Intermittant RF spikes all the way across VHF & UHF band

Did the nursing home job today, and got the headend all sorted out, perfect
signals coming in & out, fine tuned with filters so signals are spot on
across all TV points etc BUT there are random RF spikes occuring all the way
across the UHF band (and below) which are trashing some of the DVB-T signals
quite badly and causing 2 parallel lines with sparklies to come up on
analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They go
up to around 48dBuV sometimes, and seem to occur in blocks of about 50mhz
across. They look like a group of 7 or so analogue channels but without the
sound carrier. These signal are definitely not coming in via the headend and
therefore can't be blocked. They occur approximately every 2 seconds, in
varying strength, and at varying frequencies right the way across the UHF
band and all the way down to 50mhz. With the headend completely disconnected
they are unchanged, so must be eminating from somewhere in the building. The
coax cabling installed is pretty ropey RG6 type with no copper tape and
limited braid, but short of rewiring the lot (80 odd rooms) I want to try
and narrow down the possibilities as to the cause.

Anyone aware of any systems in a nursing home that would cause this kind of
spiking? They've got all the usual nurse call systems / fire door auto close
systems but they assure me these are all hard wired (I haven't checked
though). The lift motor is central in the building, but doesn't seem to
correspond in any way to the RF spiking (spiking still present even when
lift not in use - lift in use has no effect in spiking etc). It looks almost
like an earth loop fault with the sparklies but I'm guessing that it's just
one or several of the cables are run alongside power cabling or near to a
thermostat / something thats giving out a healthy dose of RF. We certainly
can't find it in any void / riser / ceiling so it might not be possible to
solve it anyway, but at least if I can narrow it down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every few
seconds.

Any pointers?

"-GB-Carpy" wrote in message
...
Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of the
DVB-T signals quite badly and causing 2 parallel lines with sparklies to
come up on analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They
go up to around 48dBuV sometimes, and seem to occur in blocks of about
50mhz across. They look like a group of 7 or so analogue channels but
without the sound carrier. These signal are definitely not coming in via
the headend and therefore can't be blocked. They occur approximately every
2 seconds, in varying strength, and at varying frequencies right the way
across the UHF band and all the way down to 50mhz. With the headend
completely disconnected they are unchanged, so must be eminating from
somewhere in the building. The coax cabling installed is pretty ropey RG6
type with no copper tape and limited braid, but short of rewiring the lot
(80 odd rooms) I want to try and narrow down the possibilities as to the
cause.

Anyone aware of any systems in a nursing home that would cause this kind
of spiking? They've got all the usual nurse call systems / fire door auto
close systems but they assure me these are all hard wired (I haven't
checked though). The lift motor is central in the building, but doesn't
seem to correspond in any way to the RF spiking (spiking still present
even when lift not in use - lift in use has no effect in spiking etc). It
looks almost like an earth loop fault with the sparklies but I'm guessing
that it's just one or several of the cables are run alongside power
cabling or near to a thermostat / something thats giving out a healthy
dose of RF. We certainly can't find it in any void / riser / ceiling so it
might not be possible to solve it anyway, but at least if I can narrow it
down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every
few seconds.

I was asked to look at a very similar problem in a nursing home. The culprit
tuned out to be the power supplies built into all the maintained lights and
maintained exit signs. The TV cables were cheapo and they were on the same
try as the mains feeding the lights. The cure was painful -- to change all
the coax to CT100.

In another case the fault was a single disused VCR, which was putting a
terrific amount of ****e onto the mains.
One approach is to connect a log periodic via a masthead amp to the
analyser, and stand some distance outside the building, and do a sweep. Even
with mains borne interference you can sometimes get an idea of which end of
the building is 'hot'. Walking around the perimeter can also be helpful, as
can prowling though the building.

I suggest you arrange to attend in the middle of the night when all the
residents are in bed. Either that or attend mid afternoon when movements are
few and many are snoozing. Turn off each mains circuit one at a time until
you find one that relates to the interference. Obviously arrangements will
have to be made re fire alarms, CCTV, nurse call, etc. Power the head end
from an inverter and a battery while you do this.

