[BC] Transmitter failures

[DHultsman5@aol.com]

In a message dated 4/28/2007 6:24:19 AM Central Daylight Time,  
WFIFeng at aol.com writes:

That's  certainly one of the big benefits of these modern transmitter 
designs! 
The  less off-air time, the better!




*************************
 
One of the main advantages of solid state  is that not all the eggs  are in 
one or two tubes.   Called "Soft Failure"   loss of  one or two modules only 
reduces power output.  It does not affect the air  sound in other ways.  Simple 
replace the module and back to normal.   In many systems loss of more than two 
modules begins to changed the combiner  system which becomes less efficient 
meaning it makes more heat.
 
Still one of the problems is that in FM we are still using a 48 volt device  
(MOSFET)  with VHF capability of 88-108 mHz of 300 to 400 Watts analog  Class 
C FM Power.  Depending on your output power it starts with combing  two of 
these devices and going up.
 
Maybe FM will get a 100 or 200 Volt MOSFET allowing more efficient solid  
state transmitters by making more power per single device using fewer  combiners
 
Dave Hultsman
Continental ELectronics



************************************** See what's free at http://www.aol.com.