Tuners UKP150 and less
 

On Mon, 26 Jul 2004 09:40:05 +0100, tony sayer
wrote:

In article , Dave Plowman (News)
writes
In article ,
Nicolas Hodges wrote:
re aerial: I am getting someone round to do sort it out. Are all FM
aerials the same? (I am 20 miles from a big transmitter.)

No. And the round omni types that are so popular with riggers are about
the worst possible choice.


In fact the losses on these are around 15 odd dB's!!, much better is the
vertical single dipole, but sod all aerial riggers know that much about
FM these days:(

In a lot of instances you'd be better off doing the job yourself:)

I would never recommend a vertical dipole for FM. By far the worst
problem that causes distortion in FM is multipath reception, and a
vertical dipole does nothing for that. Just like for analogue TV, you
need as much directivity as you can put on your roof to get a decent
FM signal. A nice, big Yagi is the way to do that.

Of course, if you aren't interested in Hi Fi quality, but just want to
get as many stations as you can from all round, then by all means go
with the vertical dipole.

d
Pearce Consulting
http://www.pearce.uk.com

Tuners UKP150 and less
 

In article ,
Stewart Pinkerton wrote:
32ks/s (==16kHz bandwidth)? Isn't FM capable of up to 19kHz? ISTR
hearing that, or at least, that the difference signal (?) is stuck up
19kHz above the main signal.

Yes, it is, which means a 'brick-wall' filter from 15kHz to suppress the
pilot tone, since brick walls weren't so high back in the '50s!

Or didn't bother - as Quad with the FM3.

--
*Make it idiot-proof and someone will make a better idiot.

Dave Plowman London SW
To e-mail, change noise into sound.

Tuners UKP150 and less
 

"Don Pearce" wrote in message
...
On Mon, 26 Jul 2004 09:40:05 +0100, tony sayer
wrote:

In article , Dave Plowman (News)
writes
In article ,
Nicolas Hodges wrote:
re aerial: I am getting someone round to do sort it out. Are all FM
aerials the same? (I am 20 miles from a big transmitter.)

No. And the round omni types that are so popular with riggers are about
the worst possible choice.


In fact the losses on these are around 15 odd dB's!!, much better is the
vertical single dipole, but sod all aerial riggers know that much about
FM these days:(

In a lot of instances you'd be better off doing the job yourself:)

I would never recommend a vertical dipole for FM. By far the worst
problem that causes distortion in FM is multipath reception, and a
vertical dipole does nothing for that. Just like for analogue TV, you
need as much directivity as you can put on your roof to get a decent
FM signal. A nice, big Yagi is the way to do that.

Of course, if you aren't interested in Hi Fi quality, but just want to
get as many stations as you can from all round, then by all means go
with the vertical dipole.

d
Pearce Consulting
http://www.pearce.uk.com

But if you want Hi Fi quality and also the means of getting as many stations
as you can from all round then get that nice big Yagi and a rotator....but
actually logging all those 'new' stations is a tad anorak ;-)

Tuners UKP150 and less
 

On Mon, 26 Jul 2004 10:55:55 +0100, "Mike Gilmour"
wrote:


"Don Pearce" wrote in message
.. .
On Mon, 26 Jul 2004 09:40:05 +0100, tony sayer
wrote:

In article , Dave Plowman (News)
writes
In article ,
Nicolas Hodges wrote:
re aerial: I am getting someone round to do sort it out. Are all FM
aerials the same? (I am 20 miles from a big transmitter.)

No. And the round omni types that are so popular with riggers are about
the worst possible choice.


In fact the losses on these are around 15 odd dB's!!, much better is the
vertical single dipole, but sod all aerial riggers know that much about
FM these days:(

In a lot of instances you'd be better off doing the job yourself:)

I would never recommend a vertical dipole for FM. By far the worst
problem that causes distortion in FM is multipath reception, and a
vertical dipole does nothing for that. Just like for analogue TV, you
need as much directivity as you can put on your roof to get a decent
FM signal. A nice, big Yagi is the way to do that.

Of course, if you aren't interested in Hi Fi quality, but just want to
get as many stations as you can from all round, then by all means go
with the vertical dipole.

d
Pearce Consulting
http://www.pearce.uk.com

But if you want Hi Fi quality and also the means of getting as many stations
as you can from all round then get that nice big Yagi and a rotator....but
actually logging all those 'new' stations is a tad anorak ;-)


Overkill. Just have a Yagi and an omni on the roof. Plug in the Yagi
for Hi Fi listening, and the omni for all those other stations.

d
Pearce Consulting
http://www.pearce.uk.com

Tuners UKP150 and less
 

In article , John Phillips
wrote:


Back to BBC Radio 3 FM, I think the signal is compressed to prevent
over-deviation and keep low-level detail above the transmission system's
noise floor. It certainly sounds "warm" to me compared to DAB (yes I
know about the arguments but at least R3 gets some bandwidth). This
does not detract from my keen enjoyment of the best of R3 on FM, BTW.

I am not sure how representitive it was, but a friend and I did a
comparison a year or two ago. He recorded onto CDR from his DAB tuner.
(Forgotten the model.) I recorded the same concert from FM (Yamaha CT7000)
onto a CDR. We then made copies and swapped them for comparison. The
broadcast was a lunchtime concert R3 broadcast of various solo piano items.

We both also felt the FM was 'warmer' (or similar attempts to describe the
difference in English! ;- ).

