Recent content by kd5byb

  1. K

    ADS-B DIY Antenna

    Excellent! Please let us know how they work out. thanks much and 73, ben, kd5byb
  2. K

    ADS-B DIY Antenna

    Good afternoon all, I have edited the model on the 10mm closed-stub antenna. The results are not very good. As I suspected, the PE insulation over the conductor does cause the wires to look longer than they are, resulting in a high SWR at 1090 MHz with a lower SWR at a lower frequency. The...
  3. K

    ADS-B DIY Antenna

    Actually, I do believe it is possible with a diplexer. Some time ago when I was looking on eBay for satellite amplifiers like abcd has shown in his photo, I found some splitters / combiners that may work for this purpose. One can be seen here: http://www.ebay.com/itm/380148691933 I bought a...
  4. K

    ADS-B DIY Antenna

    Good catch on the wire diameter. Yes, the wire diameter makes a difference. All things equal, a fatter wire will have a wider bandwidth. Something else I noticed - my models are for bare copper wire, while in the photos your antenna appears to be covered in insulation. I assume this was...
  5. K

    ADS-B DIY Antenna

    I was able to make some minor improvements to the above antenna. Specifically, the model showed favorable results if the little "stubs" at the end of the feedpoint were removed. I can show this better with pictures from the model. Here is the original antenna feedpoint: Here is the modified...
  6. K

    ADS-B DIY Antenna

    Good evening all, So I got a little bit of time this evening and figured I'd share some of my findings modeling the Franklin Collinear Dipole antennas presented earlier in this thread. The first one will be the 10mm, open-stub design as shown in this drawing: This design is a very good...
  7. K

    ADS-B DIY Antenna

    Good evening! No thanks needed - I'm new to EZNEC and this was a great opportunity to learn some of its features. Up until buying EZNEC, I had been evaluating my ADS-B antennas in the same fashion as you have been doing - maximum range evaluation. Here at my house, plane traffic varies...
  8. K

    ADS-B DIY Antenna

    Good evening! I've been looking at this thread for some time with a great deal of interest, as I've been looking for an ADS-B antenna with a good bit of gain for a good while. This afternoon I got some time and made an EZNEC (antenna modelling software) model of your open-stub Franklin...
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