Questions tagged [efhw]
End-Fed Half Wave is a type of antenna.
8
questions
2
votes
1answer
51 views
Is there value in grounding the virtual null in an auto transformer?
I've been learning how to make 49:1 auto transformers to run end fed half wave antennas.
As I understand it, the twisted lead forms a zero voltage point which acts like a ground.
Assume I'm using ...
3
votes
1answer
147 views
EFHW: better to get far end really high, or middle somewhat high?
I built a 40m end fed halfwave antenna and unun, and the wire is about 66 ft long. I have some tall trees nearby I can hang it in, semi-permanently.
Which of the following would be better?
A) hanging ...
0
votes
1answer
120 views
Troubleshooting the MFJ 1982 EFHW
I am a beginner with not much experience in HF. My shack consists of a Xiegu G90 connected with 20ft of RG-8x to an MFJ 1982 end fed half wave antenna. There is a small coil of coax next to the ...
3
votes
2answers
230 views
How do you calculate the number of turns for a common mode choke?
I want to build a common mode choke for my end-fed wire antenna, using turns of coax through an FT140 or FT240 ferrite. I can find various finished products for sale, but I want to make my own. I ...
3
votes
2answers
303 views
horizontal EFHW antenna attached to gutter
I'm brainstorming methods of mounting an EFHW. Unfortunately, I have no trees, so I'm considering a horizontal gutter mount which would afford me about 70 feet. Is this workable or should I consider a ...
0
votes
3answers
358 views
Loop a long wire antenna or EFHW
For a typical EFHW antenna, let's say we are in a very space-restricted environment, says a hotel room.
I am thinking of the idea loop around the wire around the room, maybe even many loops.
This is ...
1
vote
2answers
300 views
Multi-wire EFHW?
I have an EARCHI EFHW (40:1 unun)antenna that I used quite successfully until it fell from a tree. I wasn't able to get it back up, so ran it along my wooden fence temporarily. Unfortunately, the ...
2
votes
1answer
142 views
How Much Does the Radiation Pattern of an "EFHW" Antenna System Vary Across its Bands?
This NEC4.2 analysis shows one example of such variation.
