EF14 & EF12 size...

Hi!

I was just trying to make a EF12 tube fit where an EF14 (UF14, VF14 etc) would go, and it seems that my EF12 is physically taller.

Then I looked at this data sheet...

http://www.mif.pg.gda.pl/homepages/frank/sheets/076/e/EF14.pdf

It seems to imply that there are two heights of EF14, and they look to have slightly different bases too. Does anyone know anything about this?

Tak!

Stewart

OK, so one is a metal can and the other is glass (but painted black!).

I don't know about a difference between EF12 and 14, but I have EF12 both in glass and steel with the same socket. Afaik the glass ones were later reproductions, when they didn't do the steel housing any more.

hope this helps a bit...

Michael

It does help, Michael. Thank you.

Are your glass ones taller than the steel ones?

On the EF14 data sheet I linked to above, the dotted line (large size, glass?) is marked Vorläufige Ausführung, which I think is a preliminary design? Is that right? And then the short metal can is the final design?

Hi,


  the RFT ones are bigger iirc. They are also glass(?)


  kindest regards,


    ANdyP

unfortunately german only
http://www.hts-homepage.de/DStahl/DStahl.html
http://www.hts-homepage.de/DStahl/DSAufbau.html
http://www.hts-homepage.de/DStahl/DSFertigung.html

and
http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/Stahlroehren/Stahl.htm

rft was not in the posession of a ringschweissmaschine (circular welding machine) so they developed a alternative glass housing.

Some good links there. Thanks!

So I am staring at one of each of the telefunken ef12 and ef14's now and the ones I have are both steel and both exactly the same size.

Later repro's RFT I understand went glass as mentioned above.

The only difference at least between the ones I have here is the sonic footprint between the two. There is definately a difference in tone to them and obviously different pin out.

Please note there were several versions of Telefunken EF12/EF14 steel tubes, the older pre-war and part war-time variety had higher steel bulb and quite wide socket ring (this also applies to older EF12 tubes from Philips/Valvo, Tungsram was also different), the next generation was not that tall and had a normal, small socket ring, both can be seen on this page:

http://www.hts-homepage.de/DStahl/DSEF12.html

The glass RFT EF12/EF14 versions are equally different, with large bakelite socket ring (also pictured on the page, linked above). All of these EF12s are pin compatible, but the Telefunken 1940s/1950s versions have the smallest form factor... Hope this helps!

Hi Dark1,

Thanks for the information and welcome to the forum!

The big ones are a real squeeze to fit into U47 bodies, for what it's worth.