Testing a car aerial

[Tim+]

Our transit based motorhome has radio reception problems. Okay in strong
signal areas but unusable anywhere else (like on the M5 round Birmingham).

Transits are known to have problems with their door mounted aerials so
we're currently trying a stick-on screen mounted one which is better, but
still crap.

We're beginning to wonder if it's the radio that's the problem rather than
the aerial but it certainly behaves like a radio with a duff aerial.

Is there any way of testing a car aerial short of trying another radio?

Tim

[Dave Plowman (News)]

In article
<1031853705429181550.06568...@news.eternal-september.org>,

Assuming a basic aerial with a standard cable length, the centre of the
co-ax is connected direct to the tower part of the aerial. The screen to
the bodywork where the aerial mounts. However, if the cable is much longer
than the norm, it may not be able to test the centre in this way.

And, of course, many aerials these days have an amp built into the base.

FWIW, I've found screen mounted aerials rubbish. If you do need a new one
which isn't a direct replacement for the original, fit it on the roof.

--
*What do you call a dinosaur with an extensive vocabulary? A thesaurus.*

Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.

[R. Mark Clayton]

"Tim+" <timdow...@yahoo.co.uk> wrote in message
news:1031853705429181550.06568...@news.eternal-september.org...

Take out the radio and test it with another aerial. Just a metre or two of
wire [outside the car] will do, but you will need a Motorola plug.


>
> Tim

[Brian Gaff]

The radio may well be a bit duff, but stick on aerials are probably the
worst thing sinced sliced beread, indeed a slice of toast might work better.


Even a rear window heater works better!

A decent roof mounted aerial has a lot going for it. Its high and normally
can be angled a bit and when it hits things many seem to bounce back
again, though the noise can be disconcerting.

If that fails then try the radio, but at least in most of theones friends
have bought, the ones with amplifiers in them overload near transmitters and
screw up fm and am reception big time with warbles and other sundry noises.
Don't know what dab is like.

They ask me for some reason they seem to think I know... I've never driven
a car in my life, and I bet you are glad!

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
news:5433e69...@davenoise.co.uk...

[Tim+]

"Dave Plowman (News)" <da...@davenoise.co.uk> wrote:
> In article
> <1031853705429181550.06568...@news.eternal-september.org>,
> Tim+ <timdow...@yahoo.co.uk> wrote:
>> Our transit based motorhome has radio reception problems. Okay in strong
>> signal areas but unusable anywhere else (like on the M5 round
>> Birmingham).
>
>> Transits are known to have problems with their door mounted aerials so
>> we're currently trying a stick-on screen mounted one which is better,
>> but still crap.
>
>> We're beginning to wonder if it's the radio that's the problem rather
>> than the aerial but it certainly behaves like a radio with a duff aerial.
>
>> Is there any way of testing a car aerial short of trying another radio?
>
> Assuming a basic aerial with a standard cable length, the centre of the
> co-ax is connected direct to the tower part of the aerial. The screen to
> the bodywork where the aerial mounts. However, if the cable is much longer
> than the norm, it may not be able to test the centre in this way.
>
> And, of course, many aerials these days have an amp built into the base.
>
> FWIW, I've found screen mounted aerials rubbish. If you do need a new one
> which isn't a direct replacement for the original, fit it on the roof.

It might come to that but I'd just like to be certain that it is an aerial
problem before making any unnecessary changes.

I'd like to just replace the Transit one but the way it's mounted involves
destructive disassembly of the door mirror surround just to get at the
mount and then extraction of headless shear bolts. Easier to just fit a new
one!

Tim

[Brian Gaff]

Which Maplin sell. Not easy to solder apparently though.
Why did they go with this odd plug I wonder?

Brian

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

"R. Mark Clayton" <nospam...@btinternet.com> wrote in message
news:joOdnflTMIdIMHnO...@bt.com...

[Tim+]

"Brian Gaff" <brian...@gmail.com> wrote:
> The radio may well be a bit duff, but stick on aerials are probably the
> worst thing sinced sliced beread, indeed a slice of toast might work better.

Well it's working better than the Transit one! ;-) Oddly, reception is
better with the aerial mounted horizontally rather than vertically. Don't
understand that.

Tim

[Brian Gaff]

Note a slightly bent coathanger end can be gently connected to these
sockets, but be very careful not to strain the socket. some are on short
fly leads not on the radio. Presumably this is due to the cramped conditions
in the back of the radio mounting position.

Many motor caravans seem to include a kind of entertainment system with a
remot in the front these days and usually a completely useless aerial on the
top that claims to also work with tv.

well....

Funny nobody ever gets back to me about how their shiny new mobile home was
on Coronation street in the welsh valleys...

Brian
--
From the Sofa of Brian Gaff Reply address is active
"R. Mark Clayton" <nospam...@btinternet.com> wrote in message
news:joOdnflTMIdIMHnO...@bt.com...
>

[Woody]

It is possible that you may have a heat coated windscreen
which is also a very effective signal blocker! Have a look
at a reflection of the windscreen from outside preferably
with polarised sunglasses. If it looks a pink or purple
colour all over then it has the heat coating. Also
electrical heating of the windscreen (very fine wires
embedded in the glass top to bottom) which is common on
Fords have the same effect even when switched off.

You say it is bad around Birmingham but station are you
listening to, FM or MW? FM is broadcast from Sutton
Coldfield about 10 miles north of the city (R2=88.3) MW is
broadcast from Droitwich which is close to M5 J5 - the two
big masts are a marker - R5L=693KHz. Both of them should
give a near saturation signal - certainly do in my
experience of the M5/M6/M42.


--
Woody

harrogate three at ntlworld dot com

[Dave Plowman (News)]

In article
<907639948429190829.059243timdow...@news.eternal-september.org>,

RF is a black art.;-)

It could be the edge of the roof is acting as a reflector.

--
*Does fuzzy logic tickle? *

[Johny B Good]

Funnily enough, this follows on from my replying to Brian's post in
the preceding thread "What does PACW stand for in coax descriptions".

I forgot to mention, for LW and MW where a Hi-Z coax connection to an
'electric field probe' antenna forms part of the first tuned circuit's
capacitance, such radios have a padding trimmer capacitor to
compensate for variations in this external capacitance.

This is usually, via a small hole to allow a small screwdriver access
to a mica compression capacitor, often located by the tuning knob on
the front panel or else via a hole near the antenna socket on the rear
panel.

If the car radio uses permeability tuning for the LW and MW bands and
your problem relates to these bands, it's worth trying to locate the
padding trimmer to 'tune' the front end to the car aerial's actual
capacitance.

