HPT Series FSK CALL SIGN CHIP INSTALLATION
To install the call sign chip properly, proceed as follows:
Locate the transmitter VCO/Synthesizer module. This can be identified by the one with a coax cable running to the transmit PA stage. In addition, the transmitter synthesizer has two more chips installed than the receiver synthesizer. These are small 8-pin chips for the transmit audio.
Make a note of which way the notch on the end of the chip is oriented. The notch identifies which end pin 1 is on. Carefully remove the existing 40-pin microprocessor chip from the synthesizer module. This may be done by carefully prying up each end of the chip a little at a time. The chip may be put aside and saved for a spare.
Make sure the pins are all straight and aligned on the new chip before attempting to install it. Orient the chip with the notch on the correct end and install it in exactly the same manner as the old one was oriented. Failure to properly orient the chip will result in destruction of the chip.
Turn on the unit with the transmitter into an antenna or dummy load and ensure that it locks up properly on the frequency set on the front panel. Lockup may take up to 30 seconds.
This completes the installation. The unit will now identify periodically by frequency shift keying with the call sign written on top of the chip. The new chip is a microprocessor with a program that defines the operating frequency of the unit, enables an internal timer program and on a preset time, shifts the frequency of the VCO by a small amount to identify the station.