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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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24th Jan 2011, 10:46 pm | #101 |
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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? |
25th Jan 2011, 1:20 am | #102 |
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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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25th Jan 2011, 4:13 am | #103 |
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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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25th Jan 2011, 9:11 am | #104 |
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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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25th Jan 2011, 10:20 am | #105 |
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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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14th Aug 2011, 10:04 pm | #106 |
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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. |
14th Aug 2011, 10:18 pm | #107 |
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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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14th Aug 2011, 10:25 pm | #108 |
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Re: Philips B3X85U troubleshooting
That's affirmative.
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14th Aug 2011, 10:38 pm | #109 |
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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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14th Aug 2011, 10:42 pm | #110 |
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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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14th Aug 2011, 10:56 pm | #111 |
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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. |
14th Aug 2011, 10:57 pm | #112 |
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Re: Philips B3X85U troubleshooting
Plugged in and switched on.
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14th Aug 2011, 11:07 pm | #113 |
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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 |
15th Aug 2011, 12:22 am | #114 |
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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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15th Aug 2011, 5:40 pm | #115 |
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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. |
15th Aug 2011, 5:43 pm | #116 |
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Re: Philips B3X85U troubleshooting
Are pins 3.6 and 7 tied together to earth?
Cheers, Steve P.
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15th Aug 2011, 5:44 pm | #117 |
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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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15th Aug 2011, 6:15 pm | #118 |
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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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15th Aug 2011, 6:27 pm | #119 |
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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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15th Aug 2011, 6:31 pm | #120 |
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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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