John Stewart
Shreveport, LA

Amateur Radio Station

Johnson Viking Challenger Transmitter

General Description: The E.F. Johnson Viking Challenger is a shortwave transmitter that covers 80 through 6 meters (minus WARC bands), CW and Phone (AM). Frequency may be controlled either by an external VFO or crystals. Input power is 120 watts CW and 70 watts phone for approximately 100 and 50 watts output, respectively. Several tubes are used (see pictures below). The 6DS5 serves as a crystal oscillator, a 6DQ6A is a RF buffer-driver, a pair of 6DQ6A's in parallel (bridge neutralized) serves as the final amplifier. A 12AX7 dual triode is a two stage speech amplifier and drives a 6AQ5 clamp tube modulator. A 5U4GB rectifier delivers DC power.

Physical characteristics: Size: 9.0"h x 13.25"w x 10.0"d; Approx. Weight: 24 lbs

Power: 120V AC, No 3-way plug, chassis should be grounded for safety.

Serial Number: 46001

This transmitter was donated to QCWA Chapter 85 and sold at auction.

Front View
Back View
Side1 View
Side2 View
Top View
Bottom View

More Pictures