Date   
40m Antenna Comparison

John VA3KOT
 

Gadzooks! Snow almost gone and southern Ontario daytime temperatures above freezing! So I hauled wire, poles and radio into the backyard for a comparison test. These are the antennas I tested:
1. Vertically polarized Delta loop
2. Half Rhombic (full wave, end fed wire, center supported at 23ft with ends up about 6 feet)
3. End Fed Full Wave wire up 8ft
4. Quarter wave sloping vertical

All four antennas produced multiple RBN spots but the Delta loop was the clear winner both in distance and signal strength of reception reports (up to 24dB S/N). The half Rhombic was a good second and the End Fed Full Wave wire came a close third. All three used the same 137ft wire. In last place was the quarter wave sloping vertical which produced disappointing results but used only 33ft of wire worked against ground through a GTU (Ground Tuning Unit - a series connected LC tuner). All tests were done at 5 watts.

Tomorrow I plan to hold my first outdoor operating session of the season in a place where the ground is solid 3 billion-years-old Canadian Shield rock. That will be a new challenge that will really put the Delta loop to the test. If you're around during the early afternoon (Eastern Time zone) listen up for me around 7.030MHz CW.

John, VA3KOT

Re: Multiple operators?

N5VMO Pat
 

Hi Tom  ...... the same here .... I have two live - in state park rangers ( now Hams ) come by most times they see me out and got em hooked that way 8-)    I even go visit when they are off work and we talk radios and antennas =)


On Tue, Mar 26, 2019 at 11:47 AM Greg Lane <LaneKG@...> wrote:
I have a ham friend Dennis that does the RaDAR Challenge with me. I would say sure go ahead and enhance the experience.

Thanks,

Greg N4KGL 

On Tue, Mar 26, 2019, 9:22 AM KC3TOM <tom.pghmtb@...> wrote:
Hi,
I'm trying to get some more people in my club interested.  I invited another member to go with me, but I don't want him to get bored.  Is it OK if he uses my callsign and takes a turn at the microphone?  There is no mention of this in the rules.  
Thanks
Tom.



--
73's Pat  N5VMO


Re: Multiple operators?

Greg Lane
 

I have a ham friend Dennis that does the RaDAR Challenge with me. I would say sure go ahead and enhance the experience.

Thanks,

Greg N4KGL 

On Tue, Mar 26, 2019, 9:22 AM KC3TOM <tom.pghmtb@...> wrote:
Hi,
I'm trying to get some more people in my club interested.  I invited another member to go with me, but I don't want him to get bored.  Is it OK if he uses my callsign and takes a turn at the microphone?  There is no mention of this in the rules.  
Thanks
Tom.

Multiple operators?

KC3TOM
 

Hi,
I'm trying to get some more people in my club interested.  I invited another member to go with me, but I don't want him to get bored.  Is it OK if he uses my callsign and takes a turn at the microphone?  There is no mention of this in the rules.  
Thanks
Tom.

Re: Introductions

N5VMO Pat
 

Welcome to RaDAR Tom =)   Sounds like you are ready for the challenge coming up in April =)   Look forward to making contact =)


On Mon, Mar 25, 2019 at 12:31 AM KC3TOM <tom.pghmtb@...> wrote:
Hi all,
This April's RaDAR challenge will be my first.  I've fallen in love with QRP operation.  While testing a shorter/lighter wire to use with my 49:1 endfed transformer I made contact with a station in California from my front yard here in Western PA with about a 33 ft sloper antenna up about 15 feet.  I do have pretty good elevation for the region I live in.  I was using some really thin SOTA beams wire.  I about got my gear all put together and plan on hitting a trail I know.  I'll be using my Yaesu FT-817nd, love that little guy.  I've been learning CW and start the CW academy next month.  I'm trying to get more members from my club involved.  I've never been one to let the weather stop me, some come rain or shine I plan on being out there.

Cheers,
Tom - KC3TOM about 30 miles SW of Pittsburgh PA.
_._,_._,_




--
73's Pat  N5VMO


Re: 40m Delta Loop

John VA3KOT
 

Thanks for the tip Pat!


