[Icom] IC-775DSP: an undocumented feature ???

Wed, 7 Apr 2004 07:38:26 +0100

By now I have a confirmation of the same behaviour of the 775 from
G0UUT/4Z4UN (Thanks, Elan!!!).

As you don't notice anything, Anders, it might be another proof of the idea
that there can be a leakage of a signal through a non-fully locked
pin-diode. Quality of diodes may vary, some of them allow the leakage, some
others don't.

Anyway, thanks for your tries.

73,
Vladimir EU1SA

> I can not notice the same. Maby I have bad hearing?
>
> /Anders
>

>
>
> > No any response so far. Though it would be very interesting to know if
> > anybody else can repeat the same experience.
> >
> > Thanks and 73,
> >
> > Vladimir EU1SA
> >

> >
> > > Have you got any respons in this issue?
> > >
> > > I will try it next weekend.
> > >
> > > 73 de Anders
> > >
> > > ----- Original Message -----
> > > From: "Vladimir V. Sidorov" <[email protected]>
> > > To: <[email protected]>
> > > Sent: Sunday, March 28, 2004 10:22 AM
> > > Subject: [Icom] IC-775DSP: an undocumented feature ???
> > >
> > >
> > > > Hi all,
> > > >
> > > > Playing with the radio some time ago I've noticed something new for
me
> > at
> > > > the 775. Supposingly the APF is only working for CW. But apparently
if
> > the
> > > > button is pressed in SSB mode, it also works. The effect is not as
> > drastic
> > > > as in CW, but certainly the overall sound changes itself. It is
> > noticeable
> > > > for rather weak signals, only.
> > > > It looks like there comes a resonant frequency within the bandpass,
and
> > the
> > > > resonant is around 1200 Hz what makes the incoming signal more
ringing
> > and
> > > > more readable. At some weak signals the button works like a switch,
> > > > illigible - non-illigible.
> > > > The only explanation I can imagine is the fact that switches in the
> > > > transceiver are made on pin-diodes. Accordingly there might come
leakage
> > of
> > > > an incoming signal through the non-fully unswitched diode and the
APF
> > > > circuit partially remains working.
> > > >
> > > > Before posting this message I have made several checks to be sure, I
am
> > > > quite far from gallucinating... and for sure there is an effect on
weak
> > > > signals, as described.
> > > >
> > > > Did anybody else notice the same?
> > > >
> > > > And if somebody wants to repeat my experience, let me remind you
once
> > again,
> > > > it is only working for weak signals, there is no any difference in
> > receipt
> > > > of strong ones.
> > > >
> > > > Thanks and 73,
> > > > Vladimir EU1SA
> > > >
> > > > ----
> > > > Your Moderator: Dick Flanagan K7VC, [email protected]
> > > > Icom Users Net: Sundays, 1700Z, 14.316 MHz
> > > > Icom FAQ: http://www.qsl.net/icom/
> > > ----
> > > Your Moderator: Dick Flanagan K7VC, [email protected]
> > > Icom Users Net: Sundays, 1700Z, 14.316 MHz
> > > Icom FAQ: http://www.qsl.net/icom/
> >
> > ----
> > Your Moderator: Dick Flanagan K7VC, [email protected]
> > Icom Users Net: Sundays, 1700Z, 14.316 MHz
> > Icom FAQ: http://www.qsl.net/icom/
> ----
> Your Moderator: Dick Flanagan K7VC, [email protected]
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/