Assemblies for Satellite radio

out of production

SYMEK offers various assemblies and add-ons for construction of amateur satellite ground stations.

See our future SHACKBUS program of programmable VHF / UHF / SHF receiver assemblies.

The modern P3D satellites of University of Surrey (UOSAT-12 = OSCAR-36 and OSCAR-31) are transmitting their .jpg picture files with a speed of 38400 baud G3RUH-FSK modulation. With each pass of the satellite, you can receive 1-3 Mbyte data on the downlink frequency in PACSAT broadcast-protocol on 437,025MHz. Depending on the mode, UoSAT 12 transmits with 9600 or 38400 baud FSK on 437.400MHz. The satellites are equipped with 76800baud transmitters. Our receivers are ready for this speed too.

Here comments of our customers, shortly after beginning of UoSAT-12 high speed transmission:

The downlink at 38k4 on UO-36 is really spectacular! Watching the byte counter fly by is quite a treat. Efficiencies of 90-100% are easily obtained with directional antennas and a preamp.  Doppler tuning is not really necessary on the widebanded 435 Mhz downlink.
Downloads of 1.5 Megs are possible on single passes, and all three components of a color image can be captured in short order.
I used to think 9k6 was fast, at least compared to 1k2 on AO-16, now when I look at KO-25/UO-22, the byte counter seems to be moving in slow motion!
To me at least, this high speed (internet level) transfer rate, and the ability to grab images on a single pass, really brings some excitement back to the digital sats.

Hello Ulf, Order received in good condition, Equipment installed, Equipment working GOOD, Thank you very much... Alex  (NV8F)

Dear Ulf , I install on my IC820H the Symek IFD module: the most difficult is to remove the MSC condensator. I work's fine the first time without any modification!
Today I download about one MO from UO-36(38.4K) in a pass only  20° above the horizon !
Very nice  :=))      best 73 from Tahiti    Yves FO3PJ

Hi all, just wanted to say thanks for all the help in sorting out my portable digital satellite station. 
It is starting to work!  Had it receiving data from KO-25, TO-31 and UO-22...
Station list: Yaesu FT-8100R (dual band mobile has data jack and satellite TX 430 Mz up), TNC3S with 1200 and 9600 modems (the 1200 is for APRS). Compaq Presario laptop running Win 95, and WISP.
Arrow hand held beam...     Thanks, Dale KF4SIR

... So I set the system up to try Tiungsat a few minutes ago ... . It came over the horizon, with a very good signal, more than I have ever heard before, so I reconnected the TNC3 only on 38k using port 2 and lo and behold perfect copy. A solid DCD light, perfect 38k copy down to about 15 seconds before LOS, with the satellite at possibly just under 1degree elevation. I had an eye voltage of .3volts pk to pk ... (Ross, ZL1WN)

Improving 9600baud receiver of FT736

ZFD.JPG (11190 Byte)
More info
The FM-demodulator of FT736 is not ideal suited for wide band FM data reception. For this reason, we developed a small add-on board with a IF amplifier and FM-demoduator for 9600baud (up to 19200baud).
To decode the 9600baud packet signals, we recommend our high-speed packet-radio-controller TNC2H, TNC31S and TNC3S
The F-ZFD module can be used with every receiver which uses 455 kHz IF. A complete and comprehensive installation manual for FT736 is included.

Add-on receiver for reception of high-speed FSK-signals

ifd1.jpg (66597 Byte)

More Info

This is a complete receiver with wide band demodulator for reception of FM signals with  38400 up to 153600baud. The assembly can be installed in addition to the existing IF-amplifier in your amateur radio receiver / transceiver. The IF-signal is tapped directly after the first mixer (1. IF typically 40 to 70 MHz, depends on receiver) and connected to the input of IFD. There, the signal is amplified, limited and demodulated. 
As decoder for high speed packet-radio, we recommend the 16-bit systems TNC31S or TNC3S.

F-IFD is available for different transceiver types:  FT736, FT847, IC471, IC475, IC820, IC821, IC970, TS790 and for IF-frequencies 10.7 and 71.0MHz 1st IF. Standard bandwidth is for 38400 / 76800 baud use. Narrower (38kbaud only) or wider (153kbaud) filters are available upon request. With special filters, the maximum baudrate may be up to 614kbaud.

Packet-Radio-Controller for High-Speed satellite reception

The fast download data signals cannot be decoded with the Z80-based TNC2 any more. As alternative we offer the 16-bit MC68302 based TNC3 packet-radio controllers with the matching family of FSK-modems.


More info
TNC3S dual port controller + modem für 9600baud + modem for 38400baud
The best solution for high-speed satellite reception. Use a 9600baud modem as transmitter on port 1 and a 38400baud modem on port 2 to receive the satellite-signals.
Advantage: Reception of  9600baud and 38400baud is possible without switching, even simultaneously. Transmission using port 2 with 38400baud (if required) is possible as well.
+Special modem
TX9600 / RX38400

More info
TNC3S dual port controller + mixed-speed modem for TX 9600 / RX 38400 baud
Only ONE modem is installed in TNC3. This modem is made for satellite communication with 9600baud uplink and 38400baud downlink.
Advantage: Port 2 of the TNC3 is empty and can be used for later expansion.
Disadvantage: Reception (downlink) with 9600baud is not possible.
+Special modem 

More info
TNC31S single port controller + mixed-speed modem for TX 9600 / RX 38400 baud
With TNC31,only ONE modem can be installed, e.g. a special mixed-speed modem for satellite operation. The modem transmits with 9600baud and receives 38400 Baud on the downlink.
Advantage: low cost. Disadvantage: Reception of 9600baud is not possible, expansion (second modem) is not possible. Change of the modem however is always possible with all TNC3/31.

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