Digital radio switchover gets poor reception

"tony sayer" wrote in message
...
In article

.com, scribeth
thus
On Jun 2, 10:57 pm, tony sayer wrote:
In article [email protected], Woody
scribeth thus

"Dave Plowman (News)" wrote in
message
...
In article [email protected],
Woody wrote:
Band 1 has never been used for TV in the UK.

Eh?

--
Sorry, senior moment. Should have read '...never been used
for
PMR in the UK.'

Has .. but very limited use but darn sarff, and IIRC now
fallen out of
favour...
--
Tony Sayer

Wouldn't all that PMR stuff just above the old ch B5 be within
Band
I?

Bill

Well Band 1 is up to 68 MHz and what's called VHF Low band is
from 68 to
88 MHz. The lowest in current use in Low band data which is
usually 68
mobile TX and 81/2 base Tx but these are quite few and far
between...

--
Tony Sayer




Wasn't it the other way around Tony?

The original pairings of E-band were
85 base Tx with mobile Tx 13.5MHz lower (such as the AA)
87 base Tx with mobile Tx 10MHz lower (such as the RAC)
Some single frequency working around 86MHz.
In earlier days the Police (P-band) had base Rx around 79-82MHz

Then the wonders of the RA and WARC came along and plonked Fire
Tx around 71-72MHz with receive somewhat variant in the 80-84MHz
area. Somehow I doubt 68MHz would have been a viable base receive
frequency with 100W+ transmitters only a meg or two away.

I may be wrong as I know I only ever worked on one 68/81MHz
system (13.5MHz spacing) but I have a fair certainty that it was
base TX low.


--
Woody

harrogate three at ntlworld dot com

[snip]
Rather unusual practice, in the UK normal CTCSS would be used
works very
well...

[snip]

Actually CTCSS alone to trigger T/T was and still is very rare.
It became a requirement the better part of 25 years ago that for
new licences CTCSS was mandatory if T/T was required by
commercial users. The AA, RAC, and most ambulance services
commonly used T/T but the former two and almost all of the latter
never had CTCSS. For ambulance use CTCSS was most often used in
east and southern coastal services to save Control Room staff
having to listen to trawlers etc who seemed to like to use any
frequency they fancied. Even then it was usually one way only -
mobile Tx.

On the other hand selcall triggered T/T was surprisingly common.
I knew of quite a few ambulance services around the country (knew
as they are now all on Airwave) who had selcall triggered
repeaters on remote hilltop sites so that they could be switched
on easily if a major event occurred in an area normally
considered to be outside main system coverage. Such kit was also
often used by the Mountain Rescue organisations.



--
Woody

harrogate three at ntlworld dot com

"tony sayer" wrote in message
...
In article , MB
scribeth thus



BBC RT use, we had a talk-through system from a 141 MHz channel which
could
be activated by a SELCALL system.

Rather unusual practice, in the UK normal CTCSS would be used works very
well...

The 47 MHz part was fixed so it was a folded dipole on the tower but I
have
used a 50 MHz quarter wave and it is not particular unwieldy especially
when
you consider many taxis at that time were using 70/80 MHz anyway.

Well lets say 50 Mc/s thats 1350 mm not insignificant and if you put a
loading coil on that its efficiency is much less as the receive will be
13.5 or 10 MHz away..

We've had transit vans on Lowband and lorries too, average aerial life
is around a couple of weeks even spring loaded ones!..


I heard that someone in the power industry was trying to get a temporary
network set up around 50 MHz for the night of the Millennium to enable
direct comms between various points in the system independent of any
hall-top sites or the telephone system.

Blimey haven't they got enough spectrum already;?..

Just dragging it back to broadcast there are some Audio point to point
and Talkback links in there around 48 to 52 MHz odd..

http://www.jfmg.co.uk/pages/freq/ground/40_100mhz.htm



It was a very unusual system in many ways!

Everyone went crazy on Millennium night. I think someone just fancied
playing on low VHF but it could have given some long paths direct with no
need to use any other resources.

"Woody" wrote in message
news:[email protected]
[snip]
Rather unusual practice, in the UK normal CTCSS would be used works very
well...

