On Sun, 06 Mar 2016 23:34:55 +0100, Dimitrij Klingbeil wrote:

It's only my guess, but I think that they intended this supply to run
rather somewhere below resonance than somewhere above. This would mean
that adjusting the pulse frequency down to 17.35 kHz should do no harm
as that value would be lower than the setting right now.

I've just noticed that towards the bottom of (true) page 106, it states
the following:-

"The oscillator frequency is approximately 25kHz, determined by network
C1811, R1823 and is adjustable by means of R1824."

It then goes on to specify the duty cycle. Two things stand out as
requiring further investigation here. Clearly, the 25kHz clock frequency
mentioned is *miles* away from what my clock is running at - and the
frequency adjustment is made with R1827, not R1824 (which is fixed
anyway). I'm guessing the reference to R1824 is just a typo, but can we
say the same for 25kHz??
Since this *completely* changes our former assumptions, I'm going to
confine myself to just replacing the flaky polyester caps for the time
being. Be interested to hear how you think I should proceed now in the
light of this...