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.

6 comments:

  1. Ziet er goed uit Bas. Ik ben zeer benieuwd hoe straks de resultaten op 160m zullen zijn. Ik ben weer langzaam actief aan het worden, hier veel gebeurd, ik bel je woensdagavond na 21 uur. Ik hoor wel of je dat uitkomt. 73 Hans,mPE1BVQ

    ReplyDelete
    Replies
    1. We hebben ondertussen gebeld Hans...het was weer een goed gesprek. Hoop dat je de hobby gauw weer helemaal kan oppakken. Doe het rustig aan. 73, Bas

      Delete
  2. Good evening Bas, a very nice picture of the antenna with the rainbow in the background.
    73,
    Mike
    VE9KK

    ReplyDelete
    Replies
    1. It was a one time opportunity during the contruction of the antenna....73, Bas

      Delete
  3. The question is: did you build the swing for the kids, or for the antennas? ;-) Ha ha! Anything that will support an antenna becomes one eventually! Working at the coast will be fun at this time of year, but it would be nice to see some test results.

    ReplyDelete
    Replies
    1. Not the first antenna that was supported by the swing. I always dream to work from the coastline like you. But I need to simplify the portable digital setup. I'm still busy with it. 73, Bas

      Delete

Thanks for your comment. Bedankt voor je reactie. 73, Bas