Balcony antennas made from mobile antennas (Hamsticks)


Preamble

Depending on your balcony or installation site, you will have certain limitations.
For example the next story or limited space in general.
The following report heavily depends on my local conditions.
I live in 16th floor of a house with 16 floors and got the approval for temporary installations.
That means that nothing may be mounted to the balcony rail and the fact that there
can be sudden and heavy winds at the 16th floor is a challenge on itīs own.


My part list

Mounting options


Depending on your local conditions, you may be limited to only one option.
The first thing I did was setting up a vertical with the balcony rail as the counterpoise.
This picked up a large amount of noise from the electronics in the house.
So I looked for something that does not depend on the balcony rail.
This approach may also be positive with regards to TVI, BCI or other kinds of influences.


Option 1, the V-Mount:

In option 1, two hamsticks are mounted in a "V-Dipole" position by means of the WIMO V-Mount.
The 45 degree angle should provide a maximum decoupling from the reinforced concrete structures of the house.
This solution does not pick up so much noise, but is very difficult to tune.
There is no deep dip and a tuner is required.
The positive point is that no parts of the antenna stick out.
In case of space limitations to the top, a horizontal mount may be an alternative.
For 6m, only the telescopes can be used and the tuning is much easier.

Wiring:

The WIMO R1 V-mounting center part has a PL output, here the choke balun is connected.
The other end of the choke balun is connected to the 
coax input of the MFJ-993BRT remote tuner.

Tuning:

Tuning the antennas can be a challenge because of nearby reinforced concrete structures.
For example, the 20m hamsticks:
After the initial tuning based on the manual, the lowest SWR could be found somewhere around 13 MHz.
Without an antenna analyzer (like the the RigExpert AA-54), I would have been lost.
However, after shortening the antenna whips, I could find a match around 14 MHz.
In my case, the whip needed to be moved in 10 cm, but this moved the whip into
the loading coil.
Moving the lower end of the whip near or into the coil will cause high temperatures in the coil and may cause damage.
Cut the whips to make sure the coil is not influenced by the whip.

Dimensions:

Length of the whips or telescopes.

Band
Whip Length *
Telescope Lenght **
40m107 cm
-
30m103,5 cm
-
20m100 cm
-
17m-
full
15m
-
122 cm
12m
-
73 cm
10m
-
60 cm

* 40, 30 or 20m hamstick with original whip.
** 12m hamstick with 3/8 telescope instead of whip.


Option 2, the vertical dipole:

In option 2, two hamsticks are mounted in a 90 degree angle by means of truck mirror mounts, so that one is vertical and the other one is horizontal.
This is basically a vertical antenna with an elevated radial.
This antenna also performs good, but it picks up more noise than the V-Mount.
It is much easier to tune than option 1 because it has a deeper dip.
A tuner should not be required.

Wiring:

The mirror mounts have a PL output, I have connected a banana plug to each of them.
The other side of the the wires is connected to the wire post inputs of 
the MFJ-993BRT remote tuner.
A
choke balun is connected to the tuner output that points to the transmitter.

Another option is to solder the wires to a PL socket, followed by a choke balun and 5m Aircell 7 coax.
The end of the coax is connected to the coax input of the tuner.
This allows moving the antenna mast up, so that the antenna is less affected by the house.

Tuning:

Tuning of the antennas in 90 degree mount is easier than the V-Mount, however an Antenna Analyzer is still recommended.

Using multiple bands with one pair of hamsticks in combination with telescopes and loading coils:


Hamsticks for 15m and lower bands have lossy loading coils, so I have been looking for an option to optimize this.
I found a way to combine hamsticks,  telescopic antennas and loading coils.
After doing the math, I found that a 12m hamstick would be a good staring point, it is only helical wound and has no lossy loading coil.
The
telescopic antenna and the MFJ-67 loading coils are  " - 24 threaded and can be easily combined.

I have been able to tune it on 20, 30 and 40m by moving alligator clip around at the coil.
Changing the band just by changing the alligator clip is a very welcome option.

Later I have chosen not to use the MFJ-67 loading coil and 12m hamstick in combination with the full telescope
as the horizontal part of the antenna for mechanical reasons.



Dimensions for mounting the antenna on top of the telescopic mast with maximum lenght.


Band
Coil windings
Vertical part
Horizontal partComment
40m
V: 28
Full Telescope
40m hamstick with normal whip
30m
V: 10
Full Telescope30m hamstick with normal whip
20m
V: 4
Full Telescope20m hamstick with normal whip
17m
V: 4Full Telescope
12m hamstick with maximal whip
15m
Coil not needed12m hamstick with maximal whip12m hamstick with maximal whip
15m
Coil not needed
140 cm
12m hamstick with maximal whip
12m
Coil not needed61 cm
12m hamstick with maximal whip
10m
Coil not needed12m hamstick without whip12m hamstick with maximal whip
6m
Coil not neededTelescope 140cm
Telescope 140cm



Dimensions for mounting the antenna on top of the telescopic mast with minimum lenght.

Band
Coil windings
Vertical part
Horizontal partComment
60m
V: 14 H: 23
40m hamstick with full telescope40m hamstick with normal whip

60m
V: all H: all
40m hamstick with normal whip 40m hamstick with normal whip
40m
V: 28  H: 28
Full telescope
12m hamstick with maximal whip
40m
V: 26
12m hamstick with maximal whip 40m hamstick

40m
V: 18
Full telescope 40m hamstick
30m
V: 11  H: 17
Full telescope 12m hamstick with maximal whipConnection 1/4 turn to the right
30m
V: 14
Full telescope30m hamstick
20m
V: 4  H: 7
Full telescope 12m hamstick with maximal whip
20m
V: 10
12m hamstick with maximal whip 20m hamstick
20m
V: 4/5 (SSB/CW)
Full telescope 20m hamstick
17m
Coil not needed
Full telescope12m hamstick with maximal whip
15m
Coil not needed80 cm
12m hamstick with maximal whip
15m
Coil not needed 12m hamstick with maximal whip 12m hamstick without whip
12m
Coil not needed38 cm
12m hamstick with maximal whip
10m
Coil not needed12m hamstick without whip12m hamstick with maximal whip
6m
Coil not neededTelescope only
Telescope only

This can be used for windy days. This option allows usage of the coil at the horizontal part of the antenna.



Combinations for extreme windy days

Two 12m antennas with maxinal whip in 90 degree mount.

Band
Coil windings
40m 33 windings
30m 16 windings
20m 7 windings
17m 2 windings


Two 12m Antenna with shortest possible telescope in 90 degree mount.

Band
Coil windings
30m 22 windings
20m 11 windings
17m 6 windings
15m 4 windings (CW)
15m 3 windings (SSB)





A shorter variant to be used in case of obstackles, for example a balcony above:




Band
Coil windings
30m

20m
15
17m
9
15m
6
12m

10m





Conclusion:

There should always be an option to use a mobile antenna on the balcony.
However, what needs to be done heavily depends on the local situation.
Experimenting and optimization are a a part of our hobby.
Do not expect that all works right away.