Johnson matchbox tuner manual

The Johnson Matchbox is an Antenna coupler designed for matching Antenna and transmission line impedances to a 52 ohm impedance within the amateur bands from to 30 megacycles. The Matchbox also provides band switching and transfer of the coupler from Transmitter to Receiver and in addition mutes the Receiver and grounds the Receiver Antenna terminals . I compared the Johnson Matchbox and three other methods of feeding my balanced antenna: the K3 with built in tuner and a BL2 balun (4 to 1 ratio), the K3 with built in tuner and a BL2 balun (1 to 1 ratio), and the K3 with built in tuner and no balun (direct connection to the ladder line). I used an MFJ Balanced-Current Meter. Here’s what I found:File Size: KB. The Ameritron ATR10 antenna tuner used a network functionally identical to the Johnson Matchbox series. The ATR was a single-ended tuner with an output balun. The ATR used a tapped inductor instead of a coupling link. The basic simplified ATR10 antenna tuner matching circuit is shown below: Tap A is from a standard rotary switch contact.

The Johnson Kilowatt Matchbox true balanced tuner. The purpose of this topic is to inform, to revisit this wonderful tuner which is most often dismissed by many modern Hams. The Kilowatt Matchbox was originally designed as an accessory item for the Johnson Desk Kilowatt transmitter. The shear power of this transmitter lead Johnson to design a. Nye Viking tuners bear a strong resemblance to the Johnson Matchbox. They should. Mr. Nye bought the rights to build a Johnson Matchbox equalivent. I'm using my MB-II with a Dentron Clipperton L, and it handles all that the amp can dish out. I'm tuning a pair of coaxial double bazookas so the match only needed a touch up for example, the one thousand watt Johnson Matchbox was rated to handle a watt plate modulated AM transmitter (four kilowatts PEP transmitter input and watts PEP RF output). The Heathkit SB

The Ameritron ATR10 antenna tuner used a network functionally identical to the Johnson Matchbox series. The ATR was a single-ended tuner with an output balun. The ATR used a tapped inductor instead of a coupling link. The basic simplified ATR10 antenna tuner matching circuit is shown below: Tap A is from a standard rotary switch contact. I compared the Johnson Matchbox and three other methods of feeding my balanced antenna: the K3 with built in tuner and a BL2 balun (4 to 1 ratio), the K3 with built in tuner and a BL2 balun (1 to 1 ratio), and the K3 with built in tuner and no balun (direct connection to the ladder line). I used an MFJ Balanced-Current Meter. Here’s what I found. JOHNSON drop swR. Ands W R swa the at SwR ATE the the the JOHNSON or RADIATION OV AN RATE CALIBRATE asc - STR ANTENNA COUPLER 52 swR with SVR JomSON the. Title.