Consistent poor Radio 4 FM reception -

[ShivaYash]

Dear all,

Some weeks back I asked whether getting a DAB antenna was a good option. Many thanks for the replies.

I opted to stay with FM, for cost reasons, as due to a limited range of Alpine DAB head units.

I did however fit another (my second) Hirschmann antenna, the HIT AUTA 200, their cheapest offering, but this time, I replaced the cable as well.

Radio reception has improved a little but I still get the annoying crackles frequently. What is really annoying however is that other stations are now crystal clear. Also, I was determined the Alpine head unit (14 months old) was defective, so this too was replaced, and whilst there has been a marginal improvement, it still bothers my radio listening.

I've studied the head unit manual and am perplexed by the radio tuning options. Does anyone have words of wisdom, to obtaining the best possible signal?

Is AF a good option, I think 93.2FM is the better signal for Central London, but the radio skips this and sometimes finds only 93.5. Does having TP weaken the signal? Likewise, can radio text and other options reduce the signal? Although I went with the cheapest Hisrchmann roof mounted option, my car did not leave the factory with the automatic option at the rear, it's technical spec is the same and it was one of the taller options, 52cm, better therefore in areas of weak signal, no? The head unit is brand new (swapped by Halfords yesterday, as is the antenna, direct from DE, I was told perhaps the first one was damaged).

My next step will be to write to the BBC technical department and demand they improve their broadcast signal for my bit of London ;-)

With best,

 

[television]

You might solve the problem by fitting a antenna amp, if the new antenna came with the thin 50 ohm coax as all signals do not pass through it readily, it is a complicated subject when using the impedance/ frequency tables, one also has capacity involved.

 

[ShivaYash]

It came with a nice thick cable, certainly thicker than the old cable. I've tried an antenna amp, cheap thing I got from ebay and its powered. But no difference.


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[television]

Thanks for posting back, you could ask the BBC engineering dept if they are working on the transmitter, the power is always reduced when this takes place, plus they could be using another transponder. I could understand a problem at one location due to reflections from buildings.

You have done all you can I think and reception can change at this time of the year, where I live now and when I lived in Herts, I was plagued with French stations during September, and if the Channel has been cloudy,and I think it has then all of these stations can get trapped under the cloud and travel great distances.

Re AM it horrible and all Japanese radios use a 455 khz IF frequency and this just does not work well in the UK as the stations in the UK and much of Europe do not divide equally into the 455khz IF frequency, all of the English manufactured radios and car radio's used 465khz , its often all hetrodyne whistles crackles and pops.

 

[buster651]

over the years i have always found radio 4 signal has been poor whist radio 2 has been good never have understood

 

[hotrodder]

You can look up transmitter info here to see if any there's any local problems/work planned and which channels will be affected... http://www.bbc.co.uk/reception/

The new aerial is earthed properly right? I don't really listen to R4 but have just played with my HiFi as the tuner can display signal strength and while it found R4 on both 93.2 and 93.5FM the later was by far the better signal and a match in strength to BBC R1, 2 & 3. That's in Bexley though and while obviously HiFi seperates should be better than a car it's not like i've got a proper roof aerial or anything, it's sharing the TV aerial in the loft via a basic splitter

The AF function should let the tuner select the strongest signal for a given channel so is usually good unless the tuner is stupid and can't 'make up it's mind'

ETA 93.2FM is what Crystal Palace transmits on but according to the internet is relayed from Wrotham (93.5FM at 125kW) and only 4kW

 

[television]

One other thing that I have just thought of is drive out to where the 93.2 signal works fine and store the station while there and see what its like when you get back nearer home.

I have the situation down here that in some spots if I try and tune BBC2 it just is not there at all, and not shown on the station list, but if I have been listening to radio 2 and drive through the same spot it stays all good and clear.

 

[ShivaYash]

Dear all,

Here is the official line from Auntie (aka the Beeb):

--

Thank you for your E-mail regarding poor reception of Radio 4 on FM in the car.

FM reception can be difficult when travelling in built-up areas or in deep valleys. In these areas the sound can suffer from distortion caused by the radio receiving two signals which interfere with each other. A direct signal from the transmitter and another reflected from a nearby building or hill. Little can be done to prevent this. A good aerial and radio installation will minimise the difficulty.

Car radio aerials are generally of the telescopic rod (which should always be fully extended), although there are a number of cars fitted with heated rear window aerials or stubby helical wound types. The aerial should be as high as possible, preferably on the roof and far away from the engine. If adjustable the aerial should not be angled as a vertical aerial well clear of the bodywork is the most effective.

