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Rob wrote:
FM *is* used as a band name here, although of course it formally is
just as wrong as AM.
** Wot drivel.
Again, it is the only band reserved for high quality FM broadcasting.
But it\'s not called \"high quality FM broadcasting\", it\'s just called \"FM\".
What about all the other frequencies where narrow band FM is used for
walkie-talkies, remote controls etc. etc.?
Rob wrote:
FM *is* used as a band name here, although of course it formally is
just as wrong as AM.
** Wot drivel.
Again, it is the only band reserved for high quality FM broadcasting.
But it\'s not called \"high quality FM broadcasting\", it\'s just called \"FM\".
What about all the other frequencies where narrow band FM is used for
walkie-talkies, remote controls etc. etc.?
Phil Allison wrote:
Only dumb, ASD sufferers treat words as if they are math.
How insulting to people with ASD.
Phil Allison wrote:
Only dumb, ASD sufferers treat words as if they are math.
How insulting to people with ASD.
I don\'t think a loop aerial on a car window would work at all well
surrounded by the much bigger thinker more conductive loop consisting of
the metal body of the vehicle in which the window is fitted.
** Not true.
AM loops sense the magnetic field of the incoming EM wave.
Some are made from co-ax with the outer shield grounded to eliminate the E field.
Less static noise that way.
The nearby car bodywork has little effect on a window loop.
It wouldn\'t be just nearby or just shielding it would form a shorted turn.
With shielded loops the shield is not connected all round to form a
shorted turn.
I don\'t think a loop aerial on a car window would work at all well
surrounded by the much bigger thinker more conductive loop consisting of
the metal body of the vehicle in which the window is fitted.
** Not true.
AM loops sense the magnetic field of the incoming EM wave.
Some are made from co-ax with the outer shield grounded to eliminate the E field.
Less static noise that way.
The nearby car bodywork has little effect on a window loop.
It wouldn\'t be just nearby or just shielding it would form a shorted turn.
With shielded loops the shield is not connected all round to form a
shorted turn.
On 29/07/2021 05:18, Phil Allison wrote:
 Rob wrote:
FM *is* used as a band name here, although of course it formally is
just as wrong as AM.
** Wot drivel.
Again, it is the only band reserved for high quality FM broadcasting.
But it\'s not called \"high quality FM broadcasting\", it\'s just called \"FM\".
What about all the other frequencies where narrow band FM is used for
walkie-talkies, remote controls etc. etc.?
On 29/07/2021 05:18, Phil Allison wrote:
 Rob wrote:
FM *is* used as a band name here, although of course it formally is
just as wrong as AM.
** Wot drivel.
Again, it is the only band reserved for high quality FM broadcasting.
But it\'s not called \"high quality FM broadcasting\", it\'s just called \"FM\".
What about all the other frequencies where narrow band FM is used for
walkie-talkies, remote controls etc. etc.?
FM *is* used as a band name here, although of course it formally is
just as wrong as AM.
** Wot drivel.
Again, it is the only band reserved for high quality FM broadcasting.
But it\'s not called \"high quality FM broadcasting\", it\'s just called \"FM\".
What about all the other frequencies where narrow band FM is used for
walkie-talkies, remote controls etc. etc.?
Oh, I forgot.
In the US there are narrow band FM weather broadcasts.
NOAA weather I think it\'s called.
Definitely FM (albeit narrow band FM).
Definitely not in the 87.5-108 MHz band (somewhere around 162MHz IIRC).
you may have noticed that few modern cars have any visible AM/FM
antennas these days.
[snip]
The answer ( found by Googling) is they often use the rear window
\"defroster\" grid for AM and FM reception.
[snip]
If anyone knows more, make my day.
you may have noticed that few modern cars have any visible AM/FM
antennas these days.
[snip]
The answer ( found by Googling) is they often use the rear window
\"defroster\" grid for AM and FM reception.
[snip]
If anyone knows more, make my day.
Phil Allison wrote:
Some makers ( BMW ?) have two printed antennas on rear side windows that are boosted and fed into a selector unit that sends the stronger one to the receiver. This is called \"antenna diversity\" as is commonly used with radio mics.
