Syntor X

[ABANAKA]

I have a dual control Syntor X system with UHF/VHF the system has securenet but not being used. The UHF Syntor X works normally but the VHF does not. I can use the Handset control and it will control the channels up down but no audio will pass. I put another UHF radio in place of the VHF radio and it works okay through the system. I double checked all the jumpers and swapped the controller (HLN4728a/b) boards between the two radio's and both controllers are working.
Thanks for any help
Mike

[Mike B]

It appears your VHF radio might be dead? Since a UHF radio will pass audio when connected to the VHF cable, it "appears" the control setup is not the problem. Have you checked the VHF programming (the PL/DPL programming in particular or removed the microphone from the hangup box to disable Rx PL/DPL if its correctly configured for it). Have you checked the VCO unlock LED on the VHF radio? Have you checked the power supply voltages from the Common Circuits Board (this is where the switched 5 volt and 9.6 volt power regulators are located)? Since you changed Personality Boards, I assume it cannot be the 12 volt unswitched internal fuse (which is on this board). Is it possible to test the VHF radio all by itself in a single radio setup?

Did this radio combination ever work together and it broke, are you changing out just one of the radios, or is it something you are putting together for the very first time?

Edit; sorry I got the HHCH interface board and Personality Board part numbers mixed up. I suppose the VHF radio 12 volt unswitched internal fuse could be bad.

[WB6NVH]

Is this one of those FBI surplus radios with the hand-held control head and securenet box and all that stuff? That's what it sounds like.