Topics

HF9V installation and tuning


Fred PA3FK
 
Edited

Hi Experts,

Let me introduce myself a little bit first.

My name is Fred Koch, 61 years young, and radio-amateur since the 1980's.  Started my career as a Radio-Electronic Officer in the merchant marine so i should be aware of the theory of antenna's and tuning, however this was 40 years ago and i have not been very active in the hobby so my knowledge has faded a lot i notice. 

But recently picked up the hobby again and in the weekend of November 9/10 2019 i have installed a HF9V into the ditch behind my house and tried to tune it.
The antenna is installed into the ditch, and the ditch holds about 1 M water depth.  I first drove a 3,5 M pole into the earth and then mounted the base of the HF9V (Pole A) so it is about 40 cm above the water level. (see pictures in the album).
Note that the ditch is not a salt water ditch, however from reading on the internet, i have found several posting showing good results putting the HF9V up this way without using radials.
As a ex R/O i will be using CW only (with perhaps an incidental exception for SSB) so i am aiming to have the best SWR around the lower portion of the bands.

Assembly of the HF9V was feasible, however i do recognize that the instructions could be improved here and there but i think i got it right in the end.

And then the tuning begins.
I have a Mini60S as antenna analyzer and there are some strange results i would like your thoughts about. (see picture in my album where i uploaded the outcome of the scans i did)

To start from lowest to highest band 
6 M:  Min SWR (1,49) at 48900..  This weekend the dip was properly at 50.000 so it seems i need to tune the 6M wire a little again but overall this seems like an acceptable SWR graph
10M: Min  SWR (1,41) at 27850 and overall very flat.  Perfect (see Improved 10M scan)
12 M: Min SWR (2,64) at 26500. Way off. This is with 12M coil fully compressed (see pictures) as per initial tuning instructions. However when extending the 12 M coil nothing changes.
15M: Min SWR (1,45) at 20975 with enough bandwith so the 28.000 -28.100 is workable.  Fine with me
17M:: MIn SWR (1,33) at 18020. could shift it a little to make lowest swr at 18080.for the moment fIne with me.  Note picture 17M scan second The first shows a different result.  MIni60S reliable???
20M: Min SWR (1,39) at 14010. Fine with me
30 M: SWR of 2,6 around 10.100..  Strange graph with second dip.  For now workable. But what does it tell?
40 M:  Two scans that both are strange. One with no dip at all (second 40M) and the first with two real sharp dips at 6650 and 6750.   This important band is unworkable.  This is my main concern as i want to be able to work properly on 40 M
80 M:  Min Swr (1,33) at 3560. Should be shifted a little bit to the left (center frequency of 3520).   Adjusting the 80M coil should achieve this. 


I am very interested to better understand the complete lack of a reliable SWR graph on 40M.  Looks as if something is not completly right there that is beyond tuning.



Next is the 12 M.

Note: I have not yet adjusted the base coil Q for an even lower SWR on 80M. 

Looking forward to your thoughts on this.


Scott AC8DE
 

Fred,

 

Welcome to the fold.  Yours is a quite unusual installation; a type that I have no personal experience with tuning myself.  However, there have been a few through here over the years that did do over freshwater installations that had good results, which we talked though.  That said, I have definitely noted some significant issues that are correctable.  The thoughts are in no specific order, as I've written them down as I've looked at your photos.  Note, it would be a lot easier to dissect if you would use the excel sheet found here.  Looking at the charts doesn't give exact info.  It's close, but an excel sheet is better.

https://groups.io/g/Butternut/files/Butternut%20Tuning%20Charts/AC8DE%20Antenna%20Tuning%20Chart%20Excel%2097-2003%20format.xls

 

First, I renamed your album to start with your call sign.  It's hard to find anything over time in a folder that doesn't start with the owner's call sign.

 

SWR is NOT in indicator of antenna efficiency, so let's get that out of the way first.  SWR is only a portion of the picture.  A dummy load has perfect SWR after all.

 

