10-05-2020, 11:55 AM
Hi Dave,
Yes, that's my scan - the same one as is in The Archive here. So that doesn't get you any further forward, sadly. Like Paul, I suspect that a modification might be required.
Fortunately, that's easy - just lift the end of R29 or C35, or perhaps R38 - the exact component you choose can be a matter of whatever easiest.
I've been looking for clues in the datasheet for the MM5316 - http://pdf.datasheetcatalog.com/datashee...223_DS.pdf
It only offers 1 alarm output (pin 25). This goes high and starts the phase-shift oscillator (TR5). Also, via D5, it turns on the radio via TR3 and 4. Pin 39 is a 1Hz output, which is used to modulate the oscillator.
Looking at the way Roberts have designed it, it doesn't look like there's a way to separate those functions - so the radio and alarm coming on together is what they intended.
I could dig my example out from the attic and investigate further if required, but I the more I look, the more a mod is looking likely, I'm afraid.
Thank you for the complement - I really must devote a bit of time to finishing some of the articles I've got in the pipeline.
All the best,
Mark
Yes, that's my scan - the same one as is in The Archive here. So that doesn't get you any further forward, sadly. Like Paul, I suspect that a modification might be required.
Fortunately, that's easy - just lift the end of R29 or C35, or perhaps R38 - the exact component you choose can be a matter of whatever easiest.
I've been looking for clues in the datasheet for the MM5316 - http://pdf.datasheetcatalog.com/datashee...223_DS.pdf
It only offers 1 alarm output (pin 25). This goes high and starts the phase-shift oscillator (TR5). Also, via D5, it turns on the radio via TR3 and 4. Pin 39 is a 1Hz output, which is used to modulate the oscillator.
Looking at the way Roberts have designed it, it doesn't look like there's a way to separate those functions - so the radio and alarm coming on together is what they intended.
I could dig my example out from the attic and investigate further if required, but I the more I look, the more a mod is looking likely, I'm afraid.
Thank you for the complement - I really must devote a bit of time to finishing some of the articles I've got in the pipeline.
All the best,
Mark
