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Bonky
14-03-2020, 21:05
Hi, so FM is a bit 'old school' but I've just picked-up a Denon TU-580RD (TU-650RD) and am beginning to love FM again after all these years.

Yes I know BBC3 is of a higher quality on the internet but there's something nice and easy about FM.

MY 3-pole rooftop aerial is wrongly polarised for my favoured transmitter (Chesterfield- to the SE of us. Tapton/Ranmoor is much more powerful and only a few miles away but we live in its dip!)

So I've made a vertically polarised dipole from thick copper wire (each arm is 740mm) but wonder how this could be improved. Web sites now seem to sell circular 'omni-directional' aerials. Are these better than a 'standard aerial' one can buy from, say, CPC?

Yes, the obvious choice is to ask for the 3-pole array rooftop aerial to be correctly polarised. This will happen later in the year...but in the interim...what should I do?

Thanks,

Richard.

dave2010
14-03-2020, 22:32
Yes I know BBC3 is of a higher quality on the internet but there's something nice and easy about FM.
AFAIK you won't get tracked if you listen to broadcast radio. Maybe not a great advantage as perceived by most people. With a good tuner, and a good aerial it can be pretty good - it is possible to get the hiss level down to almost imperceptible IIRC, though without a good aerial it's probably not great.

Also hopefully it should still work if the internet gets stuffed - which via our BT system seems to happen from time to time. Having mentioned that though, even broadcast delivery fails sometimes. One issue might be the degree of signal compression which is applied to FM and/or DAB, though I suspect that even internet delivery might have some compression applied.

Pharos
14-03-2020, 22:50
You've chosen a quarter wave dipole, you might find a half wave one better, and also slant polarisation might help.

high.spirits
15-03-2020, 11:15
I've been using a 6 element yagi direction aeriel which works very well. Shame you are a distance away otherwise you could try it.

Bonky
15-03-2020, 11:40
Thanks everyone...I'll experiment!

I think I've read somewhere that the aerial must be at least half a wavelength above the ground...not a problem but I wonder what the justification is (?). Generally the higher the better anyway. I have found (a)
I get better reception if the dipole is a few inches away from the stone walls of the house and, (b) not attached to a plastic drainpipe!

R

Firebottle
15-03-2020, 12:53
If it's attached or close to anything it affects the impedance.

RF characteristics can take a bit of getting your head around.
The higher up the better with VHF and UHF antenna installations, particularly with ham radio when you are chasing the smallest sniff of signal.

A colleague once said 'if you are not worried about your antennas when it is windy, they are not high enough' :eyebrows:

Bonky
15-03-2020, 13:31
"If it's attached or close to anything it affects the impedance."

Does the material matter - ie is mounting the dipole on wood better than say, stone work?

Thanks,

Mike Reed
15-03-2020, 14:16
FM is still great, and I doubt that R3 is any better via internet. Don't know your tuner, which could be fairly sensitive; however, three elements doesn't sound much. I've never had less than 6, which I have at the mo' on a 12' steel mast on a chimney with the transmitter 9 miles away as the crow flies.

My Nat 01 possibly needed more than this (but sounded great) but it certainly suits the cheap NAD which replaced it. Rom Smith's Galaxies are the ultimate, of course (I used to have a G23 60' above street level) but as said, proximity to walls or whatever can have a deleterious effect (and even ghosting). If you are serious, I'd be tempted to get a 6 element as high as poss. in free space. If you're uncertain about which transmitter to go for, a rotator will solve your problem (he says, with 2 h/d ones in his loft with miles of cabling!:eyebrows:)

AJSki2fly
15-03-2020, 14:38
FM is still great, and I doubt that R3 is any better via internet.

I had also been considering getting a relatively cheap early 80's FM tuner and trying it out again as I have always liked FM broadcast, but one thing that is nagging in the back my mind is if it actually be any better then 320Kbps on the internet which is available from the BBC. The thing is even it really depends on what format they are playing and if they a digitising the whole signal worst and then transmitting it both a digital and then converting to analogue to FM broadcast for transmission, in which case it would be pointless to have FM. Does anyone happen to know the answer to this?

Bonky
15-03-2020, 14:47
Googling FM vs Internet reveals:

Is Internet radio better than FM?

Internet radio
But it can offer better sound quality, for two reasons. ... Second, even if internet stations have the same bit-rate, they use much more efficient codecs. The 320kbps Radio 3 stream is encoded using AAC (Advanced Audio Coding) rather than MP2. Technically, it's better than FM

Firebottle
15-03-2020, 15:36
"If it's attached or close to anything it affects the impedance."

Does the material matter - ie is mounting the dipole on wood better than say, stone work?

Thanks,

Yes better to mount on wood than stone work. Stone, as opposed to brick, can attenuate higher frequencies such as Wi-fi particularly though not such a problem at VHF.
Best to get it out in the open.

Bonky
15-03-2020, 17:05
Yes better to mount on wood than stone work. Stone, as opposed to brick, can attenuate higher frequencies such as Wi-fi particularly though not such a problem at VHF.
Best to get it out in the open.

Thanks Alan

Pharos
15-03-2020, 17:38
There has been a long debate about the quality of FM on another forum, and the quality is thought to be limited very much by the use of Optimod, and that most tuners far exceed the inherent quality of FM.

Mike Reed
15-03-2020, 20:14
I really don't know as I've neither facilities to get internet radio to my kit nor the interest in so doing. If 'Music Planet', 'J to Z' and Jazz Requests (variable, of course) on R3 can sound live and thrilling in my sitting room from a lowly tuner (or an 01 previously), that's quite enough for me.

If I now had what I used to have; instant music at the push of a mute button (Naim, 24/7 powered), I'd also tune into a lot more R3 classical and indeed, Classic FM, which has improved s.q.-wise over the past few years (or maybe it's my pre?). I miss that, but firing everything up redefines and reduces my listening sessions somewhat.