[TenTec] Re: Omni VI+ QSK Thump and Click Mod

Paul Christensen paulc@mediaone.net
Mon, 7 Sep 1998 08:28:01 -0400


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There were far too many replies to answer each one individually.

The mod consists of unplugging connector 52 on the I.F./A.F. Board.  =
That's it.  Plug 52 should have only one wire attached to it.  Those of =
you with more recent Omni Sixes should verify this as some of the =
circuit boards have been changed to SMD types.  Once connector 52 is =
unplugged, use a nylon tie-wrap to keep it safely out of harm's way.

The theory behind the change:  Plug 52 activates a 4066 CMOS quad =
bilateral switch which is configured as a sidetone wrap-around circuit.  =
The audio click and thumps one hears is generated by the CMOS chip.  =
These chips are used in the broadcast audio world and are known to cause =
the same effect when switching audio on complicated audio mixers and =
routers.

You will note after the change that you still have sidetone control and =
the ability to control its mix relative to incoming received audio =
through the front panel's "ST" button.

Use a set of headphones to listen to your QSK audio before the mod and =
make a mental note of what you're hearing.  Then, using your headphones, =
critically listen to the QSK after the mod.  There should be a marked =
difference.

Disclaimer:

This is not a Ten-Tec approved modification.  I discovered this while =
making other modifications to my Omni Six Plus.  Use care in making this =
change if you attempt to make it.

73,

-Paul, W9AC
    -----Original Message-----
    From: Paul Christensen <paulc@mediaone.net>
    To: tentec@contesting.com <tentec@contesting.com>; Chester Alderman =
<chestert@pressroom.com>
    Date: Sunday, September 06, 1998 9:15 PM
    Subject: Re: [TenTec] Re: [CW] Kachina vs. Omni VI+
   =20
   =20
    Since I own the Kachina 505DSP, Yaesu FT-1000MP and the Omni 6+, I =
can say that Kachina's QSK comes with a noisy relay (not a reed type) =
and the T/R turnaround time is much too long.  You can hear the receiver =
between most characters, but nothing between dits and dahs.  Another =
abnormality is that when you use their excellent CW keyboard interface, =
QSK is automatically turned OFF and it cannot be changed.  Why?
    =20
    Anyway, I continue to enjoy my Omni 6+ for real CW work, =
particularly since I made my keyed waveform and chirp mods back in June, =
and eliminated the slight QSK "thump" altogether.  The last mod makes a =
tremendous improvement and requires a non-invasive mod to only one wire =
on the I.F./A.F. Board.  Everyone should at least try this since it can =
be restored simply with the push of a connector.
    =20
    By now, I thought the W1AW 20-meter signal would have improved.  =
While listening tonight, the leading edge chirp is clearly evident.  I =
don't mean to start another raging discussion on this, but it's evident =
that some Omnis manifest this slight chirp.  Hint: the source can be =
traced to the 9 MHz @ 2.4 kHz crystal filter circuit.  This is the only =
filter that shares the TX and RX function.  Those radios with chirp are =
the same radios that exhibit a truncated trailing CW waveform, =
particularly when adjusted to the most "soft" setting.  The new Omni 6+ =
SMD Control Board no longer allows you to make this adjustment.  =
Instead, a fixed resistor is now located where a pot used to reside and =
guess what?  The fixed value corresponds to what used to be the most =
"hard" setting.  Here's another hint for Ten-Tec: The source of the =
chirp is what also causes the USB receive audio to sound a bit thinner =
in low-end response and less "full" than in LSB.  Has anyone else =
noticed this?  The good news is that the chirp is correctable.  Anyway, =
compare the 20-meter signal against the simultaneous 40-meter =
transmission.=20
    =20
    Back to the Kachina:  The I.F. DSP is at least as good as the Omni =
6+.  The only drawback is that there is some audible digital distortion =
on transient-rich signals, like static crashes.  They'll get this worked =
out in time.  Their rig is 90% of the way to completely satisfying me, =
but as we all know, getting that couple percent improvement is the most =
difficult to achieve.
    =20
    -Paul, W9AC
        -----Original Message-----
        From: Chester Alderman <chestert@pressroom.com>
        To: tentec@contesting.com <tentec@contesting.com>
        Date: Sunday, September 06, 1998 8:48 PM
        Subject: Re: [TenTec] Re: [CW] Kachina vs. Omni VI+
       =20
       =20
        Jim...Unfortunately I can only offer you what I was told via =
email about the Kachina. Someone was using it at a special event station =
and complained that the QSK was very poor; mind you, I don't know =
personally.
       =20
       =20
                As for the Omni 6+ that resets to 14000kc when it's =
turned on, I'm sure your going to find when that fellow reads the manual =
and learns how to set the menu selection, that the Omni 6 will turn on =
at the QRG that it was turned off at. Mine does.
       =20
       =20
                I sure disagree with the person stating that "ultimately =
IF/DSP filter performance will surpass cascaded crystal filters."  The =
reason I disagree with that statement is because digital switching will =
probably NEVER have the stop band characteristics that a crystal filter =
can have, if designed correct. They will probably make good strides in =
using IF/DSP for SSB, but I would almost (NOTE: 'almost') bet my Omni 6+ =
that it wont happen for CW operation.
       =20
       =20
                As for TenTec's final testing, I have not witnessed it. =
However not too long ago TenTec got a military contract to build =
receivers to MilSpec and I think the result of that contract is a lot of =
what we see in the Omni 6. Meaning the very good pc board layouts, the =
excellent cabeling routing, and the overall significant improvement in =
the design of the Omni. I think most of their testing is now computer =
controlled, and certainly with computer controlled testing some things =
can be missed. All depends on the communications between the engineers =
and the computer programmer!
       =20
       =20
        73,
       =20
       =20
       =20
        >>I think the CW QSK/keying performance was better with the Omni =
also .
        >
        >Yes.  at the Kachina web site,  they say they 505 has QSK "only
        >above 30 wpm",  at QRS the "transmitter hangs",  whatever that
        >means.  They go to say it is because the Kachina completes
        >each CW character for you!!  That is different.
        >
        >>I'm sure that ultimately all rigs will be computer-controlled =
to the degree
        >that
        >>the Kachina is, and I'm sure that ultimately IF/DSP filter =
performance will
        >>surpass cascaded crystal filters.  Give them 5 years or so!
        >
        >
        >But,  I think I will need to order a new rig next week!  =
However,  a bit
        >put off by the fellow who just got his new Omni+ from Ten Tec,  =
I
        >guess yesterday,  and it would reset to 14000 and 1200 o'clock =
each
        >time he turned in off  and later back on!  Ten Tec says they =
burn
        >each rig in for several hours,  then check performance again,  =
but
        >maybe they didn't/don't turn them on/off a couple of times as =
part
        >of the check??
        >
        >73,   Jim,  KH7M
        >
        >73,  Jim,  KH7M
        >
        >
        >
        >--
        >FAQ on WWW:               =
http://www.contesting.com/tentecfaq.htm
        >Submissions:              tentec@contesting.com
        >Administrative requests:  tentec-REQUEST@contesting.com
        >Problems:                 owner-tentec@contesting.com
        >Search:                   =
http://www.contesting.com/km9p/search.htm
        >=20
       =20
        Chester Alderman
        Tom - W4BQF
        chestert@pressroom.com


