All posts by Nick
Below are all of Nick's postings, with the most recent are at the bottom of the page.
hi, nmugford.
Do you mean make the existing dipole shape from copper instead of aluminium?
The only times I have done that, the only difference has been a heavier aerial.
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Hardy,
thank you for the link to wi fi aerial. I have made several like that, even double biquad, but they are not powerful enough. Adding directors has proved no better, presumably because the added gain is negated through mismatch of impedance. It is very frustrating making wi fi aerials when you know you have good designs but have no way of knowing the impedance nor of how to match. Far and away my best wi fi aerial is a sky dish with cantenna, but took many days of experimenting with where to place the receiving rod, [length 30mm] within the can,how far to place the can from dish, angle of that can to dish etc.
Many of my designs are based on a 1950's book designed for builders of aerials for band 1!
Since we have also moved on to cb aerials, would a SWR meter, and a box to adjust SWR for cb aerials, be of any use with aerials for 2.4ghz? I guess not.
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Hardy, you are a mine of information.
If you know how to make a balun for 2.4 ghz,be it 4 to 1 or whatever, please let me know. Also, how do I find out the swr of the wi fi aerials I build?
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Hardy, I think when you talk of a mile, you mean point to point, ie both ends with sat dish. I am talking about piggybacking on neighbour's wi fi across the street.
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Hardy
I think swr is crucial for 2.4ghz, that is why however elaborate my aerials, it is difficult to improve on the two 'rabbit ears' on the Edimax box set on wisp.
I use the Edimax, with its aerials removed and substituted with sat dish. It provides no amplification of signal and whilst setting up, noticeable how the signal varies almost second by second, sometimes from 90 down to 40 percent. Presumably this is why it frequently cuts out during use.
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Hardy,
I alternatively use an Alfa dongle. It has more oomph than the Edimax, but can only be used on the pc, connected, unlike Edimax it does not transmit to phones/tablets.
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Hardy
that biquad, something wrong, space between dipole and reflector usually 15mm, not 30.
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Friday 31 August 2018 7:57PM
Hardy
do you remember the J Beams with 'wiggly' directors? They were in the form of 4 arms, the bottom part at 45 degrees, the top horizontal.
Group a had very large 'arms', c/d small. How do you square this with the shallow x's with their short arms which apparently make them wideband? If short arms do this, then all those old J beams would have had the same length short arms!