  • Feed point height:  The height of the feed point above the ground plane should be a maximum of 6", with 3" being optimum.  You have your feed point at 15.75" above the water level/ground plane.  This is generally problematic for antenna tuning, but really problematic for efficiency.  Think of the results if you separate the two halves of a dipole by more than a couple inches.  Same thing with a vertical and its ground plane, as the ground plane is the "other half" of the antenna.  However, even with this high feed point, it may still be quite workable in an above water install, just understand the effect on bandwidth and efficiency.
  • Coil positions - This appears to be your biggest problem. It appears you have your 80M and 40M coils switched.  The coil with more turns (about 16-17) of the two is the 80M coil, which belongs BELOW the insulator.  The 40M coil typically has about 10 turns.
  • 80M:  If I visually drop the lowest SWR to 1:1 (which happens with Q coil adjustment), it appears that you are getting about 50 KHz of bandwidth below 2:1 by my estimate.  It should only be about 20-25KHz.  This is usually indicative of poor ground plane coupling/effect for the ground and hence, low antenna efficiency.  The usual advice is to install more radials, but in your case, I have no suggestion.  Drop the feed point as much as possible.  These comments may change considerably when you get the coils swapped.
  • 40M:  The first thing that jumps out and bites me is that your 30M coil assembly is tapped in the completely wrong place on the 40M coil.  (Although this is the wrong coil to begin with as installed.)  Its proper starting point is the 3rd or 4th turn down from the TOP of the 40M coil; usually the 4th.  I'd bet my house that the wrong coil and tapping point combination is causing your 40M problem and an improper tune of 20M.  Probably does some weird stuff to 30M as well.  These comments may also change considerable when you get the coils swapped.
  • What am I seeing in this photo?  https://groups.io/g/Butternut/photo/183823/14?p=Created,,,20,2,0,0  Is this a guy point?  If so, what is the big metal bracket you are using?  Seems like some massive overkill that adds capacitance and stress.  All you heed is a hose clamp and some D-rings and the smallest rope you can get.  There is very little wind loading on a Butternut, so small guy lines and light brackets are all that is needed.  It doesn't need to be any more than this, which has withstood 70 MPH winds. https://groups.io/g/Butternut/photo/25953/18?p=Created,,,20,2,0,0
  • Once you get the 80, 40 and 30M coils all sorted out, things will be quite a bit different.  If there are any questions on tuning procedure, look at the latest version of the instructions here. https://groups.io/g/Butternut/files/Butternut%20Manuals%20-%20New%20DX%20Engineering%20Versions/HF6V%20&%20HF9V/BUT-HF9V_Rev3.pdf
  • 10M: The tune for 10M should NOT be that flat.  You should just barely pick up all the band below 2:1 and usually the ends of the band are just slightly above 2:1. This is probably the effect of the higher feed point.  Not a deal breaker, but again, is a sign of poor ground plane coupling.
  • I am not seeing any sign of anti-oxidant compound on your tubing joints or other aluminum junctions at the coils.  This is going to be problematic in short order, especially over water.  DX can sell you what you need.
  • And finally, for the love of all that is holy, reform your 80M and 40M coils.  You are killing my OCD.  Doesn't affect function, but you're killing me.  LOL

 

I won't comment on the rest of the tuning until you get those coil position issues addressed, which is key.

 

73,

Scott AC8DE

 

 

From: Butternut@groups.io On Behalf Of Fred PA3FK
Sent: Tuesday, November 12, 2019 8:54 AM
To: Butternut@groups.io
Subject: [butternut] HF9V installation and tuning

 

Hi Experts,

Let me introduce myself a little bit first.

My name is Fred Koch, 61 years young, and radio-amateur since the 1980's.  Started my carreer as a Radio-Electronic Officer in the merchant marine so i should be aware of the theory of antenna's and tuning, however this was 40 years ago and i have not been very active in the hobby so my knowledge has faded a lot i notice. 

But recently picked up the hobby again and in the weekend of November 9/10 2019 i have installed a HF9V into the ditch behind my house and tried to tune it.
The antenna is installed into the ditch, and the ditch holds about 1 M water depth.  I first drove a 3,5 M pole into the earth and then mounted the base of the HF9V (Pole A) so it is about 40 cm above the water level. (see pictures in the album).
Note that the ditch is not a salt water ditch, however from reading on the internet, i have found several posting showing good results putting the HF9V up this way without using radials.
As a ex R/O i will be using CW only (with perhaps an incidental exception for SSB) so i am aiming to have the best SWR around the lower portion of the bands.

Assembly of the HF9V was feasible, however i do recognize that the instructions could be improved here and there but i think i got it right in the end.

And then the tuning begins.
I have a Mini60S as antenna analyzer and there are some strange results i would like your thoughts about. (see picture in my album where i uploaded the outcome of the scans i did)

To start from lowest to highest band 
6 M:  Min SWR (1,49) at 48900..  This weekend the dip was properly at 50.000 so it seems i need to tune the 6M wire a little again but overall this seems like an acceptable SWR graph
10M: Min  SWR (1,41) at 27850 and overall very flat.  Perfect (see Improved 10M scan)
12 M: Min SWR (2,64) at 26500. Way off. This is with 12M coil fully compressed (see pictures) as per initial tuning instructions. However when extending the 12 M coil nothing changes.
15M: Min SWR (1,45) at 20975 with enough bandwith so the 28.000 -28.100 is workable.  Fine with me
17M:: MIn SWR (1,33) at 18020. could shift it a litlle to make lowest swr at 18080.for the moment fIne with me.  Note picture 17M scan second The first shows a different result.  MIni60S reliable???
20M: Min SWR (1,39) at 14010. Fine with me
30 M: SWR of 2,6 around 10.100..  Strange graph with second dip.  For now workable. But what does it tell?
40 M:  Two scans that both are strange. One with no dip at all (second 40M) and the first with two real sharp dips at 6650 and 6750.   This important band is unworkable.  This is my main concern as i want to be able to work properly on 40 M
80 M:  Min Swr (1,33) at 3560. Should be shifted a little bit to the left (center frequency of 3520).   Adjusting the 80M coil should achieve this. 


I am very interested to better understand the complete lack of a reliable SWR graph on 40M.  Looks as if something is not compeltly right there that is beyond tuning.


Next is the 12 M.

Note: I have not yet adjuested the base coil Q for an even lower SWR on 80M. 

Looking forward to your thoughts on this.


