Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: ST style 550V rectifier  (Read 580 times)
W7ETA
Member

Posts: 2528




Ignore
« on: October 29, 2008, 04:37:08 PM »

I'm looking for suggestions for an ST style full wave rectifier that can deliver 200ma with 550-0-550V transformer.

I've got an extra 5U4G, but it seems as if the xformer I want to use exceeds it's max designed input.

I'm looking for the ST style simply because I smile whenever I look at them.  I figure if I going to build the power supply, I might as well try to build one that I like the looks of.

I ran across a 5U4GC from China with the ST style and 5U4GB specs.  But, the rumor is that this isn't a reliable tube.

The power supply will be used for a cw transmitter, using two ST 6L6GC type tubes.

TKS
Bob
Logged
AC5UP
Member

Posts: 3822




Ignore
« Reply #1 on: October 29, 2008, 06:22:00 PM »

The 5U4GB should work FB although it would be a bit slim on the PIV margin. The tube has a forward drop of approximately 50 volts so the worst case scenario of no load would squeeze the 1550 volt PIV rating fairly tight but can we assume the TX will always draw some current, even with the key up? If so you're within the voltage rating. With a current rating of 225 mils that should cover 200 mils with 10% to spare and considering the duty cycle of CW be more than adequate.

If you want to extend the life of the rectifier go with a 5R4 instead. If I recall that's the stoutest of the common full wave rectifiers and you'd have to score a mercury vapor tube to do better... 50 years ago that was No Prob, but today not so much.
Logged

Never change a password on a Friday                
AC5UP
Member

Posts: 3822




Ignore
« Reply #2 on: October 29, 2008, 06:33:57 PM »

One more thot... Take a look at this:

http://www.nj7p.org/Tube4.php?tube=5U4G

If you can scrounge up a three Henry choke and hang it on the filter input you're looking at regulation within 30 volts from half to full load with a 550-0-550 volt transformer. Bottom of the page, and it shows as typical operation...

(?)
Logged

Never change a password on a Friday                
W7ETA
Member

Posts: 2528




Ignore
« Reply #3 on: October 29, 2008, 10:25:08 PM »

Of course!  The 5R4G.
For some reason, I insisted on looking up 5AR4s!
Still stumbling around in the dark with the simple stuff.
73
Bob
Logged
N2EY
Member

Posts: 3835




Ignore
« Reply #4 on: October 30, 2008, 06:25:07 AM »

Pair of 5R4Gs.
Logged
W7ETA
Member

Posts: 2528




Ignore
« Reply #5 on: October 30, 2008, 12:14:06 PM »

Whats the advantage of the second one?
Logged
N2EY
Member

Posts: 3835




Ignore
« Reply #6 on: October 30, 2008, 01:30:06 PM »

Lower voltage drop and easier on the tubes if you use two 5R4s. One will work.

73 de Jim, N2EY
Logged
W7ETA
Member

Posts: 2528




Ignore
« Reply #7 on: October 30, 2008, 04:56:20 PM »

Tie both plates together to turn it into a half wave?

Parallel 2 of them?  Feed them both from the same 5V supply?

I'm still a novice with the simple stuff.

I'm limiting my confusion to electrons flow from negative to positive.

TKS
Bob
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!