Philips 584A - UK Vintage Radio Repair and Restoration Discussion Forum

Sideband · 19th Feb 2006, 10:19 pm

I've made a start on this radio having spent a while dismantling it. You have to dismantle the tuning drive on this to get the chassis out of the cabinet

....should be great fun getting it all back again

.

At the moment all I'm doing is cleaning 70 odd years worth of grime out of it. There is a lot under the chassis and it's very well packed in so I thought it would be a good idea to familiarise myself with the layout and circuit before I 'dive in'. It's very original underneath...only the smoothing capacitors have been replaced.

Now the first thing I want to do is establish that the mains transformer is OK. Now this set has a lot of primary tappings...it looks as if it is suitable from 100 - 255 volts. This leads to problem #1. Does anyone have a diagram of the 240v setting? I want to make sure that the tappings are correct before I apply mains to the transformer. Needless to say the paper diagram showing the connections has disintegrated

and it isn't shown in the trader diagram. Once I've established the transformer is OK, I can start replacing the paper capacitors...there are plenty, plus two in a metal can that will need to be opened.

Another anomaly is the VP4A. There appear to be two versions of this valve and the data I have shows the British 7 pin base. Is this correct? The one in this set has British 5 pin....somewhat confusing when I was trying to work out the base connections!!

OK that will do for now. I think this is going to take longer than I first expected. I'll probably go as far as rebuilding the paper capacitors to keep the set as original-looking as possible.

Rich.

Ed_Dinning · 20th Feb 2006, 1:22 pm

Hi Richard, yes there are 4 and 7 pin versions of the VP4A along with several other valves of that era.
With reference to the transformer :
Remove all valves and run the transformer up on a variac. Plot volts and amps.
This should be a reasonably straight line, starting to curve over near to it's correct voltage level. This test will allow you to see that you are not on the 110V tap.
With a reasonable voltage applied, measure the voltage at the other points, then by simple maths it should be possible to find which are the correct taps.
(Or you may get lucky with the drawing)

HTH Ed

Sideband · 20th Feb 2006, 2:22 pm

Quote:

Originally Posted by Ed_Dinning

Hi Richard, yes there are 4 and 7 pin versions of the VP4A along with several other valves of that era.

Thanks for that info Ed. I suspected something like that. I've worked out the base connections for the 5 pin version now and marked them on the circuit.

Ref the transformer, I'm reliably informed that the set was in use 15 years ago and was tried again last year (will they never learn)! So it seems likely that the tappings are set correctly. What I'll do is connect it to a variac with the valves removed and start it off at about 110 volts and just monitor the outputs as I increase the mains. There are some drips of pitch hanging off the bottom of the transformer but they look old so maybe....!

Rich.

20th Feb 2006, 1:22 pm	#2
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: Philips 584A Hi Richard, yes there are 4 and 7 pin versions of the VP4A along with several other valves of that era. With reference to the transformer : Remove all valves and run the transformer up on a variac. Plot volts and amps. This should be a reasonably straight line, starting to curve over near to it's correct voltage level. This test will allow you to see that you are not on the 110V tap. With a reasonable voltage applied, measure the voltage at the other points, then by simple maths it should be possible to find which are the correct taps. (Or you may get lucky with the drawing) HTH Ed

19th Feb 2006, 10:19 pm	#1
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,566	Philips 584A I've made a start on this radio having spent a while dismantling it. You have to dismantle the tuning drive on this to get the chassis out of the cabinet ....should be great fun getting it all back again . At the moment all I'm doing is cleaning 70 odd years worth of grime out of it. There is a lot under the chassis and it's very well packed in so I thought it would be a good idea to familiarise myself with the layout and circuit before I 'dive in'. It's very original underneath...only the smoothing capacitors have been replaced. Now the first thing I want to do is establish that the mains transformer is OK. Now this set has a lot of primary tappings...it looks as if it is suitable from 100 - 255 volts. This leads to problem #1. Does anyone have a diagram of the 240v setting? I want to make sure that the tappings are correct before I apply mains to the transformer. Needless to say the paper diagram showing the connections has disintegrated and it isn't shown in the trader diagram. Once I've established the transformer is OK, I can start replacing the paper capacitors...there are plenty, plus two in a metal can that will need to be opened. Another anomaly is the VP4A. There appear to be two versions of this valve and the data I have shows the British 7 pin base. Is this correct? The one in this set has British 5 pin....somewhat confusing when I was trying to work out the base connections!! OK that will do for now. I think this is going to take longer than I first expected. I'll probably go as far as rebuilding the paper capacitors to keep the set as original-looking as possible. Rich. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....