Kenwood CG-922 PAL TV pattern generator (maybe also Leader LCG-409 or LCG-403C)

[1980s_john]

Hi,
I bought a Kenwood CG-922 PAL TV pattern generator, this is a very neat unit that runs off four 1.5V batteries or a 6V DC supply, and outputs to composite video or UHF TV outputs. Issue it has is on the UHF output the test tone sound (1kHz) is not at the right offset from the video carrier frequency (for PAL-I this should be 6MHz, I think the unit offsets more than this based on manual tuning my TV).

I've found the Kenwood CG-921 / 922 user manual, but can't find a service manual. Closest I found was this supplier shows it as out of stock:

https://www.pacparts.com/part.cfm?part_no=B51%2D1109%2D00&mfg=JVC%2FKenwood

Googling around I think the Leader LCG-409 (NTSC) or LCG-403C (PAL) may be the same device.

Does anyone have a service manual or can point towards which adjustment sets the offset please?

Thanks,
John