Is there any geographical pattern? Any one part of the building more/less
afected than the rest?

Presumably you've been in the office and checked for RF devices? The nurse
call will almost certainly be RF, with a whip aerial in the loft. The whip
might be right next to the TV cables! I had one once where they put the whip
outside on my TV aerial mast, with the actual whip between the UHF TV aerial
elements. I'm afraid I reacted badly and took destructive action. Ha ha!

Bill

Can these be picked up on , say a portable radio scanner? You might get some
kind of louder signal if you got near the source. Sounds too wide band to
be intentional to me. Some kind of weird spurii from a psu maybe? Though one
would imagine if its this bad, it would be trashing whatever it is
operating. I had to remove the supplied psu for an answering machine in my
house due to spikes from meidium wave all the way up to 700mhz at what
appeared to be huge peak power, and fit an analogue version a while back.
Damn Chinese crap.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"-GB-Carpy" wrote in message
...
Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of the
DVB-T signals quite badly and causing 2 parallel lines with sparklies to
come up on analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They
go up to around 48dBuV sometimes, and seem to occur in blocks of about
50mhz across. They look like a group of 7 or so analogue channels but
without the sound carrier. These signal are definitely not coming in via
the headend and therefore can't be blocked. They occur approximately every
2 seconds, in varying strength, and at varying frequencies right the way
across the UHF band and all the way down to 50mhz. With the headend
completely disconnected they are unchanged, so must be eminating from
somewhere in the building. The coax cabling installed is pretty ropey RG6
type with no copper tape and limited braid, but short of rewiring the lot
(80 odd rooms) I want to try and narrow down the possibilities as to the
cause.

Anyone aware of any systems in a nursing home that would cause this kind
of spiking? They've got all the usual nurse call systems / fire door auto
close systems but they assure me these are all hard wired (I haven't
checked though). The lift motor is central in the building, but doesn't
seem to correspond in any way to the RF spiking (spiking still present
even when lift not in use - lift in use has no effect in spiking etc). It
looks almost like an earth loop fault with the sparklies but I'm guessing
that it's just one or several of the cables are run alongside power
cabling or near to a thermostat / something thats giving out a healthy
dose of RF. We certainly can't find it in any void / riser / ceiling so it
might not be possible to solve it anyway, but at least if I can narrow it
down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every
few seconds.

Any pointers?

"-GB-Carpy" wrote in message
...
Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of the
DVB-T signals quite badly and causing 2 parallel lines with sparklies to
come up on analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They
go up to around 48dBuV sometimes, and seem to occur in blocks of about
50mhz across. They look like a group of 7 or so analogue channels but
without the sound carrier. These signal are definitely not coming in via
the headend and therefore can't be blocked. They occur approximately every
2 seconds, in varying strength, and at varying frequencies right the way
across the UHF band and all the way down to 50mhz. With the headend
completely disconnected they are unchanged, so must be eminating from
somewhere in the building. The coax cabling installed is pretty ropey RG6
type with no copper tape and limited braid, but short of rewiring the lot
(80 odd rooms) I want to try and narrow down the possibilities as to the
cause.

Anyone aware of any systems in a nursing home that would cause this kind
of spiking? They've got all the usual nurse call systems / fire door auto
close systems but they assure me these are all hard wired (I haven't
checked though). The lift motor is central in the building, but doesn't
seem to correspond in any way to the RF spiking (spiking still present
even when lift not in use - lift in use has no effect in spiking etc). It
looks almost like an earth loop fault with the sparklies but I'm guessing
that it's just one or several of the cables are run alongside power
cabling or near to a thermostat / something thats giving out a healthy
dose of RF. We certainly can't find it in any void / riser / ceiling so it
might not be possible to solve it anyway, but at least if I can narrow it
down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every
few seconds.

