[ICOM] New IC-7700 announced at Dayton

[Adam Farson]

Hi Dick,

Actually, with Dual Watch (as in the Pro3) you can monitor adjacent bands -
e.g. 14 and 18 MHz - with some degradation of sensitivity on the secondary
band (the one on which you are not transmitting). When Dual Watch is
selected, Sub switches to the same mode (emission) as Main, as the IF chain
and DSP are common.

The Pro3 and other DW-equipped radios select the correct RF BPF for the band
on which you are transmitting. Receive sensitivity on that band will be up
to spec. If Dual Watch is enabled and Sub is set to another band, the
received signal will have to pass through a BPF which will not be the
correct one for that band, so sensitivity will be degraded. The greater the
separation between the bands, the more severe the degradation will be.

http://www.ab4oj.com/icom/dw.html explains this in more detail.

I would have liked to see Dual Watch; I often use it in conjunction with
Split. During 20m or 40m QSO's with friends in the US, I sometimes transmit
below the US phone band to get away from the QRM. Split + Dual Watch comes
in very handy for such cases. (Canada has no sub-bands by emission type, so
there is no regulatory issue here.)

Cheers for now, 73,
Adam VA7OJ/AB4OJ


-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of Dick Flanagan
Sent: Thursday, May 17, 2007 19:45
To: ICOM Reflector
Subject: RE: [ICOM] New IC-7700 announced at Dayton

At 06:53 PM 5/17/2007, AD5VJ  Bob wrote:
 >Let's be sure we are being fair Dick. I don't think they said instead of
>Dual Watch we are adding the capability to connect to  >another RX.

You are correct.  That was merely my observation.

 >Being able to watch two bands at the same time during a contest is a great
>advantage. Works especially well at night for 80 and 40  >to monitor both
for activity at the same time.

I believe that even with Dual Watch on the 756 P3 you can't listen to two
bands at the same time.  Different frequencies within the same band, yes,
but not on two different bands.  Perhaps Adam can expand on this.

73, Dick
--
Dick Flanagan K7VC NV SM
k7vc at arrl.org


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