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Author: Subject: Help with old car radio please
Humbug

posted on 16/10/14 at 06:03 PM Reply With Quote
Help with old car radio please

So, in the interests of going more retro on my MX5, I bought an old Grunding MW/LW radio off ebay plus a rear plug/cable to pipe in phone (with FM radio app) or MP3 player. I've got it wired in and get great (loud) sound coming when I have the external input, but the reception from the radio is exceptionally quiet. The actual quality seems to be OK i.e. when I listen carefully I can hear that it is clear and make out words, but it seems like there is a missing wire/connection somewhere because it isn't amplified... unless I have missed off a connection somewhere.

I've even got the electric aerial working when I switch on the unit, so it isn't an aerial problem - I also double checked on my Sony unit that I can get MW loud and clear.

The radio wasn't that expensive, so it wouldn't be a disaster to either ditch it or just use the external input, but it would be nice if I could get it working on old-fashioned MW/LW as well.

Any thoughts on what to try?

Cheers,

Simon

Grundig Weltklang 2503, in case anyone's interested... I Googled it and apparently it was made in the late 60s/early 70s.

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bi22le

posted on 16/10/14 at 07:53 PM Reply With Quote
That is a lovely unit. More old skool than your car!!

all of the way through this I was saying to myself amplified aerial!! Untill I read that you have the electric up down working.

it can only be the unit itself as you said your sony was fine. You could buy an inline aerial amp to boost it even more.





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Humbug

posted on 16/10/14 at 08:03 PM Reply With Quote
Thanks! I realise it it older than my car but then the MX5 is the spiritual successor of things like the Elan and MGB, so maybe that's OK? Anyway, I liked the look of this unit so there!

just thinking... I think the power out from the unit to trip the aerial may be 5v rather than 12v (can't remember where I saw that). Maybe the power is enough to send the aerial up but not enough to amplify it. Another experiment tomorrow!

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Dusty

posted on 16/10/14 at 08:08 PM Reply With Quote
Most old radios had an aerial trimmer on the body of the radio. Look for an adjustment screw. Twiddle one way or the other to get best signal on a poor station on the MW.
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rusty nuts

posted on 16/10/14 at 08:22 PM Reply With Quote
quote:
Originally posted by Dusty
Most old radios had an aerial trimmer on the body of the radio. Look for an adjustment screw. Twiddle one way or the other to get best signal on a poor station on the MW.


Just under the second G of Grundig that looks like the trim screw. Another thing to check is the aerial earth y turning the radio on and holding the mast, if the volume increases then you have a bad earth

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Humbug

posted on 16/10/14 at 08:34 PM Reply With Quote
Keep 'em coming! I just went and tried the different power source to the aerial and no joy.

Yes, there is a little screw in that hole... I'll try turning that but what does the trimmer actually do?

...and I'll try the holding the aerial thing as well (though I don't think that is the issue since the aerial worked fine with the modern radio I just took out.

Simon

ETA I've googled the trimmer and found some instructions - seems that the radio may need to be adjusted to the specific aerial I have.

[Edited on 16.10.2014 by Humbug]

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Humbug

posted on 17/10/14 at 07:34 AM Reply With Quote
No... adjusting the trimmer makes very little difference. The weird thing is that the few receivable stations do seem very clear, just very quiet.


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MikeRJ

posted on 17/10/14 at 11:09 AM Reply With Quote
Did the radio come with the original DIN shorting plug for the socket on the back? If so is the radio output still very low with this in place instead of your MP3/Phone connection cable?
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Humbug

posted on 17/10/14 at 01:39 PM Reply With Quote
Not sure what you mean by "DIN shorting plug"? The aerial is just plugged straight into the socket, no extra plugs or anything. The line-in is via a separate 6-pin DIN socket and cable. The quite radio problem happens whether or not the line-in cable is connected.

Simon

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posted on 17/10/14 at 06:49 PM Reply With Quote
If you cant sort it there are firms who convert the radio to a modern version without altering the front, which is the reason that you have it....
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Humbug

posted on 18/10/14 at 10:08 AM Reply With Quote
Problem solved! (or at least problem identified). After MikeRJ's suggestion above I realised that I was trying the radio without the little plastic stopper plugged into the 6 pin DIN socket in the back. Looking closely, I see that it has contacts bridging 2 of the pins, presumably the "shorting" he mentions). With the stopper in the socket, the radio works!

The secondary issue is that the adapter cable I have (3.5mm to 6 pin DIN) doesn't include this shorting function so when it is plugged into the socket and I'm not playing through the line in, no radio. Nothing a small switch won;t solve, methinks

Anyway, thanks for all the suggestions - got there in the end. I knew I could rely on Locostbulders

Simon

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