Jim's Amateur Radio Satellite Resources Page
Jim DeLoach, WU0I
This page contains resources for Amateur Radio satellite operation that I have found to be particularly helpful.
Presentation for 2024 Pacificon
- Build a Satellite Roving Station for Your Next Road Trip or POTA Activation!
- Add some extra fun to your next road trip or POTA activation by bringing along a simple 'roving' satellite station! A portable satellite station is far easier to assemble than most hams realize. In this presentation, I explain how you too can put together a simple satellite station to take along on your next road trip or POTA activation!
Satellite Status Pages
AMSAT Amateur Radio Satellite Resource Links
AMSAT should be your first stop for all topics related to Amateur Radio satellites!
Satellite Tracking Apps & Hardware Controllers
- Nice list of satellite tracking apps for Android and iOS
- Look4Sat is my favorite Android satellite tracking app for roving operations on the road! It is accurate, intuitive, and add-free! If you are looking for a simple app that has all the features you need yet keeps the interface simple, this one is for you.
- The CSN Technologies Self-contained Antenna Tracker (S.A.T.) is an increasingly popular controller device that provides path prediction, rig control, and rotor control in a small, portable package. It works great with and was essentially made for the Icom IC-9700.
- Heavens Above is a popular path prediction web site. They also have a mobile app.
- www.n2yo.com is another popular path prediction web site.
- The SatPC32 PC program is popular for path prediction, rig control, and rotor control for the home QTH market.
Mapping Resources for Planning Satellite 'Roving' Trips
The free Google Earth Pro tool enables users to overlay and visualize custom map data over geospatial images, maps, and other geographic information. I use this tool to overlay Maidenhead gridsquare boundaries and related information over satellite imagery and street maps to plan North American road trips and find suitable activation sites -- including sites on gridsquare boundaries. Google earth comes in several flavors, but I typically use the Google Earth Pro PC-resident version. Download Google Earth Pro here.
Keyhole Markup Language (.kml) files can be loaded into Google Earth to visualize custom map data. Double click on a .kml file to open it in Google Earth. I have created the following .kml files to assist me in satellite roaving trip planning:
- North_American_Gridsquares.kml (~6MB) shows boundaries and labels for North American gridsquares.
- Worldwide_Gridsquares.kml (~58MB) shows boundaries and labels for all gridsquares worldwide, excepting those at poles.
- KJ7DZ_grids_needed_by_top_gridchasers.kml visualizes Continental US gridsquares needed by the top grid chasers. Frank, KJ7DZ, put together a list of grids needed by every ham who is at least 90% of the way towards achieving the prestigious AMSAT Gridmaster Award. I then visualized this list by showing each grid needed by at least one such ham -- color-coded by how many hams need the grid. Double-click the dot in the center of any grid to display the callsigns of the specific hams needing that grid. Congratulations to Frank for being the 66th recipient of the Gridmaster Award!
Other Helpful Amateur Radio Satellite Resource Links
Sample Kenwood TM-V71A Chirp Satellite Programming File
Kenwood_TM-V71_Sample_Satellite_Chirp_File.csv
This Chirp file shows how memories in your rig can be used to simplify Doppler shift management. When using memories, you eliminate the need to track the direction of the Doppler shifts. Instead, you track where in the pass you are -- at acquisition, between acquisition and the midpoint, at the midpoint, between the midpoint and satellite loss, and at satellite loss -- with transmit uplink frequencies stored in one memory bank and receive downlink frequencies stored in another memory bank. A common nomenclature can then be used.
In this example Chirp file, transmit uplink frequencies are in the 800 bank and receive downlink frequencies are in the 900 bank. My naming convention first shows the satellite designator followed by one of these codes:
- 'A': The channel to use when first acquiring the satellite.
- 'AM': The channel to use between acquisition & midpoint 'AM' memories are only needed on 70cm and will be 5 kHz BELOW for transmit uplink and 5 kHz ABOVE ).
- 'M': The channel to use when the satellite is at the midpoint of its pass and thus closest to you. Since there is zero relative motion at this point, the is the frequency without Doppler correction.
- 'ML': The channel to use between midpoint and loss (only needed on 70cm).
- 'L': The channel to use when the satellite is about to set and be lost.
This table shows the amount of offset applied for each code on 2-meters and 70-cm for the transmit uplink and the receive downlink:
Code |
Phase of the satellite pass |
Uplink Doppler shift (2-m) |
Uplink Doppler shift (70-cm) |
Downlink Doppler shift (2-m) |
Downlink Doppler shift (70-cm) |
A |
at acquisition |
-5 kHz |
-10 kHz |
+5 kHz |
+10 kHz |
AM |
between acquisition and the midpoint |
|
-5 kHz |
|
+5 kHz |
M |
at the midpoint |
0 kHz |
0 kHz |
0 kHz |
0 kHz |
ML |
between the midpoint and satellite loss |
|
+5 kHz |
|
-5 kHz |
L |
at satellite loss |
+5 kHz |
+10 kHz |
-5 kHz |
-10 kHz |
(c) Jim DeLoach, WU0I, 2024.