Garmin apollo sl30 comm Manuale Utente

Microphone input connections should be made using a twisted pair shielded cable. Attach the 
signal ground to the mic ground pin on the rear connector and connect the shield to the rear 
connector plate. 

The TxKey input on the rear connector must be pulled low to ground to enable the 
transmitter. This input should be connected to a microphone or yoke mounted momentary 
push button switch. 

The SL30 includes a voice activated intercom function that can be enabled by an external 
control switch. This is an optional connection. 

 

When making connection for the intercom selection, connect the intercom selection input to a 
remote mounted normally open switch (an alternate action switch can be used). Connect the 
other terminal of the switch to ground. The intercom function is enabled when the input is 
pulled low to ground.  

The SL30 includes a remote flip/flop input. This is an optional input that can be connected to 
a remote mounted (such as on the yoke) momentary push button switch which pulls the input 
low to ground. The remote flip/flop input will only toggle the Comm frequencies when Comm 
frequencies are displayed and will only toggle NAV frequencies when NAV frequencies are 
displayed. 

The SL30 requires a standard 50

Ω vertically polarized Comm antenna and a horizontally 

polarized NAV/VOR/Localizer/Glideslope antenna. Follow the antenna manufacturer’s 
installation instructions for mounting the antennas. The Comm antenna should be a standard 
Comm antenna that operates on Comm frequencies between 118.00 and 137.000 MHz. The 
NAV antenna should be a VOR/Localizer/Glideslope NAV antenna that receives VOR 
frequencies between 108 and 117.95 MHz, and localizer frequencies between 108 and 112 
MHz and glideslope information between 328.6 and 335.4 MHz.  

 

The NAV and Comm antennas should also be mounted as far apart as practical from the ELT 
antenna, preferably one on top and the other on the bottom of the aircraft fuselage. Some 
ELTs have exhibited re-radiation problems generating harmonics that may interfere with GPS 
signals. This can happen when the Comm (SL40 or any other Comm) is transmitting on 
certain frequencies such as 121.15 or 121.175 MHz, which may cause the ELT output circuit 
to oscillate from the signal coming in on the ELT antenna coax. 

 

The antenna coax cable should be made of RG-142B or a comparable quality 50

Ω coax. 

Assembly instructions for the rear coax connector are included in Figure 6.