I have two of these I rescued from the DSE Engineering Department when they closed down.
The both used to work, now neither one does.
I opened up one and I suspect it has a faulty 2SK55 JFET as the voltages on that don't look right.
I had a brief go at tracing out the circuit but what I've drawn thus far doesn't make a whole lot of sense.
Does anybody have any experience with these, or even better a circuit diagram?

A mate of mine Noel Everding and I used to know a guy that worked for Dick Smith "Steelo" who might be able to help -

I see from period advertising (Jan 1986) that it had a mate: the Q-1310 AF sig gen.

I have resorted to taking a photo of the PC board, sorting it out in an image editor, printing it and then playing join the dots.

Some of the early FETS became a short if they lost gate voltage.

They're easy to understand. You apply a source, open the gate & the whole lot goes down the drain.

I think I have the circuit. I will look for it this weekend.

Wayne.

GTC:
"I see from period advertising (Jan 1986) that it had a mate: the Q-1310 AF sig gen."

Yeah, got two of those as well. THEY still work....
I'm actually working on a 1935 Sparton 666 6 valve superhet..
It has an unusual IF of 345kHz.
Before I had a circuit I'd assumed it was 455kHz and tried to align the IFs using a small 455kHz generator I have.
Not only wouldn't it peak up, but when I tried to screw the trimmers back in again, I found that the nuts had fallen off and I had to dismantle the IF cans to put them back on!
I've only just got round to replacing the rubber mounts for the tuning capacitor (which had turned to black slime after 80-odd years). It was a hell of a job getting it back together; never seen so many earth straps!
Then, when I pulled out my trusty DSE signal generator to finish the job, I found out it wasn't so trusty any more and had stopped working. Well never mind, I'll just drag out the backup- oh crap; that's stopped working as well!
In the end I resorted to the old(/new) trick of working out the oscillator frequency for a known station, setting the tuning knob so the oscillator produces that frequency (using a frequency counter) , and then peaking up the IFs (making SURE I'm peaking them to the correct station!)
Now that I have that all that sorted out it really performs; whether using the 2 inches of wire hanging out the back, or connecting a 30 foot antenna, it sounds much the same.

"A mate of mine Noel Everding and I used to know a guy that worked for Dick Smith "Steelo" who might be able to help"

Rudolph Transfield I presume?
I remember your name; everything else escapes me these days

Labrat:
"I think I have the circuit. I will look for it this weekend"

Thanks. I seem to remember there was a circuit in the back of the manual.
I still have all the Dick Smith project files on a portable Hard drive somewhere.
I wish I knew where!

Hi Keith, my e-mail address is open .

Hi Keith.
I have what I believe to be the manual for this generator, but your e-mail address is hidden.

e-mail me with your e-mail address, and I shall send the circuit to you.

Regards

Wayne.

I resorted to the old(/new) trick of working out the oscillator frequency for a known station, setting the tuning knob so the oscillator produces that frequency (using a frequency counter) , and then peaking up the IFs (making SURE I'm peaking them to the correct station!)

I vaguely recall being shown that technique by an old hand, but it was many moons ago now.

I have mentioned it before, but there are traps with counters. I have an early EA, DSE kitset one and a Fluke. Both will give the wrong frequency if fed modulated RF.

One must be rather cautious if coupling to RF coils & resonant circuits as any change in loading, capacitance etc. can throw them off frequency.

The IF frequency is independent of the mixer oscillator. So one injects a low signal at IF frequency into into the signal grid of a Pentagrid & calibrates it first. After that you sort out the oscillator & antenna coils & padder if fitted.

"Both will give the wrong frequency if fed modulated RF."

You don't measure the Intermediate frequency, you measure the oscillator frequency.
Take the example of 1170 2CH. 1170 + 345 = 1515kHz.
You monitor the oscillator frequency and adjust the tuning knob until the counter reads 1515kHz.
Then you adjust the IF coils for maximum output on 2CH (Using a different radio if necessary to make sure you are peaking 2CH!)
If the local oscillator is set to 1515kHz, then 2CH must be producing a beat of 345kHz.
(With a 455kHz IF the frequency would be set to 1170 + 455 = 1625kHz)
Attaching the frequency counter may shift the oscillator frequency, but that doesn't matter, it will just mean that the antenna coil alignment will be a little off. With a strong enough signal, that won't matter.

Thanks to Labrat for the circuit.
As he says, there was one line left off the "Curcuit Diagram", but once you figure out where that went, it's easy to understand how it works.
More importantly, the voltages on the oscillator definitely indicate that the FET is FUBAR

After a refit on a superhet I normally hook an Oscilloscope to the OP and go for alignment to ensure that part is working before worrying about the front end. That picks up distortion & faults not seen & the oscilloscope can then be used as a signal tracer.