VE7SL via rec.radio.amateur.moderated Admin
2016-05-24 16:27:36 UTC
VE7SL - Steve - Amateur Radio Blog
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630m Transverter Project
Posted: 23 May 2016 09:50 AM PDT
http://ve7sl.blogspot.com/2016/05/630m-transverter-project.html
I've ordered parts from Digikey for the summer workbench project, a 630m
transverter. With the nice 630m WSPR signals received here from Roger
(VK4YB) this spring, I think it might be possible for us to work each
other using JT9, if the path continues to improve over the next few
seasons. On more than one night, Roger's signal was at JT9 QSO levels and
had we been on a schedule, a QSO may have happened. Roger's signal was
peaking late in his evening, which for me will require making schedules in
the wee hours of the morning.
I've been wanting to build another SMD project for some time since making
a little SMK-1 40m transceiver several years ago. This was a very
inexpensive kit put out by the NorCal QRP Club as a way of introducing SMD
construction techniques to beginners. I found working with the 1206 sized
parts (basically the largest ones commonly available) to be fairly
laborious and would only solder a few parts at a time before setting it
aside for the next day. I think my frustration had a lot to do with my
positioning and soldering methods and I'm anxious to try doing it with a
more refined technique. As I recall, there were 72 SMD components on the
board and it took me a couple of weeks to finish it all.
My SMK-1 40m SMD transceiverAlthough I was dreading the initial
smoke-test, since troubleshooting would likely be a challenge, the
transceiver fired-up with no problems and I made dozens and dozens of
contacts with it. My QRP logbook indicates 27 states were worked with the
little 350mw transceiver. It looks like this kit may still be available
from Pacific Antenna but I have not confirmed if that's the case.
The parts I have ordered are also 1206 sized but the older I get, the
smaller these things seem to look. The transverter will be based partially
on the popular G3XBM circuit but will eliminate the PA. Instead, I'll just
use a few volts of the transverted squarewave signal and a doubler, so
that I can feed the signal directly into my present homebrew amplifier
which uses two switching FET modules into a power combiner. Hopefully this
system will let me run several of the non-linear digital modes such as
WSPR, JT9, JT65 etc.
My 630m PA
As a way of getting back into the SMD-soldering groove, I have ordered and
now received, an "SMD Practice Kit" from E-Bay ... a real bargain at $1.78!
courtesy: Tradeworld2105
Although there are many similar practice kits being offered on E-Bay, this
was the only one I found that had two IC's to practice with ... all of the
others had just one. Since the transverter's doubler circuit has an IC
chip, a couple of practice opportunities will be helpful. My only hope is
that I don't run out of SMD steam with the practice board before getting
down to the actual transverter board.
As soon as the parts arrive from Digikey, I'll start designing the
transverter's PCB ... but with all of the usual distractions of summer, as
well as trying to maintain vigilance on the magic band once again, my
summer project may not progress as quickly as I hope.
All of this assumes that my old eyeballs hold out as well.
///////////////////////////////////////////
630m Transverter Project
Posted: 23 May 2016 09:50 AM PDT
http://ve7sl.blogspot.com/2016/05/630m-transverter-project.html
I've ordered parts from Digikey for the summer workbench project, a 630m
transverter. With the nice 630m WSPR signals received here from Roger
(VK4YB) this spring, I think it might be possible for us to work each
other using JT9, if the path continues to improve over the next few
seasons. On more than one night, Roger's signal was at JT9 QSO levels and
had we been on a schedule, a QSO may have happened. Roger's signal was
peaking late in his evening, which for me will require making schedules in
the wee hours of the morning.
I've been wanting to build another SMD project for some time since making
a little SMK-1 40m transceiver several years ago. This was a very
inexpensive kit put out by the NorCal QRP Club as a way of introducing SMD
construction techniques to beginners. I found working with the 1206 sized
parts (basically the largest ones commonly available) to be fairly
laborious and would only solder a few parts at a time before setting it
aside for the next day. I think my frustration had a lot to do with my
positioning and soldering methods and I'm anxious to try doing it with a
more refined technique. As I recall, there were 72 SMD components on the
board and it took me a couple of weeks to finish it all.
My SMK-1 40m SMD transceiverAlthough I was dreading the initial
smoke-test, since troubleshooting would likely be a challenge, the
transceiver fired-up with no problems and I made dozens and dozens of
contacts with it. My QRP logbook indicates 27 states were worked with the
little 350mw transceiver. It looks like this kit may still be available
from Pacific Antenna but I have not confirmed if that's the case.
The parts I have ordered are also 1206 sized but the older I get, the
smaller these things seem to look. The transverter will be based partially
on the popular G3XBM circuit but will eliminate the PA. Instead, I'll just
use a few volts of the transverted squarewave signal and a doubler, so
that I can feed the signal directly into my present homebrew amplifier
which uses two switching FET modules into a power combiner. Hopefully this
system will let me run several of the non-linear digital modes such as
WSPR, JT9, JT65 etc.
My 630m PA
As a way of getting back into the SMD-soldering groove, I have ordered and
now received, an "SMD Practice Kit" from E-Bay ... a real bargain at $1.78!
courtesy: Tradeworld2105
Although there are many similar practice kits being offered on E-Bay, this
was the only one I found that had two IC's to practice with ... all of the
others had just one. Since the transverter's doubler circuit has an IC
chip, a couple of practice opportunities will be helpful. My only hope is
that I don't run out of SMD steam with the practice board before getting
down to the actual transverter board.
As soon as the parts arrive from Digikey, I'll start designing the
transverter's PCB ... but with all of the usual distractions of summer, as
well as trying to maintain vigilance on the magic band once again, my
summer project may not progress as quickly as I hope.
All of this assumes that my old eyeballs hold out as well.