Questions tagged [efhw]

End-Fed Half Wave is a type of antenna.

Filter by
Sorted by
Tagged with
2 votes
2 answers
66 views

Receiving -80 dBm on HF

When using my EFHW antenna, I saw that it was -80dBm to -90dBm. So, I can barely make out anything they are saying. I read that you are supposed to have the antenna running north to south, and the ...
o'o's user avatar
  • 113
1 vote
1 answer
163 views

What can you do to prevent exposure of RF?

When I bought my transceiver, I found out that it only puts out less than half a watt (which can't travel a 1 mile radius from the antenna, according to google). So, I bought a power amplifier. It ...
o'o's user avatar
  • 113
0 votes
1 answer
124 views

Why are the signals that my antenna is receiving weak? [closed]

I recently bought the EFHW antenna kit from ARRL, put it together, and set it up. But, my received signals were not clear enough to hear clearly. Is the problem specific to the antenna from ARRL, my ...
o'o's user avatar
  • 113
2 votes
2 answers
974 views

Hi SWR with End Fed HF Wire 9:1 UNUN

Good Day I understand every antenna set up is different, so I'm looking for advice on what I could change to alter my findings. The set up is new including the EFHFW - 20 which was bought off the ...
Simon Hefford's user avatar
1 vote
2 answers
536 views

Can fanned/parallel endfed antennas be used to get higher gain in some directions?

I have two pieces of antenna wire which are roughly 10 m long, with banana plugs at the ends, which I bring to hang in the trees when operating portable. I also bring a 49:1 unun and hopes that my ...
EdvinW's user avatar
  • 378
3 votes
4 answers
2k views

Issues with high SWR on HF Kits EFHW 49:1 UnUn kit

I recently tried assembling a EFHW kit, and some problems came up in testing. I believe this is the kit; I bought it through ARRL: HF Kits website. This is my first time making an UnUn and EFHW kit. ...
nerdenator's user avatar
2 votes
1 answer
107 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 ...
wbg's user avatar
  • 301
5 votes
1 answer
3k 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 ...
User5754448's user avatar
0 votes
1 answer
492 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 ...
WH6GBR's user avatar
  • 1
3 votes
2 answers
2k 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 ...
Joel Clark's user avatar
3 votes
2 answers
1k 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 ...
Alan's user avatar
  • 133
0 votes
3 answers
1k 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 ...
Matthew Wang's user avatar
2 votes
2 answers
1k 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 ...
JayH Dee's user avatar
2 votes
1 answer
296 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.
Richard Fry's user avatar
  • 2,922