[ICOM] Mic gain on the 706 MKIIG

[Clif Holland]

I checked the distortion on the FM transmitted signal.

Test parameters:
28.6 Mhz (Icom sets it at 29.1 Mhz)
Power out 6w
Audio In; 1 Khz @ 30mv
Test Equip: HP 8920A Service Monitor

It was 6.3% no matter where the mike gain was set.
The Deviation did not change with gain setting
The sine wave wasn't pretty (6.3% distortion) but it did not change.
Changing the input level from 5-30 mv did not change the distortion
Changing the frquency to 1500 Hz gave a much better looking sine wave. 
(Distortion not measureable as the meter is set for a 1 Khz tone)

A note, when the mike gain was turned to "0" deviation was the same. Keep 
turning it down and deviation went to zero. Audio off. The "0" did not 
change but there is a lower setting. Turning back up the deviation came up 
(still at "0" on display). Wierd.

Clif Holland KA5IPF
www.avvid.com


----- Original Message ----- 
From: "John Luthy" <jluthy at worldnet.att.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Wednesday, May 31, 2006 11:23 AM
Subject: Re: [ICOM] Mic gain on the 706 MKIIG


> Clif,
>
> I highly value your input and your knowledge.
>
> It seems to me, on my radio that the mic gain has a huge effect on FM
> audio quality.
>
> Would you suggest that I set my gain for normal SSB operation and then
> set the FM dev.  ?  I have a friend  (just one )  who has a service
> monitor so betwen the two of us we should'nt do too much damage.
>
> Also I have been told that my audio is way bad on AM unless I set the
> mic gain way down.. around a setting of 2 or 3.  the same setting I
> use on FM.
>
> Or should I keep my big fat fingers out of the radio and just change
> the gain setting when I change modes?
>
> Thanks
>
> N7JL
> John
>
> ----- Original Message ----- 
> From: "Clif Holland" <radio.service at verizon.net>
> To: "ICOM Reflector" <icom at mailman.qth.net>
> Sent: Wednesday, May 31, 2006 8:24 AM
> Subject: Re: [ICOM] Mic gain on the 706 MKIIG
>
>
>> The mike gain setting has nothing to do with FM deviation. Deviation
> is set
>> by an internal pot. The front panel Mike Gain setting is for SSB.
>>
>> Clif Holland KA5IPF
>> www.avvid.com
>>
>>
>> ----- Original Message ----- 
>> From: "John Luthy" <jluthy at worldnet.att.net>
>> To: "ICOM Reflector" <icom at mailman.qth.net>
>> Sent: Wednesday, May 31, 2006 9:18 AM
>> Subject: Re: [ICOM] Mic gain on the 706 MKIIG
>>
>>
>> > Jack
>> >
>> > I also have this issue with my 706.   I think I have my gain set
> to 3
>> > and I yell at it on SSB and hold the mic about a foot away on FM.
>> >
>> > There must be some way to set things so this dosent happen.  What
>> > makes it worse is My kenwood d700. I always have to yell at that
> thing
>> > so I find my self over driving my 706 on FM.  just 'cause I'm
> trained
>> > to.
>> >
>> > N7JL
>> > John
>> >
>> >
>> > ----- Original Message ----- 
>> > From: "Jack - K4WSB" <K4WSB at arrl.net>
>> > To: "ICOM Reflector" <icom at mailman.qth.net>
>> > Sent: Wednesday, May 31, 2006 3:52 AM
>> > Subject: [ICOM] Mic gain on the 706 MKIIG
>> >
>> >
>> >> Am I missing something?  Every time I switch between FM & SSB I
> have
>> > to
>> >> reset the mic gain.  I understand this is also a problem with the
>> > 910h also.
>> >> This is most inconvenient, especially mobile.
>> >>
>> >> Is there a fix?
>> >>
>> >> Does the 7000 have the same problem?
>> >>
>> >>
>> >> Jack Hartley
>> >> K4WSB
>> >> ARRL - QCWA - OOTC
>> >> DXCC Honor Roll
>> >>
>> >> ----
>> >> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
>> >> Icom Users Net: Sundays, 1700Z, 14.316 MHz
>> >> Icom FAQ: http://www.qsl.net/icom/
>> >
>> > ----
>> > Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
>> > Icom Users Net: Sundays, 1700Z, 14.316 MHz
>> > Icom FAQ: http://www.qsl.net/icom/
>> >
>>
>>
>> ----
>> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
>> Icom Users Net: Sundays, 1700Z, 14.316 MHz
>> Icom FAQ: http://www.qsl.net/icom/
>
> ----
> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
>