If it's a VHF / DAB reception issue, I suspect this fix probably
doesn't apply (but what do I know?).
--
J B Good

[Tim+]

"Dave Plowman (News)" <da...@davenoise.co.uk> wrote:
> In article
> <907639948429190829.059243timdow...@news.eternal-september.org>,
> Tim+ <timdow...@nospampleaseyahoo.co.uk> wrote:
>> "Brian Gaff" <brian...@gmail.com> wrote:
>>> The radio may well be a bit duff, but stick on aerials are probably
>>> the worst thing sinced sliced beread, indeed a slice of toast might
>>> work better.
>
>> Well it's working better than the Transit one! ;-) Oddly, reception is
>> better with the aerial mounted horizontally rather than vertically. Don't
>> understand that.
>
> RF is a black art.;-)

I shall start practicing a few incantations. Would a hexagram drawn on the
windscreen help? ;-)

>
> It could be the edge of the roof is acting as a reflector.

The only place to put it vertically is near the end of a windscreen blind
that has a magnetic strip along its edge. Could this affect things?

Tim

[Tim+]

We were driving from Ross-on-Wye to SW Scotland and the radio was almost
unusable for the whole journey on FM. Little joy on AM either. Oddly
though, in my home town (Ayr) it seems to work pretty well, although not
without some hissing and signal loss at times.

Tim

[Bill Wright]

If the screen mounted aerial is better than the rod aerial than the rod
aerial is faulty. For confirmation use a short length of wire, attach
the bared end to a small screwdriver, gently touch the screwdriver to
the inner terminal of the Motorola socket in the back of the radio. With
the wire outside the car that will work quite well as an aerial.

It isn't a big deal to buy a new aerial and fit it. Best place is on top
of the roof (assuming a metal rather than GRP roof). But angle it
backwards so it doesn't get snapped off (quite so often!).

Have you checked that the problem isn't interference from something in
the motorhome? LCD screens, digital display modules, inverters, various
types of light, can all give a greatly raised noise floor which seems
like a duff radio or aerial.

I don't suppose the radio has the old type of trimmer adjustment?

Bill

[Johny B Good]

On Fri, 8 Aug 2014 12:40:15 +0100, "Brian Gaff" <brian...@gmail.com>
wrote:

>Which Maplin sell. Not easy to solder apparently though.
> Why did they go with this odd plug I wonder?
> Brian

To distinguish it from the more usual Lo-Z co-ax feeder connection
(50 to 90 ohms versus a few hundred ohms for the car aerial 'co-ax'
feeder - in reality, an electric field shielded bit of wire connected
to the electric field probe antenna).

This harks back to the days of LW and MW only car radio design where
the extremely short antenna (a tiny fraction of a percent of the
wavelengths of interest) meant that it had to be treated as an
electric field probe with its capacitance and that of the 'feeder' had
to form part of the input parallel tuned circuit which, out of
necessity had to use permeability tuning (iron dust slugs initially
then ferrite tuning slugs in the later years). It would have been
impossible to achieve the 10:1 capactor tuning ratio in the presence
of the shunt capacitance due to the co-ax and antenna probe.

Such permeability tuned front ends will include a variable padding
capacitor to compensate for variations in the car aerial's 'stray'
capacitance. Unless you're familiar with this type of tuning method
and the reasons for its use or have actually "RTFM"ed, it's easy to
overlook the need to adjust this trimmer on a new installation.
--
J B Good

[Dave Plowman (News)]

In article <7vh9u9tg7i9idg1do...@4ax.com>,

Johny B Good <johnny...@invalid.ntlworld.com> wrote:
> If the car radio uses permeability tuning for the LW and MW bands and
> your problem relates to these bands, it's worth trying to locate the
> padding trimmer to 'tune' the front end to the car aerial's actual
> capacitance.

I think most radios do this automatically these days and have done for
some time. Or everything is made to a fixed standard, so no adjustment
needed

> If it's a VHF / DAB reception issue, I suspect this fix probably
> doesn't apply (but what do I know?).

Not with FM. DAB usually needs a separate aerial - or a special one with
two feeders. Or rather my aftermarket ones does. Not sure about maker's
installations.

--
*When companies ship Styrofoam, what do they pack it in? *

[Tim+]

Bill Wright <bi...@invalid.com> wrote:
> Tim+ wrote:
>> Our transit based motorhome has radio reception problems. Okay in strong
>> signal areas but unusable anywhere else (like on the M5 round Birmingham).
>>> Transits are known to have problems with their door mounted aerials so
>> we're currently trying a stick-on screen mounted one which is better, but
>> still crap. > > We're beginning to wonder if it's the radio that's the problem rather than
>> the aerial but it certainly behaves like a radio with a duff aerial.
>>> Is there any way of testing a car aerial short of trying another radio?
>>> Tim
>
> If the screen mounted aerial is better than the rod aerial than the rod
> aerial is faulty. For confirmation use a short length of wire, attach the
> bared end to a small screwdriver, gently touch the screwdriver to the
> inner terminal of the Motorola socket in the back of the radio. With the
> wire outside the car that will work quite well as an aerial.

I'll try that.

>
> It isn't a big deal to buy a new aerial and fit it. Best place is on top
> of the roof (assuming a metal rather than GRP roof). But angle it
> backwards so it doesn't get snapped off (quite so often!).

It a bit like this.
http://showroom.southdownsmotorcaravans.co.uk/images/stock_vehicle-photos/2179-new-hobby-classic-t500-gfsc-motorhome-n2179_001.jpg

Dunno how easy it is to fit an aerial to this type of roof.

>
> Have you checked that the problem isn't interference from something in
> the motorhome? LCD screens, digital display modules, inverters, various
> types of light, can all give a greatly raised noise floor which seems
> like a duff radio or aerial.

Well there is a screen for the rear view camera above the radio on the
dash. I've tried turning it off which makes no difference. Is it possible
that it could cause interference even when in "standby" mode? It's a "soft
switch" so I suppose there's always power to the monitor.

>
> I don't suppose the radio has the old type of trimmer adjustment?

I could have a look. Would that help FM reception?

Tim

[Tim+]

Johny B Good <johnny...@invalid.ntlworld.com> wrote:

Bill's also mentioned this. I'll have a look.

Tim

[Ian Jackson]

In message <gni9u95pajiavss76...@4ax.com>, Johny B Good
<johnny...@invalid.ntlworld.com> writes

In the 'radio shack', I've use a Cancer Shop �3 Panasonic RD526LEN car
radio / tape player. The aerial is a 100MHz quarterwave vertical wire in
the loft, connected to 75 ohm coax (braid to cold water pipe entering
the plastic water tank). The run is maybe 20'. There is absolutely no
sign of the traditional aerial tweaking capacitor.