Any pointers?

Thx for the replies. I'd already planned to go back with a log and do a bit
of ghostbusters type hunting, but I'm not overly enthusiastic about how much
luck i'll have finding the source. I think many of the residents hanging
onto sanity might just be tipped over the edge as I appear around the corner
with LP in hand sweeping for signals! Especially if I wear a gas mask for
added effect.

There's no whip aerial anywhere near the headend that I can find, nor
outside. They did say on several occasions that the nurse call system was
hard wired but I'll look into this a bit more. There are also quite a few
dodgy problems I found on the installation day - a few TV sockets are
missing with the cable hanging out, and someone has stripped down naff
flyleads and twisted it to make a connection. Need to get these little bits
done but can't see them being the culprits.

It's the usual setup where the boss of the home says the problems only
started a few weeks ago, but everyone else including the maintenence people
all say it's been like this for years!

The inteference is pretty much the same intensity wherever I test it. Having
the headend connected, or disconnected doesn't make any difference to the
strength of the RF spikes either. It does look like mains borne RF to me, so
knowing my luck it will be a cheapo TV cable routed right next to something
that's impossible to get to. A rewire would be mega expensive and some would
have be done externally (unless they want to get messy with the walls) which
I know won't go down well.

Will report back once I've done a bit more investigation.

On Oct 30, 10:14*am, "-GB-Carpy" wrote:
"-GB-Carpy" wrote in message

...





Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of the
DVB-T signals quite badly and causing 2 parallel lines with sparklies to
come up on analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They
go up to around 48dBuV sometimes, and seem to occur in blocks of about
50mhz across. They look like a group of 7 or so analogue channels but
without the sound carrier. These signal are definitely not coming in via
the headend and therefore can't be blocked. They occur approximately every
2 seconds, in varying strength, and at varying frequencies right the way
across the UHF band and all the way down to 50mhz. With the headend
completely disconnected they are unchanged, so must be eminating from
somewhere in the building. The coax cabling installed is pretty ropey RG6
type with no copper tape and limited braid, but short of rewiring the lot
(80 odd rooms) I want to try and narrow down the possibilities as to the
cause.

Anyone aware of any systems in a nursing home that would cause this kind
of spiking? They've got all the usual nurse call systems / fire door auto
close systems but they assure me these are all hard wired (I haven't
checked though). The lift motor is central in the building, but doesn't
seem to correspond in any way to the RF spiking (spiking still present
even when lift not in use - lift in use has no effect in spiking etc). It
looks almost like an earth loop fault with the sparklies but I'm guessing
that it's just one or several of the cables are run alongside power
cabling or near to a thermostat / something thats giving out a healthy
dose of RF. We certainly can't find it in any void / riser / ceiling so it
might not be possible to solve it anyway, but at least if I can narrow it
down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every
few seconds.

Any pointers?

Thx for the replies. I'd already planned to go back with a log and do a bit
of ghostbusters type hunting, but I'm not overly enthusiastic about how much
luck i'll have finding the source. I think many of the residents hanging
onto sanity might just be tipped over the edge as I appear around the corner
with LP in hand sweeping for signals! Especially if I wear a gas mask for
added effect.

There's no whip aerial anywhere near the headend that I can find, nor
outside. They did say on several occasions that the nurse call system was
hard wired but I'll look into this a bit more. There are also quite a few
dodgy problems I found on the installation day - a few TV sockets are
missing with the cable hanging out, and someone has stripped down naff
flyleads and twisted it to make a connection. Need to get these little bits
done but can't see them being the culprits.

It's the usual setup where the boss of the home says the problems only
started a few weeks ago, but everyone else including the maintenence people
all say it's been like this for years!

The inteference is pretty much the same intensity wherever I test it. Having
the headend connected, or disconnected doesn't make any difference to the
strength of the RF spikes either. It does look like mains borne RF to me, so
knowing my luck it will be a cheapo TV cable routed right next to something
that's impossible to get to. A rewire would be mega expensive and some would
have be done externally (unless they want to get messy with the walls) which
I know won't go down well.