[snip]

Actually CTCSS alone to trigger T/T was and still is very rare. It became
a requirement the better part of 25 years ago that for new licences
CTCSS was mandatory if T/T was required by commercial users. The AA, RAC,
and most ambulance services commonly used T/T but the former two and
almost all of the latter never had CTCSS. For ambulance use CTCSS was most
often used in east and southern coastal services to save Control Room
staff having to listen to trawlers etc who seemed to like to use any
frequency they fancied. Even then it was usually one way only - mobile Tx.

On the other hand selcall triggered T/T was surprisingly common. I knew of
quite a few ambulance services around the country (knew as they are now
all on Airwave) who had selcall triggered repeaters on remote hilltop
sites so that they could be switched on easily if a major event occurred
in an area normally considered to be outside main system coverage. Such
kit was also often used by the Mountain Rescue organisations.



I think Scottish Ambulance are still trunked or partially trunked.

A SELCALL system is used from the CIC hut on Ben Nevis to call the local
police station and I think it can be switched to operate as a talk-through
from one of the MR channels.

In article [email protected], Woody
scribeth thus
"tony sayer" wrote in message
...
In article

.com, scribeth
thus
On Jun 2, 10:57 pm, tony sayer wrote:
In article [email protected], Woody
scribeth thus

"Dave Plowman (News)" wrote in
message
...
In article [email protected],
Woody wrote:
Band 1 has never been used for TV in the UK.

Eh?

--
Sorry, senior moment. Should have read '...never been used
for
PMR in the UK.'

Has .. but very limited use but darn sarff, and IIRC now
fallen out of
favour...
--
Tony Sayer

Wouldn't all that PMR stuff just above the old ch B5 be within
Band
I?

Bill

Well Band 1 is up to 68 MHz and what's called VHF Low band is
from 68 to
88 MHz. The lowest in current use in Low band data which is
usually 68
mobile TX and 81/2 base Tx but these are quite few and far
between...

--
Tony Sayer




Wasn't it the other way around Tony?

The original pairings of E-band were

That's Pye talk)..

85 base Tx with mobile Tx 13.5MHz lower (such as the AA)

Yes..

87 base Tx with mobile Tx 10MHz lower (such as the RAC)

Yes..

Some single frequency working around 86MHz.

Very little .. at one time that frequency was allocated to IBA aerial
riggers;!..

In earlier days the Police (P-band) had base Rx around 79-82MHz

With TX around 101-etc

Then the wonders of the RA and WARC came along and plonked Fire
Tx around 71-72MHz with receive somewhat variant in the 80-84MHz
area.

OK..

Som
ehow I doubt 68MHz would have been a viable base receive
frequency with 100W+ transmitters only a meg or two away.

Well 68 the low side is used for mobile receive..

I may be wrong as I know I only ever worked on one 68/81MHz
system (13.5MHz spacing) but I have a fair certainty that it was
base TX low.

Other way round all the ones I've seen but then again thats not that
many..

The Fire brigades have now gone to Airwave round this area so all rather
academic now....



--
Tony Sayer

"tony sayer" wrote in message
...
In article , Steve Terry
scribeth thus
"tony sayer" wrote in message
...
In article , charles
scribeth thus
In article ,
Dave Plowman (News) wrote:
In article ,
tony sayer wrote:
snip
FWIW Band 1 has hardly any PMR thereon due to the absurdly long aerials
required, the impossibility of using portables and the lack of type
approved equipment/s..

Wot like this?
http://www.doubleradius.com/Motorola...dio-35-50-MHz-
Lowband-16-Channel

35 to 50MHz is heavily used in the US especially by police depts,
just not here.

No there not at all efficient even at 77 odd MHz theres no comparison
with a VHF hi band portable on say 170 MHz.

Lowband handheld to handheld maybe because of poor groundplain and erp
at both ends. But lowband handheld to lowband mobile or base will beat
highband handheld to mobile or base everytime.

In around 25 years of PMR operation we must have sold around 3 or 4
handportables for VHF Lo;!.

That's a UK peculiarity, probably because of the high number of highband
and UHF urban repeaters?

