I did some tests recently with a G5RV in inverted V configuration. I was very disappointed. Don’t get me wrong, I know that the G5RV is a compromise antenna, but I found that some DX signals were inaudible compared with my 20m dipoles in the loft. Why?Turns out that if you use a long multiband antenna as an inverted V it really changes the radiation pattern. The lobes contract quite badly and the radiation angle goes up dramatically. I lost about 7db east-west and the low-angle DX capability went through the floor.
An inverted V half-wave dipole doesn’t do this, so if you must have an inverted V for 20m, use a half-wave dipole, not a G5RV or OCF (Windom).
Save your inverted V G5RV or Windom for 80m where they seem to work quite well with high-angle radiation.
Above right: The red trace is a G5RV inverted V with the apex at 12m and the ends at three metres. The blue trace is a flat-top G5RV at 12m. These were produced with MMANA-GAL, an excellent program.
Well, there is ''it won't work'' and ''it bloody does'' scenarios, I mean technically you may be right, but life brings exceptions and surprices. I have G5RV in V confing, and it is for my circumstances the best antenna I can have, if you want a proof look up 2E0FHM, 73's !
ReplyDeleteI got licensed at age 17 back in December ‘99. January 1, 2000 dad and I installed a 50ft galvanized push up pole and a G5RV Inverted V. In the early 200s I worked the Swan Island, Easter Island and South Cook Island dxpeditions. Swan Island and Easter Island, I got through the huge pile up and worked both on the 4th call and got through the huge pile up with South Cook Island on the 6th call. Working all 3 of those dxpeditions with my late 80s IC-761 at 100w and my G5RV Inverted V. In May ‘08 I bought a new AL-811H and replaced the G5RV Inverted V with a new G5RV Inverted V and upgraded the coax to RG-213. I also added a 10’ galvanized antenna mast to the top of the 50’ push up pole, getting the top of the G5RV close to 60’ up. 90% of the time when I do need to use the AL-811H, 300w is all I need to get the job done. Over the past 17 years, I can count on both hands the number of times I’v ran the amp above 550w in order to work a DX station. For 25 years my G5RV Inverted V has been working like a champ and twice on Sundays. It tunes 80m - 10m to a 1.1 SWR like a champ. On 80m, below 3.840, my MFJ-969 manual tuner and LDG AT-1000ProII both start having some trouble with getting the SWR down to a 1.1, but thats ok since 80m is my least worked band and when I do work that band, most of the time Im above 3.900. My first G5RV Inverted V, I used a 4:1 balun. My second G5RV Inverted V that I installed in May ‘08, which Im still using today, I have an 8 turn 6” diameter coax choke. In my very strong opinion, the G5RV Inverted V is hands down the biggest 80m - 10m bang for the buck. Which is the reason after 25 years, its been the only HF antenna Iv used at my QTH. I’v got no need for a $2,000 tri-band beam that you need to rotate. The G5RV is a very simple antenna to install, extremely low maintenance and if you do need to replace it, you easily can for under $100. Heck you can build your own G5RV Inverted V easily for half the price of buying a new G5RV. Half the reason the G5RV gets such a bad rap is because people that have never used one believe far too much of what they read on the internet.
ReplyDelete