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: Prev 1 [2]   Go Down
  Print  
Author Topic: Help me compare these two power amp transistors  (Read 5312 times)
KE3WD
Member

Posts: 5689




Ignore
« Reply #15 on: July 23, 2013, 04:06:04 PM »

If you do that, you should use the same source's transistor for the other side, Complementary Pair and not the original.  So find the BD 437's complementary PNP and order it up as well, for the other side. 

Doubtful the amp is being pushed all that hard in this application. 
Logged
KE4JOY
Member

Posts: 1384




Ignore
« Reply #16 on: July 23, 2013, 04:59:00 PM »

No the amp is not pushed hard at all, frankly I wondered about the 40watt requirement. Would probably rip the speaker to shreds.

So the BD437 & BD438 looks like a good pair?

http://www.st.com/web/en/resource/technical/document/datasheet/CD00000910.pdf
« Last Edit: July 23, 2013, 05:02:40 PM by KE4JOY » Logged
KE3WD
Member

Posts: 5689




Ignore
« Reply #17 on: July 24, 2013, 07:01:53 AM »

Any amplifier is nothing more than a modulated power supply. 

Therefore the actual power output of any amplifier is limited by whatever amount of power its power supply can deliver.  In this case, that would be the combined power of the two DC rails, minus the Efficiency factor of the amplifier design type.  Amplifier design type (or class) is what the power dissipation spec brings to the subject.  Bear in mind that this figure is NOT the same as "power output capability" -- it refers to how much power, in heat, that the device can safely dissipate without destroying itself. 


73
Logged
KE4JOY
Member

Posts: 1384




Ignore
« Reply #18 on: July 24, 2013, 10:44:14 AM »

Understood, I must give many thanks for your help and patience with this.

Parts are on order, sure to miss that receiver puts my tube rig(s) to shame  Cheesy
Logged
Pages: Prev 1 [2]   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!