Will report back once I've done a bit more investigation.- Hide quoted text -

- Show quoted text -

Hi,

This sounds like a very wideband noise source, so you could also try a
medium wave transistor radio tuned between stations and see if you can
hear any noise bursts which match what you are seeing on the speccy.

If you can hear it on the radio you may then be able to use it to
locate the source. Use signal nulling by rotating the radio and
ferrite rod antenna.

Much less conspicuous than ghost busting.

I've found arcing theromstats and similar using this method.

Good luck.

UKM

-GB-Carpy wrote:
Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of
the DVB-T signals quite badly and causing 2 parallel lines with
sparklies to come up on analogue stations every few seconds.

Are you anywhere near the coast?
(Foreign) Military radar can do this.

A

Does this site have some form of back up battery supply for emergency
lighting or whatever? If yes, find it and look at whatever charges it up, it
may well be a test and charge type of device. Quite how some devices I've
seen actually pass any kind of RF emmission test baffles me.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"-GB-Carpy" wrote in message
...

"-GB-Carpy" wrote in message
...
Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of
the DVB-T signals quite badly and causing 2 parallel lines with sparklies
to come up on analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They
go up to around 48dBuV sometimes, and seem to occur in blocks of about
50mhz across. They look like a group of 7 or so analogue channels but
without the sound carrier. These signal are definitely not coming in via
the headend and therefore can't be blocked. They occur approximately
every 2 seconds, in varying strength, and at varying frequencies right
the way across the UHF band and all the way down to 50mhz. With the
headend completely disconnected they are unchanged, so must be eminating
from somewhere in the building. The coax cabling installed is pretty
ropey RG6 type with no copper tape and limited braid, but short of
rewiring the lot (80 odd rooms) I want to try and narrow down the
possibilities as to the cause.

Anyone aware of any systems in a nursing home that would cause this kind
of spiking? They've got all the usual nurse call systems / fire door auto
close systems but they assure me these are all hard wired (I haven't
checked though). The lift motor is central in the building, but doesn't
seem to correspond in any way to the RF spiking (spiking still present
even when lift not in use - lift in use has no effect in spiking etc). It
looks almost like an earth loop fault with the sparklies but I'm guessing
that it's just one or several of the cables are run alongside power
cabling or near to a thermostat / something thats giving out a healthy
dose of RF. We certainly can't find it in any void / riser / ceiling so
it might not be possible to solve it anyway, but at least if I can narrow
it down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every
few seconds.

Any pointers?

Thx for the replies. I'd already planned to go back with a log and do a
bit of ghostbusters type hunting, but I'm not overly enthusiastic about
how much luck i'll have finding the source. I think many of the residents
hanging onto sanity might just be tipped over the edge as I appear around
the corner with LP in hand sweeping for signals! Especially if I wear a
gas mask for added effect.

There's no whip aerial anywhere near the headend that I can find, nor
outside. They did say on several occasions that the nurse call system was
hard wired but I'll look into this a bit more. There are also quite a few
dodgy problems I found on the installation day - a few TV sockets are
missing with the cable hanging out, and someone has stripped down naff
flyleads and twisted it to make a connection. Need to get these little
bits done but can't see them being the culprits.

It's the usual setup where the boss of the home says the problems only
started a few weeks ago, but everyone else including the maintenence
people all say it's been like this for years!

The inteference is pretty much the same intensity wherever I test it.
Having the headend connected, or disconnected doesn't make any difference
to the strength of the RF spikes either. It does look like mains borne RF
to me, so knowing my luck it will be a cheapo TV cable routed right next
to something that's impossible to get to. A rewire would be mega expensive
and some would have be done externally (unless they want to get messy with
the walls) which I know won't go down well.

Will report back once I've done a bit more investigation.

