The QRPer Board

An example, using a radiator (wire) of 84ft and a counterpoise of 17ft a 9:1 and a wideband choke (Guanella) both wound on FTxxx-43, we'll have a random covering all bands (including WARC) from 80 to 6 meters

as for the radiator length, see here https://k7mem.com/Ant_End_Fed.html#Not_Random_Multi ensure to add a good guanella choke after the 9:1 and use at least one counterpoise wire with a lenght around 1/16 Lambda at the lower frequency (e.g about 5m if the lowest frequency is 3.5MHz, eventually add a ...

https://www.alphaantenna.com/wp-content/uploads/2022/09/What-Coax-Should-I-use.jpg https://www.alphaantenna.com/wp-content/uploads/2022/09/What-Coax-Should-I-use.jpg consider that every 3dB of gain or loss the power doubles or halves, so a 3dB cable loss means that the antenna will receive half of t...

looks good !

the carabiner hole is useful both when the antenna is deployed and to hang it to a backpack wnen the antenna is wrapped, the velcro stripes will help keeping the wire/coax wrapped

Just to try explaining it better, see the image below (ugly but hopefully "readable")

Please, post an update when you'll try it !

A suggestion, make the "box" hosting the 9:1 and choke a bit longer so that the two toroids will sit flat side by side laying on the bottom and not one over the other, also consider enlarging the sides a bit and having some rectangular slot holes at the sides, these will serve to host some...

Ok, now I feel like a dummy. I have a TransWorld TW2010 (pretty much a commercial version of your double T bar) but I was concerned about taking up too much space in the car. Next time... if the antenna is this one https://www.dxengineering.com/parts/dxe-tw-2010-p then once closed it isn't too big ...

Considering how easy it is to build https://vk6ysf.com/unun_9-1_v3.htm I think it won't be a problem building one of them as desired :) the "ground" goes to the counterpoise(s) or to ground stake, a small IP66 electrical junction box will host the toroid, the wire connectors and the coax o...

the double t-bar may be unsuitable for some spots, but imVVHo will serve you well in all other cases when you can't set up an endfed wire