On Fri, 05 May 2006 23:53:07 +0200, switcher
wrote:
Strange thing is that with var cap + 10nF the loop only tunes between
say 207 and 225 khz, while on AM (without the 10nF), it tunes 1 MHz wide
..

explanation ??

Your variable capacitor (probably in the 20 to 400pF range) is a small
percentage of the total capacitance when the 10nF is added to it.
Alone, and at a higher frequency, it is enough to cover that much
range.

I saw that some people make their own var cap ... (with very large
plates...)

Now, I intend to buy some nF caps from 1-50nF or so, to see what's
happening ...

Buy some 1-50nF? You may discover why others build them.

Today I picked up two old grundigs, and after some tweaking (knobs) they
work !
melody boy 500 (excellent condition, the AM-FM- etc knobs aren't touched
...)
and a Yacht boy with lamp, batt indication, AFC ... tunes very well on
SW...
Great sound on both radios ...

yes indeed.

---and now, for a great song: ---
http://www.asklyrics.com/display/Chu...rics/12119.htm

Chacun à son Goût!

73's
Richard Clark, KB7QHC