Norman NZ5L <kopernic30@...>
 

Fred

If the ditch on your lot is not salt water, I see no advantage of mounting the antenna there as opposed to the highest point on your lot. 
I think you would have better results, and perhaps easier tuning, from the highest point in the clear with an extensive radial field.  (16=good, 32=better, 64=best.  More just invokes the law of diminishing returns)


From: Butternut@groups.io <Butternut@groups.io> on behalf of Fred PA3FK <killerbee1958@...>
Sent: Tuesday, November 12, 2019 8:54 AM
To: Butternut@groups.io <Butternut@groups.io>
Subject: [butternut] HF9V installation and tuning
 

[Edited Message Follows]

Hi Experts,

Let me introduce myself a little bit first.

My name is Fred Koch, 61 years young, and radio-amateur since the 1980's.  Started my career as a Radio-Electronic Officer in the merchant marine so i should be aware of the theory of antenna's and tuning, however this was 40 years ago and i have not been very active in the hobby so my knowledge has faded a lot i notice. 

But recently picked up the hobby again and in the weekend of November 9/10 2019 i have installed a HF9V into the ditch behind my house and tried to tune it.
The antenna is installed into the ditch, and the ditch holds about 1 M water depth.  I first drove a 3,5 M pole into the earth and then mounted the base of the HF9V (Pole A) so it is about 40 cm above the water level. (see pictures in the album).
Note that the ditch is not a salt water ditch, however from reading on the internet, i have found several posting showing good results putting the HF9V up this way without using radials.
As a ex R/O i will be using CW only (with perhaps an incidental exception for SSB) so i am aiming to have the best SWR around the lower portion of the bands.

Assembly of the HF9V was feasible, however i do recognize that the instructions could be improved here and there but i think i got it right in the end.

And then the tuning begins.
I have a Mini60S as antenna analyzer and there are some strange results i would like your thoughts about. (see picture in my album where i uploaded the outcome of the scans i did)

To start from lowest to highest band 
6 M:  Min SWR (1,49) at 48900..  This weekend the dip was properly at 50.000 so it seems i need to tune the 6M wire a little again but overall this seems like an acceptable SWR graph
10M: Min  SWR (1,41) at 27850 and overall very flat.  Perfect (see Improved 10M scan)
12 M: Min SWR (2,64) at 26500. Way off. This is with 12M coil fully compressed (see pictures) as per initial tuning instructions. However when extending the 12 M coil nothing changes.
15M: Min SWR (1,45) at 20975 with enough bandwith so the 28.000 -28.100 is workable.  Fine with me
17M:: MIn SWR (1,33) at 18020. could shift it a little to make lowest swr at 18080.for the moment fIne with me.  Note picture 17M scan second The first shows a different result.  MIni60S reliable???
20M: Min SWR (1,39) at 14010. Fine with me
30 M: SWR of 2,6 around 10.100..  Strange graph with second dip.  For now workable. But what does it tell?
40 M:  Two scans that both are strange. One with no dip at all (second 40M) and the first with two real sharp dips at 6650 and 6750.   This important band is unworkable.  This is my main concern as i want to be able to work properly on 40 M
80 M:  Min Swr (1,33) at 3560. Should be shifted a little bit to the left (center frequency of 3520).   Adjusting the 80M coil should achieve this. 


I am very interested to better understand the complete lack of a reliable SWR graph on 40M.  Looks as if something is not completly right there that is beyond tuning.



Next is the 12 M.

Note: I have not yet adjusted the base coil Q for an even lower SWR on 80M. 

Looking forward to your thoughts on this.


Norman NZ5L <kopernic30@...>
 

Scott

Since the subject has been brought up, I am curious as to whether the 15 M wire element can be replaced with one for 17 M?
I have an antenna for 15, so did not hook up the 15M wire on mine, as it spoiled the top symmetry, but if I could operate 17 just by lengthening it somewhat I would try that.

Norm/NZ5L


From: Butternut@groups.io <Butternut@groups.io> on behalf of Scott AC8DE <ac8de@...>
Sent: Tuesday, November 12, 2019 10:14 AM
To: Butternut@groups.io <Butternut@groups.io>
Subject: Re: [butternut] HF9V installation and tuning
 

Fred,

 

Welcome to the fold.  Yours is a quite unusual installation; a type that I have no personal experience with tuning myself.  However, there have been a few through here over the years that did do over freshwater installations that had good results, which we talked though.  That said, I have definitely noted some significant issues that are correctable.  The thoughts are in no specific order, as I've written them down as I've looked at your photos.  Note, it would be a lot easier to dissect if you would use the excel sheet found here.  Looking at the charts doesn't give exact info.  It's close, but an excel sheet is better.

https://groups.io/g/Butternut/files/Butternut%20Tuning%20Charts/AC8DE%20Antenna%20Tuning%20Chart%20Excel%2097-2003%20format.xls

 

First, I renamed your album to start with your call sign.  It's hard to find anything over time in a folder that doesn't start with the owner's call sign.

 

SWR is NOT in indicator of antenna efficiency, so let's get that out of the way first.  SWR is only a portion of the picture.  A dummy load has perfect SWR after all.

