TW wrote:

Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page
26: "Receiver Hook-up: You may patch most receivers directly into your
VEC QRP-CW Transmitter's receiver jack without risk of damage.
Transmitter output is typically around + 32 dBm and the energy
reaching your receiver through the T/R switch is normally 25 dB lower,
or about +7 dBm. This is a very strong signal, but a high-quality
receiver with a wide AGC range can usually handle it without blasting
out the speaker! If you are able to leave the receiver on during
transmit, you'll enjoy the benefit of full QSK operation."

It would strike me that if you really wanted a full T/R switch, and you
did not want to spend the five dollars or so for a fast relay, you could
probably build an acceptable switch using 1N4007 diodes. I would think
that with these current levels at HF that there would be no need for a
fancy switching PIN diode.

Another alternative, by the way, is just to use a vertical for transmitting
and a horizontal dipole for receive. This also has some major benefits in that
your receiver noise will be lower with the horizontal and your transmitted
signal will be slightly better with the vertical.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:

On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch
wrote:

You really don't need receiver muting for c.w. QSK,
just a receiver who's AGC can be turned off, or is very fast.
..

the receiver's input stage. The signal is still loud, but if you
switch the AGC off, you can hear a breaking station between dits.

Thanks. I'd prefer to something more like Tentec's concept of QSK
and not listen to a thumping receiver or hammer my S-meter against
the pin.

Done right, QSK is a delight.

I think it can be done with off-the-shelf pieces. Looks like the
key is the www.radioadv.com keyer-TR switch and just about any QRP
transmitter kit, or at least that's what folk are telling me.

de ah6gi/4

I'll admit it's not done very well in the stock Vectronics units.
Using the 20m companion receiver, it's more like an AK47 in the
headphones! Good thing they don't come with an S-meter! Hey, I paid
$19 for a 30m model when TechAmerica had their closeout in
Atlanta...minimal expectations. They are good for experimentation.
I'm working on a solution for that QSK action, something better than
the 1N914 they use.

Good luck,

Ted KX4OM

On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:

On Thu, 16 Dec 2004 06:27:16 UTC, Edward Knobloch
wrote:

You really don't need receiver muting for c.w. QSK,
just a receiver who's AGC can be turned off, or is very fast.
..

the receiver's input stage. The signal is still loud, but if you
switch the AGC off, you can hear a breaking station between dits.

Thanks. I'd prefer to something more like Tentec's concept of QSK
and not listen to a thumping receiver or hammer my S-meter against
the pin.

Done right, QSK is a delight.

I think it can be done with off-the-shelf pieces. Looks like the
key is the www.radioadv.com keyer-TR switch and just about any QRP
transmitter kit, or at least that's what folk are telling me.

de ah6gi/4

I'll admit it's not done very well in the stock Vectronics units.
Using the 20m companion receiver, it's more like an AK47 in the
headphones! Good thing they don't come with an S-meter! Hey, I paid
$19 for a 30m model when TechAmerica had their closeout in
Atlanta...minimal expectations. They are good for experimentation.
I'm working on a solution for that QSK action, something better than
the 1N914 they use.

Good luck,

Ted KX4OM

On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:

On Thu, 16 Dec 2004 08:29:16 UTC, TW wrote:

On 15 Dec 2004 14:19:25 GMT, "No Spam " No wrote:

I've searched the web but haven't found the answer to my
QRP CW question.

I'm looking for a QRP CW transmitter kit that includes QSK and
will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1.

I realize that some receivers might not recover fast enough for
QSK.

I've looked at website ads for Ramsey, Vectronixs, and still
don't have an answer. They might do it out of the box; they
might do it with a mod but I haven't found the answer.

A couple watts of CW and capable of working with the WA6OTP PTO
kit.

Anyone got something like that working?

de ah6gi/4

Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page
26: "Receiver Hook-up: You may patch most receivers directly into your
VEC QRP-CW Transmitter's receiver jack without risk of damage.
Transmitter output is typically around + 32 dBm and the energy
reaching your receiver through the T/R switch is normally 25 dB lower,
or about +7 dBm. This is a very strong signal, but a high-quality
receiver with a wide AGC range can usually handle it without blasting
out the speaker! If you are able to leave the receiver on during
transmit, you'll enjoy the benefit of full QSK operation."

