Conference hips::uk_audioo

    As far as I know, there are no good omnidirectional FM roof aerials. If
    you ever find one, let me know!

Somewhat off the subject:

Has anyone any recommendations for aerial installers in the Reading area?  I'd
like to get my FM aerial out of my loft and onto the roof, but it's the kind of
thing I could regret if it were done badly.  Hate heights so I'm not doing it
myself...

Nick

    re          <<< Note 140.0 by IOSG::CARLIN "Dick Carlin IOSG" >>>
                      -< VHF aerial / antenna questions >-
    
    Try the following:
    
    Use a 3-element array, as high as possible, directed at the weakest/most 
    distant signal. More strong/local signals may (I say "may") give a strong 
    enough signal in the aerial side lobes for acceptable reception.
    
    The more elements you have, the more directional the aerial, and the
    higher its gain (front-to-back signal ratio), but it has smaller
    side lobes which may not pull in the local stations enough. I have a
    similar problem and get by very nicely with a 3-element, but as we have
    a local "booster" for Radios 2, 3 and 4 the local signal can be had
    with a piece of wet string anyway. The tuner is a NAD 4225.
    
    If a 3-element won't deliver, you could always fork out for a rotating
    DX type antennae.
    
    Dav

    re .2
    
    For aerial installations there are some recommendations in the 
    Reading notes file. See notes 103 and 323. 

    I also have problems getting a decent FM reception in Reading for 
    near enough all stations except 210. Radio 3 is particularly bad. 
    I wonder why the BBC serve Reading so badly? 
    
    Can you also elaborate more on what the local "booster" is. I thought 
    it was the job of the tuner to pick up the signal! 
    
    Malcolm 
    

    Malcolm
    

    
    I may have mentioned this company in the Reading conference as well,
    but I'll (re)post here anyway.
    
    I've used Reading Aerial Services on the Wokingham Road twice now, and
    been happy with the service. 
    
    We live in Sonning Common, and have a four element aerial that points
    in the general direction of London. I did ask the bloke from RAS
    whether it would be better to point at somewhere a bit more local, and
    he said it wouldn't.
    
    I can receive Radio 2, Radio 4, Radio 1 (98.8), Capital, GLR, 210, and
    LBC well. Radio 3 is occasionally a bit hissy, but always OK in mono. I
    can't get the 98.2 Radio 1 Oxfordshire frequency (presumably because
    the aerial points the wrong way). 
    
    I did read an explanation somewhere about why Radio 3 is generally
    worse than the other stations. I think it's to do with the dynamic
    range of their usual music - because classical music has a wide range,
    if they turned the power of the transmitter up so that there was less
    problem receiving it, it would blow your radio up in the loud bits.
    
    Trevor

    re .4....
    
    The "booster" I refer to is a low power, local transmitter on a
    different frequency (but in the same band) as the "wide-area"
    transmitter. It's often used in difficult fringe areas like valleys,
    etc.
    
    I didn't mean "booster" in the sense of a type of amplifier on the
    aerial. Sorry to confuse!!
    
    Dave

    Radio 1 on 98.8 is significatly better than it was on 104.6.
    
    FWIW in Sandhurst, Capital reception is crap but Radio 3 is wunnerful.
    
    That's over 3 tuners, btw.

    Ref 140.7
    
    Does your BBC engineer friend know what number of poles aerial I
    will need to pick up Radio 1,2,3,4 and BBC radio Oxford from Faringdon
    in Oxfordshire ?
    
    Would it be better to point the aerial towards Swindon for the national
    network transmissions ?
    
    Where are the transmitters located ?
    
    Thanks,
    
    Tim

    Hi,
    
    I just phoned up Radio 3 and spoke to an engineer. I'm not 
    exactly on first name contact! 
    
    The engineer said that there are no hills between Reading 
    and London so there should be no difficulty in getting a good
    reception. I doubt if you'd be better pointing your aerials 
    between Swindon but for an authorative answer I'd suggest 
    you give them a phone call as well (and post the answer in here as
    well). 
    
    I would not be surprised if you actually need 2 aerials, unless 
    Radio Oxford is quite strong where you live. 
    
    I still wonder about the merits of expensive tuners over middle range 
    ones and if they make a noticable improvement in reception in those
    more distant places.  
    
    I also wonder about the aerial amplifiers like are seen for TVs. Can 
    these makeup for any loss in a not so good aerial? 
    