 

  • Feed point height:  The height of the feed point above the ground plane should be a maximum of 6", with 3" being optimum.  You have your feed point at 15.75" above the water level/ground plane.  This is generally problematic for antenna tuning, but really problematic for efficiency.  Think of the results if you separate the two halves of a dipole by more than a couple inches.  Same thing with a vertical and its ground plane, as the ground plane is the "other half" of the antenna.  However, even with this high feed point, it may still be quite workable in an above water install, just understand the effect on bandwidth and efficiency.
  • Coil positions - This appears to be your biggest problem. It appears you have your 80M and 40M coils switched.  The coil with more turns (about 16-17) of the two is the 80M coil, which belongs BELOW the insulator.  The 40M coil typically has about 10 turns.
  • 80M:  If I visually drop the lowest SWR to 1:1 (which happens with Q coil adjustment), it appears that you are getting about 50 KHz of bandwidth below 2:1 by my estimate.  It should only be about 20-25KHz.  This is usually indicative of poor ground plane coupling/effect for the ground and hence, low antenna efficiency.  The usual advice is to install more radials, but in your case, I have no suggestion.  Drop the feed point as much as possible.  These comments may change considerably when you get the coils swapped.
  • 40M:  The first thing that jumps out and bites me is that your 30M coil assembly is tapped in the completely wrong place on the 40M coil.  (Although this is the wrong coil to begin with as installed.)  Its proper starting point is the 3rd or 4th turn down from the TOP of the 40M coil; usually the 4th.  I'd bet my house that the wrong coil and tapping point combination is causing your 40M problem and an improper tune of 20M.  Probably does some weird stuff to 30M as well.  These comments may also change considerable when you get the coils swapped.
  • What am I seeing in this photo?  https://groups.io/g/Butternut/photo/183823/14?p=Created,,,20,2,0,0  Is this a guy point?  If so, what is the big metal bracket you are using?  Seems like some massive overkill that adds capacitance and stress.  All you heed is a hose clamp and some D-rings and the smallest rope you can get.  There is very little wind loading on a Butternut, so small guy lines and light brackets are all that is needed.  It doesn't need to be any more than this, which has withstood 70 MPH winds. https://groups.io/g/Butternut/photo/25953/18?p=Created,,,20,2,0,0
  • Once you get the 80, 40 and 30M coils all sorted out, things will be quite a bit different.  If there are any questions on tuning procedure, look at the latest version of the instructions here. https://groups.io/g/Butternut/files/Butternut%20Manuals%20-%20New%20DX%20Engineering%20Versions/HF6V%20&%20HF9V/BUT-HF9V_Rev3.pdf
  • 10M: The tune for 10M should NOT be that flat.  You should just barely pick up all the band below 2:1 and usually the ends of the band are just slightly above 2:1. This is probably the effect of the higher feed point.  Not a deal breaker, but again, is a sign of poor ground plane coupling.
  • I am not seeing any sign of anti-oxidant compound on your tubing joints or other aluminum junctions at the coils.  This is going to be problematic in short order, especially over water.  DX can sell you what you need.
  • And finally, for the love of all that is holy, reform your 80M and 40M coils.  You are killing my OCD.  Doesn't affect function, but you're killing me.  LOL

 

I won't comment on the rest of the tuning until you get those coil position issues addressed, which is key.

 

73,

Scott AC8DE

 

 

From: Butternut@groups.io On Behalf Of Fred PA3FK
Sent: Tuesday, November 12, 2019 8:54 AM
To: Butternut@groups.io
Subject: [butternut] HF9V installation and tuning

 

Hi Experts,

Let me introduce myself a little bit first.

My name is Fred Koch, 61 years young, and radio-amateur since the 1980's.  Started my carreer as a Radio-Electronic Officer in the merchant marine so i should be aware of the theory of antenna's and tuning, however this was 40 years ago and i have not been very active in the hobby so my knowledge has faded a lot i notice. 

But recently picked up the hobby again and in the weekend of November 9/10 2019 i have installed a HF9V into the ditch behind my house and tried to tune it.
The antenna is installed into the ditch, and the ditch holds about 1 M water depth.  I first drove a 3,5 M pole into the earth and then mounted the base of the HF9V (Pole A) so it is about 40 cm above the water level. (see pictures in the album).
Note that the ditch is not a salt water ditch, however from reading on the internet, i have found several posting showing good results putting the HF9V up this way without using radials.
As a ex R/O i will be using CW only (with perhaps an incidental exception for SSB) so i am aiming to have the best SWR around the lower portion of the bands.

Assembly of the HF9V was feasible, however i do recognize that the instructions could be improved here and there but i think i got it right in the end.

And then the tuning begins.
I have a Mini60S as antenna analyzer and there are some strange results i would like your thoughts about. (see picture in my album where i uploaded the outcome of the scans i did)

To start from lowest to highest band 
6 M:  Min SWR (1,49) at 48900..  This weekend the dip was properly at 50.000 so it seems i need to tune the 6M wire a little again but overall this seems like an acceptable SWR graph
10M: Min  SWR (1,41) at 27850 and overall very flat.  Perfect (see Improved 10M scan)
12 M: Min SWR (2,64) at 26500. Way off. This is with 12M coil fully compressed (see pictures) as per initial tuning instructions. However when extending the 12 M coil nothing changes.
15M: Min SWR (1,45) at 20975 with enough bandwith so the 28.000 -28.100 is workable.  Fine with me
17M:: MIn SWR (1,33) at 18020. could shift it a litlle to make lowest swr at 18080.for the moment fIne with me.  Note picture 17M scan second The first shows a different result.  MIni60S reliable???
20M: Min SWR (1,39) at 14010. Fine with me
30 M: SWR of 2,6 around 10.100..  Strange graph with second dip.  For now workable. But what does it tell?
40 M:  Two scans that both are strange. One with no dip at all (second 40M) and the first with two real sharp dips at 6650 and 6750.   This important band is unworkable.  This is my main concern as i want to be able to work properly on 40 M
80 M:  Min Swr (1,33) at 3560. Should be shifted a little bit to the left (center frequency of 3520).   Adjusting the 80M coil should achieve this. 


