Category Archives: hardware
so far for the bike

Note the Fatique crack.
I am heading off with a car now.

my UnUn for vertical antennas

Yesterday during a few drinks after our regular CW operators meeting in Vienna I told a friend how I wind Baluns (yes I know this one is an UnUn)
So here is a picture first:


I wind this by rolling some wire usually with 4 windings per coil over my Hand. I then fix that Wire ring with insulation tape. depending on how
long it should last I add plugs.

I use this UnUn usually together with a 6,5 or 10 m antenna wire and some Antennatuner as near as posible to the UnUn.


Usually 1:9 transmission is good enough to get good reports even with QRP Power on the 80m band.

The UnUn you see in the first picture also has a connection for 1:4 and 1:16 transmission, as shown in the next circuit diagram:


I am using this UnUn on almost all of my mobile operations. and it seems to have a good performance, however I would not try to
place it on a metal plate.

yet another key

This time it is from the Ukraine, I got it on a flea market in Altlengbach last weekend.


I bought it because of that really HUGE antisparking filter box below that key, and really,
as I thought. it is exactly 70mm x 120 mm which is happily the size of for example a small MA12

It is as far as I have googled a Soviet TKF Key manufactured between 1988 and 1992 by
Cherkassy Telegraph Equitment. I wonder what they plan to key with that. But the key has a
good feeling and will surly key a MA12 as mentioned above.

Features for a Sonic Screwdriver

In this post I will collect ideas what we can build into a sonic
screwdriver today, to make it a really useful tool.

  • TV-B-Gone the famous TV on off switch is easy to integrate, and makes a good effect.
  • A mechanical screwdriver (nothing special)
  • A laser pointer
  • A flashlight
  • A pen
  • A USB storge
  • A small radio scanner
  • A voltagetester
  • Some capacitive buttons on the side to control screwdriver functions
  • morse code controlled embedded shell
  • a sound amplifier that you can use for various things even for finding telephone cables
  • motion sensors and blinking leds
  • screwdriver OS
  • mp3/ogg player
  • a recording and playback device
  • speed indicator
  • electronic compass
  • GPS sensor with cw output
  • infrared temperature sensor
  • crypto infrastructure (signing and encryption of data)
  • optical mouse pointer
  • a camera
  • some sort of status display or laser beamer
  • a wire cutter
  • add on interfaces….

so far, I’m sure i will get more ideas soon….

Debian Architectire Change i386 to AMD64

Last week I upgraded the Debian System on my Laptop from i386 to AMD64. Some people
may say: “this never works” but from a technical point of view it should not be a problem in a well
packaged linux environment, so I started to try it out.

Basically you have to exchange every binary on the system with the 64bit version. which means
that you have to reinstall every package on the system. All of the config files user data and
some databases in /var should stay as they are.

My first Problem was the Kernel. My original Kernel that I used was 32 bit only. The Debian AMD64
Kernel freezes during Hardware detection. I think there is some problem with the Firmware Loader
infrastructure and 64bit. ifconfig does not return when the firmware cant be loaded. (note to
myself: report that to the kernel people) The compiler suite could only produce 32 bit binarys
and therefore 32 bit kernels by default. I think there is a way to let it produce 64 Bit binarys
but I simply used the Kernel from a grml life system.

After I could boot a 64bit system I was able to debootstrap a new Installation to the harddisk,
download a kernel source and compile a fresh 64 bit kernel.

I then installed the same packages on the bootstrapped system as there are on the original one.
therefore I fetched a package list with aptitude, stripped out all automatic installed packages
and did an apt-get install on the bootstrapped 64bit system. Sorry that I cant write down every
command I used for this but I didn’t make to many notes, but you are surely an awakened head so
you may figure out the right shell commands for yourself.

I planned to use /etc and /home as well as the mountpoints in /media as they are. /var needs to be
migrated for the LDAP Database Log, Cups and Mysql. /usr/src and /usr/local schould be delivered
from the i386 System. All the other Files should come from the new
system. In /etc the /etc/ should come from the new system, the passwd and group should
come from the old one, especially the passwd is a bit tricky.

Because some of the users are installed dynamically, userids change from the old system to the new
one. A good solution would have been to copy the passwd directly after bootstapping, but i missed that
point, so I had to adopt all the userids of the existing (amd64) system users to the UIDs on my old system.
I did that with “find -uid” by finding all filed owned by all old uids, giving them a temorary new uid. I then
mapped all temporary uids to the old (i386) passwd database. With that two step process I ensured that I do
not switch an existing uid to another one I have to chane later.

I later discovered that the alternatives system is also messed up a bit at the moment, I have to fix that,
but it does not harm operations at the moment.

After copying all the files together all I had to do was to make the new system bootable, create a new initrd,
recompile any customized packages (like wmii-hg) reboot, and experience the really fast amd64 performance.

The Vertical Dipole

I plan for a while to try out another vertical concept, since I figured out,
that my 6.5 Meter Vertikal having some trouble coming to its full performance
because my Truck roof is definately not enough for Bands below 17 Meters.

The Question of the right radials on a multiband vertical is a good question,
it should be $frac{1}{4} lambda$ most of the designs simply add verticals
for each band to the design. You could also use an earth tuner to match your
antenna to your vehicle, note to me: schedule some experiments with earth tuners
on the sidecar radio outfit.

