If you capture WREN on 437.405 MHz and it works, you can try to get a SSTV-picture as follows:
Sending commands to WREN by toggling the carrier (FM)
Carrier on/off: 1=long, 0=short, leave a noticable silence between the bits.
Activate/HK: 110011 -> wait until answer
Camera ON: 11111 -> wait until answer
Snapshot & Thumbnail receive: 110 -> decoder should display thumbnail picture 12*14 pixel
SSTV send: 110100 -> Martin-1 SSTV picture comes... in 320x240 pixels color
WREN should answer to the commands within two seconds. Wait always at least two seconds after having received data before sending to WREN
Send the Activate/HK command first, else Wren won´t react to other commands. When camera is OFF, a snapshot or SSTV command will send WREN into sleepmode. ALWAYS SWITCH CAMERA ON FIRST BEFORE SENDING CAMERA COMMANDS. WREN´s housekeeping data will show the status of camera power (ON or OFF).