I am very interested to better understand the complete lack of a reliable SWR graph on 40M.  Looks as if something is not compeltly right there that is beyond tuning.


Next is the 12 M.

Note: I have not yet adjuested the base coil Q for an even lower SWR on 80M. 

Looking forward to your thoughts on this.


Fred PA3FK
 
Edited

Hi Scott,

How stupid.  Indeed the 80-40 meter coil is reversed. I had the 30 M initially on the 4th tap, but had to change that to get 30M in the spot i wanted it too be.
Need to find a moment with acceptable weather to correct this. 

WIll update this thread once done.

BTW; I also was a bit skeptic about the guying hardware. Was advised to use this by the supplier of the antenna however i agree a much leaner guying point hardware (like the hose you suggest)
Also i have applied Penetrox anti-oxidant to all joints and connection points. SO perhaps not visible but i did use that. 
And for your sake i will reform the coils to relieve your OCD.  :-)


Scott AC8DE
 

Fred,

 

My OCD thanks you for the reforming of the coils.  ;-D

 

73,

Scott AC8DE

 

From: Butternut@groups.io On Behalf Of Fred PA3FK
Sent: Tuesday, November 12, 2019 11:04 AM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V installation and tuning

 

Hi Scott,

How stupid.  Indeed the 80-40 meter coil is reversed. I had the 30 M initially on the 4th tap, but had to change that to get 30M in the spot i wanted it too be.
Need to find a moment with acceptable weather to make this happen.

WIll update this thread once done.

BTW; I also was a bit sceptic about the guying hardware. Was advised to use this by the supplier of the antenna however i agree a much leaner guying point hardware (like the hose you suggest)
Also i have applied Penetrox anti-oxidant to all joints and connection points. SO perhaps not visible but i did use that. 
And for your sake i will reform the coils to relieve your OCD.  :-)


Fred PA3FK
 
Edited

Hi Norman,

The reason to do it like this is to avoid having all these radials running around in my garden.
Believe me, i already had quit a challenge to get this setup accepted by the real boss around the house.   :-)

Trying to bury 32 or 64 radials into the (artifical) grass will not get the WAF (wife acceptance factor)

So i will stick for now with the experiment of mounting it on the water surface. I have read good stories about it, so i am interested to see how well the HF9V will perform once i have the coils corrected and have the coax routed from my shack to the HF9V (which will be another interesting project also since my shack is on the top floor of my (free standing) house.  Need to find a way to get again up the ladder and onto the roof to feed the coax into the shack and then through the shrubs around the house onto the HF9V.  Coax is already in house. 
Also here i have the mind the wife.   :-)


Fred PA3FK
 

One more remark on the tuning guide.

The box came already with a printed manual Revision version 4. Perhaps wise to change the link to this newest installation and tuning guide?


Scott AC8DE
 

Indeed, I just updated both the HF6V and HF9V manuals online.

 

https://groups.io/g/Butternut/files/Butternut%20Manuals%20-%20New%20DX%20Engineering%20Versions/HF6V%20&%20HF9V/BUT-HF6V_Rev4a.pdf

 

https://groups.io/g/Butternut/files/Butternut%20Manuals%20-%20New%20DX%20Engineering%20Versions/HF6V%20&%20HF9V/BUT-HF9V_Rev4a.pdf

 

73,

Scott AC8DE

 

From: Butternut@groups.io On Behalf Of Fred PA3FK
Sent: Tuesday, November 12, 2019 1:04 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V installation and tuning

 

One more remark on the tuning guide.

The box came already with a printed manual Revision version 4. Perhaps wise to change the link to this newest installation and tuning guide?


Norman NZ5L <kopernic30@...>
 

An elevated base is also a possibility, either making your own tuned radials or buying (or building--see some previous posts of last month)
up to a dozen STR, or Stub-Tuned Radials, constructed with 300 ohm twin lead.  These are tuned multi-band counterpoises, like having a multi-band antenna.  In the Philippines I used 8 factory purchased STRs  (two kits) on my rooftop installation, and talked to The States every afternoon for a year with only my TR4C.    Height was about 16'.  You need far fewer radials for an elevated vertical.


