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 specialised teletext processing board (decoding) "talks" to other modules in the EH-1000 via special "click fit" ribbon connectors (these will be offered separately) and there is no soldering required to fit this board into another EH-1000
Now it's time to take out the "scalpel" and start the op!
One of the first things to note is that this board looks entirely different to the other modules in the EH-1000, in fact I believe it is 3rd party sourced. Major differences are the phenolic substrate, single sided and there are no 9xxx code numbers on this board but instead it appears to have been manufactured by a company called CME
Another aspect that surprised me a little is the extensive use of IC sockets for the integrated circuits on most of the PCB's, except this board. This board will not easily "give up" many chips, in fact only one chip is sitting in a socket.
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 ...
TELETEXT PROCESSOR MODULE
PCB type: phenolic, single sided
Part #CME L61710432
The PCB is populated with a number of passive devices, nothing too special about these (2x crystals, mix of metal and carbon resistors, trimmer cap) and the active devices are:
Socketed: RCA CDM6116AE3 (2K x 8 SRAM 150nS)
Soldered through hole: Philips SAA5243/PE (625 line teletext decoder on a chip) & a Philips SAA5231 (Teletext video processor)
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 teletext module could come in very useful, if not then perhaps just the SRAM may be of use
PCB DIMENSIONS:
100mm x 95mm x 20mm height
WEIGHT: 55g
This CME teletext 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 that SRAM in particular.
