|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
16th Nov 2019, 10:20 am | #21 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,483
|
Re: What FM aerial to install?
For what it's worth, the original BBC Television Sutton Coldfield 405 line transmitter Service Area, attached, at 61.75 mHz with an ERP of 32kW indicates an average 1.2 mv/m field strength in Shrewsbury. I'm unable to find the 250 kW FM field strength contour map and of course Shrewsbury has moved from Salop to Shropshire but nevertheless its all still positive for FM reception at 100 mHz.
Chris Last edited by simpsons; 16th Nov 2019 at 10:35 am. |
16th Nov 2019, 4:04 pm | #22 | |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,785
|
Re: What FM aerial to install?
Quote:
Some people simply don't have access to a strong clean FM signal even with a good aerial though, and for those people the internet stream is always going to provide the best fidelity. |
|
16th Nov 2019, 4:06 pm | #23 |
Rest in Peace
Join Date: Nov 2010
Location: North Hykeham, Lincolnshire, UK.
Posts: 515
|
Re: What FM aerial to install?
|
16th Nov 2019, 4:11 pm | #24 | |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
|
Re: What FM aerial to install?
Quote:
I still don't get it. Most VHF/FM transmitters use mixed polarisation, and the rest are purely vertical, so the obvious choice for an omni is a vertical dipole. Sure, if the mast is in the way there will be a nul, but a halo natively exhibits a similar nul anyway.
__________________
-- Graham. G3ZVT |
|
16th Nov 2019, 4:18 pm | #25 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,785
|
Re: What FM aerial to install?
I very much agree, but the halos don't take up much space in the van, are easier to mount on the mast, and don't stress the mast as much in high winds. They're also cheap. The typical customer will know nothing about FM reception and will just ask for 'an aerial'. Righto says the rigger, and reaches for another halo. Job's a good 'un.
|
16th Nov 2019, 8:13 pm | #26 |
Dekatron
Join Date: Jul 2008
Location: Kington, Herefordshire, UK.
Posts: 3,657
|
Re: What FM aerial to install?
Difficult, but not impossible. The pity is that the BBC could put the matter beyond question as far as quality is concerned by using FLAC, as they did experimentally for a Proms season a couple of years ago. It still doesn't deal with internet glitches, but you can't otherwise argue with a lossless digital link from continuity.
Last edited by Ted Kendall; 16th Nov 2019 at 8:26 pm. |
16th Nov 2019, 10:25 pm | #27 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,483
|
Re: What FM aerial to install?
Terry, I'm not as green as I am cabbage looking!!
Down South, some, myself included still send letters to Middlesex. Sad to say all we now are is a Post Code. Chris from Harrow, Middlesex |
16th Nov 2019, 11:07 pm | #28 |
Dekatron
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,440
|
Re: What FM aerial to install?
Your local installer should have a clue - I'd go 3 element or 5 element yagi. My dad uses a 3 element for reception from Hedgehope for RNZ Concert, and we use a 5 element for relay between our Gore and Mid Dome Life FM sites.
Here I cut down our old band I/III VHF TV aerial to band II after VHF analogue shut down in 2013, but you guys have had no VHF for a lot longer so I doubt that's an option Good quality coax is essential. Everything here is quad-shielded RG6. |
17th Nov 2019, 9:23 am | #29 |
Tetrode
Join Date: Nov 2019
Location: Shrewsbury, Shropshire, UK.
Posts: 81
|
Re: What FM aerial to install?
Plenty of food for thought here. I didn't expect so many responses to my question so thanks to all.
I liked this - 'If any of them suggest an omnidirectional aerial that's a good sign that they're incompetent cowboys' I tend to concur with Ted's comment ' I'd have clean 15kHz bandwidth and 65dB s/n over lossy compression any day of the week'....but I will do another comparison of a live BBC3 concert broadcast between internet stream and FM. If FM is the winner I'll speak to some local installers and report back. |
17th Nov 2019, 9:39 am | #30 | |
Tetrode
Join Date: Nov 2019
Location: Shrewsbury, Shropshire, UK.
Posts: 81
|
Re: What FM aerial to install?
Quote:
|
|
17th Nov 2019, 10:07 am | #31 |
Dekatron
Join Date: Jul 2008
Location: Kington, Herefordshire, UK.
Posts: 3,657
|
Re: What FM aerial to install?
In the context, this is a circular argument - we started from the point that your s/n ratio on FM stereo is unsatisfactory, so as things stand it isn't going to give of its best against streaming - I'd just do it.
|
17th Nov 2019, 10:49 am | #32 |
Tetrode
Join Date: Nov 2019
Location: Shrewsbury, Shropshire, UK.
Posts: 81
|
Re: What FM aerial to install?
I take your point Ted but actually I want to remind myself what the internet stream lacks for me.
I remember when I owned a Little Pink Thing (Pink Triangle) turntable and I bought a PT 1 deck. The latter turned out to have a damaged jewelled bearing but still sounded head and shoulders above the LPT. |
17th Nov 2019, 4:58 pm | #33 |
Octode
Join Date: Feb 2007
Location: Harrow, London, UK.
Posts: 1,483
|
Re: What FM aerial to install?
Avinunca, I would be very interested, as I am sure others, in your Internet v FM comparison as I did one a few years back listening to the Proms. My comparison was based on:- FM/amp - Beomaster 8000, Internet Laptop, Freeview - Sony TV and SKY - Thomson box.
All this through Celestion Ditton 44's and with analogue audio. I found the timbre of the sound different on each platform but to say it was a true A/B comparison wasn't strictly true as the delay on each transmission made it tricky but nevertheless interesting. Getting the audio levels similar was on another level. No pun intended. Which was true to the source is another matter and perhaps having personal experience in the theatre is necessary. In conversation with the BBC, they put it down to the different feeds each platform received but did not elaberate. Chris |
17th Nov 2019, 5:05 pm | #34 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,785
|
Re: What FM aerial to install?
The Freeview transmission is only 192k MP2, so I would certainly expect that to sound worse than both the internet stream and a good FM tuner.
|
26th Dec 2019, 1:14 pm | #35 |
Tetrode
Join Date: Nov 2019
Location: Shrewsbury, Shropshire, UK.
Posts: 81
|
Re: What FM aerial to install?
Just a quick update to say that I did install my 3 element aerial in the loft. Not ideal as it still points toward the end of the party wall. Reception is quite good albeit with a little noise heard on quiet passages but good enough, especially at lower volume listening. Classic FM is a much better signal than R3 devoid of noise.I've no idea why as they are both from Sutton Coldfield. I haven't yet made a comparison between FM and internet but will do so. The new toy - Teac X1000 has my attention at the moment. I'm currently listening to a recording from last night at 7.30 of the BBC Proms Prom 71 : Bach Night. Sounds pretty good.
|
26th Dec 2019, 1:59 pm | #36 |
Heptode
Join Date: Oct 2015
Location: Gloucestershire, UK.
Posts: 719
|
Re: What FM aerial to install?
Because Classic FM is compressed, Radio 3 is not. Regardless, my advice is to get the aerial ouside. You can diplex it with the TV download if it is decent stuff, saves running additional feeds.
|
26th Dec 2019, 2:55 pm | #37 | |
Tetrode
Join Date: Nov 2019
Location: Shrewsbury, Shropshire, UK.
Posts: 81
|
Re: What FM aerial to install?
Quote:
Why does compression affect noise? I thought it only affected audio. Isn't what I hear an RF issue? |
|
26th Dec 2019, 3:06 pm | #38 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,785
|
Re: What FM aerial to install?
Greater compression masks a high noise floor, but it's also true that signals from the same transmitter location can vary a lot in strength, particularly in marginal reception areas. The stations may use different physical transmitters and/or antenna arrays, and indoor aerials are very vulnerable to frequency selective effects. You may find you can improve reception by experimenting with the aerial position and alignment rather than just aligning it towards the transmitter using a compass. Good reception with a loft aerial is very much a black art.
|