SK6WM 2304 MHz EME

The antenna for SK6WM 2304 MHz EME is the  25.6 m dish of Onsala Space Observatory (OSO). The gain of the antenna is over 53 dBi on this frequency.

SK6WM 26.5 m dish

The hams involved in this operation was SM6EBM, Björn (now SK), SM0PYP, Paul and SM6FHZ, Ingolf. Other participants were the members of the astronomy evening class taught by Christer Andersson of OSO.

The transmitter was crystal controlled to 2304.267 MHz, CW only. Final amplifier was a Thompson TWT delivering 10 W RF. The TWT was situated at the feed in "tubus" just behind the vertex of the dish. Preamplifier and protection relay was connected directly to the polarizer/coax-WG transition. This polarizer/coax-WG transition was especially made for connecting to a suitable cut/flange in the conical feed horn for the cassegrain feed system of the dish. We had receive capability on both 2304 and 2320 MHz. 

Echoes from the moon peaked a solid 4 S-units above the noise in 2.4 kHz BW, very nice. The liberation fading could be seen very clearly on the s-meter of the receiver. We measured about 3 dB of moon noise, i.e. the receive performance was in practice moon noise limited. We did not measure sun noise.

Moon and 25.6 m dish at OSO The OSO 25.6 m dish with the faint moon behind (11 o clock almost full moon)

EME operating  table at OSO Operators: In rear Christer Andersson (Head of OSO 25.6 m telescope), SM0PYP, Paul, tuning the receiver, Unknown operator and SM6EBM, Björn (with his back to the camera) making tape recordings.

EME operating table at OSO From left to right: Christer Andersson (Head of OSO 25.6 m telescope) controlling the dish position S/W, SM0PYP, Paul, tuning the receiver, Unknown operator in blue jacket and SM6EBM, Björn (with his back to the camera) making tape recordings.

We apologies for the bad photo quality, the pictures were taken with a old steam camera and later scanned in order to get it into this space. Thanks to Paul, WA6PY, SM0PYP, for finding the pictures to share with us!

SK6WM 2304 MHz EME QSO list:

Initial # Call Date UTC Time UTC Square Square # Field # EME DXCC # State # Mode Distance QSL
1 OE9XXI 1988-10-22 17:58 JN47UL 1 1 1   CW 1113 OK
2 OE9FKI 1988-10-22 18:24 JN47TG         CW 1137 OK
3 IN3HER 1988-10-22 19:09 JN56 2   2   CW   OK
4 OK1KIR 1988-10-22 19:23 JN79DW 3   3   CW 844 OK
5 F2TU 1988-10-22 19:38 JN38LG 4   4   CW 1069 Sent
6 LX1DB 1988-10-22 20:08 JN39CO 5   5   CW 946 Sent
7 SM3AKW 1988-10-22 20:24 JP92AO 6 2 6   CW 671 OK
  F2TU 1988-10-22 22:31 JN39CO         SSB/CW   -
  W4HHK 1988-10-22 23:00 EM55         Heard 599!   -
8 K0KE 1988-10-22 23:35   7   7 1 ? CW   Sent
9 WB5LUA 1988-10-23 00:00 EM13QC 8 3   2 Tx CW 7976 OK
10 VE4MA 1988-10-23 01:04 EN19LW 9 4 8   CW 6455 OK

Updated January 10, 2011.