From: Butternut@groups.io <Butternut@groups.io> on behalf of Fred PA3FK <killerbee1958@...>
Sent: Tuesday, November 12, 2019 11:25 AM
To: Butternut@groups.io <Butternut@groups.io>
Subject: Re: [butternut] HF9V installation and tuning
 
Hi Norman,

The reason to do it like this is to avoid having all these radials running around in my garden.
Believe me, i already had quit a challenge to get this acceptance by the real boss around the house.   :-)

Trying to bury 32 or 64 radials into the (artifical) grass will not get the WAF (wife acceptance factor)

So i will stick for now with the experiment of mounting it on the water surface. I have read good stories about it, so i am interested to see how well the HF9V will perform once i have the coils corrected and have the coax routed from my shack to the HF9V (which will be another interesting project also since my shack is on the top floor of my (free standing) house.  Need to find a way to get again up the ladder and onto the roof to feed the coax into the shack and then through the shrubs around the house onto the HF9V.  Coax is already in house. 
Also here i have the mind the wife.   :-)


 

Fred,
I think you are going to have frustrating results with the antenna mounted as shown.  There is going to be considerable variables in the conductivity of the water depending on the time of the year and the makeup of the ground that the water is in contact with.  Even if the water were somewhat conductive, you still need to couple into the water for the antenna to act properly. If the ditch is lined, then there will be no conductivity into the surrounding soil that will help the antenna load in all directions.  Runoff during rain is also going to change the chemical makeup of the water.
Scott has hit the nail on the head and when you change the coils, you should see way better results.  Please be sure to follow the tuning instructions in order.  The bands do interact.  In particular the 30M coil has a secondary resonance just above the 17M band and then again near the 12M band.  That is likely why the coil is fully depressed.
I agree that you need to do some body and fender work on the coils.  They do have some capacitive coupling the antenna tubing and it is best for this to be linear along the length.  Working one turn at a time, you can coerce the wire back to near it's original shape.  Bending the top and bottom wire and/or the aluminum strip allows you to center the coil on the tubing.
Unless you live in a very windy area, guy lines are not needed.  From the looks in your photos, you have a lot of trees that will block the wind.


 

Norman,
The wire element for 15M is an open 1/4 wave transmission line that is shorted at the top.  This essentially isolates the top of the antenna on 15M making the bottom a 1/4 wave radiator.  The overall height of the antenna does not allow a 1/4 wave line to placed on the antenna such that a 1/4 wave radiator on 17M would be realized.  The lengths just don't add up.
The 17M kit adds just enough lumped impedance to load the antenna on 17M 
Al
WB9UVJ


Norman NZ5L <kopernic30@...>
 

Thanks.  Saves me the trouble of trying it.


From: Butternut@groups.io <Butternut@groups.io> on behalf of Al WB9UVJ <markaren1@...>
Sent: Tuesday, November 12, 2019 5:05 PM
To: Butternut@groups.io <Butternut@groups.io>
Subject: Re: [butternut] HF9V installation and tuning
 
Norman,
The wire element for 15M is an open 1/4 wave transmission line that is shorted at the top.  This essentially isolates the top of the antenna on 15M making the bottom a 1/4 wave radiator.  The overall height of the antenna does not allow a 1/4 wave line to placed on the antenna such that a 1/4 wave radiator on 17M would be realized.  The lengths just don't add up.
The 17M kit adds just enough lumped impedance to load the antenna on 17M 
Al
WB9UVJ


Jerry N9XR
 

"SWR is NOT in indicator of antenna efficiency, so let's get that out of the way first.  SWR is only a portion of the picture.  A dummy load has perfect SWR after all."

For my purposes, SWR is a measurement for the transmission line.  There's an SWR loss table that can be found on the internet in many places such as...

https://www.rcgroups.com/forums/showthread.php?1966664-FrSky-Taranis-X9D-hardware-hacks/page493

As we can see here, the percent of loss with a 1.1:1 SWR is 0.2%.  The percent loss with a 1.5:1 SWR is 4.0%.   The percentage loss with a 2:1 SWR is 11.1%.  With a 3:1 SWR, you've lost a quarter of your power being transferred to the load/antenna.  If it's a dummy load then your dummy load is going to be missing power being transmitted due to reflected losses.  It doesn't get any better than this.  There are tables for lossy line that shows a lower efficiency. 

So if you have a 100W transmitter, and your SWR is 3:1 at the antenna, the best you can hope for is the antenna transmitting 75 watts.  Certainly with losses, it will be less. 

I don't know why this wouldn't be an indicator of efficiency.  The higher SWR, the more losses incurred.  It's right there in the SWR table.  Of course there's more to it as I explained above from lossy line, but this is an indicator of the best you can be. 

Your antenna may be putting the signal into the clouds or warming the earthworms.  But the SWR is an indication of the efficiency of the signal input being transferred to  the load at the other end.  There's no other way to put it.  You may have an antenna with the best gain in the world, but if it isn't matched, you have a higher SWR and you aren't transmitting what you were hoping. 

73,

Jerry N9XR


Scott AC8DE
 

Jerry,

 

No one is arguing SWR is not important.  It is.  But there is the misconception that having a great SWR is the end all in antenna system efficiency.  And that is the point.  Too many times people worry so much about getting a good match they miss the bigger picture.

 

What I've learned dealing with the multi-band Butternut is that bandwidth will get narrower (system Q gets higher) and the SWR gets higher a bit as more radials are laid, but yet the antenna clearly works a lot better.  And that is my point.

 

So perhaps I should have said; SWR is only a part of antenna system efficiency and should not be relied upon as the only indicator.

 

73,

Scott AC8DE

 

From: Butternut@groups.io On Behalf Of Jerry N9XR
Sent: Tuesday, November 12, 2019 8:15 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V installation and tuning

 

"SWR is NOT in indicator of antenna efficiency, so let's get that out of the way first.  SWR is only a portion of the picture.  A dummy load has perfect SWR after all."

