[MohawkARC] Direct conversation with astronauts onboard the ISS

[joe B]

Two Meter VHF Voice mode

A Common mode is direct conversation with the astronauts onboard the ISS.
Occasionally during their free time, they will appear on the VHF radio.
While over North America, they receive on 144.490 Mhz (the uplink
frequency) and transmit on 145.800 Mhz (the downlink frequency). You will
need to adjust your radio to transmit with a minus 1.31 Mhz offset. (See
the manual for your radio for details.) For future use, its a good idea to
store the transmit/receive pair in a memory channel in your radio.

   - Freq=145.80 Mhz, Offset = -1.31 Mhz.

In order to gain maximum advantage in the contact, it is advantageous to
compensate for the effects of doppler shifting in the transmit and received
frequencies. As the space station approaches you, the frequencies will
appear to increase due to the oncoming motion. It is like the increase in
pitch of a car horn as it approach you. Similarly, the frequency appears to
drop after the space station passes overhead and heads to the horizon.
Programming additional memory with the different frequencies for doppler
compensation here are the memory channels.
Programming Memories for 5 Khz Tuning increments, VHF Voice, North
AmericaMemory
ChannelRX Doppler Offset (KHz)Transmit Frequency (MHz)Receive Frequency
(MHz)Memory Offset (MHz)CommentsM1+5144.485145.805-1.32M20144.490145.800
-1.31M3-5144.495145.795-1.30

As the ISS approaches, use Memory 1. As it goes higher than forty five
degrees high, use Memory 2 until it goes overhead and below forty five
degrees. Then, switch to Memory 3.
Programming Memories for 1 kHz Tuning increments,VHF Voice, North AmericaMemory
ChannelRX Doppler Offset (kHz)Transmit Frequency (MHz)Receive Frequency
(MHz)Memory Offset (MHz)CommentsM1+3.4144.486.6145.803.4-1.316.8M2+3.0
144.487145.803-1.316M3+2.0144.488145.802-1.314M4+1.0144.489145.801-1.312M50
144.490145.800-1.310M6-1.0144.491145.799-1.308M7-2.0144.492145.798-1.306M8
-3.0144.493145.797-1.304M9-3.4144.493.4145.796.6-1.3032I hope this info
will be of use to are New and Seasoned members of MARC Mohawk Amateur Club

Thank you for your time KC1DAI  Joe  73