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Re: Will this compromised antenna work?

Posted: Tue Oct 15, 2024 1:57 pm
by Brian - K3ES
Thank you Andrew! I had expected a stronger directional effect from the 2m whip, but your analysis lines up well with the QSO Map. The AX1 is not the best, but it is not a dummy load either. I guess even 5 watts of RF energy has to go somewhere. 😉

Best 73 de Brian - K3ES

Re: Will this compromised antenna work?

Posted: Tue Oct 15, 2024 2:23 pm
by Andrew (grayhat)
Ok, added the car, the wireframe model is really raw, but it should give you a better idea and... yes, the car has an influence on the pattern, just look at the attached pic which shows the radiation pattern on the 20m band

download/file.php?id=179
brian02.jpg
brian02.jpg (72.11 KiB) Viewed 175 times
HTH !

Re: Will this compromised antenna work?

Posted: Tue Oct 15, 2024 3:56 pm
by KL7MJ
Brian - K3ES wrote: ↑Sun Oct 13, 2024 10:44 pm I was uncertain, but the AX1 continues to amaze me. A compromised antenna is, first and foremost an antenna.
Brian,
Location is also important. I have a homebrew DS1-type antenna (6 foot whip and a coil at the base). I can make contacts here in the lower 48, but I couldn't even hear anything on it from Denali Park last month.

73,
Mike, KL7MJ

Re: Will this compromised antenna work?

Posted: Tue Oct 15, 2024 4:10 pm
by Andrew (grayhat)
KL7MJ wrote: ↑Tue Oct 15, 2024 3:56 pm Location is also important. I have a homebrew DS1-type antenna (6 foot whip and a coil at the base). I can make contacts here in the lower 48, but I couldn't even hear anything on it from Denali Park last month.
Mike, try this; open this mapping site

https://caltopo.com/map.html

center the map on your location, then right click the map and select "simulated view", that will allow you to see if there are "obstacles" toward a given direction ;)

Re: Will this compromised antenna work?

Posted: Wed Oct 16, 2024 7:56 am
by Andrew (grayhat)
Brian, if you're in the mood of experimenting a bit, here's an idea for you; we know that the AX-1 covers the 20, 17 and 15 meters bands, now... what about adding it 30/40 meters (or even more bands) coverage :D ?

Here's the idea

We start by building or buying a 9:1 (just an idea, other ratios may be considered) UnUn and connecting it between the AX-1 and the coax feedline

Next we extend the antenna but we leave the top "thinner" section recracted and then we find a way to clamp to the top of the antenna a piece of wire which we'll then layout as an "inverted L", hanging it to (say) a tree or whatever support, such a wire may run horizontally or sloping up or down, as the conditions allow (an up slope would be nice)

Now we adjust the wire length to find a decent match on the "extra" bands we want to cover, at this point we have the antenna ready and can pack everything and bring the stuff to whatever spot we want to use for our operations, once there, we setup the antenna, add the 9:1 and deploy the additional wire

The idea is that the antenna could then be used "as is" for the "standard" bands it covers and with the additional 9:1 and extension wire to allow covering additional bands, such a setup may be useful in case the higher frequencies are "closed" or, for example, willing to play NVIS on (say) 40m when we are in a valley surrounded by mountains

What do you think ?