Cossor 1324 FM generator.

Well it certainly looks nice and tidy Andrew, fingers crossed it works just as well.  ? 

Thanks Marc, it is of a relatively simple circuit design and no doubt quite robust if the 1322 is anything to go by. I don't really need another FM generator, but this one I could not resist.

Found a circuit diagram that was a mess, I've cleaned and rebuilt it the best I can. Its now in the data library.

Another piece of test kit I own, but have never used! I also have its father - the 343 Alignment Oscillator.

Well, Cossor had to produce something to align their new FM sets with...

If I am fortunate enough to get the generator working properly, it will be interesting to pick an FM radio as a guinea pig to test it out on. Then, the results may be compared with a modern Leader FM generator, such as this one...

https://www.radios-tv.co.uk/community/in-the-workshop/leader-lsg-216-amfm-generator/

Which I have still not used for any radio alignments.

Today the generator arrived well packed and in good condition. Very good condition. In fact, almost unused by the look of it. There is a compartment inside the top and within it I found a device that I think is a dummy load or some kind of matching device. Also, a small clip possibly used for low capacity coupling a signal into a valve around the glass.

The loop in the last picture may well be for coupling signals in to a valve indirectly: when you consider that Pye's FenMan II relies entirely upon 'strays' to couple the local oscillator into the mixer...

A quick visual inside reveals little signs of use....

Wow!
Looks like it's been timewarped off the production line 🙂
What a good find, Andrew!

Thanks ? Now you see why I was tempted to buy it in the first place....how could I possibly resist such a good looking bit of vintage test gear ?   ? 

The main smoothing can is reforming nice and quickly so should be fine. The rear compartment, where the mains enters into an RF filter, will need to be examined as no doubt therein lurks a capacitor or two that may object to mains power after a 60 year or more sleep. This would naturally be folly to just plug in to the mains as I'm sure you know.

My fears have been proved unfounded as the mains RF filter box contains no paper capacitors, but naturally I'll do a few cold checks before applying mains power.

Strangely enough I was just watching an episode of Goodnight Sweetheart...the special made in 2016 when Garry finds his way back to the present from 1962. Maybe he brought this back with him......

Lol, well he may have... It works too...after a fashion.

A good 1khz audio output plus some variable RF frequencies of some description. Quite how you are meant to accurately align an FM radio from this gobbledygook heaven only knows. It resembles AM more than FM.

The FM output bears little resemblance to my Leader FM generator (below pic). But the reason for acquiring the Cossor was not for an accurate piece of test gear, but more for it's vintage collectable appeal.

Well at least it will be a good test of the AM rejection of the FM receiver.

You need to apply a sawtooth to the X terminal to get the reactance valve to do its thing. This is where your 1039 comes in handy. 

Posted by: Cathovisor

You need to apply a sawtooth to the X terminal to get the reactance valve to do its thing. This is where your 1039 comes in handy. 

Ah ha !!  Well done Mike...I was just wondering who would be the first to spot that.....ah-hem.  ? 

My 1324 when I had it worked really well and was used to align several FM sets, it was sold on to make room for a sweeper with markers.

It was in immaculate condition like yours and the crystal probe had never been used, maybe the owners forgot they were there ?

It did however need almost all the TCC and hunts capacitors replacing, two of the TCC caps were short so I replaced them all. The hunts were acting like resistors.

A bit confused, nothing unusual.

So it’s not a complete unit but requires an external sawtooth to produce an FM signal?

I am probably missing something fundamental.