Classic branded radiogram
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2201
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Got a question. I am repairing a classic radio gram.
I had a dead short circuit when I connected the record player. Now nothing works. The dial lights do not light up. Is it possible that the dial lights are in series with the heaters.
It's not likely that the transformer is blown as it tripped the protection circuit in my fuse box.
I haven't looked any further as I have been crook. The radio worked perfectly before I hooked the player up.
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Location: Werribee South, VIC
Member since 30 September 2016
Member #: 1981
Postcount: 485
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I assume you mean a 240V dead short?
Should be easy enough to trace with a multimeter.
If it's the turntable motor shorted it wouldn't be connected to the transformer secondary any way.
Does it have a mains fuse? (a lot of vintage gear doesn't).
Do you have a circuit?
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6828
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Is it possible that the dial lights are in series with the heaters.
If it's a transformer set then the dial lights are most likely in parallel with the heaters on the 6.3V AC winding.
Should be easy enough to trace with a multimeter
This.
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2201
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Ok we found the issue. You would not read about it!.Yes it was me that stupidly hooked up a record player with a dead short. But it didn't blow the transformer, it didn't blow the switch, what it did blow was a factory dry joint on the back of the switch.
It is now working better than new.
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Location: Wangaratta, VIC
Member since 21 February 2009
Member #: 438
Postcount: 5492
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It does pay to check a lot of that sort of stuff if its new to you: Its amazing what you find wrong, before it becomes an issue.
Its more common to find a turntable motor in European sets tapped off a transformer, or ballast. So it is less likely to be like that here, substantially reducing any risk to the transformer.
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2201
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Now I got to work out how to get the changer playing well. I got it to play at 78 but couldn't get it to change speeds.
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Location: Wangaratta, VIC
Member since 21 February 2009
Member #: 438
Postcount: 5492
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Invariably if it has not been serviced from the day it was made, the grease soap has probably dried out & its gummed up. That's the first thing took at.
Philips used Shell Alvania Grease. Do not use engine oil.
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2201
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A question. I nearly have this complete. I have installed a working Garrard Turntable . But I am told because it's a crystal pick up that I can install a 1-2 meg resistor to increase the volume. Where should that be placed please?
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Location: Belrose, NSW
Member since 31 December 2015
Member #: 1844
Postcount: 2549
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Re the resistor - does it work as is? Then leave it alone!
I can't see how adding a resistor around the cartridge would do anything other than decrease the volume.
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Location: Cameron Park, NSW
Member since 5 November 2010
Member #: 770
Postcount: 422
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We really need a circuit to see what load resistance the crystal is connected to. I recall that a crystal likes a load of at least 1 megohm so maybe replace it if it much lower than this. Always with the proviso that it won't affect something else.
Harold
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Location: Belrose, NSW
Member since 31 December 2015
Member #: 1844
Postcount: 2549
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The load impedance affects the equalisation from a crystal or ceramic cartridge. A higher impedance will extend the bass response, lower rolls it off but lifts the high frequencies.
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