What FM aerial to install?

[Avinunca]

Hi, I am new here and this is my first post.
I bought a Kenwood KT-5020L tuner recently with a view to recording BBC live concerts with a RTR. With the omni aerial currently installed, sharing my tv downfeed reception is not sufficiently good on BBC R3 for low noise stereo. It's a bit better on Classic FM. However the SQ is very promising.
I want to have a new aerial with probably a separate downlead installed.
I live in Shrewsbury and will point at Sutton Coldfield, roughly 50 miles distant.
I'm wondering if I need a 3 element antenna. I would love to do the installation myself but I couldn't cope with the height getting up to the chimney
I plan to ask a local installation company to do the job though I have no idea what the going rate is these days.

As you seem to need someone else to do the high level stuff I would simply get a quote from three local aerial firms, telling them you are getting other quotes too. Could just need an antenna swap, those omnis are c**p.

[Skywave]

The installation company should be able to advise you of the best transmitter to use, taking into account the nature of the terrain between your location and the chosen transmitter site and the stations you wish to receive. That will determine the type of aerial and its height above ground. Generally speaking, for VHF reception with a good S/N ratio, the higher the aerial, the better.

Don't use an 'omni'. In my experience, if you can literally see the transmitter, then they're ok, otherwise no. You may want to consider installing a rotator for the selected aerial, but that's a different topic.

Al.

[paulsherwin]

Shropshire and North Staffordshire do have less than wonderful national BBC FM coverage. The Wrekin transmitter was built to fill in the holes in TV coverage, but it doesn't carry national FM.

Have you considered using a different technology, such as a Freeview box or an internet streamer?

Have you considered using a different technology, such as a Freeview box

Freeview box seconded, you can get Radio 4 extra in stereo as a bonus! Mind you ones with a display on them (to see which channel it's tuned to) are a bit rare.

[simpsons]

Subject to there being no difficulty is getting into your loft space, may I suggest that you do as I have and install your FM aerial there. 100mHz is no problem through a wall etc. In the days of 405 line TV many aerials were installed in the loft. It maybe a 3 element will work but the larger the better so check out the direction you need the aerial pointing towards and go from there.

If in doubt, your post code will help members give further advice.

I would use a seperate downlead for connection to your FM receiver if only because I assume the omni directional aerial has been diplexed ino your TV aerial lead. If not, joining the new aerial coaxial cable into the existing one might be an option.

Lastly, what is a RTR?

Chris

[Avinunca]

Originally Posted by paulsherwin

Shropshire and North Staffordshire do have less than wonderful national BBC FM coverage. The Wrekin transmitter was built to fill in the holes in TV coverage, but it doesn't carry national FM.

Have you considered using a different technology, such as a Freeview box or an internet streamer?

I can access the stations I am interested in using the BBC Sounds player on my MacBook and with an external Dac. The sound quality is good. It is however my experience that listening on a quality FM tuner, with a good signal, provides extra atmosphere/fidelity - particularly with live concerts. I read somewhere that the equivalent bit rate using a Nicam based transmission system is better than double that of the 300kB/s internet offering. I don't know what Freeview offers.
Despite the noise from the currently inadequate radio signal, the sound quality provided by my tuner is quite exhilarating. I was listening to a concert last night. My tuner is apparently one known for good rf sensitivity/selectivity etc and audio SQ.
My hope is that with Sutton pushing out 250kW I might be able to get a good if not perfect signal. I read somewhere that R3 was affected by changes to the network to benefit listeners to BBC Wales.

[Half a Mullard]

RTR - reel to reel?

[Avinunca]

Originally Posted by simpsons

Subject to there being no difficulty is getting into your loft space, may I suggest that you do as I have and install your FM aerial there. 100mHz is no problem through a wall etc. In the days of 405 line TV many aerials were installed in the loft. It maybe a 3 element will work but the larger the better so check out the direction you need the aerial pointing towards and go from there.

**Not really enough space in the loft. We don't have a shed or garage so that's well all the storage is.

If in doubt, your post code will help members give further advice.

**SY2 5DU

I would use a seperate downlead for connection to your FM receiver if only because I assume the omni directional aerial has been diplexed ino your TV aerial lead. If not, joining the new aerial coaxial cable into the existing one might be an option.

**Yes the omni is diplexed and I thought it better to use a separate cable. It was installed by the previous house owner. I know they are rubbish.

Lastly, what is a RTR?



Chris

Sorry - RTR = reel to reel

[Avinunca]

Originally Posted by paulsherwin

Shropshire and North Staffordshire do have less than wonderful national BBC FM coverage. The Wrekin transmitter was built to fill in the holes in TV coverage, but it doesn't carry national FM.

Have you considered using a different technology, such as a Freeview box or an internet streamer?

As far as I know, Freeview radio is 192kB/s

[paulsherwin]

You will get maximum fidelity using the 320k AAC internet stream, as even top grade FM reception has inherent limitations, but I appreciate that some people just like to use analogue hifi kit (I do, but I have a strong and clean FM signal). If you live in a location with poor FM reception, you can try to improve things with fancy aerial setups, but you may never get a completely clean sound - that's analogue for you!

