Recent content by MalcolmB

Have you thought of using a MOC3041 zero crossing opto triac?

Apologies if you already know this but here's my 2p. An Arduino has pwm outputs on pins 3, 5, 6, 9, 10 and 11. You could use a pot connected between 5V and ground from the Arduino with the wiper connected to an analogue input pin (A0 to A5 but stay away from A4 and A5 unless you really have to...

What a sad loss and at a relatively young age too. He will be deeply missed in the PF community. My deepest condolences to his friends, family and anyone who interacted with him in this community and elsewhere. RIP Old Jim.

TIL that a J47 jet engine igniter box is like a Model T Ford trembler coil on steroids.

The phlogiston theory.

Socapex 19 pin connectors as used in stage lighting systems might be useful. They're generally used for six separate circuits - three each of line, neutral and Earth with an additional overall Earth connection. See: -...

J J Thompson, who was credited with the discovery of the electron was reputed to have given the toast: - "The electron: may it never be of any use to anybody" How things have changed...

I traveled to Penzance in the UK for the August 11 1999 eclipse and it rained! I had better luck for the March 29 2006 one in Side,Turkey. We were right on the eclipse track and the BBC team were in the next hotel. Unfortunately dear old Patrick Moore was too ill to attend. I got some great...

Hi... Find your local amateur radio club/group/society. You will find them more than helpful and you might end up with an interesting and rewarding hobby. Malc M6MYB

Try contacting your local amateur radio club. You'find they'll be able to help you out.

I love the neat tagboard construction.

Try thin carbon fibre cloth. I used to use it for making electrodes for simple electrophoresis.

Nice Amp - wish I still had one!

Thanks for all your replies guys - it's really appreciated. The 730-1a is my first real restoration although I've done other small stuff before. I ran it up slowly with a variac and all the valves light up with V14 producing a nice violet glow. There's some kind of life in it because I can get a...

Thanks for the info - most useful.