Of course, it works fine on FM - but it also performs well on the LW and
MW. I would have expected the 75 ohm coax to be a killer. How does it do
this?
--
Ian

[Dave Plowman (News)]

In article
<1027741122429197168.160860timdo...@news.eternal-september.org>,

Tim+ <timdow...@nospampleaseyahoo.co.uk> wrote:
> > Such permeability tuned front ends will include a variable padding
> > capacitor to compensate for variations in the car aerial's 'stray'
> > capacitance. Unless you're familiar with this type of tuning method
> > and the reasons for its use or have actually "RTFM"ed, it's easy to
> > overlook the need to adjust this trimmer on a new installation.

> Bill's also mentioned this. I'll have a look.

How old is the radio? Last time I saw a trimming capacitor was on a 1980s
radio. Not seen it on a recent one. Of course I've not seen them all. ;-)

--
*Before they invented drawing boards, what did they go back to?

[Ian Jackson]

In message
<1984935344429196855.478175timdo...@news.ete
rnal-september.org>, Tim+ <timdow...@nospampleaseyahoo.co.uk> writes

>
>Dunno how easy it is to fit an aerial to this type of roof.
>

How about trying an FM quarterwave on a magmount?
>
>

--
Ian

[Brian Gaff]

I remember those trimmers. If you had a car with a rear mounted aerial, many
of the motorola radios could not be trimmed enough to cover the extra cable.
Brian

--
From the Bed of Brian Gaff.
The email is valid as bri...@blueyonder.co.uk
Blind user.
"Bill Wright" <bi...@invalid.com> wrote in message
news:ls2ieh$ooo$1...@speranza.aioe.org...

[Brian Gaff]

Not good if the roof is not metal though.


For fm, the best aerial I designed for our caravan was a full wave circle of
copper tape glued to the inside of the fibreglass roof!
My Mother was not impressed by the wire hanging down on the end though.
Sigh. Fun times.

Brian

--
From the Bed of Brian Gaff.
The email is valid as bri...@blueyonder.co.uk
Blind user.

"Ian Jackson" <ianREMOVET...@g3ohx.demon.co.uk> wrote in message
news:zPoLSiEb...@g3ohx.demon.co.uk...

[Woody]

"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in
message news:5433fa3...@davenoise.co.uk...

> In article <7vh9u9tg7i9idg1do...@4ax.com>,
> Johny B Good <johnny...@invalid.ntlworld.com> wrote:
>> If the car radio uses permeability tuning for the LW and
>> MW bands and
>> your problem relates to these bands, it's worth trying to
>> locate the
>> padding trimmer to 'tune' the front end to the car
>> aerial's actual
>> capacitance.
>
> I think most radios do this automatically these days and
> have done for
> some time. Or everything is made to a fixed standard, so
> no adjustment
> needed
>
>> If it's a VHF / DAB reception issue, I suspect this fix
>> probably
>> doesn't apply (but what do I know?).
>
> Not with FM. DAB usually needs a separate aerial - or a
> special one with
> two feeders. Or rather my aftermarket ones does. Not sure
> about maker's
> installations.
>

Tuning matching slugs have not been fitted on car radios
since FM came along back in the early 80's. You cannot have
an aerial matched to and part of a tuned circuit for LW/MW
when it also has to feed FM. Most radios nowadays have an
almost resistive match with both AM and FM tuners
effectively having high impedence inputs.

[R. Mark Clayton]

"Brian Gaff" <brian...@gmail.com> wrote in message
news:ls2deu$31a$1...@dont-email.me...

> Note a slightly bent coathanger end can be gently connected to these
> sockets, but be very careful not to strain the socket. some are on short
> fly leads not on the radio. Presumably this is due to the cramped
> conditions in the back of the radio mounting position.
>
> Many motor caravans seem to include a kind of entertainment system with a
> remot in the front these days and usually a completely useless aerial on
> the top that claims to also work with tv.
>

Until 2009 my 2000 BMW had the radio aerial in the screen and a fin with the
TV aerial. This used to get satisfactory to good TV and teletext reception
on the built in TV, however the receiver was analog and stopped receiving
anything once Granada land went digital in 2009.




PS the screen blanks if the gearbox is taken out of 'park'

[Dave Plowman (News)]

In article <ls2vhd$4a8$1...@dont-email.me>,

Brian Gaff <bri...@blueyonder.co.uk> wrote:
> I remember those trimmers. If you had a car with a rear mounted aerial,
> many of the motorola radios could not be trimmed enough to cover the
> extra cable.

A decent extension lead had the capacitance equalised.

--
*Drugs may lead to nowhere, but at least it's the scenic route *

[R. Mark Clayton]

"Brian Gaff" <brian...@gmail.com> wrote in message

news:ls2cus$vge$1...@dont-email.me...

> Which Maplin sell. Not easy to solder apparently though.
> Why did they go with this odd plug I wonder?
> Brian

See elsewhere for the technical explanation. It is called Motorola after
the company. They made the first car radios (before the war) and so the
plug is named after them.

RCA got a plug named after them too.

I don't know who jack was...

[Ian Jackson]

In message <54340f9...@davenoise.co.uk>, "Dave Plowman (News)"
<da...@davenoise.co.uk> writes

>In article <ls2vhd$4a8$1...@dont-email.me>,
> Brian Gaff <bri...@blueyonder.co.uk> wrote:
>> I remember those trimmers. If you had a car with a rear mounted aerial,
>> many of the motorola radios could not be trimmed enough to cover the
>> extra cable.
>
>A decent extension lead had the capacitance equalised.
>

I think that 'equalised' meant that it had an integral series capacitor
(possibly, over part of the length, there were two insulated inners,
twisted together). This allowed you still to peak the MW signal (near
the HF end) - presumably at the expense of a little signal strength.

In the mid-70s, I fitted a LW/MW/FM radio to my Chevette, and put the
aerial at the rear end. This entailed using an extension lead. I recall
that the instructions said not to shorten it. The trimmer certainly
peaked as normal, and everything seemed to work OK.
--
Ian

[The Other Mike]

On Fri, 8 Aug 2014 12:00:39 +0100, "R. Mark Clayton"
<nospam...@btinternet.com> wrote:


>Take out the radio and test it with another aerial. Just a metre or two of
>wire [outside the car] will do, but you will need a Motorola plug.

That is of course assuming it has a Motorola plug, the vast majority of
manufacturer fitted kit these days don't, they use either something like the one
on the right

http://thumbs2.ebaystatic.com/d/l225/m/m80aFM_xf_jLKjk_8iOgQww.jpg

or on anything produced in the past 10 years or so most likely this

http://www.molex.com/molex/products/family?channel=products&chanName=family&key=fakra

Or maybe even one of the other types listed here

http://www.dabonwheels.co.uk/Car_radio_aerial_connector_identification.html




--

[Graham.]

On Fri, 08 Aug 2014 16:00:02 +0100, "Dave Plowman (News)"
<da...@davenoise.co.uk> wrote:

>In article
><1027741122429197168.160860timdo...@news.eternal-september.org>,
> Tim+ <timdow...@nospampleaseyahoo.co.uk> wrote:
>> > Such permeability tuned front ends will include a variable padding
>> > capacitor to compensate for variations in the car aerial's 'stray'
>> > capacitance. Unless you're familiar with this type of tuning method
>> > and the reasons for its use or have actually "RTFM"ed, it's easy to
>> > overlook the need to adjust this trimmer on a new installation.
>
>> Bill's also mentioned this. I'll have a look.
>
>How old is the radio? Last time I saw a trimming capacitor was on a 1980s
>radio. Not seen it on a recent one. Of course I've not seen them all. ;-)

The last time I saw the backside of a DIN fitting radio it has a
trimmer, but I doubt if I could remove a modern one to look, without
deploying all the air-bags!


--

Graham.

%Profound_observation%

[Graham.]

On Fri, 8 Aug 2014 18:21:02 +0100, "R. Mark Clayton"
<nospam...@btinternet.com> wrote:

>
>"Brian Gaff" <brian...@gmail.com> wrote in message
>news:ls2cus$vge$1...@dont-email.me...
>> Which Maplin sell. Not easy to solder apparently though.
>> Why did they go with this odd plug I wonder?
>> Brian
>
>See elsewhere for the technical explanation. It is called Motorola after
>the company. They made the first car radios (before the war) and so the
>plug is named after them.
>
>RCA got a plug named after them too.

Don't we call those Phono plugs here? Odd that because we don't call
record players phonographs do we?

>
>I don't know who jack was...

"A plug called Wander"
"The Banana Plug Show"


--

Graham.

%Profound_observation%

[Graham.]

On Fri, 8 Aug 2014 12:48:48 +0100, "Brian Gaff" <brian...@gmail.com>
wrote:

>Note a slightly bent coathanger end can be gently connected to these
>sockets, but be very careful not to strain the socket. some are on short
>fly leads not on the radio. Presumably this is due to the cramped conditions
>in the back of the radio mounting position.
>
>Many motor caravans seem to include a kind of entertainment system with a
>remot in the front these days and usually a completely useless aerial on the
>top that claims to also work with tv.
>
>well....
>
>Funny nobody ever gets back to me about how their shiny new mobile home was
>on Coronation street in the welsh valleys...
>
>Brian

I once managed to slice a bit of my forefinger off whilst stripping
the inner of some car radio coax. The dialectic is tough, but has a
very thin wall and, the solid inner wire has a spiral of plastic to
keep the wire centred.
Once the Stanley knife stated to make headway there was no stopping
it!

Amazingly my finger regenerated itself and you can't tell.




--

Graham.

%Profound_observation%

[Ian Jackson]

In message <jriau9pav1c60ilo3...@4ax.com>, Graham.
<m...@privicy.net> writes

>On Fri, 08 Aug 2014 16:00:02 +0100, "Dave Plowman (News)"
><da...@davenoise.co.uk> wrote:
>
>>In article

>><1027741122429197168.160860timdownie2003-nospampleaseyahoo.co.uk@news.e

>>ternal-september.org>,
>> Tim+ <timdow...@nospampleaseyahoo.co.uk> wrote:
>>> > Such permeability tuned front ends will include a variable padding
>>> > capacitor to compensate for variations in the car aerial's 'stray'
>>> > capacitance. Unless you're familiar with this type of tuning method
>>> > and the reasons for its use or have actually "RTFM"ed, it's easy to
>>> > overlook the need to adjust this trimmer on a new installation.
>>
>>> Bill's also mentioned this. I'll have a look.
>>
>>How old is the radio? Last time I saw a trimming capacitor was on a 1980s
>>radio. Not seen it on a recent one. Of course I've not seen them all. ;-)
>
>The last time I saw the backside of a DIN fitting radio it has a
>trimmer, but I doubt if I could remove a modern one to look, without
>deploying all the air-bags!

With all the radios I've seen with an aerial trimmer capacitor, it was
on the front (in one of the corners).
>
>

--
Ian

[Bill Wright]

Tim+ wrote:

>> It isn't a big deal to buy a new aerial and fit it. Best place is on top
>> of the roof (assuming a metal rather than GRP roof). But angle it
>> backwards so it doesn't get snapped off (quite so often!).
>
> It a bit like this.
> http://showroom.southdownsmotorcaravans.co.uk/images/stock_vehicle-photos/2179-new-hobby-classic-t500-gfsc-motorhome-n2179_001.jpg

That could be a GRP body shell and roof. If so you would have to mount
the aerial somewhere near a steel roof member so you could ground the
screen of the cable. But really I wouldn't recommend penetrating that
sort of roof if it can be avoided. You can get stress cracks forming.

> Well there is a screen for the rear view camera above the radio on the
> dash. I've tried turning it off which makes no difference. Is it possible
> that it could cause interference even when in "standby" mode? It's a "soft
> switch" so I suppose there's always power to the monitor.

Unlikely but check by removing the fuse that feeds the screen and
camera. Let's hope it isn't the same fuse for the radio.

>
>> I don't suppose the radio has the old type of trimmer adjustment?
>
> I could have a look. Would that help FM reception?

No it wouldn't help FM. If both FM and AM reception is abnormally poor
I'd say the aerial is very likely to be faulty.

As a reality check, I suggest you stand somewhere near the vehicle with
an ordinary portable radio on FM. Tune through the band and count the
number of signals the radio receives, for the whole band or a defined
portion of it, say 92 to 98MHz. Do the same with the van radio. The van
radio should receive at least as many signals as the portable. Obviously
you would count every iteration of each station as a separate signal;
for instance you might get three iterations of Radio 4.

Could you do a simple continuity check?
1. The inner pin of the aerial plug (the one on the end of the aerial
lead that goes into the back of the radio) should read zero ohms (near
enough, maybe 0.5ohms is OK) with the other meter probe/clip on the rod
of the aerial.
2. The outer barrel of the aerial plug should read zero ohms (near
enough, maybe 0.5ohms is OK) with the other meter probe/clip on the
vehicle body.
3. With one probe on the plug's inner pin and the other on the plug's
outer barrel the meter should read infinity: ie just the same as it
reads if the probes aren't connected to anything.

Is the plug contacting the radio socket properly? Have you tried
wiggling it?

Is the radio properly connected to the vehicle body? Try a fairly thick
temporary wire between the radio chassis and the nearest steelwork.

Bill

[Bill Wright]

Ian Jackson wrote:

> Of course, it works fine on FM - but it also performs well on the LW and
> MW. I would have expected the 75 ohm coax to be a killer. How does it do
> this?

