SV-COM-T25 Transceiver Receive Volume Too Low

[badia358]

I installed the SV-COM-T25 Transceiver with the SV-COM-PANEL as my second COM radio through a Garmin GMA 340. The transmit is working great, but the receive comes in too low. In order for me to hear the receive, I have to bring the volume all the way up on the SV-COM-PANEL and it is still too low.

Here is how I have made the connections:

SV-COM-T25
Pin Name Pin Number
Power In 25 Pins 24 & 25 connected together and 12V supplied through a 5A Fuse
Power In 24 Pins 24 & 25 connected together and 12V supplied through a 5A Fuse
Ground In 22 Pins 19 & 22 connected together and connected to aircraft ground
Ground In 19 Pins 19 & 22 connected together and connected to aircraft ground


Garmin GMA 340 - J1 Connector

Phones Out 2 Com 2 In Pin 13
Phones Ground 1 Ground Loop at the GMA 340

Push-To-Talk In 15 Com 2 Key Pin 30 Also connected to Transmit Interlock at COM 1 (Garmin 430W)
Microphone In 23 Com 2 Mic Pin 15
Microphone/PTT Ground 9 Ground Loop at the GMA 340

Ground 10 No Connection
Transmit Interlock 18 No Connection

SV-COM-PANEL (D15 Connector)
Power In to the 12V Fuse used for the SV-COM-T25
Ground In to Aircraft Ground
SV-COM-PANEL Enable 13 Enable Pin 6
Data RX From SV-COM-PANEL 5 Data TX To Transceiver Pin 5
Data TX To SV-COM-PANEL 6 Data RX From Transceiver Pin 4

COM 1 (Garmin 430W) continues to work great for transmit and receive
COM 2 (SV-COM-T25) transmit works great
COM 2 (SV-COM-T25) Receive is too low at the Pilot and Co-Pilot headset

Need help to fix the COM 2 (SV-COM-T25) RX is too low

Thank you...

 

[GKC Aviation]

Com #2 phones low should go to pin 14 of J1, not the ground loop
COM#2 Phones Hi - Pin 13
COM#2 Phones Lo - Pin 14

 

[badia358]

Appreciate the quick response. I will be back at this in a week and go recheck my wiring. Thank you...

 

[badia358]

GKC Aviation. Can you provide me with the pin numbers and names on the COM 2 Transceiver Block and make them in reference to the SV-COM-T25? I am getting a little confused with the naming/function of each pin based on the documentation that I have.

Thank you...
Alex

 

[GKC Aviation]

Hi Alex

COM-T25 pin 2 (phones out) goes to GMA340 pin 13 of the J1 connector
COM-T25 pin 1 (phones ground) goes to GMA340 pin 14 of the J1 connector

Cheers
Glenn

 

[badia358]

Thank you