For my purposes, SWR is a measurement for the transmission line.  There's an SWR loss table that can be found on the internet in many places such as...

https://www.rcgroups.com/forums/showthread.php?1966664-FrSky-Taranis-X9D-hardware-hacks/page493

As we can see here, the percent of loss with a 1.1:1 SWR is 0.2%.  The percent loss with a 1.5:1 SWR is 4.0%.   The percentage loss with a 2:1 SWR is 11.1%.  With a 3:1 SWR, you've lost a quarter of your power being transferred to the load/antenna.  If it's a dummy load then your dummy load is going to be missing power being transmitted due to reflected losses.  It doesn't get any better than this.  There are tables for lossy line that shows a lower efficiency. 

So if you have a 100W transmitter, and your SWR is 3:1 at the antenna, the best you can hope for is the antenna transmitting 75 watts.  Certainly with losses, it will be less. 

I don't know why this wouldn't be an indicator of efficiency.  The higher SWR, the more losses incurred.  It's right there in the SWR table.  Of course there's more to it as I explained above from lossy line, but this is an indicator of the best you can be. 

Your antenna may be putting the signal into the clouds or warming the earthworms.  But the SWR is an indication of the efficiency of the signal input being transferred to  the load at the other end.  There's no other way to put it.  You may have an antenna with the best gain in the world, but if it isn't matched, you have a higher SWR and you aren't transmitting what you were hoping. 

73,

Jerry N9XR

 


Fred PA3FK
 

Hi Al,

Thanks for your concerns.  I do appreciate it and understand this is not going to be the most optimal solution.
However, as explained, i really have stretched the WAF already by this solution, so i will give it a try.
As Scott also pointed out, there are other installations around that show decent results with this kind of setup so i will continue to try to make it as good as possible.

As i am not a contester anyway i will be very happy with a antenna that has sufficient bandwith and a SWR < 1:2.0 on all bands as this will allow me to have QSO's in all applicable bands supplied by the HF9V. The fact that my forwarded power is perhaps a bit less than the 100W outputted by my transceiver will not bother me. 

As Scott mentioned, indeed first step is to correct the 80/40M coil.  Next is to restart the tuning and see what numbers i can come up with.
I will input the result of my tuning here but i will also report back on the quality of real life connections once my antenna is connected to the shack


Fred PA3FK
 

Hi Scott (and all)

In between the showers i was able to correct the 40/80/30 M coil position and remove the oversized guying bracket.
Now waiting for some dry moments to do the measurements.

1. Feed point (measured) is at 30 Cm (about 7 inch) above the water. Not ideal and i will lower the feed point later, however that probably will be spring as the lower clamp is fastened under water and the temperature of the water does not really make me looking forward to doing it now.  :-)  (optimisation for later)
2. Coils reversed.  Should be oke now. See pictures in album
3.Let's see what the new measurement do show. I will try to put it in the supplied spreadsheet
4. Corrected the 30M coil to tap into the 40M coil at 4th turn (as per instruction manual)
5.Let wait and see
6. I will try to put the results in the supplied spreadsheet. One question. The mini60s shows SWR, Z and R. BAsed on the uploaded scan, can you tell which number goes where in the SS
7. Applied remaining penetrox on all joints and brackets that i touched today.
8. For your pleasure i tried to tidy up the coils. See picture.  Is your OCD now under control again?   ;-)



Steven AC2XM
 

Regarding SWR and coax losses, I got interested in the math of the transmission line equations, etc.

I wrote some software, along the lines of the ARRL TLW program, and I made the source code as well as executables for Windows and Fedora Linux available here:

https://github.com/stevefalco/tline

There is also a document that goes into the details of the math and the various algorithms that I used, in case anyone is interested.

This is GPL software, so you are free to grab a copy, if you like.

Steve

On 11/12/19 8:14 PM, Jerry N9XR wrote:
"SWR is NOT in indicator of antenna efficiency, so let's get that out of the way first.  SWR is only a portion of the picture.  A dummy load has perfect SWR after all."

For my purposes, SWR is a measurement for the transmission line.  There's an SWR loss table that can be found on the internet in many places such as...

https://www.rcgroups.com/forums/showthread.php?1966664-FrSky-Taranis-X9D-hardware-hacks/page493

As we can see here, the percent of loss with a 1.1:1 SWR is 0.2%.  The percent loss with a 1.5:1 SWR is 4.0%.   The percentage loss with a 2:1 SWR is 11.1%.  With a 3:1 SWR, you've lost a quarter of your power being transferred to the load/antenna.  If it's a dummy load then your dummy load is going to be missing power being transmitted due to reflected losses.  It doesn't get any better than this.  There are tables for lossy line that shows a lower efficiency. 

So if you have a 100W transmitter, and your SWR is 3:1 at the antenna, the best you can hope for is the antenna transmitting 75 watts.  Certainly with losses, it will be less. 

I don't know why this wouldn't be an indicator of efficiency.  The higher SWR, the more losses incurred.  It's right there in the SWR table.  Of course there's more to it as I explained above from lossy line, but this is an indicator of the best you can be. 

Your antenna may be putting the signal into the clouds or warming the earthworms.  But the SWR is an indication of the efficiency of the signal input being transferred to  the load at the other end.  There's no other way to put it.  You may have an antenna with the best gain in the world, but if it isn't matched, you have a higher SWR and you aren't transmitting what you were hoping. 

