13th Nov 2018, 3:18 pm | #1 |
Triode
Join Date: Oct 2018
Location: Bradford, West Yorkshire, UK.
Posts: 33
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Murphy A128
I'm picking one up in a couple of weeks.Still looking for my pilot 23/ marconi 138 though.
Anyway I want to feed Christmas music through it. I thought of an AM modulator, but I'll lose quality in the modulation and demodulation. I wondered if anyone out there could give me a bit of help, it's been 30 years since I did my electronics at Uni! I want it to still be a radio, very important to me, but wondered if its possible to add a tap so I can play an external source, probably MP3, through it. I thought of a hidden switch inside the cabinate, that would allow me to feed into the amplifier circuit. This is once a year, the rest of the time it's a radio. Can anyone help? Thanks Last edited by AC/HL; 13th Nov 2018 at 9:24 pm. Reason: Forum rule B8 |
13th Nov 2018, 3:29 pm | #2 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Murphy A128
According to the schematic the receiver has provision for external audio input via the PU sockets, switch S1 selects between Radio function and PU function.
I would connect the chassis to mains Earth if it's not already connected. Lawrence. |
13th Nov 2018, 3:31 pm | #3 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
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Re: Murphy A128
Spot on Lawrence, you beat me to it. BAA!!
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13th Nov 2018, 3:33 pm | #4 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
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Re: Murphy A128
The set has a gramophone pick-up input, so you could just feed a mono signal straight into there.
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If I have seen further than others, it is because I was standing on a pile of failed experiments. |
13th Nov 2018, 5:55 pm | #5 |
Heptode
Join Date: Apr 2016
Location: Croxley Green, Hertfordshire, UK.
Posts: 979
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Re: Murphy A128
Agreed with the last 3 posts, if the set is in good working order it will sound very good, with the sets decent speaker in the large cabinet.
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Clive |
13th Nov 2018, 7:10 pm | #6 |
Triode
Join Date: Oct 2018
Location: Bradford, West Yorkshire, UK.
Posts: 33
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Re: Murphy A128
Well spotted.
I haven't got the radio yet, and didn't notice the switch at the bottom of the diagram. Are there any particular connectors you would recommend to use, and if so any recomendations on the best place to get them. I'll just connect an iPod output to them, joining both the left and right channels together. Thanks again, for your help. I want to bring the radio home, and plug it straight in so my wife can see it working immediatley. You see, I was supposed to get one radio, but I now have 3...... 1 working 2 not...... |
13th Nov 2018, 7:21 pm | #7 |
Heptode
Join Date: Feb 2006
Location: Marlborough, Wiltshire, UK.
Posts: 917
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Re: Murphy A128
Directly joining the iPod outputs may cause damage as one output will try to overcome the other. Put a 100R or more resistor in series with each. Search the forum for previous threads on this subject.
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13th Nov 2018, 7:56 pm | #8 |
Dekatron
Join Date: Oct 2003
Location: Southport Lancashire, UK.
Posts: 3,236
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Re: Murphy A128
It will sound very good if you use the PU sockets but you will just be using it as an amplifier rather than a radio. I use a micro transmitter to transmit to radios in several places in the house and they sound al lot better than you would expect compared to modern MW transmissions. I am listening to a Murphy A46 via the transmitter as I type and it sounds great.
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Paul |