EFLW woes

[golddustpeak]

I’m trying to understand what went wrong with my newly installed EFLW antenna.

It all started with me wanting to get back on the air with something other than FT8 due to high noise levels,.

The noise level in our home was a continuous S9 and after lots of discovery and work I’ve managed to get it back to a respectable S2 to S4.
During this time, I decided that a 59-foot EFLW antenna would be my only practicable choice due to HOA and physical restrictions.

I chose 59 ft (with a 20 ft counterpoise) as the best non resonant length that would fit the property.

The feed point starts about 6 inches away from the house 20 ft above ground.

From there the wire runs up, west a few feet then south a few to an elevation of about 25 feet where it meets an insulator hung from a tree branch. At this point the wire turns and runs east for it’s length ending in an insulator hung from a tree branch at 15 feet or so.

The antenna (14 Ga wire) is fed from my radio to a tuner then a choke then the UNUN.

The wire will tune to very low SWRs (1.1 -1.9). The Radiation pattern is promptly E SE and W NW.

So far I was thinking that I was good to go but when I got the noise level down to where it should be I found there were VERY few stations to be heard on Phone or CW (on any band) with a few more during contests but at low levels.

Yes, the wire has branches to the south of it but none touching.
I am operating from a second floor level but I believe my grounding and bonding are OK.

So now I’m not sure exactly where to go next. My only current thought is to move the UNUN out a foot or so from the house.

Any thoughts or suggestions will be appreciated,

TNX

 

[golddustpeak]

I’m trying to understand what went wrong with my newly installed EFLW antenna.

It all started with me wanting to get back on the air with something other than FT8 due to high noise levels,.

The noise level in our home was a continuous S9 and after lots of discovery and work I’ve managed to get it back to a respectable S2 to S4.
During this time, I decided that a 59-foot EFLW antenna would be my only practicable choice due to HOA and physical restrictions.

I chose 59 ft (with a 20 ft counterpoise) as the best non resonant length that would fit the property.

The feed point starts about 6 inches away from the house 20 ft above ground.

From there the wire runs up, west a few feet then south a few to an elevation of about 25 feet where it meets an insulator hung from a tree branch. At this point the wire turns and runs east for it’s length ending in an insulator hung from a tree branch at 15 feet or so.

The antenna (14 Ga wire) is fed from my radio to a tuner then a choke then the UNUN.

The wire will tune to very low SWRs (1.1 -1.9). The Radiation pattern is promptly E SE and W NW.

So far I was thinking that I was good to go but when I got the noise level down to where it should be I found there were VERY few stations to be heard on Phone or CW (on any band) with a few more during contests but at low levels.

Yes, the wire has branches to the south of it but none touching.
I am operating from a second floor level but I believe my grounding and bonding are OK.

So now I’m not sure exactly where to go next. My only current thought is to move the UNUN out a foot or so from the house.

Any thoughts or suggestions will be appreciated,

TNX

A thought about the trees.
The trees are Aspen and the antenna was installed before the trees leafed out. I really can't say that there is much difference between then and now.

 

[prcguy]

You might try a resonant EFHW which would be about 64ft long for a 40-10m version. They work much better than a random wire fed with 9:1 or ?? and don't need a tuner and I've tested them side by side and have seen the difference. I would also recommend a good ferrite based common mode choke in the feedline outside before the coax enters the building to choke off RFI that might get induced onto the coax shield inside the house.

 

[Golay]

You might try a resonant EFHW which would be about 64ft long for a 40-10m version. They work much better than a random wire fed with 9:1 or ?? and don't need a tuner and I've tested them side by side and have seen the difference. I would also recommend a good ferrite based common mode choke in the feedline outside before the coax enters the building to choke off RFI that might get induced onto the coax shield inside the house.

I gotta agree. A properly working EFHW antenna is not going to be just random length. The length and the balun ratio are matched.

 

[WB5UOM]

I'd be interested in what was done done to get the noise level from S8 to S2-S4....

 

[prcguy]

I'd be interested in what was done done to get the noise level from S8 to S2-S4....

I would test with a mobile setup to see if the noise is concentrated in an area or widespread. If the noise is coming from things in the house move the antenna away from the house or find/kill the RFI making devices in the house. If the noise is all over your neighborhood or a wider area then you can't really fix that.

