[Drake] L75; What went KERPOW?? **ANSWER!!**

[staffanB]

From: "Dave Edwards" Sent: Wednesday, September 08, 2004
Subject: Re: [Drake] L75; What went KERPOW??
> What was bizarre is that the .82 resistor acts as a fuse to protect the
rest
> of the power supply components.


hi!

not that bizarre at all.
many well-designed PA are usíng resistors as fuses in addition to
"real"   fuses.
the 82 ohm is really a standard resistor value.

btw
i am just putting my Old Dentron GLA-1000 back to life afer a decade and a
half in storage.
i took out most of the power- and control circuits. there are now new
capacitors and resistors
on the +HV side, the red and green leds have newdesigned circuitry, there is
a new ac-switch, step-up
AC power-on, heater  stabilized DC-power (40V for the PL519!) and slow
power-up circuitry (1 minute!)
the tubes are PL519 and the cathode circuit is of course rebuilt.  2
resistors will act as fuses when something goes wrong in the power supply
department
soon to come is adding 160meters which will require some work on the final
pi-filter.
the bandswitching sector must also be renewed for 25, 18, 10 and 1.8 MHz.

not much left of the old (and cheap) design...:)

cheers
oh2baw