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Old 24th Jan 2011, 10:46 pm   #101
Abraham
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Default Re: Philips B3X85U troubleshooting

I have a question on the transformer.
If 110 or 220 volts goes into one side of the transformer, how many volts comes out the other side respectively?
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Old 25th Jan 2011, 1:20 am   #102
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Default Re: Philips B3X85U troubleshooting

I assume you're refering to the output transformer in your set?

I cannot answer you question without knowing the turns ratio of your transformer. I could work it out, but it's hardly worthwhile.

2 Volts across a 5 ohm speaker will give a power of about 800mW and 4 Volts about 3.2W, so there will be no dangerous voltages on the secondary winding.
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Old 25th Jan 2011, 4:13 am   #103
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Default Re: Philips B3X85U troubleshooting

The reason why I ask is because I was thinking maybe replacing the transformer. And I guess the first question ask would be 110 and 220 volts go in what voltage do I want coming out or transforming to.
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Old 25th Jan 2011, 9:11 am   #104
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Default Re: Philips B3X85U troubleshooting

That is a unique transformer with a choke tap and feedback winding so would need modification to use another transformer.
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Old 25th Jan 2011, 10:20 am   #105
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Default Re: Philips B3X85U troubleshooting

Abraham.

It is possible to replace an output transformer with a mains transformer, but it is not recommended.

As peter_sol says the output transformer in your set is a special one and there's no modern direct replacement.

If you can't repair your transformer I'll tell you how, with some changes to the wiring, you can use a modern one to replace it.
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Old 14th Aug 2011, 10:04 pm   #106
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Default Re: Philips B3X85U troubleshooting

Hello to Steve P, Station x, Geofy, and all others. I'm back from a break on my Philips
Bx385U radio eagerly waiting to get it to sound. I'm excited because when I now connected the speakers and was touching the volume control with a magnetic screwdriver, I noticed some crackling on the right bottom pin but nothing on the center pins. It is something that did not happen using a regular non magnetic tip screwdriver. Also, with the digital multimeter set on DC 1000 and the negative on chasis, I now get on the UL84 tube, Pin 1 does not measure anything but there is crackling, Pin 2 does'nt measure anything, also has crackling, Pin 3 measures 5, Pin 4 measures 0, Pin 5 measures 0, Pin 6 measures 0, Pin 7 measures 111, Pin 8 measures 111, and Pin 9 measures 101 That's the latest I got. Hoping to get it sounding, Thanks again for your help.
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Old 14th Aug 2011, 10:18 pm   #107
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Default Re: Philips B3X85U troubleshooting

Pin 1. Internal connection 0V
Pin 2. Control Grid 0V
Pin 3. Cathode 5V
Pin 4. Heater 0V
Pin 5. Heater 0V
Pin 6. Internal Connection 0V
Pin 7. Anode 111V
Pin 8, Internal connection 111V
Pin 9. Screen Grid 101V
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Old 14th Aug 2011, 10:25 pm   #108
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Default Re: Philips B3X85U troubleshooting

That's affirmative.
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Old 14th Aug 2011, 10:38 pm   #109
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Default Re: Philips B3X85U troubleshooting

Given that you have 120V mains the voltages are about right. Crackling when touching pin 2 is good too.

What are the voltage readings on the preceding valve?
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Old 14th Aug 2011, 10:42 pm   #110
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Default Re: Philips B3X85U troubleshooting

When I check the voltages, does the radio have to be on AM or can it be off but plugged in?
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Old 14th Aug 2011, 10:56 pm   #111
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Default Re: Philips B3X85U troubleshooting

On the UBC 81 tube, Pin 1 measures 81V and 85V when it's turned on MW or AM,
Pin 2 measures 0 V,
Pin 3 measures 2 V,
all other pins measure 0 V.
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Old 14th Aug 2011, 10:57 pm   #112
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Default Re: Philips B3X85U troubleshooting

Plugged in and switched on.
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Old 14th Aug 2011, 11:07 pm   #113
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Default Re: Philips B3X85U troubleshooting

UBC 81 Tube

Pin 1. 85 V
Pin 2. 0 V
Pin 3. 2 V
Pin 4. 0 V
Pin 5. 0 V
Pin 6. 0 V
Pin 7. 0 V
Pin 8. 0 V
Pin 9. 0 V
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Old 15th Aug 2011, 12:22 am   #114
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Default Re: Philips B3X85U troubleshooting

Take a look at the attachment to post #40 in this thread. Pins 3, 6 and 7 of the UBC81 should all be wired together and taken to chassis. Thus they should all read 0V, yet you show 2V on pin 3. Check again and check your wiring.
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Old 15th Aug 2011, 5:40 pm   #115
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Default Re: Philips B3X85U troubleshooting

Ok, Resistor 15 measures 219 ohm with radio off.
With the radio on, Resistor 15 measures 85 V on the side connected to the tube,
and 103 V on the other side of the resistor.
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Old 15th Aug 2011, 5:43 pm   #116
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Default Re: Philips B3X85U troubleshooting

Are pins 3.6 and 7 tied together to earth?

Cheers,

Steve P.
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Old 15th Aug 2011, 5:44 pm   #117
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Default Re: Philips B3X85U troubleshooting

R15 should be 220K or 220,000 ohms. Most likely you've misread your meter. Check again though.

Note my comment in post #114.

EDIT and Steve's comment above. We're falling over each other to help you.
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Old 15th Aug 2011, 6:15 pm   #118
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Default Re: Philips B3X85U troubleshooting

I noticed that the capacitor that runs from pin 3 to the center shield of the tube (don't know what that's called) is loose and I'm not sure if it is supposed to be soldered.
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Old 15th Aug 2011, 6:27 pm   #119
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Default Re: Philips B3X85U troubleshooting

If you look at the diagram attached to post #40 you'll see that it should be a bit of wire. I assume that one of the three pins or the centre spigot is connected to chassis at some point?
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Old 15th Aug 2011, 6:31 pm   #120
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Default Re: Philips B3X85U troubleshooting

I do notice now on pin 3, that if I push the wire of the capacitor to the center spigot, it measures 0 V. I'm thinking it does need to be soldered, so I'm gonna proceed and solder it.
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