The DX-88 is Up

After a trip to a local do-it-yourself centre to get some new U-bolts, the antenna is finally up again.
I tried to be careful in adjusting the lengths of the tuneable elements to be as accurate as possible but, apperantly, I did not succeed very well.

One of the most interesting things is the SWR on 80 meters, because the bandwidth here is rather small, not more than 40 kHz with SWR below 1:1.5. Here is the achieved result:


You can see in my previous post that I went for a center frequency at 3.60 MHz and, as you can see on the graph, I hit it very well. Also, the SWR is below 1.5 for almost 100 kHz, which is twice as good as I expected.

40 meters, on the other hand, was not too impressive: I got SWR 1.1 @ 7.200 MHz and SWR 1.5 between 7.000 – 7.030 MHz. On 20 meter it is quite good, SWR below 1.3 all the way below 14.100 MHz, while on 15 meters better than 1.1 between 21.000 – 21.300 MHz. On 10 meters the SWR was better than 1.2 in the whole 28 – 29 MHz.

I used my FT-301D as signal source and the MFJ-949E for measuring the SWR. I should say, that the FT-301D did not perform too well. It seems as the finals are getting tired, especially on the higher bands 🙁

Author: Alexandru Csete

Embedded software engineer in the satcom industry during the day. Radio amateur and SDR hacker during the night.