ICOM 802- SPEECH COMPRESSION?

[maine50]

Several recent contacts of about 1200 miles (WLO) - resulted in comments of being heard but "lite". I'm the second owner of radio - how can I determine if the speech compression has been turned on?

[svlamorocha]

With compression ON the 12V power (use amp meter in boat panel) consumed while talking with PTT on will be the same as when whistling with PTT on. A more precise version of same test uses a RF power meter inserted in the coax.

[svlamorocha]

With compression OFF power consumption while talking will be a fraction of power while whistling

[ka4wja]

Maine,
The easiest way to determine is to simply look at the M-802's power output display while speaking in a normal (to slightly louder than normal) voice, directly into the microphone, with the microphone 1" to 2" away from your lips...

Originally Posted by maine50

Several recent contacts of about 1200 miles (WLO) - resulted in comments of being heard but "lite". I'm the second owner of radio - how can I determine if the speech compression has been turned on?

If the speech compressor is ON, you will see all 8 segments illuminated on voice peaks, with an average of 4 to 5 segments illuminated on average speech, as you speak...
If the speech compressor is OFF, you will typically see only 4 to 5 segments illuminated on voice peaks (or even less), and only 1 to 2 segments illuminated on average speech, as you speak...


While you can attempt to use a DC amp meter, to measure the M-802's current draw, usually analog DC amp meters will not react fast enough to normal human speech to allow any reasonable measurement...
Of course you can tell the difference between YOUR radio with the speech compressor On versus OFF, by using a DC amp meter, it is almost impossible to compare your radio to another on another boat, using each boats' metering...
AND...
And, further, if your M-802 is properly installed is should be wired directly to the main house batteries or battery buss bar, and NOT through a DC Distribution Panel / Breaker Panel (which is usually where a vessel's DC amp meter would be located)...
ALSO...
Also, while using a "clamp-on" DC amp meter on the M-802's DC power wiring is a good way to determine its DC power consumption, be sure to understand that RF can effect some digital meters (usually the inexpensive "no-name" ones)....so, you may find that your readings aren't too accurate...
SO...

So, this is why I always recommend using an RF power meter (RF power / SWR meter)....
And, understand that the M-802 (and M-700Pro, M-710, etc.) do provide a fairly accurate RF power metering, right on their front panels....each segment represents approx. 15 to 20 watts...




Please see this page, for definitive info on the M-802's Speech Compressor...
IC-M802 Compression


And, of course....
Please have a look at this page, a sticky right up top of this page...
Where you will find just about everything "SSB", "M-802", and "Marine long-range comms" related...
http://www.cruisersforum.com/forums/...tc-133496.html




Hope this helps...

Fair winds...

John