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<DIV><FONT size=3D2>There were far too many replies to answer each one=20
individually.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>The mod consists of unplugging connector 52 on the =
I.F./A.F.=20
Board.&nbsp; That's it.&nbsp; Plug 52 should have only one wire attached =
to=20
it.&nbsp; Those of you with more recent Omni Sixes should verify this as =
some of=20
the circuit boards have been changed to SMD types.&nbsp; Once connector =
52 is=20
unplugged, use a nylon tie-wrap to keep it safely out of harm's=20
way.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>The theory behind the change:&nbsp; Plug 52 =
activates a 4066=20
CMOS quad bilateral switch which is configured as a sidetone wrap-around =

circuit.&nbsp; The audio click and thumps one hears is generated by the =
CMOS=20
chip.&nbsp; These chips are used in the broadcast audio world and are =
known to=20
cause the same effect when switching audio on complicated audio mixers =
and=20
routers.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>You will note after the change that you still have =
sidetone=20
control and the ability to control its mix relative to incoming received =
audio=20
through the front panel's &quot;ST&quot; button.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>Use a set of headphones to listen to your QSK audio =
before the=20
mod and make a mental note of what you're hearing.&nbsp; Then, using =
your=20
headphones, critically listen to the QSK after the mod.&nbsp; There =
should be a=20
marked difference.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>Disclaimer:</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>This is not a Ten-Tec approved modification.&nbsp; I =

discovered this while making other modifications to my Omni Six =
Plus.&nbsp; Use=20
care in making this change if you attempt to make it.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>73,</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>-Paul, W9AC</FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT: =
5px">
    <DIV><FONT face=3DArial size=3D2><B>-----Original =
Message-----</B><BR><B>From:=20
    </B>Paul Christensen &lt;<A=20
    =
href=3D"mailto:paulc@mediaone.net">paulc@mediaone.net</A>&gt;<BR><B>To: =
</B><A=20
    href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A> =
&lt;<A=20
    href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A>&gt;; =
Chester=20
    Alderman &lt;<A=20
    =
href=3D"mailto:chestert@pressroom.com">chestert@pressroom.com</A>&gt;<BR>=
<B>Date:=20
    </B>Sunday, September 06, 1998 9:15 PM<BR><B>Subject: </B>Re: =
[TenTec] Re:=20
    [CW] Kachina vs. Omni VI+<BR><BR></DIV></FONT>
    <DIV><FONT color=3D#000000 size=3D2>Since I own the Kachina 505DSP, =
Yaesu=20
    FT-1000MP and the Omni 6+, I can say that Kachina's QSK comes with a =
noisy=20
    relay (not a reed type) and the T/R turnaround time is much too =
long.&nbsp;=20
    You can hear the receiver between most characters, but nothing =
between dits=20
    and dahs.&nbsp; Another abnormality is that when you use their =
excellent CW=20
    keyboard interface, QSK is automatically turned OFF and it cannot be =

