Recently, I’ve been bitten by the 80M DXing bug. Its not so much that 80M has taken hold, as it is that I have managed 140+ confirmed on both 40M & 20M now so all the ‘easy pickings’ are gone.
My main antenna is a 102ft ladder line fed dipole aka G5RV up ~45 feet at the Apex. Whilst this antenna takes QRO in its stride, and puts out one heck of a signal, it also features a whole lot of ‘high angle’ radiation on 80M & 40M.
Whilst I’ve managed 30 countries on 80M running some power (which was needed), I always found received signals to have poor SNR. As such, I decided to once again revisit the Vertical – primarily as an RX Antenna for now – to see if it could help.
Here is the pattern difference, in theory. Note the huge amount of high angle radiation the G5RV (broadside) picks up compared to the Vertical. Although the low angle figures look close, remember the G5RV has a ‘peanut’ shape even at 45ft, so when the G5RV is facing ‘narrow side’ the Vertical has over an 8dB advantage below 15 degrees.
Continue reading for more pictures and information about the project 🙂
To begin with, I decided to use what I had at hand before investing any money. As such, one of the supports for my G5RV was insulated from ground using a 50mm rod of High Density Polyethylene aka HDPE. PE is the foam used in coax cables, and it is one of the best insulators available. Not only that, its also cheap.
Here are a few pictures of the project so far. I got lazy and decided to use an Icom AH-4 remote mount tuner to match it for now, which limits my TX Power to 100 Watts, but its perfect for ensuring I have a nice RX Antenna which is really what I need.
Although only ~10M / 30ft high, it has a nice ‘donut’ pattern on 80M & 40M, with no high angle radiation and ever so slightly more theoretical gain at 15 degrees and below; it has exceptionally more when the dipole is ‘off axis’ aka not broadside being omnidirectional.
Here are a few photos of the project; results will follow.
Icom AH-4 Tuner, HDPE Insulator and Radiator
The 10M Radiating Element / G5RV End Support
My ‘Trenching’ Tool. 4 Radials done so far, 12+ to go!
Yes, I am aware that using a chainsaw on dirt will result in at very least a bar and chain that doesn’t last very long. However, for $99 AUD / $75 USD for a home duty electric one I thought my back was worth it.
Besides, I already have a proper 4 stroke Stihl, which does not go anywhere near the dirt!