"This means you'll be able to monitor incoming signals--and listen to
your own outgoing signal--simultaneously. If your receiver has an
attenuator switch, turning it on will help reduce the effects of
overload. By the same token, if your receiver has a pre-amplifier,
you should turn it off. Receivers unable to limit speaker or
headphone volume over a wide range of signal inputs must be turned
down or switched to standby mode while you send."

Enough said?

not enough but thanks for the terrific info. I've heard a
Triton IV and Signal/One CX7A's concept of QSK and that's not
exactly their concept.

40 years ago, I put a pot in series with the mute line on my
SX-101A. That gave me an RF gain control that worked on receive and
let me monitor my signal on SSB and CW.

I didn't have break-in but I had the monitoring part. The QSK
experience isn't just, "If I ignore the thumping of the receiver,
clacking of relays, and the excessively loud transmit sidetone, I
can maybe make out a dit between sent characters."

QSK is the change-over happening so smoothly that it sounds like
we're transmitting using code practice oscillators in the same room
and I can control the volume and tone on both oscillators.

Where you helped is this, I can combine that transmitter with the
boatanchor TR-keyer described in the 2004 handbook and sold by
www.radioadv.com to make a device that will mute my boatanchor
receivers.

Should work. Thanks.

de ah6gi/4

I just posted a Boatanchor switching topic regarding a circuit in the
2003 Handbook based on sequenced switching for transverters. Is this
the same article, or is there a separate TR article (I had borrowed
the book from the library)?

Ted KX4OM

On 16 Dec 2004 12:33:55 GMT, "No Spam " No wrote:

On Thu, 16 Dec 2004 08:29:16 UTC, TW wrote:

On 15 Dec 2004 14:19:25 GMT, "No Spam " No wrote:

I've searched the web but haven't found the answer to my
QRP CW question.

I'm looking for a QRP CW transmitter kit that includes QSK and
will mute a boatanchor receiver like an SB-303, SX-101, or 75S-1.

I realize that some receivers might not recover fast enough for
QSK.

I've looked at website ads for Ramsey, Vectronixs, and still
don't have an answer. They might do it out of the box; they
might do it with a mod but I haven't found the answer.

A couple watts of CW and capable of working with the WA6OTP PTO
kit.

Anyone got something like that working?

de ah6gi/4

Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page
26: "Receiver Hook-up: You may patch most receivers directly into your
VEC QRP-CW Transmitter's receiver jack without risk of damage.
Transmitter output is typically around + 32 dBm and the energy
reaching your receiver through the T/R switch is normally 25 dB lower,
or about +7 dBm. This is a very strong signal, but a high-quality
receiver with a wide AGC range can usually handle it without blasting
out the speaker! If you are able to leave the receiver on during
transmit, you'll enjoy the benefit of full QSK operation."

"This means you'll be able to monitor incoming signals--and listen to
your own outgoing signal--simultaneously. If your receiver has an
attenuator switch, turning it on will help reduce the effects of
overload. By the same token, if your receiver has a pre-amplifier,
you should turn it off. Receivers unable to limit speaker or
headphone volume over a wide range of signal inputs must be turned
down or switched to standby mode while you send."

Enough said?

not enough but thanks for the terrific info. I've heard a
Triton IV and Signal/One CX7A's concept of QSK and that's not
exactly their concept.

40 years ago, I put a pot in series with the mute line on my
SX-101A. That gave me an RF gain control that worked on receive and
let me monitor my signal on SSB and CW.

I didn't have break-in but I had the monitoring part. The QSK
experience isn't just, "If I ignore the thumping of the receiver,
clacking of relays, and the excessively loud transmit sidetone, I
can maybe make out a dit between sent characters."

QSK is the change-over happening so smoothly that it sounds like
we're transmitting using code practice oscillators in the same room
and I can control the volume and tone on both oscillators.

Where you helped is this, I can combine that transmitter with the
boatanchor TR-keyer described in the 2004 handbook and sold by
www.radioadv.com to make a device that will mute my boatanchor
receivers.

Should work. Thanks.

de ah6gi/4

I just posted a Boatanchor switching topic regarding a circuit in the
2003 Handbook based on sequenced switching for transverters. Is this
the same article, or is there a separate TR article (I had borrowed
the book from the library)?

