I believe I know why the previous owner did that to your Omni VI. (And I'm
assuming you care!)
Last night I made some measurements of the TX Enable signal on the back panel
of the Omni VI. This line goes low at the beginning of a dit or a dah, then the
RF comes on, just as it should. There is no problem at the leading edge.
The problem is at the trailing edge. The TX Enable goes high again, but the RF
doesn't shut off immediately, so there is a period of time when the QSK circuit
in the amp is being told to go back to receive, yet there is still RF flowing.
This is the problem.
What is needed is for this signal to stay low just a little bit longer, until
the RF ends completely, then it can go high again to turn the diodes in the QSK
unit back to receive. There is a signal that will do that in the Omni; it's
called the relay, and that explains why your previous owner used this signal.
This is the line that is affected by the front panel DLY.
I think I am going to do the same as your previous owner. That is, I'm going to
bring out a line from the relay switching transistor, Q16 on the control board,
bypass the relay, and use that as my QSK line. I don't know if it will work
yet, but that is my next plan.
True QSK or full QSK, whatever you want to call it, is really hard to achieve
with an amplifer. The way you guys speak about QSK on the reflector, you
aren't happy unless you can hear the band between dits at 50 wpm, but that just
isn't possible between an Omni and a cheap amp like an Ameritron, even with the
QSK switch. About the only advantage the QSK switch affords you is the
elimination of the mechanical relay in the amp.
Anyway, that's the way I see it. Thanks again for the information you gave me.
> -----Original Message-----
> From: firstname.lastname@example.org
> [mailto:email@example.com]On Behalf Of Steve N4LQ
> Sent: Monday, November 08, 2004 5:54 PM
> To: firstname.lastname@example.org
> Subject: Re: [TenTec] QSK with QSK-5PC
> Al. Whatever you do, call MFJ before you hook that thing up.
> I didn't and
> blew diodes out of a rig. My QSK was external which made it even more
> I can tell you this....The previous owner of my 6+ bypassed
> the amp relay in
> the rig and used the txd voltage to drive a little transistor
> which feeds
> directly to the amp relay jack. This seems to provide
> excellent keying for
> my Icom PW-1 with no sign of hot switching.
> Steve N4LQ
> ----- Original Message -----
> From: <email@example.com>
> To: <firstname.lastname@example.org>
> Sent: Monday, November 08, 2004 8:01 PM
> Subject: [TenTec] QSK with QSK-5PC
> Would someone who has successfully connected an Omni VI to an
> amplifier equipped with the internal QSK-5PC board be willing
> to contact me
> off the list? I want to know how you connected the two.
> I have read Jim KH7M's previous posts on this subject and
> they are excellent
> for the external unit QSK-5, but the connections to the QSK-5PC are
> different enough that I cannot translate the connections in my head.
> Interestingly, a search of the Internet yields no information
> whatsoever on
> this. I am thinking of using the TX enable input on the back
> of the Omni to
> receive a handshaking signal from the QSK-5PC, but I want to talk to
> somebody who has done this.
> Al W6LX
> TenTec mailing list
> TenTec mailing list
TenTec mailing list