2m Horizontal Dipole Stack

Simple horizontally polarized antenna for 2m SSB. Two dipole stack 11 dBi at 5 degrees elevation (at 6m height). Build it in an afternoon..

Since I have an Icom IC-7100 in the shack which covers 2m and 70cm all modes, why not have a horizontally polarized antenna for some 2m SSB action? Most have Yagi's but with those comes the need for a rotator etc. This I built in an afternoon to try out with scrap items or stuff easily found at a hardware store - 75 ohm coax, some wire, screws, PCV tube etc.

An EZNEC model shows a horizontal dipole 6m / 20 ft above ground to have around 8 dBi gain with a bi-directional beam-width of 80 degrees, but it has a number of nearly equally strong high angle lobes which is a waste of energy going nowhere useful, and would also lower the SNR of desired signals.

I found stacking a second dipole 1m (1/2 wave length) above boosted the gain to 11.3 dBi and significantly reduced the overhead lobes. Feeding each dipole half way between with 75 ohm coax (0.5m each) resulted in a 44.4 J0 ohms match or an SWR of 1.12:1 where they meet in the middle, close enough for 50 ohm coax.

(not to scale)

Two dipole stack 6m / 20ft height above ground elevation plot

Two dipole stack 6m / 20ft height compared to a single dipole same height

Two dipole stack azimuth plot

Model file: 2m 2 Dipole Stack.

I built this antenna in a couple of hours using some scrap PVC tube for the vertical mast, copper wire out of scrap Romex cable, scrap 75 ohm RG-6, and some sheet metal screws and washers. I also put a pair of snap on ferrites at the feed-point of each dipole, and also over the 50 ohm line leading away at the lower dipole.

Seems to work alright, SWR meter in the IC-7100 reads 1:1 at the bottom of the 2m band, and rises slightly at the top/148 MHz.

On 440 MHz SWR around 1.6:1 works ok with the local FM repeaters.

Had a QSO with another station 20 miles away on 144.200, S9 each way. On the Comet GP-15 vertical which is a 2 x 5/8 on 2m they were S2.

Trying out FT8..

I got around to trying out FT8, the HF digital mode that everyone seems to be doing these days. I guess don't knock it until you try it..

• https://www.g4ifb.com/FT8_Hinson_tips_for_HF_DXers.pdf - read the answering and calling CQ sections.
• https://www.youtube.com/watch?v=XkoQ9FD5KX8&t=490s - watched answering and calling CQ part.

It makes completing a contact very easy after setting some options.

Answering a CQ just double click station calling CQ, from there the process of your station answering, the exchange of callsigns, grid square and signal report are fully automated.

Calling CQ is simply clicking enable TX and waiting for others to answer, the same automated process takes over and completes the contact.

I can see this has it's uses with contesting, working a DX-Pedition under trying conditions to get that rare one for example since its simple, automated and completes a contact in five 15 second T/R sequences.

Here on the 17m band yesterday evening completed my very first ever FT8 contact with ZL2DD.