User's Manual

What is A Valid Output Frequency?

A valid output frequency is defined as an output frequency that is divisible by the set reference frequency (12.5 KHz

or 10.0 KHz) and one which is within the valid operating bands. All seven digits on the front panel FREQUENCY

SELECT pushwheel switches must be entered. The frequency is entered in MHz where the first three digits represent the

left side of the decimal place, and the last four digits represent the right side of the decimal place. For example, the

frequency 450.0125 MHz will simply be entered as 4500125.

If an invalid frequency is entered in, or if the same frequency that the SRPT-40A is currently locked on to is entered

in, then the SRPT-40A will remain at its current frequency and current RF output power, i.e., nothing will happen.

Changing Output Frequency via Channel Select

The frequency can also be changed by entering a channel number that was previously stored with a frequency. See

Storing Output Frequencies into Channels for instructions on how to store frequencies. There are ten channels

available for storing and recalling frequencies. These ten channels are preset with default or customer requested

frequencies at the factory.

To change frequency via channel select, the S1 dip-switches behind the front panel must be set with switches 1 and

2 in the “ON” position and 3 and 4 in the “OFF” position. These switches are in the same position as when changing the

frequency direct. Again, these are the normal dip-switch positions, and there probably is no need to remove the top

cover.

Now you’re ready to enter the channel. This is done by setting the six left-most digits (digits 2-7) of the

FREQUENCY SELECT pushwheel switches equal to zero. Then the far right digit (digit 1) is set to the channel of

choice (channel 0 – channel 9). After entering the channel, press the EXECUTE pushbutton down and then release. The

SYNTHESIZER will change to the frequency that was stored in the channel.

WARNING

THE REMAINING OPERATIONS ARE FEATURES THAT REQUIRE SETTING INTERNAL DIP-

SWITCHES.

IN ALL CASES, WHEN PERFORMING THESE OPERATIONS, THE SRPT-40A MUST BE ON AND

THE TOP COVER MUST BE REMOVED.

WHEN THE OPERATION IS COMPLETE, ALWAYS SET THE INTERNAL S1 DIP-SWITCHES WITH

SWITCHES 1 AND 2 “ON” AND SWITCHES 3 AND 4 “OFF”. THEN RE-INSTALL THE TOP COVER.

Storing Output Frequencies into Channels

The SRPT-40A must be locked on a frequency before storing that frequency into one of the ten available channels.

It is not necessary, however, that the SRPT-40A be transmitting, hence the TRANSMIT/STANDBY switch can be in

STANDBY.

First, lock on to the desired frequency either directly or via channel select. Remove the top cover of the SRPT-40A.

Set the S1 dip-switches (located behind the front panel) as follows: Switches 1, 3, and 4 set to the “OFF” position and

switch 2 set to the “ON” position.