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MG Midget and Sprite Technical - radio power?! (mg content?!)

okay
for the gt of my girl i am rebuilding an old philips radio cassette player.

but now i want to test it on the bench and it being old it has no power info on it anny where.

what should the power rating be at least for a converter to bench test a car radio
Onno Könemann

Im not sure I understand,

Most likely its 12 volt with neg. earth....just hook up a speaker to the speaker wire, hook up a negitive to a good ground and hook up the radio to a car battry...for testing you can probably use a latern battry, I doulbt it would even need to be 12 volt....6 volt or even a 3 D-cells would give some noise...BTW remember to hook up the arial to hear the music.

One natoriuos problem to remember about these old car cassette radios from the 70s and 80s, the "channels" that govern the sound that comes out the speakers tend to go bad and often...AKA you will get sound out of one speaker and the other will be dead....ussally a wire going bad that connects to the post,(the thingy with the twist knob on it) or even the post itself.

hope that helps

Prop
Prop

Use a battery with an in-line fuse holder. Typically car radios used to take about a 3 amp fuse. Obviously high output ones need more for full volume operation, but so long as it's not cranked up even 1 or 2A fuses should work, and provide some testing safety if it's buggered in some way.

FRM
FR Millmore

Onno,
Try googling the model number. Amazing what is out there. As Prop says, probably 12VDC negative earth, so run it off of a car battery. Lots of different standards for the wire colours... It is probably at least stereo, if not 4-speaker; wise to connect all the speakers before applying power so as not to destroy any of the output amplifiers.
David "Ask me how I know ;-)" Lieb
David Lieb

okay i have not made my selfe clear

i do not have a spare batery
i need the full 12 volts because i want to check all functions(mainly the cassette after replacing the drive bands)

so i vant to use a converter to convert 230v (outlet power) to 12v but what kind of amps should the converter be able to handle.

i have several lying around of verry difrent power ratings

and ofcours i will connect a speaker tocheck the output!
Onno Könemann

One thing I just thought of...Most of those old radios had a quick release in the wiring harness, where you had wires comming out of the back of the radio into a wiring block, then another block of wires (always a completely differant color) that cliped into the block and went to the car wiring

on speaker wire it will be 2 strand, a solid black which I use as positive, and a black/white wire which I use as neg.

Sorry for the simplisity,,,Im sure you are already aware...its a just in case

Prop....Im sure I blew up more of these radios then david has
Prop

Mmmm, well Id go with FRM...3 amps would be about right....definatly use a in-line fuse like mentioned above....Im not so sure id try the converter myself...with the really old stuff you will have more give in the electric, the newer stuff is going to be much more likely to let the blue smoke out

Sooooo, how are you starting your car...dosnt it use a 12 volt bat. you dont need to pull the battry just some length of wire is all

maybe a next door friend will let you use his car battry in stiu. if your not driving

Prop
Prop

yeah prop it is below zero outside here so i want to try in the comfort of my home.

the midget is still in pieces a few miles away
and since it is a surprise present i don't realy want to use the 2 6volt batery's out of my girl's GT (she might notice they are missing when she want's to go to work in the morning....)
Onno Könemann

What about a battery charger as a 12v converter? Don't they put out 14ish volts (should be about right) lots of amps available but the unit should only draw what it needs, still fuse it of course. I'm not much of an electrical guy so YMMV. I've done this when testing dash lighting on the bench.
J Van Dyke

Got it running on a 12v 300mA suply!!
Yes so little
Now i at least know i fitted the drive bands the right way.
now find a tape to play!

And mabey check out the wireing to see if i can cut out the tape player and solder in a ipod(mini jack) conection instead....
Onno Könemann

no

NO NO NO

dont use a battery charger as a 12v supply

innocent thinking like that caused a rippling current which blew up a CB radio that was once very close to my heart (complete with pretty rippling fairy lights, dammit) It was a cold midwinter then too

the smoke had a disgusting smell too

Battery chargers dont give a smooth 12-13v but often peak above 15v and are very unsteady output

Use a 12v supply and a 1amp fuse

Some stereos may be 12v positive earth, depoends on how old it is

the "Google any part numbers you have!" advice is the best you can get Onno

bill sdgpm

Bill all is fine
It is fused internaly with a 1 amp fuse.
The suply is one i once used for a digital sound board (bass guitar pedal) so is nice and stable (an other crappy one caused noise and distortion with the pedal)

it is a negative earth and i finaly have detemined a part number but the manuals are hard to find
Onno Könemann

good news at last

that sounds good, how does the stereo sound? :-)
bill sdgpm

Thanks Bill,


The battry charger idea seemed like a good idea to me also...Now Im glad it never occored to me, cause i would have tried it.

Hey Onno,

Here is some really good cassette music from amazon.com Im pretty sure music from the cassette era never got any better then this

http://www.amazon.com/Heartwarming-Songs-Porter-Wagoner/dp/B0000005HL/ref=sr_1_4?ie=UTF8&s=music&qid=1263243149&sr=1-4


http://www.amazon.com/RARE-1978-COLLECTIBLE-Impossible-Find/dp/B001A7700U/ref=sr_1_1?ie=UTF8&s=music&qid=1263243276&sr=1-1

http://www.amazon.com/Best-Hee-Gospel-Quartet-Vol/dp/B000000BBB/ref=sr_1_1?ie=UTF8&s=music&qid=1263243337&sr=1-1

http://www.amazon.com/Greatest-Hits-B-J-Thomas/dp/B000000D0B/ref=sr_1_7?ie=UTF8&s=music&qid=1263243524&sr=1-7


Prop...Ya gotta love the cassette era

the 1st is porter wagnor...I actually had his hair cut at one time
the 2nd is Ann murry
the 3rd is Hee haw gosple quartet
and the 4th is BJ thomas...rain drops keep falling on my head

Prop

screw the cassette era! ;P

i've done it!
i was able to folow the signal paths and have cut out the old tape part and worked in the mini jack!

I was just listening to some good old rock from my laptop through the old amp.
even the balance, tone and volume controls worked perfect without anny noise.

now just reasembly and hiding the mini jack in a nice place (like in the cassette slot)
Onno Könemann

ONNO...

I know your not much into modifying beyound the era...But an Idea I was kicking around was to loose one of the 2 idiot lights (high beem and ignition light) and use one of those holes for a Music Jack in plug hole....just a thought

Prop

BTW...you havent heard music till you rocked out on lawerance welk....master of the polka bands...LOL
Prop

Prop
funny you say this
my previous midget had a ingition cut out (anti theft) using a big jack plug and a jack hole between the crash-rail and the dash.

But if you read carefully this setup will be for the MG B GT of my girlfriend.

And ignition and highbeam lights are in the gauges on european cars
Onno Könemann

You're far to good to that women Onno, not only giving her the use of an MG but giving her music as well!!

How can all that excitment be topped?
Robert (Bob) Midget Turbo

giving bob?

first she loand MY mini to get to work for a year
Then i made the small "mistake" to let her drive the midget to work on sunny days.

She would not stop talking about wanting switch HER?! mini for an MG
Then she drove the GT of a friend and her mind was made up.

She had to have a GT.
Then i did the only humane thing posible.
Agreed to do the maintenance end help her find/import one.

And whell she likes the creature comforts more than speed noise and hard suspention so i can only make it more comfertable not less like in the midget ;)
Onno Könemann

LOL
Robert (Bob) Midget Turbo

This thread was discussed between 11/01/2010 and 12/01/2010

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