[Amps] HV relay

[Jim Thomson]

Well Jim,

Im changing my 2 at 3-500Z amp to a single GS-35B and in the spec's for the tube it states that the warm-up time is Aprox~ 2 minute. So instead of using  a power SCR in the mains to switch on the HV bank( and probably darn slow to disengage if a fault occurs) I would like to use a Vac relay - probably close to the Plate choke since i have room in that compartment and a delay circuit is darn easy to DIY.

Mike
KC7NOA


###  U don't need it.  [ And u don't need to delay the B+  on a 8877 amp, or any other oxide  tube either.]    My buddy just finished a 2 x  GS35B  for 6m.   We just inhibit the key line  for 2 mins.   In the meantime,
the filS  are warming up.. and B+  is going through it's step start sequence etc, etc.   The tube is cut off anyway, no current flow.    All you want to do is inhibit  drive.. AND also inhibit the tube  from drawing ZSAC ! 

##  GS35B  runs  superb on 6M  [and HF].   Things get better with more B+.   We tried it with as high as 5.6 kv  [ no load].... then backed it way down.  It now sits at   4300-4700 vdc no load.  Drive it with a FT-2000 on 6m
and it really cranks out the power.    Since 2 x tubes are used...separate  adjustable bias controls are employed. 

Later........ Jim  VE7RF