For what it's worth I found as a teenager interested in getting the
ultimate sensitivity (of my van radio you dirty bastards) the use of 75
ohm coax was to be deplored. However, I found that 75 ohm worked just
fine for linking tuned loop aerials to the loop that went around the
radio and coupled to the ferrite.

Bill

[Bill Wright]

Ian Jackson wrote:

> How about trying an FM quarterwave on a magmount?

I do know of a centrefed FM half wave glued to the underside of the GRP
canopy of a motorhome that works just fine, using 75 ohm coax.

Also I know of a vertical whip mounted on the tow hitch bracket that
works well.

Bill

[Bill Wright]

Brian Gaff wrote:
> I remember those trimmers. If you had a car with a rear mounted aerial, many
> of the motorola radios could not be trimmed enough to cover the extra cable.
> Brian
>

You had to buy a special 'compensating ' extension cable.

Bill

[Dave Plowman (News)]

In article <ls309n$ae6$1...@dont-email.me>,

Woody <harro...@ntlworld.com> wrote:
> Tuning matching slugs have not been fitted on car radios
> since FM came along back in the early 80's. You cannot have
> an aerial matched to and part of a tuned circuit for LW/MW
> when it also has to feed FM. Most radios nowadays have an
> almost resistive match with both AM and FM tuners
> effectively having high impedence inputs.

I had a Blaupunkt Frankfurt AM/FM radio which did have a trimmer for AM. A
very long time ago.

--
*A snooze button is a poor substitute for no alarm clock at all *

[Bill Wright]

Woody wrote:

> Tuning matching slugs have not been fitted on car radios
> since FM came along back in the early 80's. You cannot have
> an aerial matched to and part of a tuned circuit for LW/MW
> when it also has to feed FM. Most radios nowadays have an
> almost resistive match with both AM and FM tuners
> effectively having high impedence inputs.
>
>

I think you are almost completely right, although I'm sure I had an
early AM/FM set with a little tuning slug under one of the controls for
AM. Or did I dream it?

Bill

[Dave Plowman (News)]

In article <EiwldzBJ...@g3ohx.demon.co.uk>,

Ian Jackson <ianREMOVET...@g3ohx.demon.co.uk> wrote:
> >A decent extension lead had the capacitance equalised.
> >
> I think that 'equalised' meant that it had an integral series capacitor
> (possibly, over part of the length, there were two insulated inners,
> twisted together). This allowed you still to peak the MW signal (near
> the HF end) - presumably at the expense of a little signal strength.

Yes. If you checked it for continuity using an ohm meter, you'll be
disappointed. ;-)

> In the mid-70s, I fitted a LW/MW/FM radio to my Chevette, and put the
> aerial at the rear end. This entailed using an extension lead. I recall
> that the instructions said not to shorten it. The trimmer certainly
> peaked as normal, and everything seemed to work OK.

Not being able to shorten it rings a bell.

--
*Sometimes I wake up grumpy; Other times I let him sleep.

[Bill Wright]

You are sure the aerial doesn't have an amplifier built into the base,
which needs a power supply?

Bill

[Johny B Good]

Did this just effect the LW/MW reception or did it also peak up the
FM reception?
--
J B Good

[Ian Jackson]

In message <qj0bu9l45dhr8o8p3...@4ax.com>, Johny B Good
<johnny...@invalid.ntlworld.com> writes

Just LW/MW. As you probably know, to make the input tuning track with
the LO, you peaked up the signal near the HF end of the MW. The trimmer
had decreasing effect at lower frequencies. The FM would have been a
different part of the circuit.
--
Ian

[Brian Gaff]

Ah some kind of money making scam then.
Anyone remember those trap in the window aerials so loved by car thieves?
Brian

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

"Bill Wright" <bi...@invalid.com> wrote in message

news:ls3mrg$fku$5...@speranza.aioe.org...

[Roderick Stewart]

On Fri, 08 Aug 2014 23:34:26 +0100, Graham. <m...@privicy.net> wrote:

>>> Which Maplin sell. Not easy to solder apparently though.
>>> Why did they go with this odd plug I wonder?
>>> Brian
>>
>>See elsewhere for the technical explanation. It is called Motorola after
>>the company. They made the first car radios (before the war) and so the
>>plug is named after them.
>>
>>RCA got a plug named after them too.
>Don't we call those Phono plugs here? Odd that because we don't call
>record players phonographs do we?
>>
>>I don't know who jack was...
>
>"A plug called Wander"
>"The Banana Plug Show"

And of course if you connect audio equipment with a DIN plug, it's
because it makes a din...

Rod.

[Bill Wright]

Johny B Good wrote:

>> In the mid-70s, I fitted a LW/MW/FM radio to my Chevette, and put the
>> aerial at the rear end. This entailed using an extension lead. I recall
>> that the instructions said not to shorten it. The trimmer certainly
>> peaked as normal, and everything seemed to work OK.
>
> Did this just effect the LW/MW reception or did it also peak up the
> FM reception?

The ones I encountered peaked medium wave, had little effect on long
wave, and had no effect whatsoever on FM. I used to peak my radios for
the HF end of medium wave because that's where Caroline was!

Bill

[Bill Wright]

Brian Gaff wrote:
> Ah some kind of money making scam then.

No.

Bill

[Johny B Good]

On Sat, 9 Aug 2014 08:20:18 +0100, Ian Jackson

Thanks for that extra info, Ian.

That's just about what I was expecting. Obviously, they don't use a
'VHF section' on a common tuning coil but a completely seperate front
end tuned more conventionably with its own tuning capacitor. I guess
the screened cable must simply be used as a Hi-Z co-ax for the VHF
band signals.
--
J B Good

[Dave Plowman (News)]

In article <ls4mrp$tq0$1...@dont-email.me>,

Brian Gaff <brian...@gmail.com> wrote:
> Ah some kind of money making scam then.

No - sound engineering reasons.

--
*The more people I meet, the more I like my dog.

[Dafydd]

I have a Ford 6000CD in my 55 Focus. Radio reception is variable no
matter where I am, even in high signal areas. I blamed the aerial, but
no, it appears this range of radios have an inherent fault which shows
as weak signals - Google it!

I am based within sight of the Sutton mast + M6J7

Dave

On 08/08/2014 10:12, Tim+ wrote:
> Our transit based motorhome has radio reception problems. Okay in strong
> signal areas but unusable anywhere else (like on the M5 round Birmingham).
>
> Transits are known to have problems with their door mounted aerials so
> we're currently trying a stick-on screen mounted one which is better, but
> still crap.
>
> We're beginning to wonder if it's the radio that's the problem rather than
> the aerial but it certainly behaves like a radio with a duff aerial.
>
> Is there any way of testing a car aerial short of trying another radio?
>

> Tim
>

[Dave Plowman (News)]

In article <V5Sdnc_nYucranjO...@bt.com>,

Dafydd <sp...@spoof.org.uk> wrote:
> I have a Ford 6000CD in my 55 Focus. Radio reception is variable no
> matter where I am, even in high signal areas. I blamed the aerial, but
> no, it appears this range of radios have an inherent fault which shows
> as weak signals - Google it!