On Mon, Mar 25, 2019, 12:22 N5VMO Pat <n5vmo00@...> wrote:
Use a counterpoise wire on the ground in the opposite direction of the signal direction will be a BIG help in those =)   I have used those during Summer FD and they work great in pointing a signal where you want it =)

On Mon, Mar 25, 2019 at 10:26 AM John Corby <va3kot@...> wrote:
Of course the downside, as Tom pointed out, is that a Delta Loop takes longer to erect than, for example, an End-Fed wire. That could make it less suitable for a RaDAR exercise. I am also experimenting with other antennas involving a full wavelength of wire. 137ft is about 5% long for a full-wave on 40m but that is the recommended length for a delta loop. I also plan to setup the same wire as an End Fed Wave antenna. That's an interesting concept inspired by the US Marine Corps who used wires one or more wavelengths long, hung in a straight line, close to the ground, for HF comms in the Vietnam era. A signal along the wire interacts with its image in the ground to produce vertically polarized propagation off the end of the wire. EZNEC modeling suggests a height of about 8ft produces a lossless antenna with a takeoff angle around 55deg. If the wire is any lower (e.g. on the ground) the losses are considerable but the takeoff angle is even lower. If the wire is too high it becomes an NVIS antenna. Another variant is the End Fed Half Rhombic antenna which uses the same length of wire supported in the middle by a 30ft pole.

The purpose of the exercise is to find antennas that will keep QRP field operations alive during the solar minimum. Two or three years ago I worked DX with just a homebrew buddistick but the bands are getting a bit tricky as we pass through the solar minimum for the next couple of years.



--
73's Pat  N5VMO


Re: 40m Delta Loop

N5VMO Pat
 

Use a counterpoise wire on the ground in the opposite direction of the signal direction will be a BIG help in those =)   I have used those during Summer FD and they work great in pointing a signal where you want it =)


On Mon, Mar 25, 2019 at 10:26 AM John Corby <va3kot@...> wrote:
Of course the downside, as Tom pointed out, is that a Delta Loop takes longer to erect than, for example, an End-Fed wire. That could make it less suitable for a RaDAR exercise. I am also experimenting with other antennas involving a full wavelength of wire. 137ft is about 5% long for a full-wave on 40m but that is the recommended length for a delta loop. I also plan to setup the same wire as an End Fed Wave antenna. That's an interesting concept inspired by the US Marine Corps who used wires one or more wavelengths long, hung in a straight line, close to the ground, for HF comms in the Vietnam era. A signal along the wire interacts with its image in the ground to produce vertically polarized propagation off the end of the wire. EZNEC modeling suggests a height of about 8ft produces a lossless antenna with a takeoff angle around 55deg. If the wire is any lower (e.g. on the ground) the losses are considerable but the takeoff angle is even lower. If the wire is too high it becomes an NVIS antenna. Another variant is the End Fed Half Rhombic antenna which uses the same length of wire supported in the middle by a 30ft pole.

The purpose of the exercise is to find antennas that will keep QRP field operations alive during the solar minimum. Two or three years ago I worked DX with just a homebrew buddistick but the bands are getting a bit tricky as we pass through the solar minimum for the next couple of years.



--
73's Pat  N5VMO


Re: 40m Delta Loop

John VA3KOT
 

Of course the downside, as Tom pointed out, is that a Delta Loop takes longer to erect than, for example, an End-Fed wire. That could make it less suitable for a RaDAR exercise. I am also experimenting with other antennas involving a full wavelength of wire. 137ft is about 5% long for a full-wave on 40m but that is the recommended length for a delta loop. I also plan to setup the same wire as an End Fed Wave antenna. That's an interesting concept inspired by the US Marine Corps who used wires one or more wavelengths long, hung in a straight line, close to the ground, for HF comms in the Vietnam era. A signal along the wire interacts with its image in the ground to produce vertically polarized propagation off the end of the wire. EZNEC modeling suggests a height of about 8ft produces a lossless antenna with a takeoff angle around 55deg. If the wire is any lower (e.g. on the ground) the losses are considerable but the takeoff angle is even lower. If the wire is too high it becomes an NVIS antenna. Another variant is the End Fed Half Rhombic antenna which uses the same length of wire supported in the middle by a 30ft pole.

The purpose of the exercise is to find antennas that will keep QRP field operations alive during the solar minimum. Two or three years ago I worked DX with just a homebrew buddistick but the bands are getting a bit tricky as we pass through the solar minimum for the next couple of years.

