2-El.-6-17m-V. Mk Vl

2-El.-10-17m-25 Ohm

2-El.-10-17m-28 Ohm

3-El.-10-17m-50 Ohm

Test YP-3


Test Super Antennas Portable-Yagi YP3

by DK7ZB

The Yagi from Super Antennas was tested the first time by IS0/DK7ZB in September/October 2009 on Sardinia Island

For all details about the antenna read the manual:

The YP-3 is a 3-Element-Yagi with a lightweight construction and a clever system for changing the lengths and the resonant frequency of the beam.

As a short conclusion I can say: An excellent antenna for the portable operator! I made some simple modifications for better performance on 6 m and 12 m and a greater mechanical stability of the boom. An additional coax-choke for surpressing common waves is easy to build. The results for DX with 100 W RF and a 9 m high mounting above ground were indeed surprising!



Gain in free space

6 m


5 dBd

6 m (Mod.)


6,8 dBd

10 m


6 dBd

12 m

50 %

4,8 dBd

12 m (Mod.)


6 dBd

15 m

50 %

4,8 dBd

17 m

66 %

5 dBd

20 m

50 %

3 dBd

Without any support in stormy weather

Additional support with a 2,5-mm-steel rope

The YP-3 has a hairpin-match (Beta-match) with a variable middle part for impedance matching.

30 m above salt water gives additional 6 dB groundgain and S9-signals on 17 m from JA in the sunspot minimum!

The measured SWRs below are for a height of my mast 9 m above ground.

Changing to another band is done in 10-12 minutes.

The choke for a balanced feeding.

10 turns of RG188 PTFE-coax on  a PVC-tube 25 mm.

Without the choke my IC-706MK-IIG (it is very sensitive to RF injection!) I had interferences on SSB in the head- phones while transmitting.

50 MHz: Only SWR-test possible, no band conditions.

With this modification you get an 28-Ohm-Yagi. The gain increases from 5 dB to 6,8 dBd. Remove the hairpin-match and use a DK7ZB-choke (2xlambda/4 75 Ohm coax). Bandwidth with SWR <1,5 50-50,5 MHz


5/8 x 30

x 28

Distance 1410 mm (55 )


5/8 x 30

x 24



5/8 x 30

x 21 7/8

Distance 1270 mm (50 )

28 MHz: Only SWR-test possible, no band conditions.

24 MHz: Very good results, signals 1-2 S-units better than with a quarter-wave vertical.

Elevation pattern 10 m above ground, 0 dB = 11 dBd


With a small modification I changed the YP-3 to a 3-El.-Fullsize-Beam with 6 dBd gain and very good pattern. Remove the loading coils, the hairpin-match and the original end-pieces. Use the DK7ZB-match for 12,5 Ohm impedance.

Take the inner parts: 5/8 x 30 '', x 28 '', 3/8 x 22''

New end parts: 6x1-mm-rods (see table right)




1040 mm (41 )


980 mm (38 5/8 )


880 mm (34 5/8 )

21 MHz: Good results, the beam works like a normal trap-beam, SWR for positions CW

18 MHz: Very good results, comparable to a good 3-El.-Trap-Beam

 14 MHz: Better than expected, F/B 1-2 S-units. First SWR for position CW, the second for SSB