 

[golddustpeak]

I'd be interested in what was done done to get the noise level from S8 to S2-S4....

I started by shutting down the entire electrical system in our home (almost 40 ckts).
I then brought up each circuit one at a time making notes about noise conditions then shutting it back down.
From here I knew which circuits contained noisy devices.
The majority of the noise problems were occurring from wall warts.
I ordered A LOT of toroids and went to work on them.
I've also done my Ethernet cables on each end..
I have a few things left to do but I've made major progress.

Now I just need to get the antenna right

 

[WB5UOM]

Ok well good deal on that, sounds like you worked pretty hard finding/correcting that issue.
You mention HOA, so I am suprised you don't have noise from elswhere nearby.
my opinion (others may disagree) is that a tuner may show a low swr to the radio,but it does not in my opinion mean the antenna is effectively radiating..
what bands are you trying to use?
I have never played with an antenna like that, living out in the Country Ive had a 350ft loop coax fed for years that has been remarkable.
and tree limbs and leaves have no effect at least here for me.

 

[golddustpeak]

Ok well good deal on that, sounds like you worked pretty hard finding/correcting that issue.
You mention HOA, so I am suprised you don't have noise from elswhere nearby.
my opinion (others may disagree) is that a tuner may show a low swr to the radio,but it does not in my opinion mean the antenna is effectively radiating..
what bands are you trying to use?
I have never played with an antenna like that, living out in the Country Ive had a 350ft loop coax fed for years that has been remarkable.
and tree limbs and leaves have no effect at least here for me.

I totally agree a low SWR is NO indication of the antennas radiation efficiency.

The homes in my part of the neighborhood are well separated with underground utilities.
I had sort of hoped that the RFI might be outside and easily found but after walking around with a portable ant and spectrum analyzer it became clear as where to start.

I chose the 59 ft non-resonant EFLW as to its ability to tune all bands and having no resonant spots due to the length.

I guess I'll put up a 66 ft resonant EFHW wire fed by a 49 UNUN and see if there is any difference :-(

 

[prcguy]

I totally agree a low SWR is NO indication of the antennas radiation efficiency.

The homes in my part of the neighborhood are well separated with underground utilities.
I had sort of hoped that the RFI might be outside and easily found but after walking around with a portable ant and spectrum analyzer it became clear as where to start.

I chose the 59 ft non-resonant EFLW as to its ability to tune all bands and having no resonant spots due to the length.

I guess I'll put up a 66 ft resonant EFHW wire fed by a 49 UNUN and see if there is any difference :-(

The non resonant EF antennas are usually fed with a 9:1 transformer and some companies use a 5:1. Both rely on a counterpoise or the coax as a counterpoise and I believe they are more susceptible to noise pickup from the shield of the coax. A resonant EFHW with 49:1 or 64:1 transformer does not appear to need a counterpoise within its resonant bands as testing shows no change when using a good choke balun at the transformer vs non at all, so they might be a little less susceptible to noise riding on the coax. If you transmit way out of band an EFHW will light up the coax with RF more like a non resonant type.

In either case its good to use an effective choke balun outdoors where the coax exits the building to help strip off any RFI riding on the coax shield picked up inside the house.

 

[golddustpeak]

The non resonant EF antennas are usually fed with a 9:1 transformer and some companies use a 5:1. Both rely on a counterpoise or the coax as a counterpoise and I believe they are more susceptible to noise pickup from the shield of the coax. A resonant EFHW with 49:1 or 64:1 transformer does not appear to need a counterpoise within its resonant bands as testing shows no change when using a good choke balun at the transformer vs non at all, so they might be a little less susceptible to noise riding on the coax. If you transmit way out of band an EFHW will light up the coax with RF more like a non resonant type.

In either case its good to use an effective choke balun outdoors where the coax exits the building to help strip off any RFI riding on the coax shield picked up inside the house.

Exact ally what I said I had done in the beginning with my 59 ft EFLW fed with a 9:1 UNUN. I also just said "I guess I'll put up a 66 ft resonant EFHW wire fed by a 49 UNUN and see if there is any difference :-("

But thanks