Going old school with a home-made #CW key attached to my Arrow satellite antenna. Quite refreshing. I'm a contest-grade CW operator but this wobbly setup makes me sound novice and I'm making mistakes like 20 years ago. #amsat#hamradio#morsekey#morsecode#hamr
Recently, tens of #amsat ops made their 1st #moonbounce QSO. The thrill of #EME with a biggun creates an illusion of similarity to other modes. EME is different. How small a station you can hear? This thread elaborates on accurate predictions. No magic, only Physics! #hamradio
2/10 #EME is the only field in #hamradio that allows reliable predictions of station sizes that one can work. No smaller station beyond this prediction can be contacted under any conditions! You cannot bend the theory. The link budget can be expressed in Signal-to-Noise ratio-SNR
3/10 SNR represents the ratio of System Gain to Noise Temperature. #WSJTX in Q65 computes SNR in the bandwidth B=2500 Hz. That is the report that you exchange with each other. We want to maximise it by increasing the numerator and decreasing the denominator #hamradio#moonbounce
This is a simplified guide describing a bare minimum (!) for #EME operation of WSJT-X in Q65-60B on 432 MHz. A few settings are TRX-specific. Consult to your rig's manual for those
Step 2: Install WSJT-X and open Settings 1) Fill in "My Call" and "My Grid" 2) Tick "Enable VHF and Microwave submodes" 3) Tick "Decode after EME Delay"
Step 3: Navigate to Radio tab 1) Choose your rig model 2) Choose your serial port and baud rate 3) Choose CAT as PTT 4) Mode and split operation depends on your rig. A minimum non-destructive set: Non and Fake it, respectively
You test CAT by a button
Bernd DL7APV asked me to QSP to the #AMSAT community that he will QRV this coming Thu, Sat, Sun and listen especially for #satellite setups. Use your chance to make your first ever #EME QSO - biggest challenge in #AmateurRadio 🌗
If you work via #GreenCube, try #EME with big guns. I promise, you will be amazed! As a proof of concept, I made a quick #moonbounce QSO with DL7APV with just a Yaesu FT-818, 40W, 1dB NF LNA and 15 el Diamond antenna held by hand! Easy QSO. Read on🧵 #amsat#io117#hamradio#hamr
2/9 There are a number of extremely capable #EME stations on 70cm: DL7APV, HB9Q, NC1I. If you are enjoying decode rates above 80% on #GreenCube, don't wait and try #EME. You will likely complete your first QSO over the Moon faster than on the congested #IO117 #amsat#hamradio
3/9 I used my portable #Greencube set: Yaesu FT-818ND - 40W amp / 1dB NF preamp - Diamond A430S15 14.8dBi on wooden extension, held by hand and pointed visually. With a low NF frontend you can go with a 7el Arrow #EME#amsat#hamradio#hamr#moonbounce
LNA / preamp is an unpopular topic of the portable SAT discourse. Noise figure (NF) is assumed to be low due to absence of long cables. But what if NF of the system inherently is not top tier? Any benefit in using LNA with FT-817 & FT-818? 🧵 #hamradio#amsat#amateurradio#hamr
NF & MDS are determined by the quality of the signal chain and the venerable FT-818 is not a star in that department. Under exact same conditions (antenna, cable etc) a very weak signal readable from IC9700 would not be copyable from FT-818. 2/7 #hamradio#amsat#hamr
The comparison of NF & MDS of IC705, IC9700 and FT-818 assumes favourable IMD performance of the FT-818 with a 500 Hz filter. In the field this is rarely true and even less so with a passband of 3 or 2.7 kHz in SSB. 3/7 #hamradio#amsat#amateurradio#hamr
When operating SAT-portable, the automatic Doppler correction of 2xFT-818 can be conveniently performed by a #RaspberryPi Zero W running #Gpredict and #Hamlib. Proven solid and reliable in DXing over the last 2 years. Read on for details 🧵
Doppler adjustment can be made manually but beyond calling CQ things get cumbersome. An automated tracking allows to quickly hop between different stations in the very limited time of the pass. For DX skeds this setup brings you spot on on the transponder frequency. 2/8 #amsat
RasPi connects to the WiFi hotspot of my iPhone enabling control and time sync. RTCZero backs up the system time. 2x CH340 USB-TTL converters connect the FT-818s to the Pi through Zero4U hub. 3/8 #amsat#hamradio#amateurradio#hamr#raspberrypi