Remember reading somewhere just how little makers spend on OEM car radios.
Probably why DAB took so long to arrive, given it was designed to improve
mobile reception.

--
*I got a sweater for Christmas. I really wanted a screamer or a moaner*

[Graham.]

Is it true that a Jay-Z connector mates with a BNC?

(I really need my coat now).

--

Graham.

%Profound_observation%

[Graham.]

On Sat, 09 Aug 2014 11:06:12 +0100, Bill Wright <bi...@invalid.com>
wrote:

The instructions invariably told you to adjust the trimmer for a peak
in volume of a weak station at approx 200 meters.



--

Graham.

%Profound_observation%

[James Heaton]

"Ian Jackson" <ianREMOVET...@g3ohx.demon.co.uk> wrote in message
news:riWrwTAC...@g3ohx.demon.co.uk...

I remember my father's (later my) 1989 Bluebird having instructions in the
manual on trimming, it was something like removing the radio from the dash,
tune to a weak MW signal near 1000khz, and adjust a screw until you got the
loudest signal.

Can recall having to do it on my 87 Metro which had a very dodgy radio - was
one of the base models that didn't come with one as standard, and the
aftermarket fit was a very cheap and nasty one!

James

[Bill Wright]

Graham. wrote:

>> The ones I encountered peaked medium wave, had little effect on long
>> wave, and had no effect whatsoever on FM. I used to peak my radios for
>> the HF end of medium wave because that's where Caroline was!
>>
>> Bill
>
> The instructions invariably told you to adjust the trimmer for a peak
> in volume of a weak station at approx 200 meters.

The radios I used to get from the dodgy man on the market didn't come
with instructions!

Bill

[Graham.]

On Sun, 10 Aug 2014 01:01:17 +0100, Bill Wright <bi...@invalid.com>
wrote:

I realise that you are probebly referring to a time before anti theft
codes, but I have often wondered what is the point if any market
trader with a laptop can re-write the NVM.


--

Graham.

%Profound_observation%

[Chris Whelan]

On Sun, 10 Aug 2014 11:34:50 +0100, Graham. wrote:

[...]

> I realise that you are probebly referring to a time before anti theft
> codes, but I have often wondered what is the point if any market trader
> with a laptop can re-write the NVM.

No need on anything other than the newest stuff; there is freely
available software that can identify the code from the serial number.

Chris

--
Remove prejudice to reply.

[Woody]

"Chris Whelan" <cawh...@prejudicentlworld.com> wrote in
message news:ls7j0c$l4i$5...@dont-email.me...

On some of the up-market vehicles the car 'talks' to the EMU
checking the radio model and serial which is coded into the
EMU against the data provided by the radio unit. It will not
work without a handshake from the EMU rendering it useless
to any thief - not that the scroat would know that!


--
Woody

harrogate three at ntlworld dot com

[Dave Plowman (News)]

In article <abieu9pjni6b7ku8n...@4ax.com>,

Graham. <m...@privicy.net> wrote:
> >The radios I used to get from the dodgy man on the market didn't come
> >with instructions!
> >
> >Bill

> I realise that you are probebly referring to a time before anti theft
> codes, but I have often wondered what is the point if any market
> trader with a laptop can re-write the NVM.

My fairly expensive aftermarket Blaupunkt unit takes an SD card. If it is
powered down totally, you need to use the supplied card to initiate it.
After initiation, that card can be removed, and stored safely. It will
play MP3 etc files recorded to an SD card using that slot - or will also
record from the radio to a blank one. All in all pretty clever.

--
*I don't have a license to kill, but I do have a learner's permit.

[Ashley Booth]

I remember using Radio Luxemburg for this. 208 metres or 1440 kc/s I
beleive.

--
Ashley

[Bill Wright]

Ashley Booth wrote:

> I remember using Radio Luxemburg for this. 208 metres or 1440 kc/s I
> beleive.
>

No, quite wrong. Luxy was on 208.4m.

Bill

[R. Mark Clayton]

"Bill Wright" <bi...@invalid.com> wrote in message

news:lsblel$hti$1...@speranza.aioe.org...

Marketed as "Fab 208".

Reception in the UK relied on reflection from the Heavyside layer and the
reeived frequency varied a lost as a result.

[Johny B Good]

On Tue, 12 Aug 2014 01:00:21 +0100, Bill Wright <bi...@invalid.com>
wrote:

Now who's being a pedant? :-)
--
J B Good

[Bill Wright]

R. Mark Clayton wrote:

>> No, quite wrong. Luxy was on 208.4m.
>>
>> Bill
>
> Marketed as "Fab 208".
>
> Reception in the UK relied on reflection from the Heavyside layer and the
> reeived frequency varied a lost as a result.

That's because the Heaviside Layer wobbled around a lot as a result of
being so unbalanced that parts of it receded and approached the earth
fast enough to cause the doppler effect. Incidentally it was called the
Heaviside Layer because it was the heavy side that was first discovered.
It was only when this was seen to wobble around so much that astronomers
realised that the bit they observed must be part of a bigger whole that
had a light side.

The doppler effects caused by the wobble can be so extreme that medium
and short wave stations can move as much as 100kHz, causing French
resistance workers during World war II to hear Germany Calling when they
thought they were listening to the BBC.

The man who discovered the Heaviside Layer, Oliver Flangebottom of
Batley, West Yorks, later went on tour giving astronomy lectures, when
he changed his name to Heaviside as a sales gimmick.

In case anyone doubts me on this I got it all from Tit Bits and Revallie.

Bill

[Mrcheerful]

rather at odds with wikipedia

[Bill Wright]

Mrcheerful wrote:

>> In case anyone doubts me on this I got it all from Tit Bits and Revallie.
>>
>> Bill
>
> rather at odds with wikipedia

Wikipaedia is bollocks. The best source of accurate scientific
information is my late grandma's stash of 1960s Tit Bits and Revallies.

Bill

[Mark Carver]

Actually, it was 208.47m, so to one decimal palce 208.5 metres

Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres

--
Mark
Please replace invalid and invalid with gmx and net to reply.

[Roderick Stewart]

On Tue, 12 Aug 2014 15:26:33 +0100, Bill Wright <bi...@invalid.com>
wrote:

>> Reception in the UK relied on reflection from the Heavyside layer and the
>> reeived frequency varied a lost as a result.
>
>That's because the Heaviside Layer wobbled around a lot as a result of
>being so unbalanced that parts of it receded and approached the earth
>fast enough to cause the doppler effect. Incidentally it was called the
>Heaviside Layer because it was the heavy side that was first discovered.
>It was only when this was seen to wobble around so much that astronomers
>realised that the bit they observed must be part of a bigger whole that
>had a light side.