Well, it does not have to be military, there was on on the roof of a certain
south coast power station which had some issues in this regard, but it was
confined to uhf in that case I seem to recall. I bet they cheered the day
when a crane swapping out the 25 foot aerial dropped it into the carpark....
on its end..
Guess who was involved in repairing that....
Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Andy Dee" wrote in message
...
-GB-Carpy wrote:
Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of
the DVB-T signals quite badly and causing 2 parallel lines with sparklies
to come up on analogue stations every few seconds.

Are you anywhere near the coast?
(Foreign) Military radar can do this.

A

"UKMonitor" wrote in message
...
On Oct 30, 10:14 am, "-GB-Carpy" wrote:
"-GB-Carpy" wrote in message

...





Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of
the
DVB-T signals quite badly and causing 2 parallel lines with sparklies to
come up on analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They
go up to around 48dBuV sometimes, and seem to occur in blocks of about
50mhz across. They look like a group of 7 or so analogue channels but
without the sound carrier. These signal are definitely not coming in via
the headend and therefore can't be blocked. They occur approximately
every
2 seconds, in varying strength, and at varying frequencies right the way
across the UHF band and all the way down to 50mhz. With the headend
completely disconnected they are unchanged, so must be eminating from
somewhere in the building. The coax cabling installed is pretty ropey
RG6
type with no copper tape and limited braid, but short of rewiring the
lot
(80 odd rooms) I want to try and narrow down the possibilities as to the
cause.

Anyone aware of any systems in a nursing home that would cause this kind
of spiking? They've got all the usual nurse call systems / fire door
auto
close systems but they assure me these are all hard wired (I haven't
checked though). The lift motor is central in the building, but doesn't
seem to correspond in any way to the RF spiking (spiking still present
even when lift not in use - lift in use has no effect in spiking etc).
It
looks almost like an earth loop fault with the sparklies but I'm
guessing
that it's just one or several of the cables are run alongside power
cabling or near to a thermostat / something thats giving out a healthy
dose of RF. We certainly can't find it in any void / riser / ceiling so
it
might not be possible to solve it anyway, but at least if I can narrow
it
down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every
few seconds.

Any pointers?

Thx for the replies. I'd already planned to go back with a log and do a
bit
of ghostbusters type hunting, but I'm not overly enthusiastic about how
much
luck i'll have finding the source. I think many of the residents hanging
onto sanity might just be tipped over the edge as I appear around the
corner
with LP in hand sweeping for signals! Especially if I wear a gas mask for
added effect.

There's no whip aerial anywhere near the headend that I can find, nor
outside. They did say on several occasions that the nurse call system was
hard wired but I'll look into this a bit more. There are also quite a few
dodgy problems I found on the installation day - a few TV sockets are
missing with the cable hanging out, and someone has stripped down naff
flyleads and twisted it to make a connection. Need to get these little
bits
done but can't see them being the culprits.

It's the usual setup where the boss of the home says the problems only
started a few weeks ago, but everyone else including the maintenence
people
all say it's been like this for years!

The inteference is pretty much the same intensity wherever I test it.
Having
the headend connected, or disconnected doesn't make any difference to the
strength of the RF spikes either. It does look like mains borne RF to me,
so
knowing my luck it will be a cheapo TV cable routed right next to
something
that's impossible to get to. A rewire would be mega expensive and some
would
have be done externally (unless they want to get messy with the walls)
which
I know won't go down well.

Will report back once I've done a bit more investigation.- Hide quoted
text -

- Show quoted text -

Hi,

This sounds like a very wideband noise source, so you could also try a
medium wave transistor radio tuned between stations and see if you can
hear any noise bursts which match what you are seeing on the speccy.

If you can hear it on the radio you may then be able to use it to
locate the source. Use signal nulling by rotating the radio and
ferrite rod antenna.

Much less conspicuous than ghost busting.

I've found arcing theromstats and similar using this method.

Good luck.

UKM



Much less conspicuous visually but certainly not aurally! If I do it your
way the old foks will then think there's been some kind of radioactive
leakage in the building! Besides I've already ordered the full white NBC
suit for the ghostbusting method.

