BACKGROUND INFORMATION
PERSONAL
I tell this story because others may relate to this ...
As a youngster growing up in NZ during the 1960's I had a strong interest in all things electronics. I am an "Old Timer" now and I am talking about the days when I would ride my bicycle to and from school and pass by this funny little electronics shop. The shop was called ELEQUIP (I can still clearly remember that but not much else these days!) and it was run by this European guy with a big pipe hanging from his mouth, I think he was a Czech it was a bit tough understanding him sometimes! He only had World War II surplus gear in his "Aladdin's Cave", shelves shelves and more shelves of what was to me, weird and wonderful equipment from the British Armed Services (I seem to remember). I spent many many hours in that shop, looking at all this strange Khaki coloured equipment, he even let me open them up to take a look around inside and he would explain what some of the parts were, I was drooling! - I was young and had no money to actually buy much of that stuff. The real fun was "out the back" of his shop where he put all the "junk" he didn't want, lots of modules, old valves, transformers - all freebies.
It was this type of experience that kindled in me the urge for the "treasure hunt" - looking at lots and lots of electronic equipment and sometimes finding something very special.
Looking and working through this UNAOHM EH-1000 bought all those early childhood days flooding back ...
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 board used extensive plug & socket interconnects to the other PCB's in the EH-1000, but I do notice there have been some "solder side" mods made (components added) - I have no idea why, we certainly never modded this gear.
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.
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 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 ...
IF VIDEO & SOUND DAUGHTER MODULE(S)
PCB type: double sided
Part #9141 & #9070
Both module PCB's have absolutely no other markings or coding on either the component side or underside, just 9141 or 9070
Professionally made board using a fibreglass substrate, designed as a plug in "daughter board" to be used with the 9209 module which is advertised separately.
Both modules appear to have been meticulously manually soldered. In fact the entire construction of the EH-1000 looks as though this equipment was manually constructed from start to finish - no automation.
Not a lot of "interesting" components on these modules, some nice FRAKO electro's (ELKO 2 200 series Germany) and high tolerance metal film resistors. There is only ONE IC on each board, in a DIL socket, and they may be of interest although they are of a specialised design. The Sky Blue section at the end of each board is the nicely made "pull handle" for the module.
I will describe each board (there are two different daughter boards) and if interested in them, just select the board you want from the drop down menu
9070
IC (socketed) is a TDA4190 20 pin DIL device from SGS - a complete television sound channel on a chip! IF amp, low pass filter, audio preamp and power amp (1.5W into 8 Ohm), audio mute controls, VCR switching and thermal overload protection.
DIMENSIONS:
90mm x 43mm wide
WEIGHT: 50g
9141
SAW filter on board, SIEMENS OFWG3203, 8 pin device soldered to the PCB (doesn't look to be too difficult to remove)
IC (socketed) is a TDA5830-2 from SIEMENS, a 22 pin DIL device which performs the functions of a broadband amplifier with quadrature demodulator, sound carrier output, and internal AGC voltage generation.
DIMENSIONS:
90mm x 57mm
WEIGHT: 50g
These two modules (9141 & 9070) have now been "laid to rest" within bubble-wrap and they both have a stiff cardboard backing, everything then within a sealed clear plastic packaging, ready for a trip to another workshop to bring another EH-1000 back to life or other video/television related VINTAGE equipment.
