atwater: Request for help_ Resistance values

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Forum » Radio e altri tipi di apparecchi (dalla fisica alle TV) » MODELLI NEL SITO » atwater: Request for help_ Resistance values
Júlio Branco
Júlio Branco
P  Articoli: 199
Schemi: 124
Foto: 666
12.Jul.22 17:26
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Dear radio friends


I'm trying to recover an AT Wather model 137 Cathedral Cabinet style radio I came across a problem, the resistors have unusual codes, that is, some have two colors, others with one and the value of some for example R4 : .5 Ohm on the contrary and R15= .1 Ohm on the contrary, (Ω ), can any of your friends help to read the real value of these resistors, or if there is any common factor of multiple or divisible depending on what appears in the diagram?

Please see this schematic scrap I prepared


A big thank you in advance

From Portugal

Júlio Branco






Questo articolo è stato modificato il 12.Jul.22 18:06 da Júlio Branco .

Tomasz Szczesniak
PL  Articoli: 87
Schemi: 88
Foto: 1182
12.Jul.22 17:36
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Most probably this values are in Megaohms (MΩ). Notice the Ohm symbol on this resistors - is printed upside down: ℧.

Rolf Beckers
Rolf Beckers
D  Articoli: 201
Foto: 664
13.Jul.22 14:02
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Dear Julio,

In most old diagrams resistors are either in single Ohm e.g. 100 = 100 Ohm or 25,000 = 25kOhm. Or they come with a leading dot in MegaOhm .5 = 0.5 MOhm. The numbers of the color code are similar as today, but there are no rings, see attached table. Most old resistors are colored as shown left above.




Lars-G. Lundelin
FIN  Articoli: 138
Schemi: 32
Foto: 111
13.Jul.22 16:35
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Atwater Kent used their own color codes for certain resistor values. You will find codes in the following





Júlio Branco
Júlio Branco
P  Articoli: 199
Schemi: 124
Foto: 666
14.Jul.22 09:44
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Dear Tomasz

Thank you very much for the information, I have confirmed that the position of this inverted symbol is read in MOhmos.

Júlio Branco