Monday, December 2, 2019

1/4 wave endfed for 60m

1st prototype, coil at wrong position
Just an idea to shorten a half wave length endfed to the size of a 1/4 wave vertical. The advantage is the use for portable operations since you don't need radials. I got the idea from what I read in a dutch publication about endfed antennas. Shorten the original halfwave length is possible but you have to place the inductor for length compensation exactly in the center. Of course shortening an antenna always gives loss and it will probabely not work that good compared to a real halfwave or even a quarterwave with radials. I'll took the PE1BVQ transformer unit from my 3 band end-fed to feed the antenna.

Final tuned 1/4 wave endfed, coil at the centre

So I build my idea, it took me longer as expected to get a good SWR. But in the end it works. Compared to the inverted-V (2x20m @12m fed with open line) it's about 4dB less good. I expected that and actually I find it working the same as the 1/4 wave vertical with elevated radials I build last year. The difference between antenna's can also be loss due to the 60m coax cable between radio/antenna. However since I use aircell7 and loss is not that much on 5MHz. Besides that the vertical is placed between buildings which is not really good for this kind of antenna. I should take it out in the field, preferable near the sea to do a good test. At least I have the ability to take 60m portable.

Sunday, December 1, 2019

#10m opening to Australia

There was a good opening to VK (Australia) on 10m this morning around 10:15-10:30 UTC. I managed to make a QSO on FT8 with VK2NSS and VK3KJ both more as 16000km away. These days propagation on 10m is hardly there so I consider this as highly unusual. It has been years ago I made contact with VK on 10m anyway. Soon the ARRL 10m contest will be there again, if only we have propagation like this at the weekend the contest is on...