On1mws 'one thing led to another'
scratch-build homebrew HAM station.
In
march 2025 I had a homebrew SSB QSO with PA1LEG. John asked me during
the QSO "What I realy don't understand Danny, is why don't you just buy
new or secondhand stuff? There are so many good qaulity receivers and
tranceivers out there" The answer for me is that after you struggle to make it
work you get a sence of achievement that you can't get from gear that
you bought. The station is no match for a commercial station, but the journey has been entertaining so far. R&D as amusement.
On
the picture my three children, Mirte, Warre, and Seppe in the summer of 2016.
So choosing letters for my callsign was very easy.
From
Left to right; the CW QRP transceiver; power supply, SSB QRP transceiver, and finally a 70W linear. There
is no commercial
gear in the shack. The
homebrew effort was done in 'bursts' Sometimes I was homebrewing for
months in a row in my
spare
time. But when there was no time or enthusiasm, months went by without
any
effort
at all.
From left to right; A all-mode general coverage receiver (0-30MHZ), a
smaller but capable all-mode shortwave receiver (1,7-18MHZ) and finaly a
40 M band regenerative receiver.
Most of the projects were scrapped and rebuild, from the bottom
up, at least once. So all the projects took years to complete. The walls of my shack were painted green to
remain calm.
Since
my teen years, I loved to build audio amplifiers. Up to this day, these
circuits reward my efforts daily. I am, by the way, not an electronics
engineer. At one point, however, this hobby became too easy and I lost interest
The
new homebrew hobby started in January 2008 with short wave reception
experiments.The picture above is the test receiver setup in my garden
shed in the very beginning. Soon I was receiving world broadcasters.
The first radio amateurs were received in August 2008. With a long
wire, as I had no idea what a 50 Ohm antenna was.
I wasn’t
even sure what Ham band I was receiving, due to a lack of a frequency
counter. My first homebrew oscillator had no frequency stabilisation.
Anno 2008 I did not realise that a oscillator needs to be stable. So
that day I was very busy
retuning. Needless to say that the day after, I could hardly repeat the
listening experiment. Numerous searches on the internet for additional
information
tempted me to
improve my short-wave radio, over and over again. Until I ended up with
an all-mode
scratch-build general coverage receiver. The pictures below are the endresult. It had turned 2022 until I was satisfied.
A very hard nut to crack is building a frequency-stable
oscillator without a modern DDS kit. During an internet search for information,
in 2010, I stumbled on 'Chapter 10' from the online book 'From Crystal set to
sideband' written by Frank W Harris K0IYE. A few days later I started to
realize that ‘if there is a chapter 10 there must be more?' The other chapters
I found made me discover that it is possible to scratch-build a transmitter.
Then I thought 'Hey I could do that too' In '13 I got my license and got
started. Eventually, all of my next circuits differed much from Frank's
designs. Early
2014 I mailed Frank with some photos and up to this day we keep regular contact. Via...
email :) our homebrew stations can't reatch eatch other.
A QRP CW transceiver was build from 2013 to 2017.
For many years it was a DC receiver/transmitter with
sideband cancelation. However, later on the transceiver was changed in a
superhet design based on the magnificent BITX. The superhet has a much better
S/N ratio in my opinion.
Being very
interested in
stabelizing oscillator without modren stuff, like DDS kits, I
figured
at one point to do this with the readout of a frequency counter. During
2021 I set about to try it with PA2OHH's SUSI binary LED frequency counter.
Eventualy I had a lot of fun and succes. As this stabilizer has no name
i named it the SUSI stabilizer. My station was kinda finnisched by 2021, but
it felt like a shame to do nothing with the stabilizer circuit.
Over time all the oscillators and stabilizers of my rigs were swapped
for a SUSI circuit. Both rigs also features a homebrew tuning capacitor. Something I always wanted to try.
The all-band SSB
transceiver/linear project started in 2017. By the summer of 2020 the
project got finnisched (with a little help of the Corona lockdowns)
Many SSB QSOs have already been made on 40M and 20M. The very first QSO
with a scratch build SSB rig in august '20 with Stan, DF8WZ was very
satisfying. I could hardly believe I pulled it off.