I'll try and borrow a radio and give this a go if I can't track it down with
the log!

"Brian Gaff" wrote in message
. ..
Does this site have some form of back up battery supply for emergency
lighting or whatever? If yes, find it and look at whatever charges it up,
it may well be a test and charge type of device. Quite how some devices
I've seen actually pass any kind of RF emmission test baffles me.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"-GB-Carpy" wrote in message
...

"-GB-Carpy" wrote in message
...
Did the nursing home job today, and got the headend all sorted out,
perfect signals coming in & out, fine tuned with filters so signals are
spot on across all TV points etc BUT there are random RF spikes occuring
all the way across the UHF band (and below) which are trashing some of
the DVB-T signals quite badly and causing 2 parallel lines with
sparklies to come up on analogue stations every few seconds.

I've watched these on the analyser, and they appear totally random. They
go up to around 48dBuV sometimes, and seem to occur in blocks of about
50mhz across. They look like a group of 7 or so analogue channels but
without the sound carrier. These signal are definitely not coming in via
the headend and therefore can't be blocked. They occur approximately
every 2 seconds, in varying strength, and at varying frequencies right
the way across the UHF band and all the way down to 50mhz. With the
headend completely disconnected they are unchanged, so must be eminating
from somewhere in the building. The coax cabling installed is pretty
ropey RG6 type with no copper tape and limited braid, but short of
rewiring the lot (80 odd rooms) I want to try and narrow down the
possibilities as to the cause.

Anyone aware of any systems in a nursing home that would cause this kind
of spiking? They've got all the usual nurse call systems / fire door
auto close systems but they assure me these are all hard wired (I
haven't checked though). The lift motor is central in the building, but
doesn't seem to correspond in any way to the RF spiking (spiking still
present even when lift not in use - lift in use has no effect in spiking
etc). It looks almost like an earth loop fault with the sparklies but
I'm guessing that it's just one or several of the cables are run
alongside power cabling or near to a thermostat / something thats giving
out a healthy dose of RF. We certainly can't find it in any void / riser
/ ceiling so it might not be possible to solve it anyway, but at least
if I can narrow it down it would help.

It's just annoying because the signals are spot on now, with excellent
power, BER & C/N then along comes the RF spike and trashes it all every
few seconds.

Any pointers?

Thx for the replies. I'd already planned to go back with a log and do a
bit of ghostbusters type hunting, but I'm not overly enthusiastic about
how much luck i'll have finding the source. I think many of the residents
hanging onto sanity might just be tipped over the edge as I appear around
the corner with LP in hand sweeping for signals! Especially if I wear a
gas mask for added effect.

There's no whip aerial anywhere near the headend that I can find, nor
outside. They did say on several occasions that the nurse call system was
hard wired but I'll look into this a bit more. There are also quite a few
dodgy problems I found on the installation day - a few TV sockets are
missing with the cable hanging out, and someone has stripped down naff
flyleads and twisted it to make a connection. Need to get these little
bits done but can't see them being the culprits.

It's the usual setup where the boss of the home says the problems only
started a few weeks ago, but everyone else including the maintenence
people all say it's been like this for years!

The inteference is pretty much the same intensity wherever I test it.
Having the headend connected, or disconnected doesn't make any difference
to the strength of the RF spikes either. It does look like mains borne RF
to me, so knowing my luck it will be a cheapo TV cable routed right next
to something that's impossible to get to. A rewire would be mega
expensive and some would have be done externally (unless they want to get
messy with the walls) which I know won't go down well.

Will report back once I've done a bit more investigation.



I would imagine so, but as is the norm in these places the maintenence man
has no idea where anything is (what's he been doing all these years) and the
rest of the staff just say they don't know and refer you to him. It's more
time consuming trying to ask for information, so you end up just hunting for
things yourself. I'll have a look for the system and start a bit of analysis
there.