> You can try Ferrite suppressors in all these spots.
I've got everything plugged into spike protected extension leads. Do you
tony sayer
writes
>
>"Ben" <nos...@nospam.com> wrote in message
>news:42405f6f$0$29303$ed26...@ptn-nntp-reader03.plus.net...
>> Camouflage wrote:
>> > Apologies if multiple copies arrive
>>
>> I should think so, its confusing the hell out of me!
>
>I can only apologise again. Having thought the problem was solved, I've
>just had two posts fail on DialUp - they haven't sorted out my ADSL yet -
>with the new ISP's news server (groan) but as before I'll wait awhile before
>reposting them!
>
>> Typical - they come up with something that on the face of it has the
>> potential to be useful, then they make sure it isn't. What exactly do
>> you mean by 'under wraps'?
>
>Perhaps the wrong expression, but this site ...
> http://www.tetrawatch.net/links/links.php?id=find
>... is saying TETRA will not be put in the mast finder site until the
>network is complete. Not much help meanwhile in finding your local source
>of TV interference, or to planning democracy!
And from that same site scary stuff eh;?...
"Still unconvinced of how secret these masts are? Well, if you ask
someone who is electro-sensitive, perhaps who has been made electro-
sensitive by TETRA, we just feel them. They're quite distinctive, and we
have found a number of masts just by feeling them. And you can't keep
that a secret!"
--
Tony Sayer
tony sayer
<nos...@nospam.com> writes
Yes when they get simple EMC problems, and they are causing mind
control....
--
Tony Sayer
Java Jive
"Johnny B Good" <jcs.comp...@plugzetnet.co.uk> wrote in message
news:200503221...@plugzetnet.co.uk...
> The ferrite is meant to 'degrade' the signal carried on the outside of
> the screen. It has no effect whatsoever on the signal carried by the
> inner conductor.
>
> The idea is to reduce injection of unwanted out of band interference
> signals into the TV chassis The lengh of co-ax is effectively a long
> wire antenna with a lump of alloywork (TV antenna) stuck on the end.
Note: This is my second attempt to send this via DialUp. I've checked with
two newsreaders that the original post does not appear on three news servers
before reposting it.
Ben
Did you see that "should I be scared of" series with that Hammond guy
from Top Gear? They did an experiment where a load of supposedly
sensitive people were put up in a big house with a temporary mast
outside. They were told the mast was on for one period of time and off
for another period, but the actual periods of time it was really
switched on and off were different. You therefore had the four
combinations - off and they think its off, off and they think its on, on
and they think its off, on and they think its on. As I recall, there was
a very good correlation between reported symptoms and them thinking the
mast was on, but no correlation between their reported symptoms and the
mast actually being on.
mike ring
reader03.plus.net:
I would say roll on May 5th,
> except I can still remember Michael "I know there are children here, I
> can smell them" Howard when he was home secretary, and I don't think any
> of us want to go back to that.
Yes, it's a bugger.
"No matter who you vote for, the Government still gets in"
mike
Java Jive
> Java Jive wrote:
> > http://www.tetrawatch.net/links/links.php?id=find
>
> Grrrr!!!
> So the Telecommunications Masts (Registration) Bill (2004) says that the
> operators must inform ofcom within one month of their erection <snigger>
> and ofcom must publish this information on its website within one month
> of receiving it, but the home office thinks its above the law.
Yes, accepting that the site is probably frequented by the crankier side of
life on earth as we know it, I still found that particular statement
disturbing, particularly when put alongside what I guessed about my local
police station (guessed because to be fair, on the odd occasion I've driven
past it recently all before my own TETRA interference issue came up, I
didn't think to confirm there actually is TETRA gear there, but I'd be very
surprised if there isn't).
> I can still remember Michael "I know there are children here, I
> can smell them" Howard when he was home secretary, and I don't think any
> of us want to go back to that.
Yes, I was a poll-tax protester - my income had just halved to study
part-time when my expected contribution to local government increased
fourfold! I'll never vote for such a cynical bunch of band-wagon cowboys as
long as I live :-)
tony sayer
writes
>"Ben" <nos...@nospam.com> wrote in message
>news:4240b50a$0$29298$ed26...@ptn-nntp-reader03.plus.net...
>> Java Jive wrote:
>> > http://www.tetrawatch.net/links/links.php?id=find
>>
>> Grrrr!!!
>> So the Telecommunications Masts (Registration) Bill (2004) says that the
>> operators must inform ofcom within one month of their erection <snigger>
>> and ofcom must publish this information on its website within one month
>> of receiving it, but the home office thinks its above the law.
>
>Yes, accepting that the site is probably frequented by the crankier side of
>life on earth as we know it, I still found that particular statement
>disturbing, particularly when put alongside what I guessed about my local
>police station (guessed because to be fair, on the odd occasion I've driven
>past it recently all before my own TETRA interference issue came up, I
>didn't think to confirm there actually is TETRA gear there, but I'd be very
>surprised if there isn't).
Just because this a police station doesn't necessarily mean that theres
going to be a TETRA base station there. Site selection is done with a
lot of other factors in mind apart from the enhanced security siting
atop a nick would have!....
--
Tony Sayer
Camouflage
and the police station is the obvious site, but I agree it's circumstantial
evidence not proof - I'll try and remember to check it out next time I go
past.
tony sayer <to...@bancom.co.uk> wrote in
news:zUF$bmBsVq...@bancom.co.uk:
Java Jive
weekly shop. There are aerials on it, but none that I recognise as being
TETRA.
The search for the source continues ...
"Camouflage" <wher...@camouflage.net> wrote in message
news:1111664137.7f7d7ac23a14fc25d0aaacad2c836162@bubbanews...