Evening, I'm changing the radio in the Capri for one more fitting (literally - as being smaller than a more modern '1 DIN' it'll fit in my original dash surround).
Now, I have a power antenna on my car, I should imagine there's a relay making the aerial go up when it receives positive voltage, and down when it receives negative voltage??
The radio I have just refurbished is a tidy little Maitsu with Graphic EQ! Sounds very good, cost me £2 and needed a new cassette belt (which was a whopping 48cm long!) and clean...
How do I go about adding a Power Antenna feed to this radio, as it doesn't have one. Is it as simple as finding a circuit which becomes live when I switch on using the power switch on the radio, and then take a wire off that? As surely there won't be any excessive draw as it's basically just telling the relay "Oi, Put the aerial up??"
I also need 4 knobs for it... But i'll open a different thread for that...
Any help would be great! Cheers!
48 or 4.8cm?
Frank
48! It wraps round a huge drum, like twice its a really bizarre layout. Luckily I found a belt.
Does this Youtube video help? Its something I have never tried, I am not much help after the video.
Frank
Well done on that bargain lol....I used to have a Harry Moss radio cassette player in one car many moons ago. It had "auto-reverse" and never worked properly. It always chewed up tapes. Was gutted when it ruined my "Chart-Blasters '82" cassette 
To understand the black art of electronics is to understand witchcraft. Andrew.
As far as I remember the power aerial feed is just a connection to the output of the sets power switch via a low value resistor. The resistor is probably optional. Quite surprising that a set "upmarket" enough to have EQ doesn't have a power aerial feed - examination of the pcb may find that the relevant tracks are provided but the parts aren't fitted - is there a space on the back for a terminal?
Niall said
As far as I remember the power aerial feed is just a connection to the output of the sets power switch via a low value resistor.
I think you are right. Its a very long time since I repaired a car radio but I seem to remember that it was just as you say....some had a fuse in series as well. The idea of course is that when you switch the radio off, the relay (in the car aerial) looses it's holding voltage and the contacts change over to bring the aerial down and a limit switch then turns the power off when a cam in the gearbox activates it. When the radio is switched on, the relay is activated and operates the aerial motor again and the power is then switched off (to the motor) by the limit switch. The relay is held 'on' by the power feed from the radio via the on/off switch.....something like that anyway.
sideband said
Niall said
As far as I remember the power aerial feed is just a connection to the output of the sets power switch via a low value resistor.I think you are right. Its a very long time since I repaired a car radio but I seem to remember that it was just as you say....some had a fuse in series as well. The idea of course is that when you switch the radio off, the relay (in the car aerial) looses it's holding voltage and the contacts change over to bring the aerial down and a limit switch then turns the power off when a cam in the gearbox activates it. When the radio is switched on, the relay is activated and operates the aerial motor again and the power is then switched off (to the motor) by the limit switch. The relay is held 'on' by the power feed from the radio via the on/off switch.....something like that anyway.
So as I said in my post it should be just a matter of finding a circuit in the radio which becomes live on the switch, and soldering on a wire to feed said Electric Aerial relay?
That looks like it Jamie, I was a bit confused when you suggested positive or negative voltages for raising and lowering, that did not appear correct.
I am sure you will get it sorted.
Frank
Jamie said
So as I said in my post it should be just a matter of finding a circuit in the radio which becomes live on the switch, and soldering on a wire to feed said Electric Aerial relay?
I'd take it as close to the switch as possible. Although it is years since I had a car radio in bits, I have a mental picture of a green component with coloured bands in series with the aerial supply so it could have been an inductor which makes sense as the potential problem is interference conducted into the set by the aerial power wire. I think usually all inputs and outputs of a car radio are filtered. Worth bearing in mind if you get a lot of interference when you install it.
I think we have the Saisho badged version of this, or one very like it, in one of the tractors! Actually quite a good sounding set when connected to some halfway decent speakers. It's been a while since I last sat in a tractor cab, but I do remember the radio and its impressive sound. I know there are some ICs in there by Sony, Panasonic and Philips, so not unreasonable that it should sound OK.
