> i like the blue LED under the valve BTW
I do too - these usually wind up on my desk at work and it's always a conversation starter if I'm listening and working and someone drops by...
> so the hiss went with the lower voltage glad to hear.
Last night, I added two 1000uf caps across power at two places, along with a couple of .1uf at a couple of locations. Seems to quieted a bunch of hum (with lab supply) and hiss. Now not quite so twitchy on voltage - I can run it off of a Heathkit lab supply for 12V to about 13V, no issues. But, regarding a SMPS - ditto - I have a bucket full of (various brand) discarded laptop power supplies (all about 15 to 19 VDC, all at LEAST 1.5 amp, some to 3A), so yup, a nice filter / regulator is what I've already sketched out..
>heres a quick pic Mike of my LM3785 Gainclone testbed till i get round to a proper enclosure...
Oooooooo. Handmade / homebrew trumps fancy Hammond enclosure most anytime. I like it! It Just needs a lid.
> .(Rogers) ..Both sides of the MOSFET and LM317 ...
Nope - used four TO-220 mica insulators, with a sort-of nylon shoulder insulator for the bolt. Also some heatsink grease, for what it's worth - dunno if it'll transfer THAT MUCH more heat. Topside, just screw against metal. Due to some misalignment, the mica insulator actually bared a bit of metal to the tab, so I did have a short in initial testing, but after some realignment and fudging, it works fine now. I think I had a shard of drill debris hanging on.
Yup - always good to check that TAB if it's mounted on ground - and I grounded the lid just for convenience - I love the PC boards, but I'm always just using a perf-board and point-to-point wiring, so it's convenient (and sometimes necessary for RF applications) to have a nice, large ground-plane to tie to or to just 'be near-by'.
I will crank out the 'good' camera and shoot some good images later this week, I hope... if work doesn't kill me...
Mike Y