–Tri it out–
I actually attached it to the antenna base of a car and tried using it. (Obviously, you can’t drive on public roads in this condition.)
There were no suitable satellites, so I only communicated via FT8 ground wave.
On another day I went to the Tamagawa riverbed in Akishima City to try it out, but…
Even in B mode (transmit 435MHz/receive 145MHz), the transmitted radio waves interfered with the received ones.
Maybe I need to add another duplexer…?
Here too, I ended up using FT8 to get around it.
No problems with radiation and stability. The only thing left to do is to see how much coverage the fixed elevation angle will provide…
－・・・－
Happy New Year 2022! I’m back on the same hill again. Today I brought two duplexers and put them on both the transmitting and receiving antennas. Thanks to that, there is absolutely no interference in satellite B mode (receiving 145 MHz – transmitting 435 MHz) and the signal is clear.
Ten minutes later, satellite CAS-4B appears due north in an orbit with a maximum elevation angle of about 30°, so I wait until AOS (the satellite rises above the horizon) and start the VP rotator at a speed of “half a rotation every 15 minutes.”
There are many things to do when communicating with a satellite, and it is not possible to directly monitor which way the antenna is facing from the driver’s seat, so I turned the door mirror all the way up and just looked to see if it was moving from time to time, but it rotated 80% properly.
The reason it “did not rotate 20%” is because the coaxial cable (2 x 3D2V) in the photo was not very flexible, probably due to the cold, and it created a lot of resistance when it wrapped around the VP as it rotated.As a result, the “bamboo shoot clutch mechanism” on the previous page (part 3) was activated and slipped, so the rotation angle was limited to 80%. So the safety device was activated, and this is actually normal behavior. (But I’ll have to be careful next time I set it up…)
First communication with this antenna was with 2 stations. …These two amateur stations were truly coincidental, one of them was the one who gave me lots of guidance when I wanted to get into amateur satellite mode, the other was a miraculous satellite radio operator with exceptional hearing who used a beam antenna mounted on his car to transmit high-speed CW from all over the country. So I met my satellite mentors today!
→To the next page (Vinyl Pipe Rotator for Amateur Satellite part-4)
→Back to Index