UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - MK14 programming interface

SiriusHardware · 22nd Apr 2019, 10:24 pm

Just catching up as I have been off grid for the whole of the Easter weekend. Those new results with the original 365 are just bizarre. I've just arrived back but I will take a look at the components on mine, especially in the reset area since they seem so different in that particular area. Why can mine be reset so much faster?

Can you just confirm that your reset opto collector resistor really is 120R, not some other value? If it were bigger then obviously it would take a lot longer to discharge the reset capacitor.

I've also just checked that mine really is 120R - since I used SM resistors throughout for mine, it would have been all too easy to make the mistake of putting a part marked '120' (12 ohms) in there instead of '121' (120 ohms).

I've also managed to wangle a quantity of TI SN74LS365 sourced directly from RS UK, you are welcome to a handful of those (free) if you want them - the least I can do after all the beta testing you've been doing.

22nd Apr 2019, 10:24 pm	#67
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,553	Re: MK14 programming interface - MK2 Just catching up as I have been off grid for the whole of the Easter weekend. Those new results with the original 365 are just bizarre. I've just arrived back but I will take a look at the components on mine, especially in the reset area since they seem so different in that particular area. Why can mine be reset so much faster? Can you just confirm that your reset opto collector resistor really is 120R, not some other value? If it were bigger then obviously it would take a lot longer to discharge the reset capacitor. I've also just checked that mine really is 120R - since I used SM resistors throughout for mine, it would have been all too easy to make the mistake of putting a part marked '120' (12 ohms) in there instead of '121' (120 ohms). I've also managed to wangle a quantity of TI SN74LS365 sourced directly from RS UK, you are welcome to a handful of those (free) if you want them - the least I can do after all the beta testing you've been doing.