LT23S  Connectors and Controls



Front Panel Features


‘ON’ switch


This controls the DC power to the unit.  The LED is lit for normal operation.

‘TX’ switch

Allows manual switch-over to transmit.  The LED is lit on transmit.

‘F1 - F2’ switch

Selects of one of two crystal oscillators.  The frequency 2 (F2) oscillator has a crystal fitted for the default IF range. The switch allows the default IF range,  as quoted in the technical description,  to be overridden.

‘Power Output’

Reads UHF power output directly in Watts.



Rear Panel Connectors


‘1296 MHz out’

Provides a maximum 10W UHF output on transmit.

‘144 MHz in/out’

Connection to 2m transceiver.  Do not exceed the maximum drive power!  Always keep to the minimum 2m drive necessary.

‘+/- 14.5V’

A heavy-duty cable should be used for connection to the power supply.  A supply voltage of 12V is not enough for the LT23S to produce an output of 10 Watts;  this voltage would produce a  maximum output power to approx. 7.5 Watts. 


The supply voltage (14.5V) should be measured directly at the connection to the LT23S when transmitting with full power.


‘Cinch’ socket for connecting the P.T.T. line from the transceiver. Grounding this terminal switches the LT23S to transmit.

“+ Relais” (+ relay)

On receive  this terminal shows a voltage of approx. 14V (measured with respect to earth potential). This voltage is used to power the antenna relay.  In addition,  it can be used to power an external GaAs FET pre-amplifier.



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©  GJ Coyne & G Mussler  Dec-2003