73,

Jerry N9XR

 


Scott AC8DE
 

Fred,

 

>1. Feed point (measured) is at 30 Cm (about 7 inch) above the water.

30 Cm is about 12", not 7".  Again, a lower feed point is better for sure.  It is most critical on the upper bands due to wavelengths.  12" is livable usually, just not optimum and can potentially cause some issues.

 

>2. Coils reversed.  Should be ok now. See pictures in album

>4. Corrected the 30M coil to tap into the 40M coil at 4th turn (as per instruction manual)
Looks mucho better!  Note that when you do move the tap around on the 40M coil OR you are adjusting the 40M length for tuning, take the 30M coil loose from the main radiator so you don't distort the 40M coil.

 

>6. I will try to put the results in the supplied spreadsheet. One question. The mini60s shows SWR, Z and R. Based on the uploaded scan, can you tell which number goes where in the SS
I think you are wondering about Z for Xs on the spreadsheet.  Xs is from an MFJ analyzer, which should be reactance alone.  Z should be an indication of complex impedance, which includes R.  So Z doesn't exist on my version of the spreadsheet.  You'd simply have to change the spreadsheet for your analyzer's readout and add the column for Z.

 

>8. For your pleasure I tried to tidy up the coils. See picture.  Is your OCD now under control again?   ;-)
Oh no, not even close to my standards, but you don't have to be me.  It's better though and completely workable.  Frankly, I've worked on some pretty bad condition Butternuts that had coils super mangled that made your coils look almost new that still tuned up just fine.

 

I've rebuilt quite a few old Butternuts.  At some point on distorted coils, I've found that I could no long reform the coil by trying to reshape them.  So what I do is I completely uncoil the aluminum wire.  Then try to take as many of the lumps and bumps out of the wire so it is as die straight as possible.  Then I reform it completely compressed around some 2.5" schedule 40 PVC pipe, which is 2.875" OD.  This pipe is just a bit smaller that a Butternut coil, but I've found that the wire springs back a bit anyway and then I just relax it a bit more by hand to get the coil back to its OE supplied condition of exactly 3" ID.  I also clean it up a bit with some oil and Scotchbrite before reforming.  Not too much though just to the point it feels smooth, as you want to keep the oxidation on it for protection, as it will just oxidize again anyway.  I'm not suggesting going to that trouble, but that is how one can do it easily and they come out looking factory new except for the oxidation.

 

73,

Scott AC8DE

 

From: Butternut@groups.io On Behalf Of Fred PA3FK
Sent: Wednesday, November 13, 2019 9:23 AM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V installation and tuning

 

Hi Scott (and all)

In between the showers i was able to correct the 40/80/30 M coil position and remove the oversized guying bracket.
Now waiting for some dry moments to do the measurements.

1. Feed point (measured) is at 30 Cm (about 7 inch) above the water. Not ideal and i will lower the feed point later, however that probably will be spring as the lower clamp is fastened under water and the temperature of the water does not really make me looking forward to doing it now.  :-)  (optimisation for later)
2. Coils reversed.  Should be oke now. See pictures in album
3.Let's see what the new measurement do show. I will try to put it in the supplied spreadsheet
4. Corrected the 30M coil to tap into the 40M coil at 4th turn (as per instruction manual)
5.Let wait and see
6. I will try to put the results in the supplied spreadsheet. One question. The mini60s shows SWR, Z and R. BAsed on the uploaded scan, can you tell which number goes where in the SS
7. Applied remaining penetrox on all joints and brackets that i touched today.
8. For your pleasure i tried to tidy up the coils. See picture.  Is your OCD now under control again?   ;-)


VE9AA - Mike
 

Hi from Canada Fred,
My wife is Dutch and I have been to your fine country and loved it.

OK, that out of the way....you are missing 1/2 of your antenna.  Even if it was on a salt water polder, you still need some minimal radials !

  I have read most of the comments (quickly) and skimmed over most of the pictures.
I think I understand the situation.  If it were me, I would still put down radials, but here's what I would do.  Instead of raised (ugly factor, wife frowns) or
buried radials....big work, fall into the slote (sp?) get all wet, I would make up 30 or so 30' radials out of insulated wire (seal the tips where copper sticks out) and staple them on the side of the bank or toss them out into the ditch/slote in a bowtie pattern.  They would either be on the bank or sink, nobody would see them, (wife doesn't know) but they could still collect return currents.  You water is not very conductive.  Even if it were, you are operating at a great loss.

I operated away from home in the California QSO party a month or so ago using a similar situation.  I had a screwdriver antenna (not an HF9V) and had made up 24 or something radials which I had tested here in my driveway with the radials deployed in a 360*degree circle.  All was good.
When I got to VE1 land (I live in VE9) I found because of the location of my rental cabin, I could not deploy the radials like at home, so had to put them out in a bowtie pattern, running from a small tripod, a meter (3'_) across a deck, and then into the grass surrounding the deck.  All SWR curves were pretty much the same as at home, except on 80m where I couldn't get as good of a match.

I feel without some kind of radial field, you are doing yourself a great disservice.

I do wish you the best and some antenna is better than no antenna...but you could do a lot better!

(If I missed it that you do have radials, that;'s a big boo-boo on my part.  Am off work sick today, slept late and am drinking my first coffee so not firing on all cylinders)

73 de Mike VE9AA