rf spectrum usage

You know with all this talk of what is going to change in the usage of the
uhf spectrum, it got me wonding about the lower frequencies. at the moment
by the blind eys of offcom we are gradually obliterating everything from
long wave up to low vhf with switch mode power supplies and internet over
the mains systems etc. This surely should be seen as a valuable resource
for communications, not just a dumping ground for interference, surely?

Brian

--
From the Sofa of Brian Gaff Reply address is active

On Wed, 21 Nov 2012 09:20:27 -0000, "Brian Gaff"
wrote:

You know with all this talk of what is going to change in the usage of the
uhf spectrum, it got me wonding about the lower frequencies. at the moment
by the blind eys of offcom we are gradually obliterating everything from
long wave up to low vhf with switch mode power supplies and internet over
the mains systems etc. This surely should be seen as a valuable resource
for communications, not just a dumping ground for interference, surely?


There is lttle demand for anything below about 60MHz by Ofcom's famous
'citizen consumers'. Available bandwidths are too small and
propagation charactersitics are unsuitable for mass-market products.

What is the most efficient use of the MF spectrum?

a. 0.1% of the population using it for short-wave listening or ham
radio

OR

b. 10% of the population using it for mains LANs and 100% of them
interfering with it by using SMPs

Discuss...

wrote in message
...
On Wed, 21 Nov 2012 09:20:27 -0000, "Brian Gaff"
wrote:

You know with all this talk of what is going to change in the usage of the
uhf spectrum, it got me wonding about the lower frequencies. at the moment
by the blind eys of offcom we are gradually obliterating everything from
long wave up to low vhf with switch mode power supplies and internet over
the mains systems etc. This surely should be seen as a valuable resource
for communications, not just a dumping ground for interference, surely?


There is lttle demand for anything below about 60MHz by Ofcom's famous
'citizen consumers'. Available bandwidths are too small and
propagation charactersitics are unsuitable for mass-market products.

What is the most efficient use of the MF spectrum?

a. 0.1% of the population using it for short-wave listening or ham
radio

OR

b. 10% of the population using it for mains LANs and 100% of them
interfering with it by using SMPs

Discuss..

Regarding shortwave listening. Just one example . . .

Next door's PLT for BT Vision prevents me from hearing SAR ops and NATS
traffic in the 5MHz band. Now I don't matter, but sooner or later somebody
who does will start having bother and by then it may be too late.

Among others, NATO is concerned about PLT noise.

http://www.compliance-club.com/PLT/N...IST-083-07.doc

Well we can and do use long and medium waves a lot. I note most people I
know use them for their radio listening during the day, but in built up
areas they are now getting unusable.
Short range communication systems could easily use the lower frequencies in
my opinion escpecially if they used some kind of low bandwidth digital
mode.


Brian

--
From the Sofa of Brian Gaff Reply address is active
wrote in message
...
On Wed, 21 Nov 2012 09:20:27 -0000, "Brian Gaff"
wrote:

You know with all this talk of what is going to change in the usage of the
uhf spectrum, it got me wonding about the lower frequencies. at the moment
by the blind eys of offcom we are gradually obliterating everything from
long wave up to low vhf with switch mode power supplies and internet over
the mains systems etc. This surely should be seen as a valuable resource
for communications, not just a dumping ground for interference, surely?


There is lttle demand for anything below about 60MHz by Ofcom's famous
'citizen consumers'. Available bandwidths are too small and
propagation charactersitics are unsuitable for mass-market products.

What is the most efficient use of the MF spectrum?

a. 0.1% of the population using it for short-wave listening or ham
radio

OR

b. 10% of the population using it for mains LANs and 100% of them
interfering with it by using SMPs

Discuss...

It is interesting that some of the plts now have notches where the ham bands
are, but not anything else.