You explain it so much better than those dreary old textbooks. :-)

Rod.

[Mrcheerful]

It was Tit-Bits in the 60's, they took out the hyphen in 1973. The
other paper was called Reveille.

[Johny B Good]

On Tue, 12 Aug 2014 15:58:59 +0100, Mark Carver
<mark....@invalid.invalid> wrote:

>On 12/08/2014 11:51, Johny B Good wrote:
>> On Tue, 12 Aug 2014 01:00:21 +0100, Bill Wright <bi...@invalid.com>
>> wrote:
>>
>>> Ashley Booth wrote:
>>>
>>>> I remember using Radio Luxemburg for this. 208 metres or 1440 kc/s I
>>>> beleive.
>>>>
>>>
>>> No, quite wrong. Luxy was on 208.4m.
>>>
>>
>> Now who's being a pedant?
>
>Actually, it was 208.47m, so to one decimal palce 208.5 metres

No, to _one_ decimal place it's 208.4m. ITYMTS, "to _two_ decimal
places" _then_ it becomes 208.5

>
>Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres

It matters not when the wavelength is being quoted to the nearest
metre for ease of announcement and memorability for public consumption
at a time when most domestic radio dials were calibrated by
wavelength.

I don't think the doppler shifts due to the vagiaries of the
Heaviside layer on MW were to the extremes mentioned by Bill. The
'Skywave' effect was more to do with varying phase delays between the
multipath reflections of the Heaviside layer.
--
J B Good

[Mark Carver]

On 12/08/2014 16:37, Johny B Good wrote:
> On Tue, 12 Aug 2014 15:58:59 +0100, Mark Carver

>>

>> Actually, it was 208.47m, so to one decimal palce 208.5 metres
>
> No, to _one_ decimal place it's 208.4m. ITYMTS,

You normally round up (if 5,6,7,8 or 9) the second digit, so 208.5 ?

"to _two_ decimal
> places" _then_ it becomes 208.5

I don't think so, that would be 208.50, or in this case 208.47

>> Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres
>
> It matters not when the wavelength is being quoted to the nearest
> metre for ease of announcement and memorability for public consumption
> at a time when most domestic radio dials were calibrated by
> wavelength.

Are you taking the piss, or has the humorous track of the sub thread
sailed over your head ?

[The Other Mike]

On Sat, 09 Aug 2014 00:49:11 +0100, Bill Wright <bi...@invalid.com> wrote:

>You are sure the aerial doesn't have an amplifier built into the base,
>which needs a power supply?


+1


--

[Bill Wright]

Mark Carver wrote:
> On 12/08/2014 11:51, Johny B Good wrote:
>> On Tue, 12 Aug 2014 01:00:21 +0100, Bill Wright <bi...@invalid.com>
>> wrote:
>>
>>> Ashley Booth wrote:
>>>
>>>> I remember using Radio Luxemburg for this. 208 metres or 1440 kc/s I
>>>> beleive.
>>>>
>>>
>>> No, quite wrong. Luxy was on 208.4m.
>>>
>>
>> Now who's being a pedant?
>
> Actually, it was 208.47m, so to one decimal palce 208.5 metres

You know the 7 is broken on my keyboard. Err whoops!

>
> Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres
>

Have you been messing with Nicky's calculator again?

Bill

[Bill Wright]

Johny B Good wrote:

>> Actually, it was 208.47m, so to one decimal palce 208.5 metres
>
> No, to _one_ decimal place it's 208.4m. ITYMTS, "to _two_ decimal
> places" _then_ it becomes 208.5

Ner ner! Even us ignorant people can be right by accident sometimes!

>> Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres
>
> It matters not when the wavelength is being quoted to the nearest
> metre for ease of announcement and memorability for public consumption
> at a time when most domestic radio dials were calibrated by
> wavelength.

As soon as father came through t'door we knew summat were up. Although
has face were masked wit' grime ot' pit his despondent manner chilled
t'air int' 'ole 'ouse. Finally, half way through tea, little Cressida
piped up, "Dad, what's up with tha'? Tha's like a wet weekend in
Cleethorpes!"

Mam froze, not knowing how dad would react, but from dad there were nowt
but a long silence. Then finally he spoke. "They've changed it! They've
bloody changed it!"

"Don't swear in front ot' children Nigel!" cried mam, outraged like.
Then she whispered, "They've changed what love?"

"They've changed t'bloody wavelength!" shouted father, his face
contorted by t'stress and t'anguish.

Mam went to him and put her arm around him. "Wavelength of what love?"
she asked quietly. "Oh, and don't swear in front ot' children."

"Wavelength of bloody Luxembourg!" We all reared back in our seats,
utterly shocked and gobsmacked, as father continued, "It's gone from
208.33 metres to 208.47 metres!"

"Well I'll go t'foot of our stairs!" exclaimed mother.

"What shall we do father?" asked Araminta, the oldest girl in our family.

Father spoke, not loudly but with the hoarse tones of a man driven to
the end of his tether. "We shall have to bloody re-tune t'bloody wireless!"

Clinging onto t'harmonium for support, mother gasped, "Oh no!" then
added, "and will will you stop fucking swearing in front ot' fucking
children you crude bastard?"

Later the family was assembled in the front parlour. Father turned on
the wireless, his touch on the knob delicate, like a man defusing a
bomb. We waited for an eternity as the wireless warmed up.

(cont p92)

>
> I don't think the doppler shifts due to the vagiaries of the
> Heaviside layer on MW were to the extremes mentioned by Bill. The
> 'Skywave' effect was more to do with varying phase delays between the
> multipath reflections of the Heaviside layer.

"'Varying phase delays between the multipath reflections of the
Heaviside layer?' What the bloody 'ell's 'varying phase delays between
the multipath reflections of the Heaviside layer?'
"It's something they use in coal mining father."
"Not that again!"
"Ee's 'ad hard day dear. His new play opens at t'national theatre
tomorrow..."

Bill

[Mark Carver]

On 13/08/2014 02:43, Bill Wright wrote:

>> Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres
>>
>
> Have you been messing with Nicky's calculator again?

Shhhhh, I'm not allowed anywhere near it

[Woody]

"Bill Wright" <bi...@invalid.com> wrote in message

news:lseiq4$6h5$1...@speranza.aioe.org...

To those of us from a certain part of the country, boy does
that ring bells!

Tha' no-us.