Ted KX4OM

On 16 Dec 2004 10:26:06 -0500, (Scott Dorsey) wrote:

TW wrote:

Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page
26: "Receiver Hook-up: You may patch most receivers directly into your
VEC QRP-CW Transmitter's receiver jack without risk of damage.
Transmitter output is typically around + 32 dBm and the energy
reaching your receiver through the T/R switch is normally 25 dB lower,
or about +7 dBm. This is a very strong signal, but a high-quality
receiver with a wide AGC range can usually handle it without blasting
out the speaker! If you are able to leave the receiver on during
transmit, you'll enjoy the benefit of full QSK operation."

It would strike me that if you really wanted a full T/R switch, and you
did not want to spend the five dollars or so for a fast relay, you could
probably build an acceptable switch using 1N4007 diodes. I would think
that with these current levels at HF that there would be no need for a
fancy switching PIN diode.

Another alternative, by the way, is just to use a vertical for transmitting
and a horizontal dipole for receive. This also has some major benefits in that
your receiver noise will be lower with the horizontal and your transmitted
signal will be slightly better with the vertical.
--scott

Hi Scott,
The existing circuit simply uses one 1N4007 and a 1N4148 in series
thru a .01 cap to the receiver muting input (it is not THAT simple,
they are across the emitter and collector of the keying transistor; I
tried to draw it in text symbols, but gave up). What I hear in the
phones on keying is a loud "square wave" thump on each character sent.

I bought the Vectronics kits a couple of years ago after a period of
inactivity due to illness, mainly to get engaged and productive on
something.

I'll check out some designs in my 2000 and earlier Handbooks for relay
and/or diode switching better than the current Vectronics QSK design.
I can in fact use a vertical and a dipole, so that is a good
suggestion. Meanwhile, I enjoy QSK with my SW-20+.

Thanks,

Ted KX4OM

On 16 Dec 2004 10:26:06 -0500, (Scott Dorsey) wrote:

TW wrote:

Quoting from the Vectronics VEC-1220K 20M transmitter kit manual, page
26: "Receiver Hook-up: You may patch most receivers directly into your
VEC QRP-CW Transmitter's receiver jack without risk of damage.
Transmitter output is typically around + 32 dBm and the energy
reaching your receiver through the T/R switch is normally 25 dB lower,
or about +7 dBm. This is a very strong signal, but a high-quality
receiver with a wide AGC range can usually handle it without blasting
out the speaker! If you are able to leave the receiver on during
transmit, you'll enjoy the benefit of full QSK operation."

It would strike me that if you really wanted a full T/R switch, and you
did not want to spend the five dollars or so for a fast relay, you could
probably build an acceptable switch using 1N4007 diodes. I would think
that with these current levels at HF that there would be no need for a
fancy switching PIN diode.

Another alternative, by the way, is just to use a vertical for transmitting
and a horizontal dipole for receive. This also has some major benefits in that
your receiver noise will be lower with the horizontal and your transmitted
signal will be slightly better with the vertical.
--scott

Hi Scott,
The existing circuit simply uses one 1N4007 and a 1N4148 in series
thru a .01 cap to the receiver muting input (it is not THAT simple,
they are across the emitter and collector of the keying transistor; I
tried to draw it in text symbols, but gave up). What I hear in the
phones on keying is a loud "square wave" thump on each character sent.

I bought the Vectronics kits a couple of years ago after a period of
inactivity due to illness, mainly to get engaged and productive on
something.

I'll check out some designs in my 2000 and earlier Handbooks for relay
and/or diode switching better than the current Vectronics QSK design.
I can in fact use a vertical and a dipole, so that is a good
suggestion. Meanwhile, I enjoy QSK with my SW-20+.

Thanks,

Ted KX4OM

TW wrote:

Hi Scott,
The existing circuit simply uses one 1N4007 and a 1N4148 in series
thru a .01 cap to the receiver muting input (it is not THAT simple,
they are across the emitter and collector of the keying transistor; I
tried to draw it in text symbols, but gave up). What I hear in the
phones on keying is a loud "square wave" thump on each character sent.