I note that something official and digital is now on the top end of the 80
metre ham band causing interference. I suspect its moved there due to
interference outside of this band, and as its shared use nobody can
complain. Surely the answer should have been to kick the areses of those
allowing crap gear into the country.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Rob Gibson" [email protected] wrote in message
...

wrote in message
...
On Wed, 21 Nov 2012 09:20:27 -0000, "Brian Gaff"
wrote:

You know with all this talk of what is going to change in the usage of
the
uhf spectrum, it got me wonding about the lower frequencies. at the
moment
by the blind eys of offcom we are gradually obliterating everything from
long wave up to low vhf with switch mode power supplies and internet
over
the mains systems etc. This surely should be seen as a valuable resource
for communications, not just a dumping ground for interference, surely?


There is lttle demand for anything below about 60MHz by Ofcom's famous
'citizen consumers'. Available bandwidths are too small and
propagation charactersitics are unsuitable for mass-market products.

What is the most efficient use of the MF spectrum?

a. 0.1% of the population using it for short-wave listening or ham
radio

OR

b. 10% of the population using it for mains LANs and 100% of them
interfering with it by using SMPs

Discuss..

Regarding shortwave listening. Just one example . . .

Next door's PLT for BT Vision prevents me from hearing SAR ops and NATS
traffic in the 5MHz band. Now I don't matter, but sooner or later somebody
who does will start having bother and by then it may be too late.

Among others, NATO is concerned about PLT noise.

http://www.compliance-club.com/PLT/N...IST-083-07.doc

In message , Brian Gaff
writes
It is interesting that some of the plts now have notches where the ham bands
are, but not anything else.

But will this continue? Already we have totally non-EMC-compliant
equipment flooding the country (like computer switchmode power supplies
with the EMC filtering components deliberately omitted).

I note that something official and digital is now on the top end of the 80
metre ham band causing interference. I suspect its moved there due to
interference outside of this band

That is indeed a good point. The amateur bands could well end up as some
of few sweet spots in the whole of the HF and VHF spectrum which are
relatively free of PLT interference, and could well be seen as highly
desirable by certain non-amateur services.

, and as its shared use nobody can
complain.

Oh yes we can. Shared it may be, but radio amateurs are the primary
users of 80m band.

Surely the answer should have been to kick the areses of those
allowing crap gear into the country.

Starting with OFCOM, of course ("Sorry - not our job").

In practice, that 24/7 data transmission on 3774 kHz is so strong that
it's unlikely to be affected by the PLT levels outside the amateur
bands. It could easily be moved to a non-amateur frequency.
--
Ian

On Wed, 21 Nov 2012 15:40:40 +0000, Ian Jackson
wrote:

In message , Brian Gaff
writes
It is interesting that some of the plts now have notches where the ham bands
are, but not anything else.

But will this continue? Already we have totally non-EMC-compliant
equipment flooding the country (like computer switchmode power supplies
with the EMC filtering components deliberately omitted).

I note that something official and digital is now on the top end of the 80
metre ham band causing interference. I suspect its moved there due to
interference outside of this band

That is indeed a good point. The amateur bands could well end up as some
of few sweet spots in the whole of the HF and VHF spectrum which are
relatively free of PLT interference, and could well be seen as highly
desirable by certain non-amateur services.

, and as its shared use nobody can
complain.

Oh yes we can. Shared it may be, but radio amateurs are the primary
users of 80m band.

Surely the answer should have been to kick the areses of those
allowing crap gear into the country.

Starting with OFCOM, of course ("Sorry - not our job").

In practice, that 24/7 data transmission on 3774 kHz is so strong that
it's unlikely to be affected by the PLT levels outside the amateur
bands. It could easily be moved to a non-amateur frequency.

Just out of interest, what it this transmission? Presumably you hams
can df it?

On Wed, 21 Nov 2012 10:29:41 -0000, wrote:

On Wed, 21 Nov 2012 09:20:27 -0000, "Brian Gaff"
wrote:

You know with all this talk of what is going to change in the usage of
the
uhf spectrum, it got me wonding about the lower frequencies. at the
moment
by the blind eys of offcom we are gradually obliterating everything from
long wave up to low vhf with switch mode power supplies and internet
over
the mains systems etc. This surely should be seen as a valuable
resource
for communications, not just a dumping ground for interference, surely?


There is lttle demand for anything below about 60MHz by Ofcom's famous
'citizen consumers'. Available bandwidths are too small and
propagation charactersitics are unsuitable for mass-market products.