[Ian Jackson]

In message <997mu91bdbbkos3us...@4ax.com>, brightside S9
<address@replyto_is_not.invalid> writes

>On Tue, 12 Aug 2014 16:37:10 +0100, Johny B Good
><johnny...@invalid.ntlworld.com> wrote:
>



>>
>> No, to _one_ decimal place it's 208.4m. ITYMTS, "to _two_ decimal
>>places" _then_ it becomes 208.5
>

>No. 208.5 is to 4 significant digits.
>
A lot of valve radios used to drift quite a bit - especially at the HF
end of the MW - and might require a slight retune as the set warmed up.
The accuracy of the wavelength of Radio Luxembourg was probably of
little concern!
--
Ian

[R. Mark Clayton]

"Mark Carver" <mark....@invalid.invalid> wrote in message
news:c4uodp...@mid.individual.net...

> On 12/08/2014 11:51, Johny B Good wrote:
>> On Tue, 12 Aug 2014 01:00:21 +0100, Bill Wright <bi...@invalid.com>
>> wrote:
>>
>>> Ashley Booth wrote:
>>>
>>>> I remember using Radio Luxemburg for this. 208 metres or 1440 kc/s I
>>>> beleive.
>>>>
>>>
>>> No, quite wrong. Luxy was on 208.4m.
>>>
>>
>> Now who's being a pedant?
>
> Actually, it was 208.47m, so to one decimal palce 208.5 metres
>
> Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres

No it isn't it is 208.2921876... metres

unless the speed of light was faster back then...

[Mark Carver]

On 13/08/2014 15:28, R. Mark Clayton wrote:
> "Mark Carver" <mark....@invalid.invalid> wrote in message

>> Actually, it was 208.47m, so to one decimal palce 208.5 metres
>>
>> Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres
>
> No it isn't it is 208.2921876... metres
>
> unless the speed of light was faster back then...

Ah, well, time used to go so much slower 40 years ago, so I assume
that light did indeed travel faster back then ?

[Johny B Good]

On Tue, 12 Aug 2014 18:29:44 +0100, Mark Carver
<mark....@invalid.invalid> wrote:

>On 12/08/2014 16:37, Johny B Good wrote:
>> On Tue, 12 Aug 2014 15:58:59 +0100, Mark Carver
>
>>>
>>> Actually, it was 208.47m, so to one decimal palce 208.5 metres
>>
>> No, to _one_ decimal place it's 208.4m. ITYMTS,
>
>You normally round up (if 5,6,7,8 or 9) the second digit, so 208.5 ?

I'm not quite sure what motivated that "correction". I'll just have
to put it down to a "Brain Fart" on my part. :-(

>
>"to _two_ decimal
>> places" _then_ it becomes 208.5

I think it was the fact that 0.47 does indeed round to 0.5 (or 0.50
to be pedantically accurate). It's just serendipitious that 0.50 need
only be quoted as 0.5 since rounding down to 2 decimal places in this
case gives no better an accuracy than a single decimal place.

Quoting the 2nd digit, even though it's zero, is required to
demonstrate that the result has been calculated (or measured) to
better than 2 decimal places before being rounded.

>
>I don't think so, that would be 208.50, or in this case 208.47

Which, as you correctly pointed out, was a load of bollix on my part.

From where, assuming you base your rounding up/down exercise on
_this_ figure alone, you could land up rounding to 209m. The rule to
round to zero decimal places is to ignore digits from the second
position to the right of the decimal point (i.e. truncate to a single
decimal digit before applying the rounding rule lest you lead yourself
astray and round up).

>
>>> Pre Nov 23rd 1978 it was on 1439 kHz, or 208.33 (reoccuring) metres
>>
>> It matters not when the wavelength is being quoted to the nearest
>> metre for ease of announcement and memorability for public consumption
>> at a time when most domestic radio dials were calibrated by
>> wavelength.
>
>Are you taking the piss, or has the humorous track of the sub thread
>sailed over your head ?

No, I was trying to continue the 'piss take' of the humorous nature
of this sub-thread and got it all mangled up. Sorry! :-(
--
J B Good

[Johny B Good]

On Wed, 13 Aug 2014 03:33:38 +0100, Bill Wright <bi...@invalid.com>
wrote:

Wonderful stuff, Bill. Inspired writing, as in inspired by Michael
Palin's "Ripping Yarns" TV series that was shown a few weeks back on
BBC4.
--
J B Good

[Steve Thackery]

Mark Carver wrote:

> Ah, well, time used to go so much slower 40 years ago, so I assume
> that light did indeed travel faster back then ?

As we are having some fun with pedantry, I'm afraid I must correct your
use of an adjective when you should have used an adverb: time used to
go more slowly, not slower.

Hah!

--
SteveT

[Norman Wells]

Unlfortunately for you, 'slower' is an adverb too:

https://www.google.co.uk/?gws_rd=ssl#q=slower

I shall refrain from repeating your vulgar triumphalism.

[Bill Wright]

Johny B Good wrote:

> Wonderful stuff, Bill.

Thank you.

bill

[JohnT]

"Johny B Good" <johnny...@invalid.ntlworld.com> wrote in message
news:8f4nu9h38ir8rb6bh...@4ax.com...

Michael Palin has been stealing Bill's material?
--
JohnT

[Steve Thackery]

Norman Wells wrote:

> I shall refrain from repeating your vulgar triumphalism.

Hummph!

--
SteveT

[Bill Wright]

JohnT wrote:

>>
>> Wonderful stuff, Bill. Inspired writing, as in inspired by Michael
>> Palin's "Ripping Yarns" TV series that was shown a few weeks back on
>> BBC4.
>
> Michael Palin has been stealing Bill's material?

Firstly you've misunderstood and got it arse about face, secondly I
didn't watch the Palin programmes as it happened. I was inspired, if
that's the word, by my real life here in the North.

Bill

[Woody]

"Bill Wright" <bi...@invalid.com> wrote in message

news:lsh0qo$nv4$2...@speranza.aioe.org...

+1 from a Cestrafeldian.

[JohnT]

"Bill Wright" <bi...@invalid.com> wrote in message
news:lsh0qo$nv4$2...@speranza.aioe.org...

The question was mine, not the valediction! And, with all due respect, I
regard Bill's part of the world as being in the South.
--
JohnT

[JohnT]

"Woody" <harro...@ntlworld.com> wrote in message
news:lshll8$hcl$1...@dont-email.me...

Chesterfield is in the Deep South. Indistinguishable from London.

--
JohnT

[Hamster]

"Bill Wright" <bi...@invalid.com> wrote in message
news:lsh0qo$nv4$2...@speranza.aioe.org...

> I was inspired, if that's the word, by my real life here in the North.

According to the booklet which accompanies the complete Ripping Yarns
series, the Eric Olthwaite episode was filmed at Beamish and Tow Law in
County Durham as apparently nowhere in Yorkshire looked miserable enough!
The chase ending at the Waterfall is at High Force.

Rod (loves trivia)...