Try putting a capacitive shunt on the line that is providing the bias
supply to the diodes, so they take a little bit of time to get up to
voltage and back down. That may slow the action up a little bit, but
it will also reduce the clicking. You may have to fiddle around with
values (and you may need a combination of a ceramic and an electrolytic
in parallel), but if the noise is caused by the rapid switching, it will
fix it.

If the noise is caused by DC offset on the output, a .1 uF ceramic in
series with the receiver input will clean that up. This might be the
case in receivers where there is a DC path through a coil winding from
antenna to ground.

I bought the Vectronics kits a couple of years ago after a period of
inactivity due to illness, mainly to get engaged and productive on
something.

I'll check out some designs in my 2000 and earlier Handbooks for relay
and/or diode switching better than the current Vectronics QSK design.
I can in fact use a vertical and a dipole, so that is a good
suggestion. Meanwhile, I enjoy QSK with my SW-20+.

After working at a military installation where the procedure was to disconnect
the UHF connector from the receiver and plug it into the transmitter between
sending and receiving, I am just glad to have anything at all.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

TW wrote:

Hi Scott,
The existing circuit simply uses one 1N4007 and a 1N4148 in series
thru a .01 cap to the receiver muting input (it is not THAT simple,
they are across the emitter and collector of the keying transistor; I
tried to draw it in text symbols, but gave up). What I hear in the
phones on keying is a loud "square wave" thump on each character sent.

Try putting a capacitive shunt on the line that is providing the bias
supply to the diodes, so they take a little bit of time to get up to
voltage and back down. That may slow the action up a little bit, but
it will also reduce the clicking. You may have to fiddle around with
values (and you may need a combination of a ceramic and an electrolytic
in parallel), but if the noise is caused by the rapid switching, it will
fix it.

If the noise is caused by DC offset on the output, a .1 uF ceramic in
series with the receiver input will clean that up. This might be the
case in receivers where there is a DC path through a coil winding from
antenna to ground.

I bought the Vectronics kits a couple of years ago after a period of
inactivity due to illness, mainly to get engaged and productive on
something.

I'll check out some designs in my 2000 and earlier Handbooks for relay
and/or diode switching better than the current Vectronics QSK design.
I can in fact use a vertical and a dipole, so that is a good
suggestion. Meanwhile, I enjoy QSK with my SW-20+.

After working at a military installation where the procedure was to disconnect
the UHF connector from the receiver and plug it into the transmitter between
sending and receiving, I am just glad to have anything at all.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Thu, 16 Dec 2004 14:51:44 UTC, K7MEM wrote:


I fully agree with you that, done right, QSK is a delight. I have been
using a Heathkit HR-1680/HX-1681 combination for over 20 years now.
The QSK works extremely well. It is virtually imperceptible that the
receiver is actually being shut down during my dots and dashes. There
is no thumping or bumping or hammering of the S-Meter, and I can hear
all of the band activity.

IMHO, I think that to have a good QSK setup, you must take the capabilities
of both the receiver and transmitter into account. This Heathkit pair
was designed to work together. There is a keying circuit inside that
controls the timing of the receiver muting, transmitter keying, and
T/R switch operation. No relays are involved at all. The low level
keying and frequency generation is all solid state and the final (tubes)
is run Class AB2, for a nice clean, well shaped, signal.

It may be beneficial to get a copy of the HX-1681 transmitter and
investigate how they implemented it. I haven't looked at the schematic
in a long time but I don't think it was very complicated. It may be
similar to Tentec's concept of QSK.

I also seem to remember that in the ARRL Handbook, 2000 I think,
there was a project for making implementing automatic T/R switching
for vintage transmitters and receivers. I don't remember if they went
into full QSK, or not, but it's another possible resource.

I'm hoping that www.radioadv.com version of the Handbook TR-Keyer
will supply that level of control.

I'm not in a rush to get this going. I'm mostly a listener and
haven't been on HF for decades. I have a TH3jr and a 204BA (with
35 foot boom) both disassembled. I've been refurbing receivers.
While I work on them, I'll listen to 40 CW or one of those 75 meter
nets.

I like to listen a couple times a month to keep my copying speed up.

The more I hear about that handbook/radioadv TR-keyer, the more
exciting it sounds. If it'll give me good QSK like a Triton IV or
your HR-1680/HX-1681, it'll be well worth it.

de ah6gi/4 qsy to 80 to listen for the QRP sprint.

--