PM 8 Epsylon Industries 8" Picture monitor - UK Vintage Radio Repair and Restoration Discussion Forum

dgb1951 · 3rd Jun 2014, 1:08 pm

Hello all from Australia,

Recently I traded 3 vintage 16bit PCs for an early Teletype for my 1968 DEC PDP8i computer.

As part of the trade I also got given a pair of PM 8 [625] 8" Picture monitors by Epsylon Industries Ltd, Feltham Middlesex England. One is serial numbered 103

I think their age is mid 1950's and they contain all valves.

Main CRT is a Ferranti type 8 / 03 TM s/n JS215

I am looking for any information that is available, like circuit drawing and especially data for the pin information of the 18 pin Belling-Lee connector mounted on the rear. Hopefully I can also find 2 mating connectors for this plug. I note it is 3 row and 1 pin at top of each of the outer rows is larger diameter than the remaining 16 pins. Maybe this is for the high current low voltage, needed for all the valve heaters.

As far as I can tell this connector brings Power into this Monitor, since there does not appear to be any AC 240v mains cable inlet. I have as yet, not tried to trace the wires from this connector.

Thus I assume there was an external power supply unit, that had provided the HV supplies and the 6.3v ac for valve heaters.

I can see a section inside the unit that is obviously the EHT section.

Have added some photos of the units to this post.

hope someone has some information please.

plan to use both as display units on a Analog Computer I am rebuilding.

regards
David Broadbent

beamcurrent · 3rd Jun 2014, 7:31 pm

Hi David

What an interesting little monitor, I have the big brother of it, a 17inch version, same style and age.

I have attached some pictures of it.

I would have expected your monitor to have an internal mains power supply, mine has and as you can see there is the multi way Connector on mine as well. My monitor is away in store and not easy to look at.

The mains would go in on a round 4 pin connector, type EP4 made by a number of manufacturers including cannon. you can just see them on the back of mine. It may have been changed for a later type of connector to meet local regulations.

Back to the connector, I would expect it to have done remote control remote brightness/contrast/cue light and maybe input switching, all common functions back then.

If you do come up with the circuit I would appreciate a copy too, my monitor will be similar.

Try to look after it, it's age makes it quite rare and it should be saved for the future.

Very Best

3rd Jun 2014, 1:08 pm	#1
dgb1951 Retired Dormant Member Join Date: Jun 2014 Location: Melbourne Australia Posts: 1	PM 8 Epsylon Industries 8" Picture monitor Hello all from Australia, Recently I traded 3 vintage 16bit PCs for an early Teletype for my 1968 DEC PDP8i computer. As part of the trade I also got given a pair of PM 8 [625] 8" Picture monitors by Epsylon Industries Ltd, Feltham Middlesex England. One is serial numbered 103 I think their age is mid 1950's and they contain all valves. Main CRT is a Ferranti type 8 / 03 TM s/n JS215 I am looking for any information that is available, like circuit drawing and especially data for the pin information of the 18 pin Belling-Lee connector mounted on the rear. Hopefully I can also find 2 mating connectors for this plug. I note it is 3 row and 1 pin at top of each of the outer rows is larger diameter than the remaining 16 pins. Maybe this is for the high current low voltage, needed for all the valve heaters. As far as I can tell this connector brings Power into this Monitor, since there does not appear to be any AC 240v mains cable inlet. I have as yet, not tried to trace the wires from this connector. Thus I assume there was an external power supply unit, that had provided the HV supplies and the 6.3v ac for valve heaters. I can see a section inside the unit that is obviously the EHT section. Have added some photos of the units to this post. hope someone has some information please. plan to use both as display units on a Analog Computer I am rebuilding. regards David Broadbent Attached Thumbnails

3rd Jun 2014, 7:31 pm	#2
beamcurrent Heptode Join Date: Mar 2008 Location: Camberley, Surrey, UK. Posts: 805	Re: PM 8 Epsylon Industries 8" Picture monitor Hi David What an interesting little monitor, I have the big brother of it, a 17inch version, same style and age. I have attached some pictures of it. I would have expected your monitor to have an internal mains power supply, mine has and as you can see there is the multi way Connector on mine as well. My monitor is away in store and not easy to look at. The mains would go in on a round 4 pin connector, type EP4 made by a number of manufacturers including cannon. you can just see them on the back of mine. It may have been changed for a later type of connector to meet local regulations. Back to the connector, I would expect it to have done remote control remote brightness/contrast/cue light and maybe input switching, all common functions back then. If you do come up with the circuit I would appreciate a copy too, my monitor will be similar. Try to look after it, it's age makes it quite rare and it should be saved for the future. Very Best Attached Thumbnails __________________ Regards Brian Visit the Virtual Broadcast TV Camera Museum