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 Post subject: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 3:55 am 
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 1514
Location: Mesa, AZ, USA 85212
I have a Radiola 18 that does not work. Measuring voltages I find I get almost nothing on terminal 8. Should be 165 VDC

Resistors R1 to R6 all ohm out good. Coil L1 ohms out OK. C1, C2 and C3 have been replaced.

What is the likely issue?


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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 7:26 am 
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Joined: Mar Thu 21, 2019 2:53 pm
Posts: 415
Location: Niosia / Cyprus
Does the power transformer gets hot?
Do you get voltage at terminal 7?
Probably the tube is dead.

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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 11:15 am 
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Joined: Jun Mon 12, 2017 7:17 pm
Posts: 259
did you measure the AC voltages at the transformer secondary?
Rich


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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 11:22 am 
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 18297
Location: S. Dartmouth MA USA
Use a VOM, not a DVM for measured voltages and resistances.

Use the VOM to measure the resistances of the "new" capacitors.

Include what reference terminal is used to measure any errant voltage.

Re-solder every joint, remake very connection to the chassis. Especially it that chassis connection is riveted even if the VOM says the connection is good.

IMHO wiring error, bad connections, open bias resistors, open chokes open HV secondary of transformer. With less than a handful of parts...

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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 11:24 am 
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 7414
Location: Bossier City, Louisiana
If your getting voltage at terminal 7 and not 8, it it is likely L1 is open or a wiring issue.
Ohm between 7 and 8. You should read through choke and the resisistor or from 8 to C-2 which you should read value of choke.

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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 7:07 pm 
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 1514
Location: Mesa, AZ, USA 85212
Thanks for the help. I had opened and repotted the can containing L1 and the 3 capacitors. I went by the terminals shown on the Riders schematic, but it must be shown from the top rather than the bottom, it is the reverse of what was in there!

All is good now.


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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 7:13 pm 
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 7414
Location: Bossier City, Louisiana
Good to hear!

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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Tue 09, 2022 9:33 pm 
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Joined: Jan Thu 01, 1970 12:00 am
Posts: 1681
Location: Bristol TN 37620
Location: Bristol TN 37620
Good job, Mike.


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 Post subject: Re: Radiola 18 power supply issue
PostPosted: Aug Fri 12, 2022 10:54 am 
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Joined: Jun Sat 02, 2007 12:37 pm
Posts: 1776
Location: Ennismore, Ontario, Canada
Location: Ennismore, Ontario, Canada
ASUMike wrote:
Thanks for the help. I had opened and repotted the can containing L1 and the 3 capacitors. I went by the terminals shown on the Riders schematic, but it must be shown from the top rather than the bottom, it is the reverse of what was in there!

All is good now.


You are right - that diagram is deceiving.

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Ennismore, Ontario, Canada


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