BACKGROUND INFORMATION
THE EH-1000
After years of use and then storage once the analog Teletext television system was turned off yonks ago, I have finally gotten around to placing this professional, very well built equipment onto the workshop bench ... the "operation" has begun
This equipment was fully functioning but of no possible further use in our digital television (with no teletext broadcasts) era so now I have extracted components and modules "of interest" which can be used to restore another EH-1000 or think of this board as a "component farm" a place where some difficult (or impossible) spare parts may lurk ...
This PCB board module sits just below the attenuator on the right hand side and is connected to another module in the EH-1000 via special "click fit" ribbon connector (these will be offered separately), meaning that there is no soldering required to fit this board into another EH-1000
One part of the PCB has the 3x push ON release OFF soft touch switches and above each are 2x 3mm Green leds. On another section of the board are 3x active integrated circuits.
Now it's time to take out the "scalpel" and start the op!
One of the first things to note is that although this is branded Unaohm and manufactured in Italy, the components inside have been substantially sourced from European and English component manufacturers, the likes of Siemens and Philips in particular. Although I have been unable to establish who made the switches (nice), I would be 99% sure they are of European or possibly English origin - NOT Asian.
Another aspect that surprised me a little is the extensive use of IC sockets for the integrated circuits on most of the PCB's, a potential source of trouble when it comes to reliability (especially since most of the sockets are double wipe but not machined) but great when the board is being used as a component farm - no fuss de-soldering useful components.
THE DONOR EQUIPMENT
UNAOHM - Teletext Video RF Analyser
Model: EH-1000
Designed & manufactured in Milano, ITALY
Circa Late 1980's (based on advertisements placed in Wireless World at the time and the date stamp on the AC transformer core)
Technology: Analog video broadcast signal analysis - specifically for examining lines of Teletext information "riding along" with the video signal
Luggable (heavy at 15kg) due to the heavy duty Aluminium outer case but more importantly, the inside welded steel frame chassis inside.
Well engineered inside, logically laid out using a number of modules which are well interconnected.
Designed for 220V 50Hz operation (because of this, we used this equipment via an AC variac many years ago)
Green emitting rectangular CRT based front panel display
Interested in the technical nitty gritty? Here is an old copy of the spec sheet
Enough of the yacker, let's "go out into the fields" and see what fruit this "component farm" could provide ...
FRONT PANEL CONTROL MODULE (WITH GREEN LEDS) MODULE
PCB type: double sided
Part #9175
There are two small PCB's which are hard wired at right-angles to each other. There is only one small interconnection male socket, special type but I have kept the ribbon cable (with connectors) that was originally installed.
One "side" of the module is the switches and leds along with a number of metal film resistors. The other section has three quite ordinary logic devices, ALL in double wipe sockets, from the 74HC series, these being a MOTOROLA MC74HC73 (), TEXAS INSTRUMENTS SN74HC14 and the last is a MOTOROLA MC14029
Please keep in mind that the EH-1000 (and thus this board) has been and was FULLY OPERATIONAL - you can be confident these devices will perform as designed.
This module was FULLY FUNCTIONAL prior to removal from the equipment, meaning that if were looking to "bring back to life" another EH-1000, this complete module 9175 could come in very useful
PCB DIMENSIONS:
60mm x 50mm x 33mm height
WEIGHT: 75g
This 9175 module has now been "laid to rest" within an ESD bag, bubble-wrap and is lying on a stiff cardboard backing, everything then within a sealed clear plastic packaging, ready for a trip to another resurrect another EH-1000 or become an "organ donor" for other equipment.