    changed.&nbsp; Why?</FONT></DIV>
    <DIV><FONT color=3D#000000 size=3D2></FONT>&nbsp;</DIV>
    <DIV><FONT size=3D2>Anyway, I continue to enjoy my Omni 6+ for real =
CW work,=20
    particularly since I made my keyed waveform and chirp mods back in =
June, and=20
    eliminated the slight QSK &quot;thump&quot; altogether.&nbsp; The =
last mod=20
    makes a tremendous improvement and requires a non-invasive mod to =
only one=20
    wire on the I.F./A.F. Board.&nbsp; Everyone should at least try this =
since=20
    it can be restored simply with the push of a connector.</FONT></DIV>
    <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
    <DIV><FONT color=3D#000000 size=3D2>By now, I thought the W1AW =
20-meter signal=20
    would have improved.&nbsp; While listening tonight, the leading edge =
chirp=20
    is clearly evident.&nbsp; I don't mean to start another raging =
discussion on=20
    this, but it's evident that some Omnis manifest this slight =
chirp.&nbsp;=20
    Hint: the source can be traced to the 9 MHz @ 2.4 kHz crystal filter =

    circuit.&nbsp; This is the only filter that shares the TX and RX=20
    function.&nbsp; Those radios with chirp are the same radios that =
exhibit a=20
    truncated trailing CW waveform, particularly when adjusted to the =
most=20
    &quot;soft&quot; setting.&nbsp; The new Omni 6+ SMD Control Board no =
longer=20
    allows you to make this adjustment.&nbsp; Instead, a fixed resistor =
is now=20
    located where a pot used to reside and guess what?&nbsp; The fixed =
value=20
    corresponds to what used to be the most &quot;hard&quot; =
setting.&nbsp;=20
    Here's another hint for Ten-Tec: The source of the chirp is what =
also causes=20
    the USB receive audio to sound a bit thinner in low-end response and =
less=20
    &quot;full&quot; than in LSB.&nbsp; Has anyone else noticed =
this?&nbsp; The=20
    good news is that the chirp is correctable.&nbsp; Anyway, compare =
the=20
    20-meter signal against the simultaneous 40-meter transmission.=20
</FONT></DIV>
    <DIV><FONT color=3D#000000 size=3D2></FONT>&nbsp;</DIV>
    <DIV><FONT color=3D#000000 size=3D2>Back to the Kachina:&nbsp; The =
I.F. DSP is=20
    at least as good as the Omni 6+.&nbsp; The only drawback is that =
there is=20
    some audible digital distortion on transient-rich signals, like =
static=20
    crashes.&nbsp; They'll get this worked out in time.&nbsp; Their rig =
is 90%=20
    of the way to completely satisfying me, but as we all know, getting =
that=20
    couple percent improvement is the most difficult to =
achieve.</FONT></DIV>
    <DIV><FONT color=3D#000000 size=3D2></FONT>&nbsp;</DIV>
    <DIV><FONT size=3D2>-Paul, W9AC</FONT></DIV>
    <BLOCKQUOTE=20
    style=3D"BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; =
PADDING-LEFT: 5px">
        <DIV><FONT face=3DArial size=3D2><B>-----Original=20
        Message-----</B><BR><B>From: </B>Chester Alderman &lt;<A=20
        =
href=3D"mailto:chestert@pressroom.com">chestert@pressroom.com</A>&gt;<BR>=
<B>To:=20
        </B><A =
href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A>=20
        &lt;<A=20
        =
href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A>&gt;<BR><B=
>Date:=20
        </B>Sunday, September 06, 1998 8:48 PM<BR><B>Subject: </B>Re: =
[TenTec]=20
        Re: [CW] Kachina vs. Omni VI+<BR><BR></DIV></FONT>
        <DIV>Jim...Unfortunately I can only offer you what I was told =
via email=20
        about the Kachina. Someone was using it at a special event =
station and=20
        complained that the QSK was very poor; mind you, I don't know=20
        personally.</DIV><BR>
        =
<DIV><X-TAB>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</X-TAB>As=20
        for the Omni 6+ that resets to 14000kc when it's turned on, I'm =
sure=20
        your going to find when that fellow reads the manual and learns =
how to=20
        set the menu selection, that the Omni 6 will turn on at the QRG =
that it=20
        was turned off at. Mine does.</DIV><BR>
        =
<DIV><X-TAB>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</X-TAB>I=20
        sure disagree with the person stating that &quot;ultimately =
IF/DSP=20
        filter performance will surpass cascaded crystal =
filters.&quot;&nbsp;=20
