Johnson Viking Matchbox Antenna Tuner, manual, balanced For Sale

• Johnson Viking Matchbox
• Directional Coupler
  
• Manual that describes its operation and includes schematics
  

This is an old manual tuner rated to about 250 Watts, usable for 160 to 10 meters HF. It is the version that includes the SWR indicator and directional coupler to feed the SWR indicator.

According to several QST articles, most recently \"Don\'t blow up your balun\" in the June 2015 QST issue, the Johnson Matchbox is still an outstanding option for the usual universal dipole fed with ladder line or window line, because this tuner is a \'balanced\' design. Most tuners that you see these days feed balanced line via a 4:1 balun located at the output of tuner. This places the balun on the non-50-Ohm-side of the tuner, which makes it quite lossy.

The tuner works just fine. Its internal components are really just a large roller inductor and capacitor which will last forever. It is a very old design going back to the days where 110V AC was fed into the tuner to a relay that enables the tuner. Without those 110V AC, the tuner would be bypassed and the coax input is instead connected to the \'receive\' antenna input. This has been changed by one of the previous owners by wedging a piece of plastic into the relay such that it is always in the \'transmit\' position. So the tuner is always \'on\', your coax input from the radio is always connected through the tuner to the balanced line antenna connectors. If you prefer to connect 110V to the relay to switch it as in olden times, you can simply remove that plastic wedge from the relay, but please don\'t kill yourself while playing with the line voltage.

As mentioned the tuner works very well, the face plate it still very nice. This is an older unit, though, long out of production. The top does show several scratches, please refer to pictures. I\'m selling it because I\'m saving up to get a Palstar BT 1500 that\'s all shiny&new and can handle more power.