[AMPS] Cathode strapped to filaments pros/cons

[Rich Measures]

>
>I noticed that on some 8877 amps they tie the cathode to one side of the 
>filament, then feed the cathode bias into the filament. What is the purpose 
>of doing this, rather than letting the cathode float?

€  To avoid the possibility of breaking down the fil./heater insulation 
during a glitch.  
Another problem is that If a heater/cathode arc takes place, it is 
possible that the heater wire can be severed.  
>
>I also notice the same practice with AB1 tetrodes, i have tried both methods 
>and they both seem to work. Is there some sort of secret to all this?
>
>I would like to know since i am building a new 220mhz 8877 project.
>
€  Above 30-MHz, the heater is tied to the cathode, and the heater is fed 
through a choke.  .  
>
-  later, Bill


Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm