The first Thermionic Valve - UK Vintage Radio Repair and Restoration Discussion Forum

Diabolical Artificer · 2nd Nov 2010, 7:21 pm

Heard this short but informative piece on the early develepment of the first valve.Can be listened to on BBC Iplayer (23.00 ish -on)An excellent example of why the BBC is the best in the world,and shouldn,t be """""" about with by silly men in suits,etc etc, Andy.

threeseven · 3rd Nov 2010, 10:55 am

Heard that too in the car on Monday evening. Quite an interesting discussion on how all electronics has derived from the valve. Coincidentally I had that exact same discussion recently with a friend who asked how electronics had "come about". Being a young guy he had no awareness at all of valves and was totally fascinated when I explained them, he now wants to see a valve radio so I will be carting one over to his place, should be an interesting reaction. I envy him, imagine never having seen a valve before !

Station X · 3rd Nov 2010, 11:00 am

This was aired on the BBC Radio 4 programme "Material World. Avalable to listen again here:-

http://www.bbc.co.uk/programmes/b006qyyb

Aerodyne · 3rd Nov 2010, 11:24 am

Interesting stuff, this. We should not forget that the crystal diode predates the Fleming thermionic valve, though. Rectifying properties of certain crystals were discovered by Braun in the 1870s and Bose, the brilliant Indian scientist, developed the crystal diode as a radio detector circa 1895-1906. Other experimenters were working on much the same lines around the same period. I maintain that the crystal, as much as the valve, provides the background to modern electronics.

Don't get me wrong - I love valves and consider their invention an essential element in the development of radio and electronics generally. Its just that the humble crystal played a very important role, too.

-Tony

m0cemdave · 7th Nov 2010, 4:09 pm

Some researchers in the 1920's discovered that adding a second cat's whisker could produce an amplifying device. But crystals were a dead technology, the future was in thermionic devices, and so there was no point in following up those odd results nor wasting R&D time on them...

neon indicator · 7th Nov 2010, 9:36 pm

Yes, the success of Valves held back semiconductors a bit. FET theory was in 1930s. It was few years after the 1947/1948 "transistor" (pretty much germanium with two "cat's whiskers

) that they figured how to make FETs, in Silicon, not Germanium.

The first patent for FET type device was 1925, but I don't think any made then. Nor was the name "transistor" used till 1948.

2nd Nov 2010, 7:21 pm	#1
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,667	The first Thermionic Valve Heard this short but informative piece on the early develepment of the first valve.Can be listened to on BBC Iplayer (23.00 ish -on)An excellent example of why the BBC is the best in the world,and shouldn,t be """""" about with by silly men in suits,etc etc, Andy. __________________ Curiosity hasn't killed this cat...so far.

3rd Nov 2010, 10:55 am	#2
threeseven Octode Join Date: May 2010 Location: Worcestershire, UK. Posts: 1,880	Re: The first Thermionic Valve Heard that too in the car on Monday evening. Quite an interesting discussion on how all electronics has derived from the valve. Coincidentally I had that exact same discussion recently with a friend who asked how electronics had "come about". Being a young guy he had no awareness at all of valves and was totally fascinated when I explained them, he now wants to see a valve radio so I will be carting one over to his place, should be an interesting reaction. I envy him, imagine never having seen a valve before !

3rd Nov 2010, 11:00 am	#3
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: The first Thermionic Valve This was aired on the BBC Radio 4 programme "Material World. Avalable to listen again here:- http://www.bbc.co.uk/programmes/b006qyyb __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

3rd Nov 2010, 11:24 am	#4
Aerodyne Octode Join Date: Jun 2004 Location: Hampton Vale, Peterborough, UK. Posts: 1,698	Re: The first Thermionic Valve Interesting stuff, this. We should not forget that the crystal diode predates the Fleming thermionic valve, though. Rectifying properties of certain crystals were discovered by Braun in the 1870s and Bose, the brilliant Indian scientist, developed the crystal diode as a radio detector circa 1895-1906. Other experimenters were working on much the same lines around the same period. I maintain that the crystal, as much as the valve, provides the background to modern electronics. Don't get me wrong - I love valves and consider their invention an essential element in the development of radio and electronics generally. Its just that the humble crystal played a very important role, too. -Tony

7th Nov 2010, 4:09 pm	#5
m0cemdave Octode Join Date: Feb 2009 Location: Bletchley, Buckinghamshire, UK. Posts: 1,223	Re: The first Thermionic Valve Some researchers in the 1920's discovered that adding a second cat's whisker could produce an amplifying device. But crystals were a dead technology, the future was in thermionic devices, and so there was no point in following up those odd results nor wasting R&D time on them... Last edited by Dave Moll; 7th Nov 2010 at 5:31 pm. Reason: unnecessary to quote preceding post in full

7th Nov 2010, 9:36 pm	#6
neon indicator Retired Dormant Member Join Date: Jun 2010 Location: Co. Limerick, Ireland. Posts: 1,183	Re: The first Thermionic Valve Yes, the success of Valves held back semiconductors a bit. FET theory was in 1930s. It was few years after the 1947/1948 "transistor" (pretty much germanium with two "cat's whiskers ) that they figured how to make FETs, in Silicon, not Germanium. The first patent for FET type device was 1925, but I don't think any made then. Nor was the name "transistor" used till 1948.