FM HT Operation | FM Base Operation

FM satellite operation is relatively easy and rewarding. A fun way to converse and chase grid squares. It's exciting to work stations using a 1/2 Watt HT and handheld antenna.
Sometimes the FM satellites are crowded; if you find this overwhelming, you may really enjoy the breathing room the SSB satellites give.

FM HT Operations

A general practice for FM satellite passes having UHF downlink and VHF uplink is to program five memories for each satellite, following the iterations below:

440MHz Downlink:    146MHz Uplink:
ƒ_center + 10kHz      ƒ_center
ƒ_center + 5kHz       ƒ_center
ƒ_center + 0kHz       ƒ_center
ƒ_center - 5kHz       ƒ_center
ƒ_center - 10kHz      ƒ_center

Thus, for AO-51, your HT's TX frequency would always be 145.920MHz, while the RX frequency would start at 435.310 and slide down to 435.290 over the pass.
You will find that the more directly overhead the pass is, the less time you will spend on the "center" memory--this is because the relative speed of the satellite is highest when it's passing directly overhead--the doppler shift starts to look like a step function.

In the rare case such as ISS that has UHF uplink and VHF downlink, do as follows:

146MHz Downlink:    440MHz Uplink:
ƒ_center              ƒ_center - 10kHz
ƒ_center              ƒ_center - 5kHz
ƒ_center              ƒ_center + 0kHz
ƒ_center              ƒ_center + 5kHz
ƒ_center              ƒ_center + 10kHz

Note that since the satellite is racing toward you in the initial half of the pass, YOU must compensate by decreasing uplink frequency.

Of course, the VHF side has Doppler shift as well, but the magnitude is small enough (3kHz maximum) that it is not relevant with an FM HT that has only 5kHz frequency intervals.

FM Base Operations

The following preliminary items should be acheived before the beginning of the satellite pass:
Note: These procedures are designed for W8SH, but the principles are generally applicable, especially to those with TS-2000 transceivers and/or Ham Radio Deluxe

1. Start Nova for Windows and select the desired satellite, ensuring the rotor control is active (at W8SH, we merely use Nova to control the old rotor controller)
2. Be sure Main and Sub bands of TS-2000 are in VFO mode, then press SAT button.
   If Multi/Ch LED is not lit, press BLUE VFO/CH button.
   Use Multi/Ch knob to select desired satellite by name.
   Note: SSB memory frequencies are in the middle of satellite passband.
3. In Ham Radio Deluxe, click Satellite>Ground Control.
   You will select the relevant satellite and check the "RX" and "TX" boxes to enable doppler frequency control.

Once the pass begins, the following steps are necessary before calling CQ or engaging in a QSO, and to maintain QSOs.

1. Once the satellite is above 5 degrees, you may hear QSOs. Toggle your DOWNlink circularity to get the best signal (AO-51 usually transmits constantly, SO-50 and AO-27 must be keyed to transmit just like a regular repeater).
   If you don't hear anyone on SO-50, try toggling RX/TX circularities, and then try transmitting a 74.4Hz PL for 2-3 seconds, switching back to 67.0Hz PL to key the transmitter.
   If you don't hear anyone on AO-27, check its schedule--it's usually only on for about 1/2 the pass. AO-27 does NOT require a PL to transmit.
2. You really do not need to adjust the TX frequency when the UPlink is VHF (as it is on all current FM satellites). If you do so desire, remember to offset it in the OPPOSITE direction as the UHF DOWNlink, by 1/3 the amount.
   Why Opposite? Because the satellite RX is on channel center, and your TX to it is shifted up--thus YOU must shift down in order to have your signal arrive on satellite RX center!
3. You can be 3 to 5kHz off the DOWNlink center frequency without much degredation--tune by ear and/or watch Nova's Doppler offset to help stay on center--if you want to really be exact, switch to USB or LSB briefly and "zero-beat" the DOWNlink carrier.

During the pass, you might hear people whistling and making other rude noises. As in the rest of amateur radio, do not acknowledge their efforts. In this case, it could be best just to raise power enough to overcome the malicious interference and continue QSOs as if the interferers aren't there. Fortunately, W8SH possesses an above average signal on FM and can 'step over' most of the casual interferers with omnidirectional antennas.
This does NOT mean to blow legimate users off the air. It is best to run at about 5 to 10W power out of the TS-2000 normally as this is more than enough under clear conditions, even at low elevations.