Bush TR 82C repair advice wanted

[Yorkie]

The bush has a OA70 detector diode, will the OA90 as mentioned in Yorkie's post on this matter do the job if I can source?

The OA70 was originally intended for use as as a video detector diode, but also used for audio.  Not only will the OA90 - or indeed just about any germanium diode (1N34 etc) suffice as a replacement - if you look at the datasheet at the link below, you'll see that back in 1968 when the OA70 datasheet was written, it states at the bottom: 'For new designs  the successor type OA90 is recommended'.

http://www.datasheet4u.com/datasheet-pdf...?id=835815

Hope that helps.

Good luck with the restoration!