[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> </DIV>
<DIV><FONT size=3D2>The mod consists of unplugging connector 52 on the =
I.F./A.F.=20
Board. That's it. Plug 52 should have only one wire attached =
to=20
it. Those of you with more recent Omni Sixes should verify this as =
some of=20
the circuit boards have been changed to SMD types. 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> </DIV>
<DIV><FONT size=3D2>The theory behind the change: Plug 52 =
activates a 4066=20
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=20
chip. 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> </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 "ST" button.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </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. Then, using =
your=20
headphones, critically listen to the QSK after the mod. There =
should be a=20
marked difference.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Disclaimer:</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>This is not a Ten-Tec approved modification. I =
discovered this while making other modifications to my Omni Six =
Plus. Use=20
care in making this change if you attempt to make it.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>73,</FONT></DIV>
<DIV><FONT size=3D2></FONT> </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 <<A=20
=
href=3D"mailto:paulc@mediaone.net">paulc@mediaone.net</A>><BR><B>To: =
</B><A=20
href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A> =
<<A=20
href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A>>; =
Chester=20
Alderman <<A=20
=
href=3D"mailto:chestert@pressroom.com">chestert@pressroom.com</A>><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. =20
You can hear the receiver between most characters, but nothing =
between dits=20
and dahs. Another abnormality is that when you use their =
excellent CW=20
keyboard interface, QSK is automatically turned OFF and it cannot be =
changed. Why?</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </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 "thump" altogether. 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. 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> </DIV>
<DIV><FONT color=3D#000000 size=3D2>By now, I thought the W1AW =
20-meter signal=20
would have improved. While listening tonight, the leading edge =
chirp=20
is clearly evident. I don't mean to start another raging =
discussion on=20
this, but it's evident that some Omnis manifest this slight =
chirp. =20
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=20
function. Those radios with chirp are the same radios that =
exhibit a=20
truncated trailing CW waveform, particularly when adjusted to the =
most=20
"soft" setting. The new Omni 6+ SMD Control Board no =
longer=20
allows you to make this adjustment. Instead, a fixed resistor =
is now=20
located where a pot used to reside and guess what? The fixed =
value=20
corresponds to what used to be the most "hard" =
setting. =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
"full" than in LSB. Has anyone else noticed =
this? The=20
good news is that the chirp is correctable. Anyway, compare =
the=20
20-meter signal against the simultaneous 40-meter transmission.=20
</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Back to the Kachina: The =
I.F. DSP is=20
at least as good as the Omni 6+. The only drawback is that =
there is=20
some audible digital distortion on transient-rich signals, like =
static=20
crashes. They'll get this worked out in time. 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> </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 <<A=20
=
href=3D"mailto:chestert@pressroom.com">chestert@pressroom.com</A>><BR>=
<B>To:=20
</B><A =
href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A>=20
<<A=20
=
href=3D"mailto:tentec@contesting.com">tentec@contesting.com</A>><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> </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> </X-TAB>I=20
sure disagree with the person stating that "ultimately =
IF/DSP=20
filter performance will surpass cascaded crystal =
filters." =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> </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>>>I think the CW QSK/keying performance was better =
with the=20
Omni also .</DIV>
<DIV>></DIV>
<DIV>>Yes. at the Kachina web site, they say they =
505 has=20
QSK "only</DIV>
<DIV>>above 30 wpm", at QRS the "transmitter=20
hangs", whatever that</DIV>
<DIV>>means. They go to say it is because the Kachina=20
completes</DIV>
<DIV>>each CW character for you!! That is =
different.</DIV>
<DIV>></DIV>
<DIV>>>I'm sure that ultimately all rigs will be=20
computer-controlled to the degree</DIV>
<DIV>>that</DIV>
<DIV>>>the Kachina is, and I'm sure that ultimately IF/DSP =
filter=20
performance will</DIV>
<DIV>>>surpass cascaded crystal filters. Give them 5 =
years=20
or so!</DIV>
<DIV>></DIV>
<DIV>></DIV>
<DIV>>But, I think I will need to order a new rig next=20
week! However, a bit</DIV>
<DIV>>put off by the fellow who just got his new Omni+ from =
Ten=20
Tec, I</DIV>
<DIV>>guess yesterday, and it would reset to 14000 and =
1200=20
o'clock each</DIV>
<DIV>>time he turned in off and later back on! =
Ten Tec=20
says they burn</DIV>
<DIV>>each rig in for several hours, then check =
performance=20
again, but</DIV>
<DIV>>maybe they didn't/don't turn them on/off a couple of =
times as=20
part</DIV>
<DIV>>of the check??</DIV>
<DIV>></DIV>
<DIV>>73, Jim, KH7M</DIV>
<DIV>></DIV>
<DIV>>73, Jim, KH7M</DIV>
<DIV>></DIV>
<DIV>></DIV>
<DIV>></DIV>
<DIV>>--</DIV>
<DIV>>FAQ on=20
=
WWW: &nb=
sp; =20
<A href=3D"http://www.contesting.com/tentecfaq.htm" EUDORA =3D=20
AUTOURL>http://www.contesting.com/tentecfaq.htm</A></DIV>
=
<DIV>>Submissions: &nbs=
p; =20
tentec@contesting.com</DIV>
<DIV>>Administrative requests: =20
tentec-REQUEST@contesting.com</DIV>
=
<DIV>>Problems: &=
nbsp; =20
owner-tentec@contesting.com</DIV>
=
<DIV>>Search: &nb=
sp; =20
<A href=3D"http://www.contesting.com/km9p/search.htm" EUDORA =3D =
AUTOURL>http://www.contesting.com/km9p/search.htm</A></DIV>> =
<BR>
<DIV align=3Dcenter>Chester Alderman<BR><B>Tom -=20
=
W4BQF<BR></B><U>chestert@pressroom.com<BR></U></DIV></BLOCKQUOTE></BLOCKQ=
UOTE></BODY></HTML>
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Search: http://www.contesting.com/km9p/search.htm