However I also did a statistical analysis of the two. The FM loudness
distribution showed a 'kink' starting at about the -12dB level w.r.t peaks.
This took about 6dB off the peak level of the FM relative to the steady
level compared with DAB.

The difference seemed to be that transients on FM were being compressed by
up to 6dB relative to DAB. The result on the piano music we had recorded
was that on FM the sustained body of notes and chords seemed to be more
noticable compared with the transients. In effect, the result was more
'sustain' and 'warmth'.

Our opinions divided as to which we preferred at the time. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Tuners UKP150 and less
 

In article , Stewart Pinkerton
wrote:
On Sun, 25 Jul 2004 17:13:33 GMT, "Fleetie"
wrote:


32ks/s (==16kHz bandwidth)? Isn't FM capable of up to 19kHz? ISTR
hearing that, or at least, that the difference signal (?) is stuck up
19kHz above the main signal.

Yes, it is, which means a 'brick-wall' filter from 15kHz to suppress the
pilot tone, since brick walls weren't so high back in the '50s!

IIRC It was common on some of the early stereo decoders to use notch
filters to kill the 19 and/or 38 kHz, combined with a relatively slow lpf.
This was a fiddle to set up for nulling the 19 kHz, but meant you could
avoid having a more demanding design to make on a production line.

Again IIRC the 'Toko' filters that were often used in the 1970's and 80's
also had an alignment that notched down at these frequencies to give
improved 19/38 rejection values without having to have ultra-high brickwall
cutoff for their LP slope.

By way of comparion, an old mono Leak Troughline I have leaks 19, 38, and
indeed, IF, like a sieve from its audio outputs. Filters? What are they?
Its got a time-constant. What more do you want?... 8-]

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Tuners UKP150 and less
 

In article , Dave Plowman (News)
wrote:
In article , Stewart
Pinkerton wrote:
32ks/s (==16kHz bandwidth)? Isn't FM capable of up to 19kHz? ISTR
hearing that, or at least, that the difference signal (?) is stuck up
19kHz above the main signal.

Yes, it is, which means a 'brick-wall' filter from 15kHz to suppress
the pilot tone, since brick walls weren't so high back in the '50s!

Or didn't bother - as Quad with the FM3.

Afraid I am not sure what you mean. The diagrams and descriptions I have
for the FM3 show third-order (?) LP filters after the output from the 1310
stereo decoder. These follow the time-contants which also tend to roll
down HF. Do you mean something else, or an earlier tuner?

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Tuners UKP150 and less
 

In article , Don Pearce
writes
On Mon, 26 Jul 2004 09:40:05 +0100, tony sayer
wrote:

In article , Dave Plowman (News)
writes
In article ,
Nicolas Hodges wrote:
re aerial: I am getting someone round to do sort it out. Are all FM
aerials the same? (I am 20 miles from a big transmitter.)

No. And the round omni types that are so popular with riggers are about
the worst possible choice.


In fact the losses on these are around 15 odd dB's!!, much better is the
vertical single dipole, but sod all aerial riggers know that much about
FM these days:(

In a lot of instances you'd be better off doing the job yourself:)

I would never recommend a vertical dipole for FM. By far the worst
problem that causes distortion in FM is multipath reception, and a
vertical dipole does nothing for that. Just like for analogue TV, you
need as much directivity as you can put on your roof to get a decent
FM signal. A nice, big Yagi is the way to do that.

Of course, if you aren't interested in Hi Fi quality, but just want to
get as many stations as you can from all round, then by all means go
with the vertical dipole.

d
Pearce Consulting
http://www.pearce.uk.com

Quite Don, I was concurring with Dave that if you want a simple FM
aerial up from the bit of wire or rabbits ears, than a Vert dipole was
better than a Halo, course a directional array 4 or 5 elements is the
way to go....
--
Tony Sayer

Tuners UKP150 and less
 

In article , tony sayer wrote:
In article , John Phillips
writes
However, on the subject of "better than any ... digital sound" sorry to
quibble but I believe the UK national "analogue FM" transmtter network
is fed with digital NICAM-encoded content. Assuming I'm right, even
though the transmission is analogue FM the source is still digital.
And what's more it's just 14-bit digital at 32 ksamples/sec before we
even get to the issue of 10-bit NICAM transcoding.

Which is quite OK for the 15 K that is required for the FM system. In
fact its referred to as NICAM "728" which is give or take the odd bit
the bitrate in use. Most all modern FM modulators are very high spec'ed
units these days, so not too surprising that the FM signal is as good as
it is:)

Quite right. You make the point more eloquently than I did that digital
audio even at a rather lower spec. than normal today can and does sound
superb in spite of it being digital.

--
John Phillips

Tuners UKP150 and less
 

In article ,
Jim Lesurf wrote:
The difference seemed to be that transients on FM were being compressed
by up to 6dB relative to DAB. The result on the piano music we had
recorded was that on FM the sustained body of notes and chords seemed to
be more noticable compared with the transients. In effect, the result
was more 'sustain' and 'warmth'.

Our opinions divided as to which we preferred at the time. :-)

My early VideoLogic DAB tuner sounded very bright compared to any of my FM
tuners, so I simply rolled it off to match. I sort of assumed this was
done deliberately to make it sound 'better' than FM at the time. It wasn't
just my sample either - a second one I tried was the same.

--
*Ah, I see the f**k-up fairy has visited us again

Dave Plowman London SW
To e-mail, change noise into sound.