Radio Reception
Discussion
Murph7355 said:
Before anyone suggests it...I know - you can't hear it much and the engine noise is great 
at Pistonheads, and the first 2 replies you've got, what did you say? 
Anyway yes, I've got the Mod-wise reception kit and it's very good for FM but like you say for AM is useless. I've had my Griff 500 11+ years now and I spec'd a CD changer, powerful amp and rear speakers because there are times when it's nice to have music or radio on in the car. Have you thought of taking it to a car radio specialist (a real specialist) and asking them what they recommend for AM reception? I’ve always thought it needs a traditional antenna for AM, perhaps fitted in the boot, I know some of the Cerbera chaps used to poke/thread one of those long fiberglass antennas up inside the door pillar - I wonder if you could thread one down the inner sill? Just some thoughts. 
That or buy a small DAB radio to plug in and listen to BBC5Live on that? Rich...Edited by RichB on Monday 8th March 08:59
Seemed like a good idea at the time, still at least it can play my London Thunder cd tho 
I use the stereo all the time in the Griffith . . 63k miles and most journeys have included the stereo . . I can hear the car overt the music and there is nothing like driving your favourite roads in the world with your favourite tune playing alongside. Yes it's great to just listen to the car, but when I listen to the latest Kasabian album for instance, I can close my eyes and reminisce on lats years tour through the Alps . .. Underdog being a particular favourite whilst ascending Grimselpass. ..
FM reception in ours is just OK but certainly could be improved. A couple of years ago I bought an aftermarket solid aerial (about a foot long) with a built-in amplifier of some sort, but haven't got round to fitting it yet.... I was planning on tucking it up above the glovebox somewhere, but have no idea whether it would improve matters or whether the GRP of the dash top would scupper it completely. Has anyone else fitted such a device in such a place?
Ta
Ruari
Ta
Ruari
A Radio Antenna can be considered to work just like any other electrical circuit where it needs a flow and return. In an ideal situation you have the antenna element which gathers the radio waves referenced to a big copper stake in the earth. With metal cars the body shell is used as a second best for the earth and has enough bulk to do a reasonable job. Things are more difficult in a plastic bodied car so as a starting point TVRs are always going to be a challenging environment for a radio.
Ideally for best performance the antenna element would be about half the wavelength you want to receive and stand vertically. So the ideal element length for radio 4 on 94.2mhz would be about 77cm which sounds reasonable. If you are a car manufacturer and don’t want to fit an external antenna you can scrunch the 77cm up a bit and make it into a squiggly line moulded into some glass (with some loss of performance) On long and medium wave things are more difficult as the ideal element length is several hundred meters and an aerial sticking up that high would tend to catch in filling station canopies and low bridges.
If you really want to use MW and LW try getting a nice long length of thin insulated wire (the longer the better) and wrap it round and round inside the largest part of the boot. Take one end to the coax centre and connect the coax outer to the chassis.
Antenna amplifiers can help, a bit, but it is far better to construct a better antenna rather than amplify nothing. Radio reception is all about signal to noise ratio and If you have a poor signal to start with and amplify it you will just have a stronger poor signal and not really be better off, unless that is the amplifier is specifically designed to pick out the frequencies that you want to listen to, which it probably won’t be. Most car antenna amplifiers will either be optimised for 88 – 108 Mhz. Or cover a very wide spectrum neither of which will help.
Ideally for best performance the antenna element would be about half the wavelength you want to receive and stand vertically. So the ideal element length for radio 4 on 94.2mhz would be about 77cm which sounds reasonable. If you are a car manufacturer and don’t want to fit an external antenna you can scrunch the 77cm up a bit and make it into a squiggly line moulded into some glass (with some loss of performance) On long and medium wave things are more difficult as the ideal element length is several hundred meters and an aerial sticking up that high would tend to catch in filling station canopies and low bridges.
If you really want to use MW and LW try getting a nice long length of thin insulated wire (the longer the better) and wrap it round and round inside the largest part of the boot. Take one end to the coax centre and connect the coax outer to the chassis.
Antenna amplifiers can help, a bit, but it is far better to construct a better antenna rather than amplify nothing. Radio reception is all about signal to noise ratio and If you have a poor signal to start with and amplify it you will just have a stronger poor signal and not really be better off, unless that is the amplifier is specifically designed to pick out the frequencies that you want to listen to, which it probably won’t be. Most car antenna amplifiers will either be optimised for 88 – 108 Mhz. Or cover a very wide spectrum neither of which will help.
Argent said:
When I bought my present Griff reception was complete c""p, plug leads were shot, fitted a set of blue Magnecors and all ok. Haven't used the radio since. 
A.
Rich, are you sure your leads are ok, I have a very small amount of noise on am. I also have an earth to the heat sheild under the bonnet though. A.
David Beer said:
Argent said:
When I bought my present Griff reception was complete c""p, plug leads were shot, fitted a set of blue Magnecors and all ok. Haven't used the radio since. A.
Rich, are you sure your leads are ok, I have a very small amount of noise on am. I also have an earth to the heat sheild under the bonnet though. A.
It's not too much bother but I've never had AM reception in my Griff, nothing, just amplified engine noise Hi Rich
if it's air bourne ht noise, keeping it awY from the aerial is the key, hence the aerial in the boot. The under bonnet heat sheild if earthed will be of benefit. So a jubilee clip opened up on the plenum will touch the shield when the bonnet is closed. You do have the earth braid from the amp to the fuel tank fitted? The amp is from a range rover, it used the rear screen as the aeial, you use the
copper strip supplied, or maybe you have the early wire? If you want any bits let me know.
if it's air bourne ht noise, keeping it awY from the aerial is the key, hence the aerial in the boot. The under bonnet heat sheild if earthed will be of benefit. So a jubilee clip opened up on the plenum will touch the shield when the bonnet is closed. You do have the earth braid from the amp to the fuel tank fitted? The amp is from a range rover, it used the rear screen as the aeial, you use the
copper strip supplied, or maybe you have the early wire? If you want any bits let me know.
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