--- In ham_amplifiers@..., FRANCIS CARCIA <carcia@...>
wrote:
I put a 50K 10 watt resistor across my fuse in the fil. C.T. so
the bias is at cut off if it ever blows.
### agreed. Basicly anything from 1 k to 1 meg is fine. When
the CATHODE fuse blows..... the amp can still be driven a bit....
so a 2-10 w resistor will work fine.
### IF u use a CATHODE fuse....make damn sure u stick a
resistor across the fuse holder... like u described.
### I once had a 4-1000.... and while re-installing it...
forgot to hook up the B- to the pos junctions of the plate +
grid meter's........ a real disaster !! The cathode will try and
assume full plate V... and the bypass caps at the cold ends of
the fil choke starting snapping away !!
### also... in schemes like the L4B... where they use +130 vdc
[and +90 vdc on cw position] to cut off the tube[s] on RX is
bad news. When the 3pdt t/r relay is in 'mid air'... the
cathode is floating for a split second ! I rewired it with a
simple 100 k-2 w mf in the center tap.... and use the same
contacts... to just short out the resistor on TX.
gotta run.... Jim VE7RF