If you want to proceed down the FM route, you will need to explain your requirements to a few local installers and ask them to suggest solutions. If any of them suggest an omnidirectional aerial that's a good sign that they're incompetent cowboys. If they know what they're doing then they'll suggest at least a 3 element aerial aligned on SC, horizontally polarised, with a dedicated satellite grade downlead and possibly a masthead preamp.

Needless to say, this won't be cheap.

[Avinunca]

Paul, if only the Beeb would broadcast in flac. Yes I do love analogue. I'm a keen vinyl fan. Is CT100 good enough for the cable.

[paulsherwin]

Yes, CT100 is what would normally be used for a high quality installation.

[simpsons]

I hope that you didn't mind me Google Mapping your street.

First, What a lovely road to live in.

2nd I can see that the roof pitch is tight.

3rd You are 50 miles from the SC Transmitter which is about the same as I am from Wrotham. SC 250kW Wrotham 125kW for Radio 3. 125 kW Classic FM

4th You have in the Kenwood a very well thought of receiver

My 5 element aerial lays on the attic floor and it was easy to assemble in the cramped eves. The aerial points into free space. There is no background noise.

Whilst I am sure the contour map of field strength for the transmitter can be found, you have neighbours with 3 element FM aerials on their roof and I would introduce myself to them and see if the signal is good enough.

There are FM aerial amplifiers but watch out that although they say TV FM, they are not just really UHF.

Bite the bullet and see if you can assemble the chosen aerial in the roof space you have. If all else fails, all you need is a man with a ladder or aerial rigger, who, under your instructions fixes it where wanted.

I like Paul's idea and have used the internet feed @320 kbits/s but as you are an analogue fan so be it. My experience was that the digital sound then, a couple of years ago, was different but necessarily wrong. Lots of conversations with BBC Technical over that. Good luck.

Chris

[G6Tanuki]

When you're 'distant' from your chosen FM transmitter, directivity becomes rather more important - not only to get signal-gain in the wanted direction but to reduce multipath signal-reflections that can cause odd and unpredictable distortion-effects [the audio-equivalent of the old TV "ghosting"]. At low signal-levels a receiver becomes rather more susceptible to this, so getting the best 'direct' signal you can will always be a bonus.

"Aerial-amplifiers" don't discriminate - they amplify the wanted and the unwanted signals equally!

Personally [having lived in a part of the Wales/Shropshire borders where The Wrekin was a spectacular RF-block for TV and radio signals from Sutton Coldfield] I'd suggest looking at an outdoor 5-element horizontally-polarised antenna. OK, for the last 40-odd years FM radio has been transmitted using "slant'" polarisation [because it works better that way with car-radios and portables with vertial-whip antennas] but when it comes to 'semi-DX' reception you're still better seeking out the horizontal component of the transmitted signal - because it's somewhat better at making it over local obstructions.

[terrykc]

Originally Posted by simpsons

... you have neighbours with 3 element FM aerials on their roof and I would introduce myself to them and see if the signal is good enough.

And, if they are satisfied, ask them who carried out the installation and how satisfied they were with it.

[Sideband]

I'll agree with all the coments about 'omnidirectional' aerials. I was given an Antiference one a few years ago 'since I knew about radio and would know what it was for....' 'The bin' I thought but I decided to give it a try seeing as it was a freebee and it must be better than the tape aerial I was currently using....no it wasn't! I've never known any sort of aerial to give less gain than a piece of wire....! I'm about 15 miles from Wrotham as the crow flies...around 25 miles by road. Currently I'm using a simple dipole which I bought from CPC for about £9, CT100 as downlead, dipole mounted as high as possible in the loft, position found by compass and experiment (Baird FM radio with tuning indicator.....). Stonking signal on all stations. So DON'T use an omnidirectional! Mine ended up in recycling very quickly.....

[paulsherwin]

Those 'horizontal halo' omnis are popular with installers because they are easy to fit on the mast and don't need aligning with the transmitter. They can actually perform acceptably well in strong signal areas simply because they are mounted high up, but you definitely don't want them if reception is difficult.

[emeritus]

My FM aerial is a loft-mounted horizontal dipole cut for a nominal 100MHz form design data I found in an old radio diary. I made it more than 40 years ago from some offcuts of 15mm copper pipe. Before the FM band filled up with local radio I used to be able to receive broadcasts from France in stereo for most of the day, as well as the local radio for Oxford. I was living near Romford in Essex at the time. I didn't bother attempting to make a balun and just use 75 Ohm coax.A horizontal diploe doesn't need aiming precicely, and its very sharp and deep end-on null can be used to null out unwanted signals if co-channel is a problem.

[Ted Kendall]

Originally Posted by paulsherwin

You will get maximum fidelity using the 320k AAC internet stream, as even top grade FM reception has inherent limitations.

I'd have clean 15kHz bandwidth and 65dB s/n over lossy compression any day of the week. Granted, spectrum space restricts the number of BBC services available, but for top quality FM is worth the effort, in spite of Optimod, which is at least used sensibly on R3. Mind you, some of the R3 balances seem a bit odd these days, but perhaps that's just me - harrumph, harrumph...