The Johnson Viking Ranger
by Greg Latta, AA8V

Typical Operating Conditions

Important Safety Note: Working on or testing equipment such as the Viking Ranger is extremely dangerous since very high voltages are present when the equipment is turned on, and may even be present when the equipment is turned off and unplugged. If at all possible, do all work with the equipment off and unplugged and be sure that the capacitors are properly discharged before working on the equipment. The operator assumes all risk and liability in such matters! Do not work on this type of equipment unless you are experienced with working around very high voltages!

Typical Operating Conditions:

Introduction:
It is very convenient to know how one Ranger compares to another when in actual operation. The Ranger operating manual does list various settings and operating conditions, but they are hard to find. Typical dial settings for a variety of frequencies are given on page 9 of the operating manual. Typical voltages and meter readings are given on page 21 of the operating manual.

Below I have documented the meter readings and dial settings on my Viking Ranger under a variety of conditions. It is important to note that these readings were taken when my Ranger was outfitted with solid state rectifiers rather than the vacuum tube rectifiers. They will therefore differ significantly from the readings given in the manual due to the higher low and high B+ voltages. Also, there can be significant differences between one Ranger and another, so these readings are by no means an absolute standard.

I hope you will find the information below useful in restoring, operating, and enjoying your Johnson Viking Ranger.
73 and see you on the air,
Greg AA8V

Reading the Ranger Meter:
The Ranger meter can be confusing to read, and the instruction manual doesn't help much. The table below shows the full scale value for each function and what each division on the meter represents:

Take a look at the picture below and then try to figure out what the reading represents. The correct readings are shown below the picture.

Keep in mind that because of inaccuracy in the meter itself and in the multiplier resistors the readings may differ by as much as 5% or more from the actual value, so isn't necessary to read the current as close as I have above. In actual operation, the most important thing is to adjust the drive control so that the grid current is 2.5 mA and to be sure that the plate current is dipped to a minimum using the final control.

The table below is a list of the typical meter readings from my Viking Ranger:

The table below lists the settings of the front panel controls on my Viking Ranger for a variety of frequencies. In each case the transmitter was operating into a 50 ohm load:

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If you have any questions or comments, you can send E-Mail to Dr. Greg Latta at glatta@frostburg.edu