jason kit wobbulator W11

[AlanBeckett]

Were is everybody this morning? It must have been a good Bank Holiday yesterday

I collected this Wobbulator yesterday. Apart from missing knobs and a few screws it doesn't look in bad nick. It will no doubt come in useful when I get to my VT4. Of course, there's no Manual of any sort. There are references to it on the other Forum, and I may have to go there, but in the meantime has anyone got a copy?

Alan


[attachment=1779]

[tiv48]

nice. the only other jason kit stuff i have seen are the tuners ,where they kits ? and if so who made them?
rob t

[AlanBeckett]

The only things I remember with Jason on them were FM Tuners, and I don't think they were kits, although you could buy them as a bare chassis and build them into your own gear.
Alan

[AlanBeckett]

Come on you lot, otherwise I'm going to have to sneak over the wall
Alan

[Shaman]

Here is a little info Alan, not found the circuit yet....regards....Alan.

http://www.g1jbg.co.uk/test13.htm

Courtesy of Ed Dining

[AlanBeckett]

Ed,
I found that thanks.
I was a bit disappointed that the manual wasn't Posted.
I'll have to contact your (almost) namesake on the opposition
Alan

[AlanBeckett]

Al,
It is indeed quite intriguing. I suspect that there was probably a detector probe with it originally. I don't think that it will be too difficult to make something suitable.
I'm afraid I've had to contact the opposition for more info
Alan

[Skywave]

Having had a look at the block & cct. diag., it looks similar to the design published in the RSGB Handbook, 4th. edition, pages 19.30 etc. I haven't tried that particular cct., but I don't see any part in it that looks an 'impossible-to-get-now' item, with the possible exception of the coils: hand-wound on Aladdin F804 7/16" formers; the more common 1/4" should be a good substitute, or even formers salvaged from old valve IF cans.
The only negative comment I can make about the RSGB design is that the amplitude of the resultant FM-ed wave varies with the chosen centre frequency, which renders any attempt to calibrate the amplitude of the output waveform impossible. However, once the centre freq. has been chosen, the amplitude appears to remain constant over the swept bandwidth. The tuning range is 50 kHz to 2 MHz, with a max. deviation of 60 kHz. Not as extensive as the Jason kit unit, sure, but adequate for most common radio IF alignment tasks.
As with the Jason kit, an external modulating wave is required; unlike the Jason Kit, which uses a sine-wave, this design refers to a traditional ramp. But producing that is not a problem: for example, a unijunction transistor oscillator with the charging cap. fed from a constant-current source will provide a linear sweep, amongst other possibilities. (Anyone got a gas-filled Thyratron spare? :D)

Looks like another 'one day round tuit' project coming my way!

Al.

[AlanBeckett]

Al is ahead of me.
Ed Dinning sent me a scan of the article in question - see attached.
I haven't had chance to study it yet.
Alan

[attachment=1834]

[PaulLavender]

The only things I remember with Jason on them were FM Tuners, and I don't think they were kits, although you could buy them as a bare chassis and build them into your own gear.
Alan

Sorry to resurrect a pre-historic topic, but does anyone have a schematic for this wobbulator? I think one was passed by PM more than 10 years ago.....