Improving signals on 80m

I’ve had a 40m inverted-V dipole set up along the side of our house for as long as I’ve had the HF set.  Prior to getting the ATU, I was restricted to 40m and 15m which are the resonant frequency bands.

Once I acquired an ATU, I found I was able to tune up 80m… albeit with some limitations in signal radiation.

The 40m dipole consisted of two 10m lengths of speaker wire running from the antenna mast on the house, running down to two plastic tent pegs hammered into the ground.  I suppose the wire was no steeper than about 40 degrees from the horizontal.  This worked okay, but it had some annoying nulls, a notable one towards Ipswich… I tried a purely horizontal configuration, but found the nulls to be even worse.

The proper dimensions for a G5RV, is about 16m each leg, and about 8m of balanced feeder to form a “matching section”.  Well, I couldn’t do much about the length of the matching section, but I figured I might as well try extending the legs of the antenna a bit — nothing ventured nothing gained.  I added the extra 6m to each leg, moved the legs out as far apart as I can.  I tried tuning it up that afternoon, and things seemed to be okay… so I left the set on 3.600MHz LSB and switched it off ready for the AWNOI net.

On calling in, I asked about my signal strength after explaining the changes made.  Well, apparently my signal was a vast improvement on last week’s signal.  A S8~S9 signal (with the transceiver momentarily cutting back power) is now a S9+20dB to many stations.

I haven’t tried other bands yet… but this is a promising start. 🙂

Update: Tried tuning it up on the other bands… the results:

Band__Test_Frequency__Power__SWR__Notes______________________________________________
80m   3.599MHz        50W    2.5  High SWR is expected for a non-resonant antenna.
40m   7.074MHz        50W    1.2
20m   14.165MHz       50W    1.9  Heard a station at 14.170MHz just as I was going
                                  to tune up, which is promising also.
15m   21.190MHz       15W    1.9  This set does not like these bands (15m & 10m)!
10m   28.450MHz       25W    1.6  Might need to consider using the CB whip for these.
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