What's on YOUR Bench?
collection of personal projects in-progress by CWTD
listeners ... Grounding system, DC power distribution box,
boat anchor refurbishing, keyer project, 75m Small
Transmitting Loop, NPOTA Adventures, burglar alarm,
Bluetooth control, mic preamp/EQ, ... and more!
See what your fellow experimenters are working on ..
and who knows, maybe you'll get some ideas for a project
that you've been thinking of!
1) I have a set
of K8IQY Designer Dream Boards (http://www.4sqrp.com/dreamboards.php),
that I have had let sit idle for too long. So I started to populate
them with the S7C "Simple Superhet" from EMRFD (http://www.arrl.org/shop/Experimental-Methods-in-RF-Design)
pages 12-16. First step was to recreate the Rick Campbell
basic R1 direct conversion receiver circuitry (chapter 8 of EMRFD)
then I created the LO and Front end filter, and now I am adding the
active mixer. I plan to also test out a dual MOSFET mixer, from the
"Clackamas" a W1FB-inspired superhet minimal component design (
NT7S's entry to 2010 FDIM QRP Challenge). So a bit of a
research project to get back to the basics with analog design
See the EMRFD Yahoo Group (https://groups.yahoo.com/neo/groups/emrfd),
and in the files section there's a file called the
2) 9850 DDS
Daughtercard -- I bought a kit from the past at a hamfest last
year - a DDS VFO AD9850, from NJQRP. It had never been opened from
the brown bubble wrapped envelope. I finally built it and so now I
am going to try interface it to my Arduino. It will then make its
way to becoming part of an Antenna SWR sweeper circuit from ARRL's
"Ham Radio for Arduino" projects book. With some modifications it
will serve as a signal source for testing.
1. QRP Labs shack
clock kit (built) that needs boxing up.
2. Kanga Acorn SDR II kit
3. Rebuilt G0FAH/ZS6BKW that needs to be hoisted into the trees.
4. Partially built 10-15-20m portable top-loaded vertical (modified
from old Ham Radio magazine article)
5. Swan 350 to troubleshoot/re-cap.
6. 30m TVI issue with DirecTV box in upstairs bedroom (close to
7. 40m Chinese Pixie kit
1) One of my projects I call a keyer keyer. I
uploaded a PDF to the files section describing it ...
There are plenty of keyers available and using
an Arduino sort of processor is nothing new. My design has a few
interesting aspects perhaps not often found in other keyer
implementations. My primary need was for a keyer that had both
dit and dah paddle outputs so it could be used with something
that was designed only to be used with paddle input. In
particular I wanted to use it with a Remoterig control unit that
I use with a TS-480. The Remoterig box takes only paddle input
to send over an internet connection to a similar Remoterig box
where the body of the radio body is located. So my keyer is
designed to key a keyer, hence the name “Keyer keyer”.
2) I am now the proud owner of an Elad FDM-DUO
transceiver as recently reviewed in QST and a Hardrock 50 amplifier
which I plan to use camping. Been playing around with PSK31, a watt
or two works well when band conditions are decent, a bit more power
will be available when they are not. ...
1) I have a box for CWTD projects, waiting for the
mother board to be release... no hurry I have plenty to do.
2) Have several Si5351 boards, I am currently
building some kits from QRPLABs... I have finished and it is
working a WSPR transmitter. took me a while to set up and don't ask
me how to do it again... I will have to do a lot of reviewing of the
3) Things I hope to get to is learn more about
Programming the and using the Arduino products. One can get by
without knowing how to program, so far that is what I have done.
4) It looks like SDR is going to be the wave of
the future, not sure where sure to jump in at.
