From the December 1964 Practical Television magazine an article titled "Vision of the future"
From the description about the set we learn that the line output stage has no role in producing the 8KV EHT and instead a separator blocking oscillator is used to generate EHT. A tapping on the Metrosil suppies the CRT focus electrode.
The special 7" Mazda CRT has the standard 28.5mm neck with the B8H base. The very narrow 42 degree scanning angle keeps the deflection power to the minimum.
These circuits apart the rest of the receiver will resemble the likes of the 405 line Perdio Portorama and Pye TT1. In fact the VHF tuner is of the same type as fitted in the Perdio.
The output from Ever-Ready 12 volt battery is regulated by a "special power regulator"
Early transistor TV sets don't seem to create much interest, especially UK made ones, which is a pity because there was quite a lot of research going on in this country into the development of such sets in the early sixties.
I found this set during the shop clearout. It is an Ever Ready development receiver and was made in 1964. Details of a similar set appeared in the December 1964 Practical Television magazine. The set was designed to operate from the special ER dry battery T.V.1. The design brief was to get the current consumption as low as possible, down to 3watts on the mark 5 405 line version.
The receiver was actually made by Thorn for Ever Ready, the CRT was made by Mazda. It is a 7 inch (17.78 cm) 45 degree deflection angle type with electrostatic focusing and magnetic deflection. Mazda's development No. V3271.
Other early UK made transistor TV receivers were the Pye TT1 and the Ferguson 743T. Both sets were announced in 1960. Also, don't forget the Perdio models. My favourite is the Pye TT1 which has a 14" CRT. Later on I'll try out the Ever Ready receiver.
There is no provision for mains operation on this set. Just the 12 volts supplied by the special Ever Ready TV1 battery. The power supply arrangements need investigation. What do those transformers in the special housings do? Note the label on them indicating that the screens have special properties.
When I worked at Solid State Logic (SSL) in the late '80s I was told that the mu-metal 'can' that completely enclosed the rear of the small CRT monitor in the centre section of their mixing consoles was one of the most expensive parts of the whole system, costing the best part of £1000. These were to be handled with great care and on no account were they to be machined, dropped etc.
At the time I'm writing this the set is in pieces. I'll reassemble it and take some better pictures of it. This set appears to be the Mark three version. The set featured in the Dec. '64 PT magazine is the Mark five version. Ever Ready never marketed a TV set. By mid 1966 Philips introduced the TVette.
Sounds like it uses a SMPSU maybe also used as Line Drive and Multiplier drive, the transformer shielded in one of the metal boxes. I wonder are they Mumetal or Aluminium? The warning could be due to Mumetal or the LOPT/Power TX core being ferrite.
The other box maybe the Field / frame drive transformer.
Could the boxes just be fitted because the circuit inside was not yet patented at the time the set was made?
They do look rather like project boxes of the period.
That TV1 battery is a new one on me as I have never seen one but I can not help thinking its a 12V battery as most portable transistor sets you could use on 12V as well as mains, the 12v was for caravan use as I remember my dad using such a thing when I was a kid in the caravan, it worked of a car battery. The only other battery the same as this TV set works of I can think of is the HP1 which was 12V for industrial use. I have been promised such a battery from a carboot seller but they keep forgetting If I get one David I will scan it for you but with regard to powering this set how long would a layer type battery last as car batteries have more amps in them than a zinc carbon layer cell which I think this battery must be. That said though those modern TVs with tiny screens used D cell batteries in series so maybe this little Ever Ready set draws less power.
Perdio did a battery TV, the Porterama model, that was transistor but used a valve for the line out put, it could also work of two 6V Silver Cadmium accumulators made by Vennac. I have never seen a TV from Ever Ready before but was this in the Tanfield factory back in the 60s. If it had gone in to mass production its name would have been a Skyvision I guess. It seems strange Vidor did TVs yet Ever Ready did not, maybe something to do with cost. I have a copy of a letter from Ever Ready an Ebay seller sent me a few years ago when I bought a battery of them, this guy came up with the idea of a torch radio back in the 70s and the reply back to the guy who was the seller I bought of as he used to work for the firm and it stated much interest in the torch radio idea but it never went in to production just like this TV sadly.
Hi Peter, the set was tested about five years ago and all I remember was that there was a hint of over-heating somewhere in the chassis. I'll dedicate a special work bench to this very interesting and unique set. It's not easiest chassis to work on having little regard to ease of service.
First all check the power regulator circuit followed by the EHT generator. These sections can be tested separately.
The line output transistor is a Texas Instruments 2G1046. The damper diode is a Mullard OA5. Other types of semiconductors present on the PCB are Texas 2G302 and OC200. There's a TO5 device which I guess is the frame output transistor. The large inductor will be collector load of the frame OP transistor.
That looks like a most interesting and distinctive project there Till- it must have stretched both the technology and the designer's minds at the time. Over the years, "battery portable CRT TV" must have seemed like an absorbing challenge to many designers from various aspects- at least, to those who weren't involved in blank-cheque military/space exotica! I think there were a few technical milestones achieved in Clive Sinclair's long quest and various incarnations of tiny tellies.
Hi Turretslug, not having any circuit diagram and only the information from the article in the Practical Television magazine this will not be an easy restoration project but if it can be seen through I'm sure the results will be very rewarding. The set has had very little use, if any. Almost in as new condition.
Further observation reveals that the line output transistor drives the scanning coils direct, no transformer. How the line output transistor receives its drive will be studied next. The frame scanning coils have a 500microfarad series DC blocking capacitor. Correction to my last post. The line output transistor is a type 2N1046, not 2G1046.
The Mullard OC200 PNP silicon transistor performs the function of frame output transistor and it's confirmed that the large choke is the collector load. The scanning coils are connected across this via the 500uF capacitor. The adjacent 2G302 is an emitter follower driver. A potentiometer marked P is between the two transistors and it is assumed it is the picture height control.
The frame oscillator is of the blocking type using another 2G302 PNP transistor.
Four 5000uF parallel connected capacitors are used to ensure the supply voltage to the scanning PCB is dead smooth.
Four 5000uF parallel connected capacitors are used to ensure the supply voltage to the scanning PCB is dead smooth.
Those are the largest value capacitors I've seen in equipment of this age. I imagine that this television would have cost an absolute fortune to make and would never have been viable as a commercial product.
The Pye TT1 all-transistor TV set of 1960/61 employed two 10,000microfarad capacitors to ensure that the 10 volt supply line was dead smooth. Such high value capacitors were well known and used in industrial and computer equipment.
I'm presently tracing out the circuit of the frame timebase and will post up my interpretation of circuits later today. The oscillator is of the blocking type, that has been confirmed. Two Lucas diodes are employed, one as a over-swing damper across the transformer collector winding. The other diode is an isolation diode between the collector of the 2G302 oscillator transistor and the sawtooth forming capacitor. You'll see something similar in the all-transistor BRC 1590 chassis which was introduced ten years after the Ever-Ready set was made. A 2G302 transistor is employed as a frame sync pulse clipper, another 2G302 is employed as the buffer between the sync separator which again is a 2G302.
The line output stage is of the type invented in the 1930s by A.D.Blumlein. The 2N1046 functions as a switch and the sawtooth waveform is generated in the high inductance scanning coils. The OA5 diode is the flyback damper.
The positions of the line and frame hold controls has been found.
If I get one David I will scan it for you but with regard to powering this set how long would a layer type battery last as car batteries have more amps in them than a zinc carbon layer cell which I think this battery must be. That said though those modern TVs with tiny screens used D cell batteries in series so maybe this little Ever Ready set draws less power.