My ~15 year old Honda estate had in-glass aerials in the rear side
windows, Itwas AM/FM only (maybe LW too) but I do remember it picked up
\'buzzing\' when going under electricity pylons, probably just on MW.
Next car (audi) had DAB, I don\'t know where the aerial was, but it did
have a sharkfin, which seems like it was just for GPS which the car
didn\'t actually have.
Current car also audi has DAB and I believe the sharkfin is combined GPS
and DAB, reception is improved, but I think that\'s as much due to
in-fill in the DAB transmitter network here.
Hi,
you may have noticed that few modern cars have any visible AM/FM antennas these days.
Many have a \"shark fin\" antenna on the roof for GPS and possibly 4G cell phones - frequencies used are similar.
Others have a short whip antenna somewhere, not much good for AM.
The answer ( found by Googling) is they often use the rear window \"defroster\" grid for AM and FM reception.
It can be made to work like a frame antenna for AM and a L shaped wire for FM. A booster amp is added near the window for impedance matching.
Some makers ( BMW ?) have two printed antennas on rear side windows that are boosted and fed into a selector unit that sends the stronger one to the receiver. This is called \"antenna diversity\" as is commonly used with radio mics.
If anyone knows more, make my day.
Hi,
you may have noticed that few modern cars have any visible AM/FM antennas these days.
Many have a \"shark fin\" antenna on the roof for GPS and possibly 4G cell phones - frequencies used are similar.
Others have a short whip antenna somewhere, not much good for AM.
The answer ( found by Googling) is they often use the rear window \"defroster\" grid for AM and FM reception.
It can be made to work like a frame antenna for AM and a L shaped wire for FM. A booster amp is added near the window for impedance matching.
Some makers ( BMW ?) have two printed antennas on rear side windows that are boosted and fed into a selector unit that sends the stronger one to the receiver. This is called \"antenna diversity\" as is commonly used with radio mics.
If anyone knows more, make my day.
..... Phil
If anyone knows more, make my day.
My \'76 Chevy C10 pickup truck has two lines running up the center of the
windshield that split off -- this is the car antenna. Some parts on the
truck were from an \'86 - so I can\'t prove if this was a feature from the
\'86 or \'76. I\'d imagine it would make replacing the windshield a bugger
if you wanted to keep your antenna in working order.
If anyone knows more, make my day.
My \'76 Chevy C10 pickup truck has two lines running up the center of the
windshield that split off -- this is the car antenna. Some parts on the
truck were from an \'86 - so I can\'t prove if this was a feature from the
\'86 or \'76. I\'d imagine it would make replacing the windshield a bugger
if you wanted to keep your antenna in working order.
Michael Trew wrote:
================
If anyone knows more, make my day.
My \'76 Chevy C10 pickup truck has two lines running up the center of the
windshield that split off -- this is the car antenna. Some parts on the
truck were from an \'86 - so I can\'t prove if this was a feature from the
\'86 or \'76. I\'d imagine it would make replacing the windshield a bugger
if you wanted to keep your antenna in working order.
** All these alternatives to the time honored telescopic whip are compromised.
1. They are *directional* - complete null in two possible orientations.
2. Framed in a steel structure so partially Faraday shielded.
Guess having no ugly antenna sells cars to those who value cosmetics above results.
No wonder the are many \"after market\" alternatives available.
..... Phil
Michael Trew wrote:
================
If anyone knows more, make my day.
My \'76 Chevy C10 pickup truck has two lines running up the center of the
windshield that split off -- this is the car antenna. Some parts on the
truck were from an \'86 - so I can\'t prove if this was a feature from the
\'86 or \'76. I\'d imagine it would make replacing the windshield a bugger
if you wanted to keep your antenna in working order.
** All these alternatives to the time honored telescopic whip are compromised.
1. They are *directional* - complete null in two possible orientations.
2. Framed in a steel structure so partially Faraday shielded.
Guess having no ugly antenna sells cars to those who value cosmetics above results.
No wonder the are many \"after market\" alternatives available.
..... Phil