Go Back   WorldwideDX Amateur Radio Forums > Amateur Radio Related > Amplifiers


Amateur Callsign Lookup
Enter Callsign:

8950 tubes.

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-21-2008, 05:38 PM
datsun66's Avatar
Senior Member
iTrader: (0)
 
Join Date: Apr 2005
Location: Billings, Montana
Posts: 246
datsun66 is on a distinguished road
Cool 8950 tubes.


I am looking into replacing the tubes in a amp that is running the 8950. 1x3.
What tube would be a drop in or something else. Maybe replacing the 4 with 2?
Just something to kick around. Bob.


Reply With Quote
  #2  
Old 02-21-2008, 07:46 PM
AudioShockwav's Avatar
Extraterrestrial Admin
iTrader: (2)
 
Join Date: Apr 2005
Location: High Sierras Near Yosemite Nat Park
Posts: 5,049
AudioShockwav has disabled reputation
Default

About the only drop in I know of is a M-2057, and it is just as hard to find as the 8950 is.
The 8950 is a 12 volt version of a 6LF6, the heater runs on 12 volts on the 8950/m-2057 and the heater on the 6lf6 is 6 volt.
I know the Swan 1200X Amps used the 8950`s ( 4 of them) and many were converted to run 6lf6`s, 6kd6`s and so on.
So If you can dig up a 6 volt filament transformer, change a few things and re-wire the socket for 6 volt you can get away with a 6lf6,6kd6 or a 6lb6. Another way to go for the 3 tubes is if you can find 3, 40lf6 tubes, you could run the filaments in series, and heat them from a 120 volt line (40+40+40 =120), but you are still stuck with a 8950 driving them.

Sweep tubes are getting harder and harder to find, and the price just goes up...I remember when you could buy 8950`s from Thrifty Drug stores for around $18 each, they had a box of them in the big tube tester by the front door...If I knew then...... I would have bought a truck load of them.
I now see 8950`s go for $70 to $80 NOS
At times you can find them on E-Bay used in the 25 to 35 dollar range, but that is a toss of the dice.
There are 5 on E-Bay right now, starting bid is $100
http://cgi.ebay.com/5-electron-tubes...QQcmdZViewItem

Or here is a Guy that says he has lots of new ones, $75 Bucks

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180170881989&ssPageNam e=MERCOSI_VI_ROSI_PR4_PCN_BIX&refitem=270208062593 &itemcount=4&refwidgetloc=closed_view_item&refwidg ettype=osi_widget&_trksid=p284.m185&_trkparms=algo %3DSI%26its%3DI%252BIA%26itu%3DCR%252BIA%252BUCI%2 6otn%3D4%26ps%3D42


I got rid of my last sweep tube amp long ago, and got a Al-811H, tubes are cheap, and easy to find.

Good Luck.

73
Jeff
__________________
Radio-active

NASA/SOHO


When I was a child
I caught a fleeting glimpse
Out of the corner of my eye.
I turned to look but it was gone
I cannot put my finger on it now
The child is grown,
The dream is gone.
but I have become comfortably numb.

Reply With Quote
  #3  
Old 02-22-2008, 05:24 AM
datsun66's Avatar
Senior Member
iTrader: (0)
 
Join Date: Apr 2005
Location: Billings, Montana
Posts: 246
datsun66 is on a distinguished road
Default

I wonder if the amp will support a ceramic type of tube.? Take out 4 and install 1.
Just a thought.

Reply With Quote
Reply

Bookmarks
Worldwide Radio Forum



Thread Tools
Display Modes

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 On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 10:03 AM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0
Worldwide Radio Forum