KA1TDQ - Jon


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Jon writes:  This is my current shack with my new homebrew dual 3-500 floor model amplifier. 

I'm now using my single tube AM transmitter on 40 meters while using the NS-40, a Class E CW rig which is housed in the aluminum chassis on the desk, as the exciter. 

 I run the transmitter and amplifier combo at 200 watts carrier. 

An Alinco DX-R8 is the receiver and I use a dipole for the antenna.

Click here for a larger photo (~2.5 Megs)

This is a plate modulated transmitter using a single 7984 tube.  

Both RF excitation and audio are external using 50 ohm and 8 ohm inputs respectively.  

The modulator uses a Heising circuit and power output is 20 watts.

Click here for a larger photo (~3.5 Megs)



On the amplifier, the plate choke was made from four pieces of 1/4 round ceramic tile glued around a wooden dowel.

The filament transformer is 6.3 volt, 30 amp center tapped but fed from a huge isolation transformer with 105 volt secondary taps.

This brings the filament voltage down nicely to 5.0 volts.

The plate transformer is vintage 1940's from a BC-610-E WWII transmitter.

More rig pictures may be found on the QRZ page for KA1TDQ

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