The First Amendment Radio Transmitting Society

Baltimore, Maryland

N3HIA in front of the 220/440MHz repeater (left cabinet) and the previous 2m

repeater (right cabinet).  The old 2m repeater was a C73MHB Motorola

Motrac Compa-Station - since upgraded to full solid-state commercial

ICOM RF equipment.

The 2 Meter Repeater N3HIA/R 147.345MHz

This east-side repeater is two commercial ICOM units linked together with a CAT controller and a four-cavity Sinclair duplexer.  The repeater transmits with about 22 watts and covers the majority of the Baltimore area with it's primary lobe up and down the I-95 corridor and bay areas.   The 2 meter repeater is on 147.345MHz, standard positive offset and is open COR (no PL tone required).

User commands for the 2m machine include:

• 703, 704, 705, 706 - Various announcements

• 375 (+ additional digits) - DTMF keypad test

The 220 MHz Repeater KB3AVZ/R 224.48MHz

The 220MHz repeater produces approximately 100 watts and covers most of the Baltimore metropolitan area with a few holes in extremely low lying areas. The transmitter frequency is 224.480MHz with a standard negative offset. The 220 machine is primarily made up of GE commercial units and is a split-site repeater.  The 220 receiver is located within 0.5 mile of the transmitter.  There is no PL on the 220 side at this time.  The 220 and 440 machines are located within the same cabinet and share the master commands of an ACC RC-96 controller.

The 440 MHz Repeater KB3AVZ/R 449.075MHz

The 440MHz repeater is a single-site machine which produces approximately 80 watts of transmit power using a tube amplifier. The 440 machine uses GE commercial RF equipment and shares the ACC RC-96 controller with the 220MHz machine.  The 440 receiver is slightly deaf - however, the lowered sensitivity was intentional to increase selectivity and eliminate incoming interference. The transmitter frequency is 449.075MHz with a standard negative offset. There is a PL of 118.8Hz at this time that also helps eliminate paging tones. **note that presently the 440 machine has an issue with receiver sensitivity and audio - to be corrected as soon as possible**