Valve....New ?

[pwdrive]

http://www.synthtopia.com/content/2015/0...uum-tubes/

Lawrence.

[Mark Hennessy]

Ah... I've used Noritake Itron vacuum-fluorescent displays a fair bit over the years. And it's well-known that a VFD can be used as a simple triode. So, I guess this was inevitable..

Looks like the target market is the musical instrument industry, but I'm sure it won't be long before the audio crowd give them a go

[Nick]

Looking at this photo:




...it seems that it is a VFD construction as the anode is fluorescing nicely.

Seems quite a small beast too, as much as you can determine the actual size from the image above...

[pwdrive]

Do you reckon the fluorescing is crucial to the devices operation or designed to enhance the overall visual appeal or a combination of both ? If it was good to 30 Mhz (the valve) I wouldn't mind one of them to mess about with, wonder what the specs are.

Lawrence.

[Nick]

Do you reckon the fluorescing is crucial to the devices operation or designed to enhance the overall visual appeal or a combination of both ? If it was good to 30 Mhz (the valve) I wouldn't mind one of them to mess about with, wonder what the specs are.

The anode fluorescence is due to this really being a VFD, made on a VFD production line, by a company that makes most of the world's VFDs

The anode coating of VFDs is what makes VFDs so useful, but its not essential (just cool). The cathode coating, OTOH, is vital - VFD manufacturers have developed coatings that make the cathodes perform flawlessly for many years - at least 3.5 years (30,000 hours) of continuous running - old purpose-built triodes like the 12AX7, used to need replacing fairly often, with lifespans of less than 10,000 hours. 

So, to save money, Noritake have used a standard VFD production line to do this - VFD form-factor, VFD internal construction, VFD anodes, grids & cathodes, VFD pin-outs etc. etc. As Mark correctly points out, pretty much any VFD can be used as a triode, some even up to RF frequencies...

Sensible move, really...

[Keithstv]

Interesting. I've got some DM160 indicators I'll have to try one as an amplifier.

Keith

[Nick]

Interesting. I've got some DM160 indicators I'll have to try one as an amplifier.

The DM160 (6977) is pretty much the smallest VFD there is - I love them - several folk on the Google! neonixie-l group have done some fun stuff with them, e.g.

.

[Alan Douglas]

DM160s work quite well as low-mu triodes.

[Keithstv]

I made a simple multivibrator with a couple of them a year or so ago. Active device and indicator all in one and a low component count.

Keith

[Alan Douglas]

They're small enough to hide in the base of a dead valve. I remember when I first tested one, in a Weston analyzer. I set it up and was watching the meters to be sure it didn't draw too much anode current. The meters were all indicating properly and I glanced up at the valve, and was somewhat startled to see it glowing bright green! Which if course is normal, but I wasn't prepared for it.

As to Noritake, my parents bought a set of their porcelain dinnerware in 1942 when they got married. That was not a popular thing to do just then! I think only one piece has broken since then, and we used it on Sundays or for guests.