Vintage KEF

[catch29]

Hi. Does anyone know the thread size for the B200/B139 retaining screws on KEF's 1970's 104 & Cadenza's?. It's not m5 or 10unf, Kef technical can't help me as no one was born then!.

[Nick]

Hi. Does anyone know the thread size for the B200/B139 retaining screws on KEF's 1970's 104 & Cadenza's?. It's not m5 or 10unf, Kef technical can't help me as no one was born then!.

Ah. Kent Electrical Factors. Maidstone, just up the road...

I have a mate who used to be their UK Marketing Manager. He may know (he's pretty good), but obviously wasn't working for them back then...

However, a better bet may be Falcon Acoustics at https://www.falconacoustics.co.uk/about-...demo-store who seem to have some of the original KEF designers... specifically Malcolm Jones who designed the 104.

[roadster]

It is probably 2BA; this is close in size to M5. BA was the standard thread series used for electrical and electronic equipment.
Rod

[ppppenguin]

I agree with Rod. BA threads were commonplace in British equipment back then.

Incidentally BA threads are actually metric. 0BA and M6 will actually fit each other though the fit and strength won't be optimal.
https://en.wikipedia.org/wiki/British_As...ew_threads

[Craig]

The original KEF datasheet is here https://us.kef.com/pub/media/pdf/Datashe...SP1044.pdf which gives all the details - other than the hole diameter!

But as has been suggested, Falcon Acoustics are a good bet. They have also remanufactured the B139 (and other KEF drive units).

[Jac Janssen]

Perhaps this helps?

   

Jac
p.s. B200 has the same screws.