On Wednesday, January 16, 2013 6:15:03 PM UTC-5, Jim wrote:
On Monday, January 14, 2013 9:55:06 PM UTC-5, Bastoune wrote:

All,







What are the pros and cons of having a common Speaker for both the radio and the vario?







My new vario (LXNAV V7) requires an external speaker. My radio Dittel FSG71 happens to have an input Audio signal. According to the manual, that audio input is processed and sent to the speaker of the radio. It looks that I could have both the Vario and Radio connected to a single speaker [Obvious to say but I am NOT planning to physically connect the vario and radio output to the same speaker!]. According to the manual again, the sound volume of the vario will still be adjusted from the Vario.







The main benefit is to eliminate the need to lodge a speaker behind my panel and use the existing Radio speaker behind me. In addition, I assume that during transmission, the Radio will shut off the speaker, thus eliminating the Bip Bip of the vario from my communications.







Does anyone have experience with this approach? What are the pros and cons?







Thanks,







Bastoune



IIRC the when I looked into doing this I uncovered something about the FSG71 using more power when enabling external audio input. It may have had something to do with the fact that the radio uses much less power (when the audio amp is "sleeping") when in squelch mode (i.e., silent). When out of squelch the audio amplifier is on. The changing of the required J4 jumper would keep the audio amp powered continuously for the vario (the radio com would still appear to squelch normally though).

Ah! I found a reference in section 3.4.5 on page 3-12: "...Jumper...is to be changed...this inhibits the automatic power saving circuit"