For all the radio hams here

  octal 19:58 15 Jan 2008

"F2FO, amateur radio since 1959, here shows the various stages of construction of a lamp triode conducted by the Centre. This lamp has helped to establish links with other amateur radio operators located on 4 continents.
If you want to know more, visit his personal website:" click here

It's nice to see home construction alive and well still.

  amonra 20:22 15 Jan 2008

For my next project, an OC 71 ???????

What dedication.

  VCR97 20:34 15 Jan 2008

Fascinating. That's real home-brew. It's a bit beyond my capabilities, though.

  Chegs ®™ 07:36 16 Jan 2008

Although I can gain enjoyment from watching craftsmen work I truly am grateful that solid state electronics was invented.

  wiz-king 09:16 16 Jan 2008

I wish I had that much spare time - and equipment.

  wolfie3000 17:12 16 Jan 2008


I was truly in awe of his skill,
I used to be an engineer myself many years back and appreciate the skills involved,

But i agree with Chegs, you cant beat solid state components.

Anyone know what machine he was using at the end?
Either a lathe or some other machining equipment.

  octal 17:29 16 Jan 2008

I was trying to work that out, I think it is a milling machine of some sort.

  g0nvs 19:59 16 Jan 2008

Never mind his skill, what about his patience !!!!

  oresome 20:04 16 Jan 2008

I've built my own audio amps, but drew the line at manufacturing the valves!

Impressive stuff.

  WhiteTruckMan 22:45 16 Jan 2008

Thermionic devices will shrug off power surges and spikes that would totally fry a p-n junction. Plus, their slower reaction times are not necessarily a disadvantage, especially in when it comes to music.


  octal 22:58 16 Jan 2008

And they are more resilient to the EMP pulse from nuclear bombs, click here and scroll down to Limitations of Electromagnetic Bombs, the Russians have been using them for years in their aircraft, the tubes are tiny, not much bigger than the OC71 transistor amonra mentioned.

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

Dell XPS 13 9370 (2018) review

No need to scan sketches into your computer with Moleskine's new smart pen

HomePod review

Streaming : Netflix ou Amazon Prime Video ?