"Dave Plowman (News)" wrote in message
...
I know that theory - but had no success with it. My 4 element band III
works fine for FM when horizontal but is dreadful on DAB
The latter being as you'd expect.

I must say that DAB aerials work very badly on FM. But FM aerials work OK on
DAB.

But if the FM aerial has a balun it tends to be crap on DAB. If the FM
aerial is a single folded dipole with a balun it is really crap for DAB.

This is based on casual practical experience. I haven't bothered to do
tests.

Bill

In article ,
Bill Wright wrote:

"Dave Plowman (News)" wrote in message
...
I know that theory - but had no success with it. My 4 element band III
works fine for FM when horizontal but is dreadful on DAB
The latter being as you'd expect.

Yes.

I must say that DAB aerials work very badly on FM. But FM aerials work
OK on DAB.

Yes too.

But if the FM aerial has a balun it tends to be crap on DAB. If the FM
aerial is a single folded dipole with a balun it is really crap for DAB.

Ah. It does indeed have a balun. However, it works ok when vertical for
DAB but not FM. That's what is confusing me. And I don't mean DXing - just
local stations.

This is based on casual practical experience. I haven't bothered to do
tests.

RF is and will remain a closed book to me. ;-)

--
*Age is a very high price to pay for maturity.

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

In message , Roderick
Stewart writes
In article , Pete Smith wrote:
I'm off to B&Q to see if my local one has any. *I got a good deal last year*
on the MegaBoost TV aerial with preamp and PSU. *£10 clearance and nearly*
£50 in Argos. *They're made by Philips.

I've just bought an internet radio in Comet for £39

I can't find such a beast on Comet's web-site. What model?

--
Si

On Jan 21, 7:21*pm, Mark Carver wrote:
Don Pearce wrote:
That should do nicely. I know DAB is supposed to use mulitpath signals
actively, but I did some simulations ages ago, and you still get much
better performance by choosing the nearest transmitter and aiming a
directional antenna at it.

As an aside. I've always used my vertical Band II (aka FM band) dipole for
DAB....

theres' a house near me whose just had a DAB aerial installed on a
pole on the roof. it's the Maplin high gain one one, mounted
horizontally!

Robert

In article , Si wrote:
I've just bought an internet radio in Comet for £39

I can't find such a beast on Comet's web-site. What model?

Magicbox "Imp". I don't see it on their website either, so maybe it was
a last-of-line sale item in that particular store. There may still be a
few left in some stores, or if not there seem to be plenty of
equivalent things - just Google search for "internet radio".

Rod.

On Tue, 22 Jan 2008 13:57:31 +0000, Paul Martin wrote:

In article ,
Bill Wright wrote:

I must say that DAB aerials work very badly on FM. But FM aerials
work OK on DAB.

But if the FM aerial has a balun it tends to be crap on DAB. If the FM
aerial is a single folded dipole with a balun it is really crap for DAB.

I'd guess that the folded dipole will be resonant at 3x the frequency
it's cut for, whereas the simple dipole has resonance at 2x, in analogy
with open and closed organ pipes.

No, it is still 3x for an open dipole (and 5x, 7x etc.)

d

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

"Dave Plowman (News)" wrote in
message
: : In article
: : , Steve
: : Firth wrote:

[snip]

: : : The sales assistant said to me "You know this doesn't
: : : qualify for our 14 day money back warranty?"
: :
: : : "Oh, why is that?"
: :
: : : "Well, basically they don't work."
: :
: : Heh heh. That's what I quite like about Maplin - they
: : do have some characters working for them. Even some
: : pretty knowledgeable ones - although you can't
: : guarantee it.

At least they were honest..!

Ivor

In a normal reception area we always use a vertical FM dipole only for
radio, adding it to the system via a 80 to 250MHz filter. There's no
problem with DAB signal strength because the aerial is up on the roof as
opposed to in someone's house (which DAB is designed for) and because the
limiting factor is almost always co-channel signals. If DAB reception is
poor (which normally means the location is officially unserved) we use one
of the European BIII aerial meant for TV. This is because UK DAB aerials
cover channels 5 up and so they are wideband, and have gain of sweet ****
all.

Some time ago you were raving about the Triax DAB 5 element. AFAICR it was
because it wasn't wideband.

I bought one and pointed it due north from my location about 30 miles south
of Sutton Coldfield. It's very good, bringing in about 100 channels (some
duplicates) but also stations from Shropshire and beyond, for which we are
well outside the service area.

The Birmingham stations are all "off the scale" whereas previously on the
internal rod antenna they weren't even being decoded.

"Doctor D" wrote in message
...
I bought one and pointed it due north from my location about 30 miles
south of Sutton Coldfield. It's very good, bringing in about 100 channels
(some duplicates) but also stations from Shropshire and beyond, for which
we are well outside the service area.

The Birmingham stations are all "off the scale" whereas previously on the
internal rod antenna they weren't even being decoded.

Interesting.

Bill

In article , Bill Wright
scribeth thus

"Doctor D" wrote in message
...
I bought one and pointed it due north from my location about 30 miles
south of Sutton Coldfield. It's very good, bringing in about 100 channels
(some duplicates) but also stations from Shropshire and beyond, for which
we are well outside the service area.

The Birmingham stations are all "off the scale" whereas previously on the
internal rod antenna they weren't even being decoded.

Interesting.

Bill



Not really. The difference an outside aerial makes from an indoor bit of
wire is very significant. A while ago I was playing about with a Denon
tuner in a Suffolk town not renowned for its signals, even mobile which
can be quite good. An ordinary vertical FM di-pole @ 10 MAGL made the
band come alive!..

If everyone were to use the right aerial then we could drop the ERP's by
a lot and therefore "save the planet" i.e. bailing out the titanic with
a teaspoon!...
--
Tony Sayer