'Noble' TRF radio (Portadyne Princess 'lookalike'). Any info please?

[Yorkie]

It doesn't seem to be commonly known but there is a solution to the log/antilog/special law potentiometer problem and it surprisingly simple!

If you put a resistor between the slider and one end of the pot, you will alter the law of the pot. For a log law, the resistor should be between the slider and the earthy end. For an anti-log law simply move the resistor so that it is between the slider and the 'hot' side of the pot.

Thanks for reading the thread Terry and for your helpful comments.

The first of these little sets I worked on was a 'Portadyne Princess', on which I wrote a thread on the forum, I think back in 2012 when the topic of adding a resistor to create an anti-log pot was discussed. The website 'Secret Life of Pots' was discussed, and Lawrence pointed out another useful site which explained how to do it. I gave it a spin but couldn't create the effect of an anti-log law plot - maybe because I wasn't measuring it correctly?

Another topic is that of 'tapped' pots which occasionally crops up - I  had a problem with a Stella 105U which used a tapped pot and was duff. I'd wondered if that too could be solved by external resistors, but the consensus was no - it couldn't.

An interesting topic worthy of discussion in its own right, so I'll start a new thread on it so it doesn't get buried in this thread as it's not just common to the Noble, Princess or Stella radios, and as time passes, and radios become even older and pots go to the 'workshop in the sky', it will perhaps crop up more often.