Vaughns Magnetrons
Pulse Modulator 3
This page is under construction; some of the links non functional
This Web page is under construction;some of the required buttons has not been added yet; I am still in the process of laying out my Web site
This magnetron pulse modulator origionally designed for the 2J21 and 725A magnetron; however since its operating output impedance
is 1 K ohm (12KV at 12 amps) it is also useful for driving the 2J50 and the 2J55. What makes this so neat is that of simplicity and
relatively lost cost. The high voltage switching is accomplished with a triggered spark gap ( trigatron) which seems to
pulse relatively clean. As far as I have been able to roughly measure; the jitter is about 40nsec or slightly more within several
seconds. At shorter time frames the statical jitter appears about half. For my purposes , as a simple magnetron tester) I am very
happy with it.
PFN output (110 ohms)to magnetron mount
110 ohm Cable ( PFN -to-magnetron mount)
The magnetron PFN pulse modulator is connected to the magnetron mount with a 100 ohm cable assembly to rough match the 110 ohm impedance
requirement. It consists of two 50 ohms cables physically laid in parallel but connected in series at each end. One of the
cables is insulated with an insulating flexable rubber hose as shown below:
PFN pulse modulator
magnetron mount
The magnetron mount ( see photos) input is designed to match the 110 ohm magnetron pulse transformer primary input.
magnetron cathode\ minus 12KV input
cathode heater shunt capacitor @ HV output
725A cathode heater shunt capacitor missing
6.3 Volt cathode heater power input
second cathode heater shunt capacitor @ input
CVR magnetron pulse current monitor
PFN drive to transformer input
neon bulb RF output indicator
The magnetron mount used with the electromagnet assembly; 725A magnetron being tested:
HV voltage probe for monitoring the magnetron cathode
Experimental Setup; 725A magnetron being tested:
screen box for enclosing DSO