Runner: This one I just saw posted is definitely on my list ...
possible refurbishment of an elderly Standard C 6500 receiver
[I'm seeking X-Ray board images and/or service manual to assist:
I found the English schematic in the German manual online]
Trying to figure
out the best plan for me to get antenna egress from the shack
through gypsum board, sheathing & Hardie Plank
Bluetooth A2DP for shack use at workbench, away from actual
beefing up of Harbor Freight cheap burglar alarm to do what I
want, when I want (not really ham, but certainly the "killer
app" that gets me into programming microcontroller boards)
for ham station, allowing use of one mic/headset for all rigs,
balancing audio in and out
tasks for ancient technology (refurb of Hallicrafter S-85; dial
restring for Drake 2-B; refurb Collins R-388; refurb National
Grounding -- Using a previous episode of CWTD as a reference,
and N2CX as my usual Elmer, I installed 3/4" copper pipe along my
operating bench, with each transceiver, tuner and amplifier strapped
to it using copper braid. The copper pipe travels out through the
basement wall to a 10-foot ground rod, which in turn has numerous
ground radial wires connected and buried just beneath the surface. I
found that this greatly improved my antenna tuning ability, and gave
me the confidence to start using higher RF transmit power levels
this winter/spring. I've been meaning to do this for many years and
found that it was well worth the effort!
2) Mic Preamp/EQ -- I have a nice Astatic microphone that I
intend on using with my boat anchor rigs, but it doesn't have the
preamp in the base as is common for this class of "D-104" mics. And
because of this, the frequency response is lacking bass and is hard
to adjust for consistent quality use in both DX and ragchew
conditions. After doing a little research, and recalling that
featured a nifty preamp in one of his many and invaluable YouTube
installments, I expanded that straightforward design to give me some
nice control of the lows and highs, in addition to overall level
control. (As Alan explains so well, it's all about impedance
matching and placing an adjustable filter in between the buffer and
gain stages.) So add a visual indicator of bass and treble adjust,
and a little AGC from a
WB6VMI article in QST some years back ...
and voila, I will (hopefully) have a pretty nifty preamp for using
and customizing just about any mic here in the shack! If the
prototyping proves successful, I think a pcb would be in order,
fitting into a black die-cast enclosure the same size as our
Midnight SNA project.
the pieces/parts for the GPSDO, waiting for the final installment.
got the SNA constructed, and now need to learn how to use it, along
with using the additional firmware for the GPS Display Terminal.
Plus need to build the return loss bridge for the SNA.
Item I’d be interested in from CWTD is a discussion on a
distribution amplifier scheme and considerations for the GPSDO. I
have several instruments that can be driven from a standard 10 MHz
source, and I’d like to provide a buffered signal for up to 5
units. (currently HP 5335a frequency counter, 8656b signal
generator, a buffered output for experimentation plus future
Here's some references on Distribution Amps Pat ...
10 MHz Video Distribution Amplifier (DL8JT)
OH2NLT Distribution Amp
really want a shot at the sw30+
1) Have you ever
considered completing your PSOC Controller project, perhaps using an
RTL-SDR dongle as the front end? Maybe you could provide the
pre-programmed PSoC and listners could attach the controls and
the PSOC project and taking it the next step would be a good
project. AD7JT and I just got one of the latest versions of the
PSOC experimenter’s board, so perhaps we could use that as the
basis for going forward …
If we are reading the specs right, the 5LP could replace the
entire MSNA platform with a single chip and adding an Si5351A
from Adafruit (https://www.adafruit.com/product/2045
) could extend the frequency range to 160 MHz (YTBP = Yet To Be
Proved) (I ordered a couple). One question though is how long
will the Cypress prototyping kit be available; it is priced at
or below the cost of the PSoC chip alone (I ordered a couple).
I'm actually getting a little excited about
this. The prototyping "kit" looks perfect to handle the 100-pin
PSoC chip (we could cut off the programming section and sell it
separately, it looks to be usable as a USB to I2C and/or UART
adaptor). I also like their way to implement a USB type A
connector. The device comes with a 32-bit ARM M3 implementation
which includes 256 KB of program memory and some peripherals
plus a collection of analog and digital cells you can configure
with their IDE. The IDE is free including the C compiler. The
only negative I can see is Cypress only uses UPS for shipping
and the shipping cost is nearly the same as the kit cost (that's
why I ordered 2 kits).
And there’s a
PSOC-based SDR project that I found …
other radio-related PSOC project references?
1) Top of the
list is the Micro908B. I had it working three years ago with the
uM-FPU math co-processor and a new vector-based computation
2) I've developed
a new concept for RF ground and a new device to implement it for QRP
3) I've also
designed a tri-band 6m/2m/70 cm antenna.
4) I put the SDR-CUBE into
a different case and am still trying to sort out the connections of
the DB25 connector to the softrock transceiver and the new band
(More coming! ... We've only just