An other way is to look how dipoles are tuned and adapt it to a groundplane
antenna. So you can use some radials with exactly the same length as
the antenna, and than feed it with a balancer unit. I did it with my antenna,
and it worked almost well, almost because the 1:1 voltage Balun I used maybe
was not the best choice, but it worked anyway. The main problem I had with the
groundplane design where the radials. 6.5 Meter to every direction means lots
of extra space around my truck, I can’t reduce length with couls because
the coilsize debends on the frequency. And the only Idea I had for the
mechanic of the radials was the use of tensioned wire.

So I need a design which is playing without radials! A vertical
Dipole for example. With a feed in the middle. There is a vertical
$frac{1}{2} lambda$ monoband design available in Rothammels
Antenna book which feeds the antenna with koax cable right through the bottom
dipole element. The design is basically the same as with a normal dipole exept
that it is vertical and the feed is not coming from the side. So should be
capeable of multiband work by adding some sort of Balun some sort of
Tuning to the feed point.

This raises to questions: How to tune, and how to do the Mechanics.
The Mechanics question was solved by ordering a Havy Duty 10 M GFK
Mast at the mast costs about 70 € but alows rapid
development of different antenna designs with much cheaper materials
than the aluminium tubing, I used since then. I can now use old RG213
Coax cable or speaker cable as antenna element for example. I also ordered
the portable 10m version from dx-wire which soon will improve
my portable antenna situation soon.

The next problem to solve was the matching problem. I want something
which I can control from the shack. It is possible to place a symetric
autotuner at the feed point i decided against to make the feedpoint
simpler and lighter. If you match in the schack you have higher losses
on the Koax cable. The choice which death to die was finally made by the
large collection of available Unsymetric autotuners, and the time i had available.
I can still add some extra antenna tuning in the next project, when I know how the
whole thing plays. Ham Radio is still an experimental Service, so what.

I build an antenna with two 3,65 m long elements. This length should work from
10-15 Meters. it is a little bit to short for 17-20 and 20 Meters. At 40 meters
there is still a little less than $frac{1}{4}lambda$ left, but a single element
is to short. On 80 Meters such an antenna will be some sort of wet towel, but still
better (longer) than my other 80m solutions.


I decided to use RG213 cable for the upper element. The schielding radiates the
waves the inner conductor is left unconnected. The case of the Feed is made of
waste pipe and sealed cable feedthroughs.


The lower antenna element is a bit more tricky, I stripped 3.65 m copper schielding
tube over the ecoflex feed cable and isolated it with shrinking tube:


The next part the (first) balun. A 1:1 Voltage balun. 8 Windings per Coil
50mm waste Pipe.


The whole antenna setup:


Now to the Problems did start:

I could match the Antenna only with a Manual MFJ T-Match not with the Autotuner I want to use.

  • With 1:1 Voltage Balun Fail 40 Meter
  • With 1:2 Voltage Balun Fail 15 and 80 Meter some bands not optimal
  • With 1:5 Voltage Balun Fail on 80 Meter and some bands not optimal

Then I tried a Current Balun:

From 10-40 Meter best match, 80 Meter is not working. So I tried out to add the Coil of the manual
L-Matchbox which I build 1.5 years ago. The SWR indicator is moving, so I need more inductivity.
I killed an old CB-SWR Meter (I have lots of them) and found an old Ferrit ring in my shack, and
made a coil. I build in a Switch that plugs in the 80m inductivity betwen the inner conductor from
the Matchbox and the inner conductor to the antenna.
With that coil and the Matchbox SWR was almost good, so I added more windings and more and more until
I had 2 ferrit rings full of cable and still the manual Matchbox in the system. I did’t know the $mu_r$
of the ferrit rings but from my calculations I expected something about 90 windings, to much for that
ring. Which after several
days of experimenting, leads to a more radical solution:




Because ham radio is still experimental I did not add any shielding to that gigantic coil. 80 windings
on 11cm waste tube, It seems to work, and it is disabled on the higher bands. I surely will soon find
out how bad/good or however this setup performs. 😉

meanwhile, i was thinking about single cylindered engines

The idea was to get around a frame mod. this time, but it was
depressing, the ural frame i have left is to small for the E75.

I think I need another frame.

gallery{Gallery here…}

Speaky riser board

I soldered the speaky raiser board for the 9 Band modules as I mentioned during an earlier post.


The following set of pictures may give you an Idea how I made it, and how it fits into the Tranceiver.


Speaky 9 Band Extension

Yesterday I did some work on my speaky. I soldered together all the remaining Band modules
and put them on a raiser board which fits into the Box.


Seriously I do not know how this will work on the HF side, mechaninally this is not a
problem because the Box is much bigger than needed due to the frequency counter.

You need to do some cleanups to bring all the modules in.


The plug for the freq dialer must be grinded down a little bit. The whole Mainboard
must go 4 mm lower what you can do by grinding $45^circ$ angles into the metal cubes
what enables you to leave the spacers away.

Test will come in a few weeks.

Speaky Progress….

The Speaky board is soldered and ready for testing.


Next Page