Next the sound IF stage, plus!

[AdrianPH]

I actually got a notification.

Thanks for the comments.

In some military chassis gear I picked up when starting out the detectors were listed as CV140, but I found CV4007 as well as the CV140 being fitted. frank.pocknet.net site lists CV140, 6D2, CV4007, 6AL5, D77, DD6, CV4025 and EB91 as all similar enough to be used.

The CV5377 is the last Mil version of the EF91 that I can find and are still cheap to buy at £3 each, they seem to have less of a lightbulb moment with the heaters when power is applied.

Adrian