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| The EA642ZB7, at the background my tower... |
I finished the EA642ZB7 for now. Not completely satisfied about the construction. But it is certainly a lot better compared to the build originally. This is a very small 3 band antenna. Ideal for someone that hasn't much room around the house. I think the 50MHz and 70MHz part will be working great. 145MHz will be less efficient compared to a monoband beam. But hey, when you haven't got the space it is good enough. You will not notice that 1 or 2dB less.
When I look at the picture at the right I realize now that it looks like I have a gigantic beam halfway my tower when you look at it from a distance. Imagine....
Originally I think the 50mm mast clamp is mounted right at the boom. I didn't like the idea of just one mast clamp, the manufacturer did of course because it is cost effective. I did make my own with 2x 50mm mast clamps. By the way, I've only used scrap aluminium from old antenna projects in this "upgrade". I'm not intending to keep this antenna for my own but sell it to someone that is really interested in it.
I mentioned the balun earlier. Personally I would use better coax on it. But since the PL chassis seems to be glued into the alu tube I can't replace it. The coax used is RG58 and there are 11 windings on the tube which has a diameter of about 20mm. And yes, it is mounted with ty-raps, that's the way also described in the manual.
SWR/resonance is good on all bands. Initially SWR on 70MHz was best at almost 72MHz. Bending the 70MHz open sleeve "dipole" ends towards the 50MHz dipole corrected this a lot. SWR on 145 is at best 1,5:1. Could get better when the antenna is mounted free and at height.
Some pics:
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| 2m resonance point? |
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