Thanks Bob, yes I'm referring to the TX signal, although RX is similar of
course. I agree with what you say, although the Omni6+ SSB filter is worse
than that in any other rig I've used. I did align the oscillators as per the
manual, in fact I had to pad one of them as there wasn't enough adjustment
range. I rarely use SSB myself so will let someone else worry about it! 73
Fraser> From: RMcGraw@Blomand.net> To: tentec@contesting.com> Date: Mon, 17 Mar
2008 20:02:33 -0500> Subject: Re: [TenTec] Omni VI Plus audio> > Typical of
filters, the shape factor or each side of the slope as measured > from the -3
dB points is typically not identical although we'd like to think > they are and
wish they were. Thus a modulated carrier placed on the side of > the slope, at
say the -3 dB points, will sound different when listening to > USB or LSB
output products of the filter. It is not a common failing, it is > a law of
economical filter design and selection of filters that have a > reasonable or
tolerable amount of insertion loss as well as a host of other > factors such as
ripple across the top, phase shift, group delay and etc.> > I do not discount
that fact that a crystal component within the filter may > fail or may change
frequency such that, in either case, the shape factor of > the filter changes.
If you have means to measure the filter and its skirts > and insertion loss
then you might find a clue as to why it sounds different > on USB and LSB.
Otherwise, invest in a new filter and then complete an > alignment of the BFO
oscillators. It is important that the alignment be > carried out in the exact
sequence as described in the manual. There is > interaction between the
adjustments. Even the FSK adjustments need to be > made although you may never
intend to operate FSK.> > I trust you are speaking of transmit signal sounding
different an not > receive signal sounding different. For receive signal
sounding different > that may be caused by and additional factor being
mis-alignment of the > PassBand tuning oscillator.> > 73> Bob, K4TAX> > -----
Original Message ----- > From: "Fraser Robertson" <g4bjm@hotmail.com>> To:
<ken.d.brown@hawaiiantel.net>; "Discussion of Ten-Tec Equipment" >
<tentec@contesting.com>> Sent: Monday, March 17, 2008 6:49 PM> Subject: Re:
[TenTec] Omni VI Plus audio> > > >> > Our club's Omni6+ option3 sounds very
different on USB and LSB, and it's > > not possible to correct it by adjusting
the BFO frequencies, so it must be > > down to the filter being asymetrical. I
understood that was a common > > failing, but perhaps our filter is faulty?> >>
> 73 Fraser G4BJM> >> Date: Sun, 16 Mar 2008 18:37:51 -1000> From:
ken.d.brown@hawaiiantel.net> > >> To: tentec@contesting.com> Subject: Re:
[TenTec] Omni VI Plus audio> > > > >> > Now I don't know why the higher bands
are different on your rig.> > > >> Wonder if you have an antenna problem? > >>
> > If the SSB Receive (or > >> transmit) audio sounds different on 10, 15, 20
> meters than it does on > >> 40, 75 meters, you should be comparing the sound
> on USB versus LSB. > >> Your SSB audio characteristic should not change at >
all due to changing > >> bands, other than because of the convention of using >
USB above 9 MHz > >> and LSB below 9 MHz. The audio characteristics also >
should not change > >> very much from USB to LSB. If it does change, that is >
an indication > >> that your BFO frequencies are misaligned for one or both >
SSB modes. > >> Another possibility, although not nearly as likely, is a >
partially > >> failed crystal filter with a non-symmetrical passband shape. >
The first > >> thing to do is check the BFO frequencies. If you install new> >
> filters, of any brand, without getting the BFO frequencies right, you > > >
will still have a problem.> > DE N6KB> > > >
_______________________________________________> TenTec mailing list> > >
TenTec@contesting.com> http://lists.contesting.com/mailman/listinfo/tentec> >
_________________________________________________________________> > Share what
Santa brought you> > https://www.mycooluncool.com> >
_______________________________________________> > TenTec mailing list> >
TenTec@contesting.com> > http://lists.contesting.com/mailman/listinfo/tentec> >
> > > _______________________________________________> TenTec mailing list>
TenTec@contesting.com> http://lists.contesting.com/mailman/listinfo/tentec
_________________________________________________________________
Who's friends with who and co-starred in what?
http://www.searchgamesbox.com/celebrityseparation.shtml
|