old tubes - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 30th March 2004, 10:08 PM   #1
diyAudio Member
 
Join Date: Mar 2004
Location: Zagreb,Croatia
Default old tubes

First of all, since this is my first post i would like to say hello to everyone on this forum!

Now i have a question,
i found a few tubes from an old radio at my grandma's, and i was wondering if they could be used to make a phono preamp, or a headphone amp or anything for that matter...

the tubes are: EAF 42 , ECH 42, EL 41, 273, AZ 1

thanks
  Reply With Quote
Old 31st March 2004, 08:03 AM   #2
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Hi,

Welcome to the forum
Use Frank Phiipes site:
http://www.mif.pg.gda.pl/homepages/frank/vs.html to look at the data on these valves. You'll find the first 3 (don't include spaces). The last 2 don't sound like standard numbers.
Sorry to say are not paticularly useful valves, and they use a socket format that was not popular (B8A), so unless you saved the sockets, it may be difficult to get more.

If you have a socket, or can fabricate something, I suggest you just use one of these (perhaps the EL41) to get a "feel" for valves. Just make a voltage amplifier, and put some audio through it. If you like it, then invest a small amount in some valves that are more useful.
  Reply With Quote
Old 31st March 2004, 11:04 AM   #3
Colt45 is offline Colt45  Serbia
diyAudio Member
 
Join Date: Feb 2002
Location: Canada
Send a message via ICQ to Colt45
Dobro došli
  Reply With Quote
Old 31st March 2004, 11:16 AM   #4
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Hi,

The AZ1 is the rectifier, could be used if it still works.

273? Inconnu au batallion....

EL41 is a predecessor of the EL34, I think.

ECH42 mixer, triode + heptode.

EAF42 diode + penthode RF demodulation.

Personally I'd rather restore this radio and later build something else.

What brand is it ?

Cheers,
__________________
Frank
  Reply With Quote
Old 31st March 2004, 11:33 AM   #5
diyAudio Member
 
Join Date: Mar 2004
Location: Zagreb,Croatia
Quote:
Originally posted by fdegrove
Hi,

The AZ1 is the rectifier, could be used if it still works.

273? Inconnu au batallion....

EL41 is a predecessor of the EL34, I think.

ECH42 mixer, triode + heptode.

EAF42 diode + penthode RF demodulation.

Personally I'd rather restore this radio and later build something else.

What brand is it ?

Cheers,
thanks for the info...
the radio is an old Tesla 55c
  Reply With Quote
Old 1st April 2004, 05:40 PM   #6
diyAudio Member
 
Join Date: Feb 2003
Location: Birmingham, UK
The EL41 was the predecessor of the EL84 I think rather than the EL34...Some old UK radios did use the pentode section of the EAF42 as an audio amp (as well as in RF/IF circuits) and it seemed to perform adequately in that role.

As for the 273, if it was a BVA 273 that would be another triode-hexode tube, so it is unlikely, but a CV 273 is a UHF triode, so that is also unlikely...
  Reply With Quote
Old 10th December 2005, 11:26 AM   #7
beamnet is offline beamnet  Netherlands
diyAudio Member
 
beamnet's Avatar
 
Join Date: Jun 2004
Location: enschede
Send a message via MSN to beamnet
got here searching for heptode.

I read the datasheet for the ech21, and it states that it could be a phase splitter.

Could anyone point me in the right direction on this?

I have the guts aof an old philips with the standard set of ech21, 2xef22 and ebl21.

Wondered, for fun, can i make an amp with ebl21 for regulated supply, ech21 phase splitter and ef22 in pushpull.

That would only require a different opt, as the original opt is for the ebl21 SE


Bas
  Reply With Quote
Old 10th December 2005, 02:40 PM   #8
Devius is offline Devius  Portugal
diyAudio Member
 
Join Date: Sep 2004
Location: Braga
EF22 is unsuitable for audio use since it is a variable transconductance tube, and as output pentode is even more unusable since it is low power. The best way would be to get another EBL21 and make a push-pull amp. Maybe you can use the triode section of the ECH21 as driver, but I'm only guessing...

As for that 273 tube, are you sure that's what it says on the tube? If those are the only letters on it maybe the real name has already disappeared and that's the manufacturing code. Can you post a picture?

Also I think the AZ1 doesn't make much sense in a radio together with the other tubes, but I'm no antique radio expert. I've seen a schematic that has this set of valves: UCH42, UAF42, UBC41, UL41 and a UY41 as rectifier. The only difference between the E and the U tubes is the heater voltage.
  Reply With Quote
Old 10th December 2005, 02:44 PM   #9
beamnet is offline beamnet  Netherlands
diyAudio Member
 
beamnet's Avatar
 
Join Date: Jun 2004
Location: enschede
Send a message via MSN to beamnet
Hmmmzz.. got to do my homework better.


Err, that AZ1 is very common in old radio's

If there's still a meshplate one in there, it is worth quite a bit

Bas
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tube Noob! need help with tubes lots of tubes therapy_fan Tubes / Valves 15 29th January 2009 09:01 PM
WTT: Various tubes for 6CA4/EZ81 rectifier tubes GordonW Swap Meet 4 27th August 2008 12:37 AM
Tubes! Geek Swap Meet 4 16th May 2008 06:20 PM
CV428 tubes (Loktal 807) tubes FS mobyd Swap Meet 3 2nd January 2008 11:26 AM
many new tubes and tubes meter for sale elviukai Swap Meet 4 30th October 2003 09:22 AM


New To Site? Need Help?

All times are GMT. The time now is 04:31 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2