For good FM reception the aerial should be of the correct length, around 80 cm (32 in) is ideal and this will also provide good AM reception. Aerials much shorter or longer than this may provide inferior results.

In addition we suggest that with a car radio, an important factor to consider is the earthing, as almost no original equipment radios are fully earthed.

This coupled with the fact even good motor cars generate a low level of interference means almost all radios do not give their best results. The only truly quiet vehicles electrically are mechanically controlled diesels. However the prevalence of electronic controls means even diesels will usually benefit from attention. The makers of the radio nearly always include a small screw stud on the back of the case. If this is earthed by way of a substantial piece of braid or wire attached to a metal part of the car’s structure, the immunity to the interference will dramatically increased. Although the radio can no longer be simply pulled out, the benefits usually far outweigh the inconvenience. Specialist installers often do this, but almost no car manufacturer.

Hope this helps

Kind Regards

James Kelly
BBC Audience Services

--

At present I have a Hirchmann 54cm rod antenna and it just about passes for acceptable, anything longer I think would a) look silly and b) be prone to damage, my car is parked in a low rise garage. Fully extending this at all times would also mean it would hit the tops of barriers to car parks etc.

Surely the suggestion as to length isn't for real? I live in zone 2, very close to the City of London, not in the countryside!

Any thoughts?

With best,

 

[television]

Dead right, aerials work any length that will divide equally into the 32" so a 16" long dipole would act as an ½ wave antenna. On a house antenna you would have 2 dipoles, but on a car you cannot. The actual voltage is developed only on the tip of the dipole.

Could you not do something like this

 

[hotrodder]

As i said...

The new aerial is earthed properly right?

I tried Radio 4 for a while after my last post, reception in my w124 is fantastic and that's with a rear wing mounted aerial (Hirschmann auta 6000) which shouldn't be as good as roof mounted i.e. unless the roof aerial is laid right back almost flat to the roof it has a much better 'view'

The Becker indianapolis in mine will display stations by best reception as well as by presets. All the Beeb channels were 'top' of the list with regards to signal strength

 

[ShivaYash]

I have found a solution to this issue. I purchased the Hirschmann AUTA 91 TOP unit, which was double the price of the AUTA 200. I was skeptical of the price difference, the cheaper one being inferior but was assured by the salesman the specs were identical. However, the TOP 91 works perfectly and I can now enjoy almost crackle free Radio 4 in the car.

The 91 unit is far heavier and actually Hirschmann branded on the cover plate, perhaps this single element makes all the difference! The whip is much much thicker and although it is shorter, it works properly! The 200 in comparison looks terribly cheap and its whip is very flexible and bendable, akin to a wire coat hanger. The 91 will no doubt last for many years to come, its powder coat also seems very well applied. I doubt a car wash would damage it, but I won't be trying this out. The whip is a removable bayonet system. Finally, it really suits the car, having a larger base. I'll post a photo shortly.

Moral of the story: buy cheap, buy twice. Lesson learnt.

http://www.amazon.co.uk/Hirschmann-AUTA-91-TOP-Handel/dp/B003NE3D7C

As i said...

I tried Radio 4 for a while after my last post, reception in my w124 is fantastic and that's with a rear wing mounted aerial (Hirschmann auta 6000) which shouldn't be as good as roof mounted i.e. unless the roof aerial is laid right back almost flat to the roof it has a much better 'view'

The Becker indianapolis in mine will display stations by best reception as well as by presets. All the Beeb channels were 'top' of the list with regards to signal strength

 

[television]

Does this antenna come with a new cable.

 

[ShivaYash]

Yes it did, its a different colour to the AUTA 200 and has a slightly different connecting bolt to it as well; being secured from the outside, and then a top cap covering it the nut assembly. However at the moment I am using the AUTA 200 cable but fully intend on swapping it over in due course. They both appear to be of the same thickness.

I think the minor crackles I am getting at the moment will disappear with the specific cable in place BUT it is shorter that the 200, so I'll need an extender from Hirchmann; things can never be simple heh?

Does this antenna come with a new cable.

 

[television]

We used to get problems where water could run down into the cable, this effectively can alter the impedance of the cable giving some flat spots..

 

[ShivaYash]

Yes I heard that was an issue with the W201 but not the W124. The o/s pillar seems nice and dry when the cover was removed for the cable to be routed. Bugger to get back on however. I forgot to mention, I get better reception with AF turned OFF, that way I can pick the signal I want and the radio maintains it.


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