And a helluva lot on VHF Hi and UHF 1 and 2. And thats not just because
of frequency availability its down to performance. VHF Lowband channels
some have sod all users on nation-wide even!....

A small country like the UK doesn't have to try and maximise coverage
like larger countries do.
Lowband is the mainstay of US state police forces.(30 to 50MHz)
Also Nato Military tactical field radios. (30 to 70MHz)

Steve Terry
--
Welcome Sign-up Bonus of £1 when you signup free at:
http://www.topcashback.co.uk/ref/G4WWK

In article [email protected], Woody
scribeth thus
[snip]
Rather unusual practice, in the UK normal CTCSS would be used
works very
well...

[snip]

Actually CTCSS alone to trigger T/T was and still is very rare.

I think by that you mean to switch TT on?..If so than apart from RFW no
its not been used for that. Most older fire ambulance police systems
were almost always line controlled...


It became a requirement the better part of 25 years ago that for
new licences CTCSS was mandatory if T/T was required by
commercial users.

Yes been so for a long time now..Or DCS even..

The AA, RAC, and most ambulance services
commonly used T/T but the former two and almost all of the latter
never had CTCSS. For ambulance use CTCSS was most often used in
east and southern coastal services to save Control Room staff
having to listen to trawlers etc who seemed to like to use any
frequency they fancied. Even then it was usually one way only -
mobile Tx.

Yes they were rather old systems and a lot were AM, well fire services
which doesn't lend itself to CTCSS operation all that well..

On the other hand selcall triggered T/T was surprisingly common.
I knew of quite a few ambulance services around the country (knew
as they are now all on Airwave) who had selcall triggered
repeaters on remote hilltop sites so that they could be switched
on easily if a major event occurred in an area normally
considered to be outside main system coverage. Such kit was also
often used by the Mountain Rescue organisations.

Well I never worked on Ambulance services and I doubt that the only
mountain rescue outfit round these parts would use them;?..

http://pidleymountainrescue.org.uk/index.html

--
Tony Sayer

In article , Steve Terry
scribeth thus
"tony sayer" wrote in message
...
In article , Steve Terry
scribeth thus
"tony sayer" wrote in message
...
In article , charles
scribeth thus
In article ,
Dave Plowman (News) wrote:
In article ,
tony sayer wrote:
snip
FWIW Band 1 has hardly any PMR thereon due to the absurdly long aerials
required, the impossibility of using portables and the lack of type
approved equipment/s..

Wot like this?
http://www.doubleradius.com/Motorola...dio-35-50-MHz-
Lowband-16-Channel

35 to 50MHz is heavily used in the US especially by police depts,
just not here.

No there not at all efficient even at 77 odd MHz theres no comparison
with a VHF hi band portable on say 170 MHz.

Lowband handheld to handheld maybe because of poor groundplain and erp
at both ends. But lowband handheld to lowband mobile or base will beat
highband handheld to mobile or base everytime.

Will it now. Well in 25 years of PMR operation and trailing this its
always proved to be the other way round. Even a research consultancy we
know of not a million miles from here was commissioned to arbitrate for
a large council who were sold a Low band system with handportables and
it was very problematical in that the range was very poor indeed and in
the end the supplier had to pay for them to use VHF Hi Band!...

If its as good as you claim can you name perhaps apart from Motorola
anyone selling Low band portables , well more than a handful per annum
in the UK?..



In around 25 years of PMR operation we must have sold around 3 or 4
handportables for VHF Lo;!.

That's a UK peculiarity, probably because of the high number of highband
and UHF urban repeaters?

Nope theres plenty of spectrum available in Low band its not used
because for most all users its not that practical.

Most all UK PMR system have their own base station more often known as a
repeater and even shared ones i.e. Common Base Systems are very few and
far between now. We had 7 Lowband ones at one time, all gone now..
..

And a helluva lot on VHF Hi and UHF 1 and 2. And thats not just because
of frequency availability its down to performance. VHF Lowband channels
some have sod all users on nation-wide even!....

