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 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."

Don't be satisfied with a simple arrangement that lets you get by. I worked CW
traffic nets at different level years ago with a thumping, banging system using
headphones and now I wear two hearing aids and regret the nights that I called
myself having a great time. Wish I could do it again and do it better!
(broke=not working, retired=not working, retired=broke)

Don't be satisfied with a simple arrangement that lets you get by. I worked CW
traffic nets at different level years ago with a thumping, banging system using
headphones and now I wear two hearing aids and regret the nights that I called
myself having a great time. Wish I could do it again and do it better!
(broke=not working, retired=not working, retired=broke)

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 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 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

--

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."

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?

I have had great luck with a Heathkit signal generator into a key.

BUT, if you want to get really fancy, check out the ARRL mobile manual,
which has a really neat project transceiver. The transmitter section is
based on a 1J6G and has an optional VFO.

The TAB Book on ham radio projects also had a really neat one-tube transmitter
that was hot chassis and built around the sweep tube. No VFO, though.

Actually, plenty of VFOs out there put out enough power to be used as
QRP rigs standalone.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."