UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > General Vintage Technology Discussions

Notices

General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc.

Reply
 
Thread Tools
Old 22nd Nov 2017, 7:47 am   #21
KeithsTV
Nonode
 
KeithsTV's Avatar
 
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,065
Default Re: What is meant by "kinkless"?

Here are a couple of plots taken from my 2016 talk at Golborne on Valves. They show the anode current vs anode voltage with the G1 and G2 voltages set to a fixed value.

Both are taken using an EF91, one configured as a tetrode with G3 connected to the anode and the second configured as a pentode with G3 connected to the cathode.

The full text of the talk is in this thread

https://www.vintage-radio.net/forum/...d.php?t=130544

Keith
Attached Thumbnails
Click image for larger version

Name:	Tetrode.JPG
Views:	22
Size:	22.8 KB
ID:	152685   Click image for larger version

Name:	Pentode.JPG
Views:	18
Size:	22.4 KB
ID:	152686  
KeithsTV is offline   Reply With Quote
Old 22nd Nov 2017, 9:37 am   #22
kalee20
Dekatron
 
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 4,259
Default Re: What is meant by "kinkless"?

Well, that's definitely a kink! Although it is not a massive fall in anode current in the 'awkward' region, the effect is definitely there!

Different samples of the same valve may give widely different results. Secondary emission is dependent on the (inside) surface of the anode, so slight variations in alloy composition or surface finish could alter things a lot. For normal, intended, pentode operation, of course this would not matter, so manufacturers did not have to control it.
kalee20 is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 10:26 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright ©2002 - 2018, Paul Stenning.