A small country like the UK doesn't have to try and maximise coverage
like larger countries do.
Lowband is the mainstay of US state police forces.(30 to 50MHz)

Lowband can and does cover quite some distance but we've never noticed
that much difference in practice between Lo and MID and HI however UHF
doesn't perform too well relatively. Thats vehicle mobile to base of
course...


Also Nato Military tactical field radios. (30 to 70MHz)

Steve Terry

--
Tony Sayer

"tony sayer" wrote in message
...
In article , Steve Terry
scribeth thus
"tony sayer" wrote in message
...
In article , Steve Terry
scribeth thus
"tony sayer" wrote in message
...
In article , charles
scribeth thus
In article ,
Dave Plowman (News) wrote:
In article ,
tony sayer wrote:
snip
FWIW Band 1 has hardly any PMR thereon due to the absurdly long
aerials
required, the impossibility of using portables and the lack of type
approved equipment/s..

Wot like this?
http://www.doubleradius.com/Motorola...dio-35-50-MHz-
Lowband-16-Channel

35 to 50MHz is heavily used in the US especially by police depts,
just not here.

No there not at all efficient even at 77 odd MHz theres no comparison
with a VHF hi band portable on say 170 MHz.

Lowband handheld to handheld maybe because of poor groundplain and erp
at both ends. But lowband handheld to lowband mobile or base will beat
highband handheld to mobile or base everytime.

Will it now. Well in 25 years of PMR operation and trailing this its
always proved to be the other way round. Even a research consultancy we
know of not a million miles from here was commissioned to arbitrate for
a large council who were sold a Low band system with handportables and
it was very problematical in that the range was very poor indeed and in
the end the supplier had to pay for them to use VHF Hi Band!...

If its as good as you claim can you name perhaps apart from Motorola
anyone selling Low band portables , well more than a handful per annum
in the UK?..


Lets just say you have experience of lowband VHF as it's used in the UK,
whereas i have a more international experience of it's use.

Steve Terry
--
Welcome Sign-up Bonus of £1 when you signup free at:
http://www.topcashback.co.uk/ref/G4WWK

"tony sayer" wrote in message
...
In article [email protected], Woody
scribeth thus
"tony sayer" wrote in message
...
In article

.com,
scribeth
thus
On Jun 2, 10:57 pm, tony sayer wrote:
In article [email protected], Woody
scribeth thus

"Dave Plowman (News)" wrote in
message
...
In article [email protected],
Woody wrote:
Band 1 has never been used for TV in the UK.

Eh?

--
Sorry, senior moment. Should have read '...never been used
for
PMR in the UK.'

Has .. but very limited use but darn sarff, and IIRC now
fallen out of
favour...
--
Tony Sayer

Wouldn't all that PMR stuff just above the old ch B5 be
within
Band
I?

Bill

Well Band 1 is up to 68 MHz and what's called VHF Low band is
from 68 to
88 MHz. The lowest in current use in Low band data which is
usually 68
mobile TX and 81/2 base Tx but these are quite few and far
between...

--
Tony Sayer




Wasn't it the other way around Tony?

The original pairings of E-band were

That's Pye talk)..

85 base Tx with mobile Tx 13.5MHz lower (such as the AA)

Yes..

87 base Tx with mobile Tx 10MHz lower (such as the RAC)

Yes..

Some single frequency working around 86MHz.

Very little .. at one time that frequency was allocated to IBA
aerial
riggers;!..

In earlier days the Police (P-band) had base Rx around 79-82MHz

With TX around 101-etc

Then the wonders of the RA and WARC came along and plonked Fire
Tx around 71-72MHz with receive somewhat variant in the
80-84MHz
area.

OK..

Som
ehow I doubt 68MHz would have been a viable base receive
frequency with 100W+ transmitters only a meg or two away.

Well 68 the low side is used for mobile receive..

I may be wrong as I know I only ever worked on one 68/81MHz
system (13.5MHz spacing) but I have a fair certainty that it
was
base TX low.

Other way round all the ones I've seen but then again thats not
that
many..

The Fire brigades have now gone to Airwave round this area so
all rather
academic now....



--
Tony Sayer



Agreed, but an interesting discussion nonetheless?


--
Woody

harrogate three at ntlworld dot com