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Radio Broadcast Technical Consulting and Sales
10032 Island Drive, Brainerd, MN  56401

1 KW AM Four-Port RF Switch

Built by M. W. Persons and Associates, Inc.
Made in Minnesota

The M. W. Persons AM RF-2 Switch is for AM radio stations with 1100 watts or less of RF power, this RF switch is a quick and easy way to select between a main and an auxiliary transmitter.  There are four N-F connectors for the RF.  IE: main transmitter, auxiliary transmitter, antenna, and dummy load.  Whichever transmitter is not on the air is connected to the dummy load.  There is no additional charge for substituting SO-239 (UHF) connectors on an order. 

The front control panel lets you switch main or auxiliary transmitter to the antenna and has LED lamps to show the operating state.  The Test/Normal switch has a blinking red LED lamp warning that both transmitters can run simultaneously....one into the antenna and the other into a dummy load.  In the normal position, only the transmitter connected to the antenna will be allowed to run.  Both transmitters can run when the switch is in the test position.  To accomplish that, this unit has relay contacts that go to the transmitter interlocks.   

This switch is fully remote controllable.  All it needs is a momentary relay closure to tell it to connect the main transmitter to the antenna or the auxiliary transmitter to the antenna.  Control is 24 VDC from the unit's power supply at less than 100 m.a. of current.  No power is required from a remote control to get the switch to work, just a closure.  The unit has 2 VDC status outputs to tell a remote control system which transmitter is connected to the antenna

A rear view shows the RF compartment open for inspection.  A 24 VDC wall transformer runs the switch.  In case of power failure, the main transmitter is connected to the antenna and the auxiliary is connected to the dummy load port.  When power is restored, the last asked for operating state is reestablished automatically. 
It is 3-1/2" high, 19 inches wide, and 7-1/2 inches deep.

Because of the lead lengths inside the box, the switch can only be used up to 8 MHz.  Higher frequencies, such as FM 88-108 MHz and higher, require a different switch architecture.  See RF-3A and RF-4A switches.

The AM RF-2 Switch, as shown, is $680.00 plus shipping and tax.  One-year warranty.  It comes complete with a schematic diagram. 

N to N RF cables are also available.

Questions?  Email Mark Persons:  teki@mwpersons.com       

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page last edited 12/21/2016