AMSAT SA has launched Mark II of its dual band 70 cm/2 m handheld beam antenna with a new, easier to hold handle and improved coaxial terminations. The Yagi has been retuned for maximum performance in the amateur radio 2 m and 70 cm satellite bands. The coax cable is terminated crimped brass lugs instead of being soldered making it environmentally more robust. The driven element has been adjusted to accommodate the change in the connection. More about the Yagi. The antenna has a 50-ohm designed driver. The Yagi has a unique element called an ’Open Sleeve’ which is a director very close to the driven element. The driven element is sized for 2 m. When operating on 70 cm the ’Open Sleeve’ acts as part of the driven element on 70 cm (the third harmonic of 2 m).
The original concept was developed in 1946 by Dr J T Bolljahn of the Stanford Research institute but was not introduced into amateur radio until the 1950s. The AMSAT SA version is based on a design by DK7ZB with modifications by WB5CXC. The first South African version was a collaboration between Guy Eales, ZS6GUY and Gary Immelman, ZS6YI. It was developed for YOTA 2018 where young people successfully used the antenna operating satellites using hand-held transceivers.
The mechanical structure was redesigned by Gary Immelmann ZS6YI. A choke around the boom was added to isolate the antenna from the coax and reduce the effect human contact has on the antenna. A handle was added on the boom end which makes it more comfortable to hold and further isolates the antenna from the handler. The AMSAT SA Yagi is manufactured in one of Gary Immelmann’s factories in Vereeniging. It has two elements on 145 MHz and 3 elements on 435 MHz.
For its size, the antenna has excellent gain: 145 MHZ: 4.12 dBd or 6.3 dBi and 435 MHz: 6.23 dBd or 8.4 dBi. The Yagi is broadband with measured SWR being almost flat over the entire bands. The antenna is plug and play, no tools are needed except for soldering on a connector to suit the application. It comes complete in a carry bag with full instructions. This antenna can be assembled and dissembled in minutes. The price of the MKII Yagi is R400 for AMSAT SA and SARL members. Non-members pay R500 (approximately $36.75 US). The courier charge is R120 (approximately $9 US, Postnet to Postnet). Ask for a quote for other courier options. Find more details and order forms on http://www.amsatsa.org.za/
I have followed the manual installation instructions and it worked with any problem (a minimal knowledge of Linux is recommended). Below you can see a SatNOGS decode from my station that has been processed by the gr-satellites integration.
This is a great add-on for the SatNOGS station/network! Nice work Daniel!
From ANS-122: PSAT2 (NO-104) VHF is alive and new DTMF mode:
Bob Bruninga writes: PSAT2 VHF awoke from an 8 month slumber on 26 Apr 2021. We have no idea why. Its telemetry looks fine. Volts between 6.2 and 7.0 volts (5 NiCds). Exterior temps between -18 and +22 C. See http://aprs.org/psat2.html
PSAT2 will NOT be in APRS mode but a brand new experimental mode for DTMF uplink and VOICE downlink. So you preload your grid and callsign into a 16 digit DTMF memory in your radio and when the satellite hears this it will assign a QSO number and QSL the grid by voice and then also generate an APRS packet for collection by APRS operators. There is even a way to send back a DTMF QSL so you can make it a 2-way DTMF. contact. Successful DTMF grids and messages will appear on a special URL on the PSAT2 page (above). To QSL, you key in that stations 2 digit QSL number and then dump your pre-loaded QSL DTMF message. Since this is the first time this transponder is on the air and because a DTMF uplink takes maybe 4 seconds, we don’t want the uplink saturated by a bunch of newbees initially until we see if it actually works. So read the docs and be sure you know what you are doing. There is a user operating manual available on the PSAT2 web page: http://aprs.org/psat2.html
[ANS thanks Bob Bruninga, WB4APR for the above information]
The following satellites, marked as inactive, have been removed from this AMSAT-NA TLE Distribution as of April 8 2021. The source is from ANS-101. A note regarding GRIFEX: according to PE0SAT it is still active.
TISAT – NORAD Cat ID 36799 JUGNU – NORAD Cat ID 37839 AO-71 – NORAD Cat ID 37854 HORYU-2 – NORAD Cat ID 38340 BEESAT-3 – NORAD Cat ID 39135 BEESAT-2 – NORAD Cat ID 39136 TRITON-1 – NORAD Cat ID 39427 DUCHIFAT-1 – NORAD Cat ID 40021 NANOSATCBR1 – NORAD Cat ID 40024 ANTELSAT – NORAD Cat ID 40034 VELOX-1 – NORAD Cat ID 40057 DAURIA DX 1 – NORAD Cat ID 40071 CHUBUSAT-1 – NORAD Cat ID 40300 QSAT-EOS – NORAD Cat ID 40301 GRIFEX – NORAD Cat ID 40379 DEORBITSAIL – NORAD Cat ID 40719 NUDT-PHONESAT – NORAD Cat ID 40900 LQSat – NORAD Cat ID 40958 OUFTI-1 – NORAD Cat ID 41458 Swayam – NORAD Cat ID 41607 AlSat 1N – NORAD Cat ID 41789 ScatSat – NORAD Cat ID 41790 Pegasus-1 – NORAD Cat ID 41846 UCLSat – NORAD Cat ID 42765 LituanicaSAT 2- NORAD Cat ID 42768