Re: Introductions

KC3TOM
 

Hi all,
This April's RaDAR challenge will be my first.  I've fallen in love with QRP operation.  While testing a shorter/lighter wire to use with my 49:1 endfed transformer I made contact with a station in California from my front yard here in Western PA with about a 33 ft sloper antenna up about 15 feet.  I do have pretty good elevation for the region I live in.  I was using some really thin SOTA beams wire.  I about got my gear all put together and plan on hitting a trail I know.  I'll be using my Yaesu FT-817nd, love that little guy.  I've been learning CW and start the CW academy next month.  I'm trying to get more members from my club involved.  I've never been one to let the weather stop me, some come rain or shine I plan on being out there.

Cheers,
Tom - KC3TOM about 30 miles SW of Pittsburgh PA.

Re: 40m Delta Loop

N5VMO Pat
 

I to like loops Tom =)    When I had a house I had a 80 meter horizontal loop about 10 meters off the ground fed with 20 meters of ladder line directly into the back of my manual tuner balanced line port =)   It worked GREAT on any band 10 to 80 meters  WARP bands where a bit to tune but worked =)   I built a 10 meter vertical delta loop for a new tech ( my first Delta Loop ) that worked and tuned by changing the feed point at the top by sliding down the feed point ( RG-58 ) a bit one side to a perfect tune all across the band =)   So I will have to make a 40 and 30 meter band Delta Loop for camping =)


On Sun, Mar 24, 2019 at 6:57 PM Thomas Robinson via Groups.Io <g0sbw=btinternet.com@groups.io> wrote:
I am very fond of delta loops. My home QTH antenna is a horizontal loop for 80m. This is fed by an auto tuner quite some distance away from the shack. The antenna is fed from the atu by open wire feeder and tunes up on all bands 80 thro 10. However I have delta loops available for 20m and 17m. These are deployed in upside down pyramid and are fed by a quarter wave of 75 ohm coax. Normal 50 ohm coax from the rig to the quarter wave.  The deltas can be horizontally or vertically polarised depending on how the are deployed. I normally use them vertically polarised as dx antennas.  They perform well in this mode. Without any salt water amplifier effect I have worked Antarctica on 17m. I have not tried them portable as yet.  But I will give them a go on the salt marsh this summer.  They should work well. Bit more work to deploy compared to an end fed half wave though.



--
73's Pat  N5VMO


Re: 40m Delta Loop

Thomas Robinson
 

I am very fond of delta loops. My home QTH antenna is a horizontal loop for 80m. This is fed by an auto tuner quite some distance away from the shack. The antenna is fed from the atu by open wire feeder and tunes up on all bands 80 thro 10. However I have delta loops available for 20m and 17m. These are deployed in upside down pyramid and are fed by a quarter wave of 75 ohm coax. Normal 50 ohm coax from the rig to the quarter wave.  The deltas can be horizontally or vertically polarised depending on how the are deployed. I normally use them vertically polarised as dx antennas.  They perform well in this mode. Without any salt water amplifier effect I have worked Antarctica on 17m. I have not tried them portable as yet.  But I will give them a go on the salt marsh this summer.  They should work well. Bit more work to deploy compared to an end fed half wave though.

Re: 40m Delta Loop

N5VMO Pat
 

John that looks like a great antenna to use =)   I have seen in the past Greg using one and I may give it a try as well =)    Hmmm .... a 30 foot push-up pole now with tent rain-fly spreaders =)


On Sun, Mar 24, 2019 at 2:58 PM John Corby <va3kot@...> wrote:
Finally got some mild weather in southern Ontario today so I put up an antenna I've been waiting to try out. It is a vertically polarized Delta loop for 40m. It uses 137ft of wire supported on a 30ft pole at the peak with the low, horizontal section just 4ft above ground. EZNEC modeling showed promising expectations so I was excited to test it outside as a possible RaDAR antenna.

I fired off some CW CQs at 5 watts using my Hendricks PFR3 radio and received an immediate spot on RBN from a station in Wisconsin 400 miles away. My signal was reported at a very strong 21dB so this antenna may be doing its job! Unfortunately I didn't get any QSOs but that has become all too common the way the bands have been lately.

Now I'm looking forward to a new RaDAR operating season with some new antenna designs. Hope to catch you all on the bands this summer.