        The reason I disagree with that statement is because digital =
switching=20
        will probably NEVER have the stop band characteristics that a =
crystal=20
        filter can have, if designed correct. They will probably make =
good=20
        strides in using IF/DSP for SSB, but I would almost (NOTE: =
'almost') bet=20
        my Omni 6+ that it wont happen for CW operation.</DIV><BR>
        =
<DIV><X-TAB>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</X-TAB>As=20
        for TenTec's final testing, I have not witnessed it. However not =
too=20
        long ago TenTec got a military contract to build receivers to =
MilSpec=20
        and I think the result of that contract is a lot of what we see =
in the=20
        Omni 6. Meaning the very good pc board layouts, the excellent =
cabeling=20
        routing, and the overall significant improvement in the design =
of the=20
        Omni. I think most of their testing is now computer controlled, =
and=20
        certainly with computer controlled testing some things can be =
missed.=20
        All depends on the communications between the engineers and the =
computer=20
        programmer!</DIV><BR>
        <DIV>73,</DIV><BR><BR>
        <DIV>&gt;&gt;I think the CW QSK/keying performance was better =
with the=20
        Omni also .</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;Yes.&nbsp; at the Kachina web site,&nbsp; they say they =
505 has=20
        QSK &quot;only</DIV>
        <DIV>&gt;above 30 wpm&quot;,&nbsp; at QRS the &quot;transmitter=20
        hangs&quot;,&nbsp; whatever that</DIV>
        <DIV>&gt;means.&nbsp; They go to say it is because the Kachina=20
        completes</DIV>
        <DIV>&gt;each CW character for you!!&nbsp; That is =
different.</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;&gt;I'm sure that ultimately all rigs will be=20
        computer-controlled to the degree</DIV>
        <DIV>&gt;that</DIV>
        <DIV>&gt;&gt;the Kachina is, and I'm sure that ultimately IF/DSP =
filter=20
        performance will</DIV>
        <DIV>&gt;&gt;surpass cascaded crystal filters.&nbsp; Give them 5 =
years=20
        or so!</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;But,&nbsp; I think I will need to order a new rig next=20
        week!&nbsp; However,&nbsp; a bit</DIV>
        <DIV>&gt;put off by the fellow who just got his new Omni+ from =
Ten=20
        Tec,&nbsp; I</DIV>
        <DIV>&gt;guess yesterday,&nbsp; and it would reset to 14000 and =
1200=20
        o'clock each</DIV>
        <DIV>&gt;time he turned in off&nbsp; and later back on!&nbsp; =
Ten Tec=20
        says they burn</DIV>
        <DIV>&gt;each rig in for several hours,&nbsp; then check =
performance=20
        again,&nbsp; but</DIV>
        <DIV>&gt;maybe they didn't/don't turn them on/off a couple of =
times as=20
        part</DIV>
        <DIV>&gt;of the check??</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;73,&nbsp;&nbsp; Jim,&nbsp; KH7M</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;73,&nbsp; Jim,&nbsp; KH7M</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;</DIV>
        <DIV>&gt;--</DIV>
        <DIV>&gt;FAQ on=20
        =
WWW:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nb=
sp;&nbsp;&nbsp;=20
        <A href=3D"http://www.contesting.com/tentecfaq.htm" EUDORA =3D=20
        AUTOURL>http://www.contesting.com/tentecfaq.htm</A></DIV>
        =
<DIV>&gt;Submissions:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs=
p;&nbsp;&nbsp;&nbsp;&nbsp;=20
        tentec@contesting.com</DIV>
        <DIV>&gt;Administrative requests:&nbsp;=20
        tentec-REQUEST@contesting.com</DIV>
        =
<DIV>&gt;Problems:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&=
nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=20
        owner-tentec@contesting.com</DIV>
        =
<DIV>&gt;Search:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nb=
sp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=20
        <A href=3D"http://www.contesting.com/km9p/search.htm" EUDORA =3D =

        AUTOURL>http://www.contesting.com/km9p/search.htm</A></DIV>&gt; =
<BR>
        <DIV align=3Dcenter>Chester Alderman<BR><B>Tom -=20
        =
W4BQF<BR></B><U>chestert@pressroom.com<BR></U></DIV></BLOCKQUOTE></BLOCKQ=
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