This weekend I started to use a new antenna, a T2FD, Tilted Terminated Folded Dipole, also known as W3HH antenna.
I bought a commercial version of the antenna, the Diamond WD330S. A, overall 10 meter long, folded dipole. There is also the WD330, that one is 25 meter long. Both antenna’s work from 2 to 30 MHz and are broadbanded. So also a good antenna for SWL purposes as written on the pages of Hardware DX.
My other, temporary antenna, is a random lenght, 18.6 meter, end fed wire antenna with 1:9 UNUN and a common mode filter at the antenna side. That one replaced my ZS6BKW wire dipole that I removed about a year ago as I had to cope with huge noise levels. Thinking that antenne could need some revision I removed that one and placed the end fed for the time being.
I did not succeed in finding the source of the noise, no PLC or such and it is not caused by my own solar panels as it does not dissapear when my house is completely down electricity wise. Also was the ZS6BKW not really in a bad shape. There was some rust on the nuts and bolts but not of that kind that I expect that to be the problem.
Then I found some articles about the TTFD and some clips on youtube where is shown that the antenna seems to be not that sensitive for manmade noise. That made me want to try this antenna.
Downside would be that the dipole wires end in a resistor, probably around 400 Ohm and about 30% of the transmitted power would be lost.
Another benefit would be that this antenna does not need a “heavy” antenna tuner as the SWR would be within the range that most onboard tuners of tranceivers can cope with. And that is indeed the case for most bands.
SWR measured with the buildin Kenwood TS-590 SWR meter:
10 meter 1:3
12 meter 1:2
15 meter 1:1
17 meter 1:1
20 meter 1:1
30 meter 1:1.2
40 meter 1:1.3
60 meter 1:1
80 meter 1:1.3
160 meter 1:3
So, not even a tuner needed for 15, 17, 20, 30, 40, 60 and 80 meter
And the Kenwood internal tuner does match 10, 12 and 160 meter.
RX wise, a real nice antenna. The noise levels are indeed (much) lower and in some cases the signals are a somewhat lower too. But overall, that still gives me a better signal to the ears and often that, overall, difference is big. From barely heard in the noise to perfect copy without noise. In other cases the T2FD not only gives less noise but also 2 or 3 Spoints better signal.
TX wise I was not able to compare the antenna’s, there was RDA contest going on and the Lighthouse weekend and both events are not the best moment to make some tests… 😉
I did however do some FT8 on 10 and 12 meter, worked about 30 calls within Europe with 20 Watt max and think my results were comparabe with the other stations on the band. They all worked only within my range, no stations I could not see or work. The only unsure factor is that I do not know what powerlevels other were using. As i often understand most people seem to work between 25 and 50 Watt in FT8 mode. Also the reports I got were comparable. sometimes -20, sometimes +5 just as I received others.
At the moment I am very happy with this antenna. I was not to active lately, mostly as is was no fun listening to S6 level noise and stations barely above that level. Did do some digital modes receive wise not much other than that.
Now i can hear lots more I guess I will be somewhat more in the shack too… 🙂