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DISTRIBUTORS, INC.

FL-760A FREQUENTLY ASKED QUESTIONS 

Q: My radio works fine but people receiving my transmissions say my voice volume is weak. 
A:

 You may need to go into the Setup Mode (power the radio up while holding down the MOD 

button) and toggle to the Mic Sensitivity screen and adjust the mic bias level up.  The Mic 
Sensitivity control range is 0 – 80 and is defaulted at the factory to approximately 60 as a starting 
level, because there is no way of knowing what kind of headset and mic will be used by the radio 
owner.  

Electret mics are probably most common these days, but for louder aircraft cabins a headset with 
dynamic mic may be a better match. These mics require different levels of bias and different 
usage techniques. Electret mics are for quieter cockpits and can usually be whispered into and be 
heard, while Dynamic mics are typically in louder aircraft (helicopters, open cockpit and fabric 
aircraft) and require the user to speak louder to generate the best mic audio level. 

We would advise adjusting the Mic Sensitivity level up or down initially by a factor of 10 to start 
with (if voice is weak at a level of 60, try boosting to 70 and transmit to someone listening on 
another radio).  If further adjustment is needed, it may take several hit-n-miss attempts with 
smaller adjustments to land on the optimum level for your headset/mic and airplane. A headset 
with an amplified dynamic mic is preferred and a windsock on the mic is also advised. 

Q: The sidetone level is too low so I am not hearing my voice loud enough in my own headset 
when I transmit. The intercom volume is also low. 

A: 

Like practically all aircraft ATC radios, the FL-760A incorporates a Sidetone Amplifier that is 

activated when you press the PTT switch.  At that point, your voice signal from the Mic Audio line 
that is feeding the radio transmitter is also routed through the Sidetone Amplifier and then back 
into your headset so you can hear what you are saying in the high noise environment.    

The built in two-place intercom system (ICS) that is featured in the FL-760A is simply using that 
Sidetone Amplifier as an intercom and giving you the option of turning it on via a voice activated 
trigger circuit (VOX) or a dedicated ICS PTT (not to be confused with your radio PTT).  The 
Sidetone Amp is pulling “double duty” essentially - it always activates to provide Sidetone when 
you press the radio transmit PTT, but when you are not transmitting on the radio, it acts as a VOX 
activated ICS or a PTT activated ICS.  

_________________________________ 

12830 E. Mirabeau Parkway, Spokane, WA 99216●(800)235-3300 

●LOCAL (509)535-8280●FAX (509)535-8266

 

Summary of Contents for FL-760A

Page 1: ...rther adjustment is needed it may take several hit n miss attempts with smaller adjustments to land on the optimum level for your headset mic and airplane A headset with an amplified dynamic mic is preferred and a windsock on the mic is also advised Q The sidetone level is too low so I am not hearing my voice loud enough in my own headset when I transmit The intercom volume is also low A Like prac...

Page 2: ...ug The tip is the PTT segment that gets grounded when you push the radio PTT button This triggers the transmitter to activate the ring is what the headset mic audio comes in on and that is sent to the transmitter to modulate it and allow your voice to be broadcast over the radio If you sourced a prewired harness from a third party such as Aircraft Spruce Specialty we ve discovered that there may h...

Page 3: ...on Page 11 of the Operations Manual referring to A TOT is essentially a Timed Out Transmit feature of the radio or sometimes known as a Stuck Mic feature The setting selections are OFF 1 min 3 mins or 5 mins If the transmitter is activated and stays on due to a stuck mic situation the radio will automatically release the transmitter when it reaches the TOT time Factory default setting is 5 mins Q ...

Page 4: ...s case is your internal ICS is set for VOX voice activation and the threshold is set too low The VOX ICS is being triggered by the rise in ambient cabin noise when you increase power for takeoff or cruise This opens the ICS squelch activating the intercom that makes the headset mics go live and the background cabin noise is amplified and heard in your headset Both the volume and the VOX threshold ...

Page 5: ...the button is pushed In a side by side two place aircraft a single momentary switch on the panel labeled ICS TALK would work In a tandem aircraft you would need a switch at each seat location with both switches wired to Pin 5 on one side and the other side to aircraft ground Q I have a 4plc airplane and don t plan to use the built in 2plc Intercom in the FL 760A Instead I am going to wire in a thi...

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