1. Set Telex SPS-2000A Party Line Power Supply to Clear Com Unbalanced mode by removing the lid of the system and changing the slide switch setting to the correct mode.
2. Attach a Y cable between the Telex SPS-2000A Ch1 port, then to the associated wired belt packs for that channel, and the other side of the Y cable to the Tempest system on Ch. A (or other channel).
3. Set Tempest slider switch on the front of the Tempest for your selected wired mode to be in Clear-Com mode. Not RTS or BAL. 
4. Illuminate the CH. A LED with the SEL push button.
5. Illuminate the 2 Wire LED across from the illuminated CH. A LED using the second SEL push button.
4. Check that the Tempest system Echo Cancellation is engaged for CH A - Menu > Basestation Settings > Tech Menu > Echo Cancellation > Check mark next to your selected Channel. Hit the menu button several times to get back to the main menu.
5. In the Main Menu hit Wired Intercom Settings > Auto Null > Null Now
6. Once done  YELL into the headset of one wirelessbelt pack a full count OUTLOUD of 1,2,3……10. Then wait about additional 10-20seconds this should help level out the system. Test between wired and wireless system to check for echo.