@A.Z
The FT-991A built in antenna tuner will only do 3:1 , not good enough for a "Random wire" , i am considering to get a MFJ-939Y Ant. tuner though.
But for a start i'll go with the HyendFeed , as it should do all the mentioned bands with a nice swr. But it also comes with a steep price.
I'm a bit worried about the counterpoise ... Does that carry any noticable RF energy. ? - Grand children playing around the trees.
And i'm not even sure i can get the antenna 17' up in the air.
Just for my understanding...
Counterpoise:
How much RF energy is approx. going down such a wire ?
A.Z says i can use an isolated wire , but i have grandchildren ....
Enough to get even a light Zap ?
Chances are that i won't use the station when they're visiting , but then again .. Their Dad might want to see the station in use ... There is trouble
/Bingo
With well designed EFHW antennas you do not need any counterpoise. The coax itself running from the transformer to your TRX works as the counterpoise (even though the counterpoise is theoretically not needed with end fed half wave antennas)..
The EFHW antenna does not require a counterpoise from principle of its operation.
"EFHW" means you feed the antenna in the point of highest impedance, the currents are pretty low there.
The "counterpoise" with EFHW works like "grounding" - the coax on the ground is coupled via its shielding capacitance to the ground.
I've never seen an issue with RF going to the hamshack or into the TRX with EFHW here - with many hams using it at their local QTH or portable. Also people usually use a choke on the coax to avoid RF..
@A.Z.: EFHW antenna IS a dipole. The exactly same antenna as a "traditional" dipole fed in the middle.
Some people call it "end fed dipole" too..
Try to spend some time with EFHW topic and you will certainly learn how it works..
The losses with EFHW come mainly from the ferrites we use. Especially the 43 is lossy and definately not the optimal one, but the best we have for 2-30MHz range. We would need a new material, something with mu' close to 1000 till 30MHz and with mu'' similar to the material 61..
But the losses should not be higher than 15% in the transformer (ie. with SSB and 100W the loss is less than 3W in an average).
The losses with EFHW come mainly from the ferrites we use. Especially the 43 is lossy and definately not the optimal one, but the best we have for 2-30MHz range. We would need a new material, something with mu' close to 1000 till 30MHz and with mu'' similar to the material 61..
But the losses should not be higher than 15% in the transformer (ie. with SSB and 100W the loss is less than 3W in an average).I would not say mainly.
I measured some different sizes and brands of 43 toroids, beginning with FT140-43, FT240-43, WÜRTH 74270097 and endet up with a WÜRTH 74270191.
Measured TWO of it as 1:49 connected face to face and got around 3.5dB at 160m, better 1.5dB between 80 and 20m, 2.5 at 10m and 4.7dB at 6m.
(Note that the loss is for two UnUn).