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Old 9th May 2009, 3:39 pm   #134
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Default Re: Roberts RT7 - problem

Quote:
Results:T2 primary measured on 20k Ohm range
TR7 - 0.01
TR6 - 1 .00 i.e. open circuit
Readings have to be multiplied by 1000, so you have 10 ohms and 1000??ohms respectively. Something wrong there. How does your meter indicate open circuit ie switched to 20K range with no leads connected? Is there a reason for your writing 1 .00 rather than 1.00? Try again using the 2000 and 200 ohm ranges.

Quote:
T2 upper secondary
TR7 - 0.01
TR6 - 0.01
10 ohms per winding. Looks OK check using the 200 ohm range

Quote:
R30 code: Red Violet Brown Silver = .37 (20k Ohm range)
Colour code indicates a 270 ohm resistor. At 370 ohms it's out of spec. Check on the 2000 ohm range.

Quote:
Voltage: T2 primary; chassis to emitters -
TR7 = 0V
TR6 = 0V
Looks OK, but an open circuit primary would still result in 0V readings.

Quote:
Upper secondary;
TR7 = 9.23V
TR6 = 9.23V
Looks OK.

Quote:
Meter check revealed a zero reading using the resistor connected as instructed.
Duff meter range?
Yes. If you're doing the test right that range is faulty. What do you get on the 200mA range? Some meters have an internal fuse for current ranges. Check it's OK.
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