03-02-2013, 04:09 PM
bit more done today.i monitored the voltage on the anode of the osc (V3B ech81) 70 volts on LW but found it dropped to zero on LW
it is fed via R16 (33k)the voltage at the hot end was a constant 112volt on ckecking i found it had risen to 42.8K so changed it.
the only othe thing is C35 its a 0.001mf wax.i had checked it but decided to change it .i now have 95 volts on LW and 90 volts on MW
the scope showes the osc is working on both wave bands saddly still no output on MW and still low output on LW .still no vhf will have to big out a few ef 80's
rob t
it is fed via R16 (33k)the voltage at the hot end was a constant 112volt on ckecking i found it had risen to 42.8K so changed it.
the only othe thing is C35 its a 0.001mf wax.i had checked it but decided to change it .i now have 95 volts on LW and 90 volts on MW
the scope showes the osc is working on both wave bands saddly still no output on MW and still low output on LW .still no vhf will have to big out a few ef 80's
rob t
if its made by hand it can be repaired by hand
