Eddystone: RF gain potentiometers logarithmic

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Martin Bösch
Martin Bösch
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28.Apr.07 22:51

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Reply  |  You aren't logged in. (Guest)   1 In Eddystone User Group Newsletter 50 I found the following useful information an replacing RF gain pots in Eddystone receivers:

Usually AF gain pots are logarithmic carbon types, RF gain pots usually used linear wire-wound types.
After replacement of RF gain potentiometers with common linear ones, many listeners found that the whole RF gain control range was passed through in the last eigth of a turn.
A careful inside inspection of a Eddystone RF gain pot revealed, that in that wire wound potentiometer three different thicknesses of resistance wire had been used. The first third in 10 kOhm pot is linear 0 - 500 Ohms, the second third 0 - 2000 Ohms, the third bit 0 - 7500 Ohms, so the whole makes 10000 Ohms.

So consider trying to clean out Your Eddystone RF - gain pot instead of simply replacing it with a 10 kOhm linear one, otherwise Your RF-gain control might suffer from the "Switch Syndrome"...

Hope that helps, kind regards Martin