    Malcolm
    

Aerial amplifiers in general won't help.  They're OK if you really have a
problem with weak signals but that's rarely the case.  Often an amplifier will
just increase noise.

Nick

    ref 140.12
    
    I rang up BBC Radio in London and Radio Oxford as well. (keen)
    Both say my house is well within the Oxford transmitter's range,
    and either an omni-directional or 3 element array should work OK.
    Apparantly, the transmitted power of Radio 1 and Radio Oxford is
    far lower than it will be after the summer, when output will be
    boosted. Radios 2,3 and 4 are at full power now.       
    
    Has anyone any experience with an omni-directional aerial ?
    Tandy do one with a -2db gain, and I presume it's the same as the
    one advertised in Argos, except you get 10 meters of co-ax cable
    with the Argos one for less than the Tandy price of the array alone
    !
    
    

	After the last great storm my TV aerial was blown down so while the guy 
was up there putting up a new one I got him to put up a VHF radio aerial as 
well. It's improved my radio reception no end. Radio 1 was always hissy on my 
internal little bit of wire but now comes through sharp & clear.

	Can anyone explain to me why there are so many different frequencies 
for each BBC station. Why isn't Radio 4 broadcast on for example 93.5 Mhz
throughout the country instead of a whole variety of frequencies? I find that 
just around Basingstoke I have to use about three different frequencies (and 
presumably 3 different transmitters) while driving around in the car listening 
to Radio 4.

Nigel

    The reason why there are separate frequencies for different
    transmitters: if you were in an area which could receive signals from
    more than one transmitter, and they were both on the same frequency,
    inevitably one signal would reach you before the other (there may only
    be a few microseconds difference, but it would exist). Therefore, the
    two signals would be slightly out of phase, and thus would interfere
    with each other. Specifically, they would tend to cancel out at some
    frequencies and "double up" on others.
    
    Does this make sense?
    
    Keith

	re .-1

	I suspected that it was something like that. Maybe in Basingstoke we 
are just in a bad position and no one transmitter gives really good reception 
while on the move.

	It does seem to be worse with Radio 4 though. I need to use 92.9 93.9 
or 93.5 depending on where I am. Radio 3 seems perfectly happy on 91.7 and also 
Radio 1 on 9n.n (I've forgotten the exact frequency).

Nigel

    
    I know someone who wants to improve his radio reception, but not to the
    point of putting an real aerial up.
    
    So, is there anything available on the market between the "crappy
    T-shaped bit of wire that comes with the tuner" and a loft or roof
    mounted FM aerial ? For example, something like an indoor TV aerial ?
    I suppose it might just not be technically possible, given the required
    dimensions of the dipole, or something.
    
    Any suggestions ?
    
    Trevor

    How About The COBRA Ariel bout 30 quid, 
    
    I used one on my NAD tuner until I got my outdoor one. 
    
    Rob. 

    Get a copy of the current issue of the U.S. audio magazine AUDIO.
    There is a decent article on FM aerials. 
    
    Bill
    

    Hi,
    
    I was asked over the weekend if a 20 year old aerial (roof mounted) 
    that is used for listening to Radio 3 should be replaced. 
    
    Some background: 
    
    The Lady that asked is a professional musician who's main interest is 
    listening to Radio 3 and to record students of piano/voice.
    
    Her real problem is that the sound of her system (old German receiver
    and Celestian speakers) often breaks up. I'm convinced that the
    receiver is at fault as I managed to play my CD player through it
    and the same problem could be heard. (But that was going through 
    the 20 year old Sony tape deck as there were only DIN connections 
    on the back of the receiver...) 
    
    So back to the original question, assuming the Lady gets a modern
    amp/tuner, do you thing it wold be worthwhile for her to get a new 
    aerial. What has changed in the last 20 years of broardcasting/aerial
    technology? Do aerials wear out? 

    Malcolm 
    
    PS: She also asked about replacing the tape deck/speakers but that 
    probably belongs somewhere else...
    

    Aerials don't wear out, but they do corrode, get damaged or blown
    off-signal by the wind, and so on. Technolgy hasn't changed, except at
    the enthusiast end of the market with the 30-plus element DX models.
    
    As copper can work-harden with flexing and vibration, the down lead
    coax may have become brittle, and maybe oxidised from being outside for
    years.
    
    Then again, it could all still be in good nick. If the tuner is being
    replaced anyway, I would suggest your friend waits until then before
    looking at the aerial. Using a professional rigger to do the job is
    also worthwhile.
    
    Dave