John, VA3KOT
EN93XX67



--
73's Pat  N5VMO


40m Delta Loop

John VA3KOT
 

Finally got some mild weather in southern Ontario today so I put up an antenna I've been waiting to try out. It is a vertically polarized Delta loop for 40m. It uses 137ft of wire supported on a 30ft pole at the peak with the low, horizontal section just 4ft above ground. EZNEC modeling showed promising expectations so I was excited to test it outside as a possible RaDAR antenna.

I fired off some CW CQs at 5 watts using my Hendricks PFR3 radio and received an immediate spot on RBN from a station in Wisconsin 400 miles away. My signal was reported at a very strong 21dB so this antenna may be doing its job! Unfortunately I didn't get any QSOs but that has become all too common the way the bands have been lately.

Now I'm looking forward to a new RaDAR operating season with some new antenna designs. Hope to catch you all on the bands this summer.

John, VA3KOT
EN93XX67

Re: Introductions

N5VMO Pat
 

Bruce check out the YouTube videos of the RaDAR group has done over the years on their outings =)   Wires and Mini-loops are used by many here as to keep a lite weight and small pack out =)    Check out Eddies blog and Greg's blogs as others =)   Each has a different answer and work for them =)    I have yet to make a mini loop antenna and usually do wire dipoles, long wire and a vertical mounted on a camera tripod =)

DSCF1701.JPG

and  wires
DSCF1671.JPG


On Thu, Mar 21, 2019 at 7:02 PM Bruce Hymon <Hymonb@...> wrote:
Bruce K8CJM
New to this group. Have not yet operated portable but I am considering a backpack station. I have watched some You Tube videos and have an idea on the equipment (plan FT981, Draws Workstation, LiFePo4 batteries) but I don’t know what will work for an antenna. Maybe we could have a section on what has worked well for other)

Thanks for the interesting group. 73, Bruce K8CJM Dayton, Ohio

--
73's Pat  N5VMO


Re: Introductions

Bruce Hymon
 

Bruce K8CJM
New to this group. Have not yet operated portable but I am considering a backpack station. I have watched some You Tube videos and have an idea on the equipment (plan FT981, Draws Workstation, LiFePo4 batteries) but I don’t know what will work for an antenna. Maybe we could have a section on what has worked well for other)

Thanks for the interesting group. 73, Bruce K8CJM Dayton, Ohio

The April 6th RaDAR Challenge is coming up soon.

Greg Lane
 


Welcome to all subscribers! 
 
See http://radarops.co.za/index.php/radar-rules/

Also, note there is a MeWe Group 


Let us know you RaDAR Challenge plans and results.

73

Greg N4KGL

Re: Introductions

N5VMO Pat
 

Glad to see you are interested in RaDAR; Mark and welcome to the group =)   You will see people from all over the world as members here and we all share the same fun of using our Ham radio outdoors or anywhere =)   Sounds like you have done the /MM before on your boat =)   RaDAR is a way of perfecting you gear and antennas for portable deployment at any time or anywhere =)   The most important thing is have fun outdoors and share your adventures =)



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73's Pat  N5VMO


Re: Introductions

Mark Bumstead
 

Hi Everyone, 
I am Mark, M0IAX. I heard about radar initially from Julian OH8STN when he was taking part in one of your challenges last year. And I found the group thanks to a post from Pat N5VMO in the JS8Call group.

This group and challenge sound quite interesting and I look forward to taking part at some point, I have a few portable/mobile station options which Im hoping to have the chance to use more often when it stops raining :-)

I'm going to be putting together a better antenna system to use Maritime Mobile in,my RIB as I really enjoy the challenge of operating from a small boat and have had success in the past but I know I can do better.

73
Mark
M0IAX

Re: Introduction

N5VMO Pat
 

Thank you Norman and look forward to it =)


On Tue, Jan 8, 2019 at 8:24 AM Norman via Groups.Io <m0fzw=btinternet.com@groups.io> wrote:
Pat
Thank you for the welcome to RaDAR. Looking forward to many QSO's with like minded operators in 2019.
73, Norman, M0FZW



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73's Pat  N5VMO


Re: Introduction

Norman
 

Pat
Thank you for the welcome to RaDAR. Looking forward to many QSO's with like minded operators in 2019.
73, Norman, M0FZW