The SSB rig is a good
example of my usual construction method. All circuit blocks soldered in
seperate tin boxes that I buy from Amazon. They are all bolted to a
aliminium ground plate. So lead inductance is minimised. All circuits
are therfore schielded from one other. Also, I do love wood. Many of
these boxes are not pure aluminium and
can be directely soldered. My prefered soldering style is 'ugly'.
Another advantage is that every circuit can be accesed very fast for
mods or troubleshooting.
Simultaneous
a linear was build. At first I tried to build a 50W linear with multiple
IRF510s, pfff. Probably it can be done for one band (but when you try it multi
band a lot of explosions occur) Eventually a very expensive RF MOSFET (MRF510) was
bought to do the job.
Schematic linear with MRF150.
However,
my favorite receiver is the one below. Well, it was my favorite until I
built the regenerative receiver in 2025. It's a BITX20A modified to
receive CW, SSB, and AM that goes along on hollidays. Originaly a 40M band receiver. It was rebuild as a multi band receiver after I build a new type of stabilizer in 2023.
The
antenna I use is a homebrew loop. The diameter is
1,6M and tuning is done remotely with a DC motor. The butterfly high
voltage
capacitor is made with the plans of ON4CEQ as a guideline. The loop was
chosen
to stay on good terms with the neighbor's which is more important to me
than my
hobby. In case you ever dought that such a small antenna can be any
good. Below the results on RBN after calling CQ on 40/30 and 20M, for
10 minutes, with 5 watt.
Another
homebrew project was a FM/Airband receiver. In 2010 I saw a “Make” article on
how to adjust a simple FM radio to receive the Airband. I was more ambitious
and salvaged ICs from cheap FM radios from our local scrap yard and tried to
build completely from scratch. That did not go well and could not make it work.
Only by 2014, after I used tin cans for the RF circuitry the radio worked. Tin
cans rule!
In
hindsight, I made a lot of detours with all sorts of circuits and components.
My conclusion is that the BITX schematic is relatively easy to build for the average
homebrewer. You can base nearly every type of rig on it, and it is simply unbeatable.
Since 2008, when I started listening to the short wave bands a lot
has changed. Only one MW station left… No more BBC world service…No
more world broadcasters… only the lower Ham band remain active. When
I listen in most of these guys are well into retirement. Soon the
Ham bands will be quiet to , I guess…
But I had a lot of fun, I might try vacuum tube stuff before the
bands become quiet... Because I don't have a clue how to build a tube
station I just might relive the joy of homebrewing. In fact, I started
a quest for an all tube regenerative shortwave receiver. So far this
turned out to be very difficult. Slight elektrocutions and smoke are
the only concrete results so far. My respect for the HAMs in the 1920s
and 1930s has grown!
Due to the setbacks with the tube regenerative radio I figured to build
a solid state regenerative receiver as an educational project in 2025. It was
dificult build but it turned out fine! The receiver is based on one of
N1TEVs designs. The radio works well for such a simple circuit.
Sensitivity is amazing, however, selectivity is not to modren
standards. I could add audio filters for CW and SSB which would pull
the radio up to the level of a good DC receiver but I am going to leave
it as it is. And experience the full 1920s experience.
The radio stays long enough
on track to actually make QSOs on the 40M band with relative ease!
Since I've got this radio I am understanding why guys like PA2OHH like
simple stuff so much. It is kinda fun to tell your 'QSO partner', wich
usally has a top range rig, that you are listening to him with two
transistors. It is like showing up at an supercar meeting in a Citroen 2 chevaux! It is now my most used radio.
Below are 2 circuits to stabilize Oscillators but they are replaced by
the SUSI circuit as I find it superior to a Huff and Puff and more fun
than a PLL....
1)The original CW transceiver used a PLL
circuit which is controlled
with a ceramic resonator and it does not use a microprocessor. It was so
simple that the circuit doesn't even feature a counter at all to
controll the PLL...
Simple PLL with ceramic resonator .
2-The original SSB oscillator was an all-band H & P oscillator. Below
a link to a PDF file describing my quest to build a oscillator
stabilized over a wide range of frequencies stabilized with a H&P.
First part is how (I think) an H&P actually does the job, second
part is an account of the experiments. Along the way I discovered what works and what does not work and a method to lock a H&P on any frequency. At the end, the actual multi band H&P oscillator, for the transceiver, is presented. Its is a pretty long PDF...
On1mws. [email protected]