What is the most efficient use of the MF spectrum?

a. 0.1% of the population using it for short-wave listening or ham
radio

OR

b. 10% of the population using it for mains LANs and 100% of them
interfering with it by using SMPs

Discuss...

On September 12, 1933, Baird demonstrated 120-line, 25 frames per second
telecine equipment at the British Association?s annual meeting, and later
that month 120-line test transmissions were made from Crystal Palace on
wavelengths around 6.25 metres (48MHz).

How about reduced framesize (320x180) Mobile Digital TV that will not rely
on line of sight http://www.transdiffusion.org/tv/baird/baird_itv. (Not
Slow Scan TV)

--
My Kindle/Mobile links page | All Kindles | http://goo.gl/ySe0d
Use these for low bandwidth | All Mobiles | http://KindLink.tk/
A really crap coded website | All Devices |
https://sites.google.com/site/themadge/
This information is provided without warranty of any kind

On Wed, 21 Nov 2012 16:28:51 -0000, madge
wrote:

On Wed, 21 Nov 2012 10:29:41 -0000, wrote:

On Wed, 21 Nov 2012 09:20:27 -0000, "Brian Gaff"
wrote:

You know with all this talk of what is going to change in the usage of
the
uhf spectrum, it got me wonding about the lower frequencies. at the
moment
by the blind eys of offcom we are gradually obliterating everything from
long wave up to low vhf with switch mode power supplies and internet
over
the mains systems etc. This surely should be seen as a valuable
resource
for communications, not just a dumping ground for interference, surely?


There is lttle demand for anything below about 60MHz by Ofcom's famous
'citizen consumers'. Available bandwidths are too small and
propagation charactersitics are unsuitable for mass-market products.

What is the most efficient use of the MF spectrum?

a. 0.1% of the population using it for short-wave listening or ham
radio

OR

b. 10% of the population using it for mains LANs and 100% of them
interfering with it by using SMPs

Discuss...

On September 12, 1933, Baird demonstrated 120-line, 25 frames per second
telecine equipment at the British Association?s annual meeting, and later
that month 120-line test transmissions were made from Crystal Palace on
wavelengths around 6.25 metres (48MHz).

How about reduced framesize (320x180) Mobile Digital TV that will not rely
on line of sight http://www.transdiffusion.org/tv/baird/baird_itv. (Not
Slow Scan TV)

Yes, I'm sure that would be very popular with the viewing public

There is of course the small problem with TV that 'will not rely
on line of sight'. Interference will not rely on line of sight either.
(vide Band I TV of sad memory)

On Wed, 21 Nov 2012 15:40:40 +0000, Ian Jackson
wrote:

In message , Brian Gaff
writes
It is interesting that some of the plts now have notches where the ham bands
are, but not anything else.

But will this continue? Already we have totally non-EMC-compliant
equipment flooding the country (like computer switchmode power supplies
with the EMC filtering components deliberately omitted).

I note that something official and digital is now on the top end of the 80
metre ham band causing interference. I suspect its moved there due to
interference outside of this band

That is indeed a good point. The amateur bands could well end up as some
of few sweet spots in the whole of the HF and VHF spectrum which are
relatively free of PLT interference, and could well be seen as highly
desirable by certain non-amateur services.

, and as its shared use nobody can
complain.

Oh yes we can. Shared it may be, but radio amateurs are the primary
users of 80m band.

Surely the answer should have been to kick the areses of those
allowing crap gear into the country.

Starting with OFCOM, of course ("Sorry - not our job").

In practice, that 24/7 data transmission on 3774 kHz is so strong that
it's unlikely to be affected by the PLT levels outside the amateur
bands. It could easily be moved to a non-amateur frequency.

Things have certainly changed.

No doubt you remember the time when before licence free allocations
etc. when the law on transmitting anything without a licence could
only be described as draconian.

You even needed a "pipe finders'" licence under the Wireless
Telegraphy Act to use a metal detector.

It must be hard for the younger generation to appreciate what a
privilege it was to be a radio amateur, in the days before ubiquitous
mobile phones and the Internet.




--
Graham.
%Profound_observation%