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Old 20th Mar 2023, 10:27 pm   #267
frsimen
Heptode
 
Join Date: Jan 2011
Location: Croydon, London, UK.
Posts: 767
Default Re: Help needed with - Racal Dana 9081

Hello Mark,

I think you have the step switch knob aligned correctly, as the switch between multiples of 5kHz and multiples of 6.25kHz is taking place at the right positions.

The odd multiples issue should be sorted out when IC15 is replaced as this has been shown to be faulty and governs the selection of the pulse multiples.

You could try different timebase settings on the oscilloscope to see if you there is a pulse waveform. If there is anything badly wrong there, the band edges will be wrong. You can check that the band limits on range 1 and range 2 are indicating as expected, despite the steps being a little odd. If they are correct, there isn't a problem.

Paula
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