Heathkit Model 0-11 - Page 1
Forum section: electronics / testgear

author: jrevard
author_rank: Newbie
timestamp: December 27, 2015, 06:00:42 pm
content: I have a Heathkit Laboratory Oscilloscope Model 0-11. Does anyone know the best way I can test this device to see what its condition is (I tried Arduino PWM but not sure if I did it correctly)? Any specific features I should try out? Basically just want to know what I've got and if it works.Thanks!!Justin

author: PaulAm
author_rank: Frequent Contributor
timestamp: December 27, 2015, 08:15:22 pm
content: 5 MHz scope marketed for color TV servicing:http://www.radiomuseum.org/r/heath_laboratory_oscilloscope_o_4.htmlI think this was a recurrent sweep scope, so setup to get something to display shouldn't be fussy.Plug it in and turn it on and see if the screen lights up. Given the age and the possibility of it being a kit, there are decent odds it won't work or the caps are shot. Probably want to make sure it has all the tubes in it too.You may want to find the manual and check voltages against the specs. Watch where you're poking though, besides the HV for the CRT, there's B+ all over the chassis.

author: Richard Crowley
author_rank: Super Contributor
timestamp: December 27, 2015, 08:20:38 pm
content: As @PaulAm suggests, you can check the basic controls and functionality, etc.Assuming it is making a trace across the screen, you could do something as simple as touching the probe (or input terminal) to see if it will show the mains-hum picked up by your body.If it doesn't already have one, I would fit a 3-pin power cord on it so that chassis is safely grounded. In fact I often just chop off the attached cords and put a modern IEC male mains connector on things to make it easy to use any old IEC power cord.

author: med6753
author_rank: Super Contributor
timestamp: December 28, 2015, 02:46:32 am
content: My first scope was a Heathkit O-10 which is nearly identical to yours. My father built it around 1955 and I started using it about 1967. It is a decent scope with 5Mhz B/W, full retrace blanking, and a regulated B+ supply. I wish I still had it. It is a far cry from earlier Heath scopes which were not much to write home about.It is a recurrent sweep scope which means it's a little fussy when syncing up wave forms. It will always drift slightly but perfectly usable. And keep in mind that this is an AC coupled scope and cannot measure DC voltages or DC offsets.Before ripping into it and adding a 3 wire line cord I would determine it's overall condition. Is it functional? Is it original? Has it been restored? These are important questions to answer first. If it's original and not working you have a long quest to get it going. That scope is loaded with wax filled tubular capacitors which I guarantee are leaky. Especially the 2 large high voltage tubular caps under the chassis. Plus all the coupling caps between stages. These type of caps were typical of 1950's design. The cans in the B+ supply are probably dried out too. Then you have to deal with all the carbon composition resistors that have absorbed moisture over the years and increased in value. I'm not trying to discourage you. I'm simply stating worst case as to what you might find. If it were my scope I would enjoy doing the restoration.Luckily the vacuum tubes are still readily available, even the somewhat rare 1V2 High Voltage Rectifier. The 5UP1 CRT was used in many scopes and is not too difficult to find. I did a quick check of flea bay and saw 2, although some clown thought his was worth $50 USD. But you shouldn't need a CRT unless yours is physically damaged.I have the schematic for the O-10 but no manual. If you want a copy let me know and I'll scan it and sent it to you. And just a word of caution. If you haven't worked much with vacuum tube circuits be careful. The B+ voltages can bite you and may show up in unexpected places due to defective parts.