Stimulated by recent discussions of IF alignment aids, I knocked up the pictured aid using bits and pieces I had lying around.
It's based loosely on one I found described online,
here
The major changes are:
i) I used transistor IFTs instead of ceramic resonators. I have lots of IFTs and precisely zero ceramic resonators at 470kHz.
ii) I tuned them to 470 kHz (which is more common in the UK than 455kHz)
iii) I used one of the spare 4011 gates with 100k 'linearising' feedback as the 'output' linear amplifier. I haven't checked on the shape of the output waveform, but I don't imagine it's critical.
iv) I powered it from an 'N' cell, using one of the cheap 1.5V to 5V step-up circuits available on eBay. Current drain is 23mA. The step-up circuit has the added benefit of a really dinky pilot LED; and the further benefit of providing a sensible use for all the 'N' cells I acquired from £1 shops as side-effects to buying batteries for my garage and car key fobs.
v) I didn't bother with an output level control (see below).
vi) I pre-set the modulation depth. Possibly 50%, but 'good enough'.
Housed in a plastic box, it radiates 470kHz (and harmonics...) like mad, so 'connecting' it it the receiver-under-repair will be quite easy!
Quite a fun thing, which should be a bit easier for quick alignment touch-ups than my full-sized sig. gen.