"STACPAC", Inside a vintage power supply - WARNING images contain 'tubes' - Page 1
Forum section: electronics / testgear

author: lowimpedance
author_rank: Super Contributor
timestamp: June 21, 2013, 04:23:48 am
content: Just finished cleaning up a couple of odd little vintage power supplies that were designed in the fifties, (yes last century!), by CSIRO and actually made in Australia. And for all those who have their hammers ready to 'adjust the nice glowing bottles', I have a couple of rather large fella's at the door who like to be called 'Sir ' who will quietly escort you out of the building.The units were named 'STACPAC' for the fact that upto 3 units could be stacked upon each actually interconnecting them and allowing series/ parallel or individual unit control. In series or parallel only one unit did the control of all outputs. Only one power lead is needed to power the whole stack.They were adjustable from 100V to 260V DC @80mA (woo hoo!) in single units. Series or parallel operation giving higher volts or current.The pictures below show the supply with its guts hanging out for servicing ,ie replacing dud caps and resistors that had drifted high.Also some photo's of the units stacked and running, one being in parallel giving 160 volts showing the lower unit doing the oupt control. The other a photo of the series output of 520V max shown on one of my ultra modern multimeters the DT360 !!.Now you didn't expect me to use anything with an LCD did you.I do have the manual if anyone else really cares for the info !!.

author: SeanB
author_rank: Super Contributor
timestamp: June 21, 2013, 04:15:25 pm
content: Change that wax dipped Hunts capacitor in the bottom, it will die sooner or later, they are not reliable ( always fail as leaky or short circuit) and it will do well.Did it have that nice smell of warm Bakelite after you turned it back on after the recap? Odd getting 20uF 450V axial electrolytics for it though, though they do look nice and original in there, especially with the nice sleeving dressing the leads. I have a roll or three of RS stocked glass fibre sleeving ( I use it for terminals on heating elements in a machine) that would look period though rather than the clear, available in colours like red, black and natural white.

author: lowimpedance
author_rank: Super Contributor
timestamp: June 21, 2013, 11:39:00 pm
content: Yeah I should get to that dipped cap to finish it off, got some nice polystyrene's in the drawer!. The original electrolytics were in fact 22uF and 16uF straight after the rectifier tube. The main B+ being in the order of 520V so the filter caps are two in series before and after the filter choke and each cap has a equalizing resistor across it.The sleeving is PTFE, the originals were large enough not to have needed it. I did not bother too much with trying for complete originality but more for renewed functionality, (not to many axial caps with the about right values easily available these days!).Oh yes I got that nice yesteryear smell when powered up againThese supplies are quite rare so I thought it would be nice to have a couple of working examples, but in the end they will probably just sit in the cupboard again

author: free_electron
author_rank: Super Contributor
timestamp: June 22, 2013, 07:59:18 am
content: Where's me double-barreled blunderbuss ... And the bag of coarse shot....

author: SeanB
author_rank: Super Contributor
timestamp: June 22, 2013, 10:28:56 am
content: Quote from: free_electron on June 22, 2013, 07:59:18 amRight next to the door Grandpaw........... Where you left it last night when you came rolling in after drinking all that moonshine you made from those windfall apples, told you they was rotten such that even the cows wouldn't eat them.

author: Bored@Work
author_rank: Super Contributor
timestamp: June 22, 2013, 11:03:12 am
content: Quote from: SeanB on June 22, 2013, 10:28:56 amThat bad booze would explain why he believes his blunderbuss is double-barreled.

author: SeanB
author_rank: Super Contributor
timestamp: June 22, 2013, 11:25:58 am
content: Just have to add I have this cheap tinny banjo music playing in my head thinking of this...............Both types, country and western!

author: rsjsouza
author_rank: Super Contributor
timestamp: June 22, 2013, 11:42:19 am
content: Very nice work indeed! In particular I absolutely love the Miniwatt "Made in Australia" in picture two - I still have two of their catalogs purchased in an old bookstore years ago, and several vaccuum tubes somewhere in the house...

author: David Aurora
author_rank: Frequent Contributor
timestamp: June 22, 2013, 01:14:54 pm
content: Quote from: rsjsouza on June 22, 2013, 11:42:19 amMaybe it's because I'm not as old as I feel, but seeing Made In Australia on ANYTHING electronic kind of blows my mind. I pulled apart an old Dept. of Education issue portable record player a few weeks back that my Grandma had in her garage. I expected to find cheap, mass-produced-in-China 80's shit inside. But nope. Found a 1962 date stamp and a Made In England marking, all hand wired point to point with Australian made tubes in there. I just don't think of Australia as being somewhere that produces components (though I remember my Nanna telling me loads of stuff that USED TO BE made here...), so it was an interesting surprise to see that stuff in there.

author: SeanB
author_rank: Super Contributor
timestamp: June 22, 2013, 02:51:12 pm
content: I do have some lamps that were proudly stamped Made in South Africa by GE, but that factory closed in the 1970's. There are still lamps made in Europe and in the USA, but most of those plants are for export only, so I get them here. Funny thing is that the stuff from those factories lasts decades longer than the PRC junk, but is only twice the price. Twice the price, 20 times the life.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 23, 2013, 03:47:37 am
content: Quote from: David Aurora on June 22, 2013, 01:14:54 pmAustralia used to make an incredible amount of Electronics stuff back in the day.Looking back,there was a lot less manufacturing in Asian countries other than Japan,& parts from the USA ,UK & Europe were not always competitive in price with the Australian made stuff.As Japan started to ramp up their production,their components & complete units became cheaper,(with a lot of help from the Japanese taxpayer).There was also the "cultural cringe" factor---"Australian made?---Really,my dear,how could you?"Rightly,or wrongly,the decision makers went with the idea that "Australian made" meant inferior,so any subsidies were dropped,& local manufacturing fell away to nothing.Of course,the local manufacturers were often their own worst enemies--there was more profit in importing something & putting your own label on it,than making it yourself.And,the Japanese stuffwasgood,& got better over the years!"Karma is a bitch",though,& we now see long established Japanese brands being pushed aside by the brash new competitors from Korea & China.

author: lowimpedance
author_rank: Super Contributor
timestamp: June 23, 2013, 11:38:52 pm
content: Quote from: free_electron on June 22, 2013, 07:59:18 amSHEILDS UP

author: gjdaus
author_rank: Newbie
timestamp: July 06, 2013, 08:39:15 am
content: Hi LowZ,Just joined the group.I have one of those Stacpac F-133-B power supplies that I hope to restore soon.If it is possible to get a scanned copy of the manual you have, I'd really appreciate it.Will sure make life easier - save me the trouble of tracing the circuit etc.Thanks,Graham