Equipment information

Johnson Challenger Transmitter
Model Challenger
Category: Radio, Communication
Group Transmitter
Description Bandswitched Shortwave Transmitter
                                    The Johnson Viking Challenger is a single knob bandswitched
shortwave transmitter which covers the amateur 80 through 6
meter bands and provides both CW and Phone operation.
Crystal or external VFO frequency control is provided by
simple front panel plug-in arrangement without switching,

The power input rating is 120 watts CW and 70 watts Phone
with the input restricted to 85 watts on the 6 meter band. A
panel mounted meter monitors plate current (power input) and
grid current of the final amplifier.

The meter leads and AC line cord utilize individual RF
filters to supplement the excellent cabinet shielding and
bonding which provides very good suppression of spurious
radiation and harmonics and reduces interference to other

The circuitry employs a 6DS5 crystal oscillator (RF
amplifier when driven by a VFO), a 6DQ6/ as an RF
buffer-driver, and a pair 6DQ6A's in parallel,
bridge-neutralized, as the final power amplifier. A 12AX7
dual triode functions as a two stage speech amplifier to
drive a 6AQ5 clamp tube modulator. On CW, the 6AQ5 clamps
the final amplifier screens to lirjiit the key-up plate
dissipation. A 5U4GB rectifier delivers D,C„ power to all

These manuals are available for the above equipment:

Manual Type Service and User Manual Johnson-5493-Manual-Page-1-Picture
Pages 13
Size 801.73 Kbytes (820975 Bytes)
Language english
Quality Scanned document, all readable.
Upload date
MD5 13f57f8ace08267f55e3a7ab578ba0ff
Downloads 214 since 01 March 2014

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