Let's Revisit the 2 Meter Two Element VHF Yagi by Albert ZS2U

Albert (Al) Akers ZS2U

 

The article about this small and compact "Sharp Shooter Antenna" was published in the PEARS  QSX News Letter of February 2008 by Al Akers ZS2U.  I constructed it in March 2008 and still has it today.  An article about this antenna was published on this Blog in December 2021 and is available HERE.  (Must read)

My final measurements using 3 mm Brass Brazing Rod were:

Driven Elements: 460 mm

Reflector Element:  1000 mm

Spacing between driven- and reflector element : 445  mm

PVC tubing length: 170 mm

Length of Coax:: 1100 mm 

Now why would one revisit this two element Yagi antenna?  There is currently once again an ARISS Slow Scan Television (SSTV) experiment from the International Space Station under way.  (More information HERE)

I decided to use this antenna to download SSTV images from the ISS.  But will it be any good?  This antenna has a very good track record here in the Southern Cape. I use this antenna as a "test antenna" when the need arises.  It is a practical, compact and fold able antenna.  It performs very well.  In  March 2008 I made the following "record breaking" contacts:

I managed to have a short QSO with Terry ZS2ABB in Port Elizabeth from Mossel Bay. A distance of over 300km. In the second attempt I worked Alex RW1ZC/MM on the 6/3/2008 on 2M Voice 144.400 Mhz Fm. Grid: KF35BP 368.3km again from Mossel Bay. 

 

Image above:  Did you know that the first contacts from the ARISS radio on the ISS happened on the 13 November 2000.  There were two test transmissions received in Russia and one in USA. The images of those contacts are now being transmitted via SSTV in the current series.

But what will the results be using this antenna to download SSTV images from the ISS?  Well you be the judge.  Here are some images I downloaded.  I specifically looked for "bad" passes with a low elevation level of between 0 - 25 Degrees.  The one image published here had  a maximum elevation of 49 Degrees.  Through the years I tried several homebrew antennas to download SSTV images.  This antenna performs well.  At a later stage I will write an article about the best antenna I used to download SSTV images from my QTH in KF15bt in Mossel Bay, ZA.

Images downloaded on 16 and 17 November 2024:

Submitted by: Johan Terblanche, ZS1I, Africa
Acquired: 2024-11-16 10:03:00

Mission: Expedition 72 - Series 22 Fortieth Anniversary

Minimum ISS Elevation: 10 Deg

Max ISS Elevation: 17.2 Deg

Antenna: Homebrew 2 Element ZS2U Yagi (Portable)

Radio: Baofeng UV82

Remarks: No Antenna Rotator or Auto Tracking used

Submitted by: Johan Terblanche, ZS1I, Select a region
Acquired: 2024-11-16 11:39:00
Mission: Expedition 72 - Series 22 Fortieth Anniversary
Minimum ISS Elevation:  10 Deg
Max ISS Elevation: 49.7 Deg
Antenna:  Homebrew 2 Element ZS2U Yagi (Portable)
Radio:  Baofeng UV82
Remarks: No Antenna Rotator or Auto Tracking used

Submitted by: Johan Terblanche, ZS1I, Select a region
Acquired: 2024-11-17 04:19:00
Mission: Expedition 72 - Series 22 Fortieth Anniversary
Minimum ISS Elevation:  10 Deg
Max ISS Elevation: 22.9 Deg
Antenna:  Homebrew 2 Element ZS2U Yagi (Portable)
Radio:  Baofeng UV82
Remarks: No Antenna Rotator or Auto Tracking used

In my opinion not to bad image downloads with a two element homebrew portable Yagi antenna.  I will download two more passes with this antenna and then switch to another portable antenna.

How versatile is this antenna really?   In my opinion a really versatile antenna and can be used for the following purposes:

1.  2m DX Long Distance Contacts

2.  Download SSTV images from ISS

3.  Satellite Contacts

4.  Foxhunting

5.  Interference Tracking Antenna 

6.  Baofeng Radio Distance Experiment  (ZS6 Region)

7.  Demonstrating Amateur Radio Communications

8.  Repeater accessing antenna

To mention just a few.

Other interesting aspects of this "Sharp Shooting" Antenna:

1.  Low cost to construct

2.  Easy construction with available hand tools

3.  Low profile when folded into parts (see image)

4.  Easy storage

5.  Vertical and Horizontal polarization by just turning the two elements by hand

6.  No large mast required but can be mounted on a tower or mast.

7.  Hand operated.  (No rotator necessary)

8.  Gain:  4 to 5 dB (Not officially confirmed) SWR:  1:1

9.  Elements can be constructed with Aluminium Wire, Copper Wire,  Coat Hanger Wire, 7 mm Aluminum Rod, 12 mm Aluminum Tubing, 3 mm Aluminium Brazing Rod or 3 mm Brass Brazing Rod. (Brass Brazing Rod Preferred)

10.  Can be used as a Half Wave Dipole by just using the driven element.  (Omitting the reflector element.)

This proved that this “little” antenna is worthwhile constructing and is a real asset to my antenna arsenal.

So what are you waiting for get to your nearest hardware supply store and gather the necessary hardware to construct this antenna. You will be amazed at it's performance!!

Many thanks to Albert ZS2U for making this antenna project available for homebrew construction.

Images:  Click on images for larger view.

Image: ZS1I operating position for the current series of SSTV images

Image:  The 2 Meter Two Element VHF Yagi dismantled for storage or transport