Topics

HF9V-X rebuild completed.


Brent WB4X
 

I finished my HF9V X today with good results. I replaced my Hustler 6BTV with it.  Swr is good on all bands with the exception of 17 meters where the swr is almost 3-1. any ideas on that would be appreciated. I did modify this one by adding the base mount from one of my Hustler BTV. That worked out great. I have made many contacts on 20 and 30 meters, with good results. I will continue to work around all the bands.  I have the antenna ground mounted with the dxe radial plate and 70 radials ranging 25 to 60 feet long.  
--
Charles  WB4X


 
Edited

Charles,
The better the radial system the more difficult it is to get a low SWR on 17M.  My antenna measured about 10+j0 on 17M and I have 64 radials.  A long time ago, I talked with the design engineer who gave me that little tidbit.  I had that feedback that the 17M kit adds resonance that sums with low impedance from the 30M kit and the wide 20M bandwidth.  If you think about it, a poor radial system would increase the radiation resistance to the point where it might actually achieve 30 ohms. 
I have recently suspected that the 17M kit might actually be in the wrong place on my antenna.  I plan to perform some experiments when I get my analyzer back from MFJ.  I did see a resonance dip in band while I adjusted the coil section but it was a very low base impedance at resonance.
--
Al
WB9UVJ


Brent WB4X
 

Hi Al, thanks for the reply. I do have a dip in the SWR on 17 but 2.8 was as low as it would go. I made a few ft8 contacts using it with my tuner. Seems to work ok even with the high swr. On thing interesting is that it just rained here and 17 meter swr came down. All other bands did not change.  Over all this antenna seems to work really good.

 

Charles

WB4X

 

Sent from Mail for Windows 10

 

From: Al WB9UVJ
Sent: Monday, August 24, 2020 8:22 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

[Edited Message Follows]

Charles,
The better the radial system the more difficult it is to get a low SWR on 17M.  My antenna measured about 10+j0 on 17M and I have 64 radials.  A long time ago, I talked with the design engineer who gave me that little tidbit.  I had that feedback that the 17M kit adds resonance that sums with low impedance from the 30M kit and the wide 20M bandwidth.  If you think about it, a poor radial system would increase the radiation resistance to the point where it might actually achieve 30 ohms. 
I have recently suspected that the 17M kit might actually be in the wrong place on my antenna.  I plan to perform some experiments when I get my analyzer back from MFJ.  I did see a resonance dip in band while I adjusted the coil section but it was a very low base impedance at resonance.
--
Al
WB9UVJ

 


--
Charles  WB4X


Brent WB4X
 

I think I found the problem with high SWR on 17 meters.  The Lowest I could get the SWR on 17 meters was 2.8-1. I was able to tune that out easily with my antenna tuner. So I decided to put sum power to it just to see what happed. (smoke test). So I put 400 watts on FT8. After several CQs and contacts, I noticed that the swr had drifted higher. I better go check. Went to the antenna and sure enough the insulator at the top of the 17 meter coil had heated to the point that it had burned and melted the insulator. So now I need and insulator, I think glass or ceramic would be better.  Your thoughts please. Did I read on this reflector about someone replacing there insulator with one made of ceramic?

 

Charles

WB4X

 

Sent from Mail for Windows 10

 

From: Brent WB4X
Sent: Monday, August 24, 2020 10:19 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

Hi Al, thanks for the reply. I do have a dip in the SWR on 17 but 2.8 was as low as it would go. I made a few ft8 contacts using it with my tuner. Seems to work ok even with the high swr. On thing interesting is that it just rained here and 17 meter swr came down. All other bands did not change.  Over all this antenna seems to work really good.

 

Charles

WB4X

 

Sent from Mail for Windows 10

 

From: Al WB9UVJ
Sent: Monday, August 24, 2020 8:22 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

[Edited Message Follows]

Charles,
The better the radial system the more difficult it is to get a low SWR on 17M.  My antenna measured about 10+j0 on 17M and I have 64 radials.  A long time ago, I talked with the design engineer who gave me that little tidbit.  I had that feedback that the 17M kit adds resonance that sums with low impedance from the 30M kit and the wide 20M bandwidth.  If you think about it, a poor radial system would increase the radiation resistance to the point where it might actually achieve 30 ohms. 
I have recently suspected that the 17M kit might actually be in the wrong place on my antenna.  I plan to perform some experiments when I get my analyzer back from MFJ.  I did see a resonance dip in band while I adjusted the coil section but it was a very low base impedance at resonance.
--
Al
WB9UVJ

 


--
Charles  WB4X

 


--
Charles  WB4X


Tom Parkinson
 

400 watts on FT8........ there is the real problem.......

-------- Original message --------
From: Brent WB4X <bsutphin@...>
Date: 8/25/20 14:26 (GMT-05:00)
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

I think I found the problem with high SWR on 17 meters.  The Lowest I could get the SWR on 17 meters was 2.8-1. I was able to tune that out easily with my antenna tuner. So I decided to put sum power to it just to see what happed. (smoke test). So I put 400 watts on FT8. After several CQs and contacts, I noticed that the swr had drifted higher. I better go check. Went to the antenna and sure enough the insulator at the top of the 17 meter coil had heated to the point that it had burned and melted the insulator. So now I need and insulator, I think glass or ceramic would be better.  Your thoughts please. Did I read on this reflector about someone replacing there insulator with one made of ceramic?

 

Charles

WB4X

 

Sent from Mail for Windows 10

 

From: Brent WB4X
Sent: Monday, August 24, 2020 10:19 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

Hi Al, thanks for the reply. I do have a dip in the SWR on 17 but 2.8 was as low as it would go. I made a few ft8 contacts using it with my tuner. Seems to work ok even with the high swr. On thing interesting is that it just rained here and 17 meter swr came down. All other bands did not change.  Over all this antenna seems to work really good.

 

Charles

WB4X

 

Sent from Mail for Windows 10

 

From: Al WB9UVJ
Sent: Monday, August 24, 2020 8:22 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

[Edited Message Follows]

Charles,
The better the radial system the more difficult it is to get a low SWR on 17M.  My antenna measured about 10+j0 on 17M and I have 64 radials.  A long time ago, I talked with the design engineer who gave me that little tidbit.  I had that feedback that the 17M kit adds resonance that sums with low impedance from the 30M kit and the wide 20M bandwidth.  If you think about it, a poor radial system would increase the radiation resistance to the point where it might actually achieve 30 ohms. 
I have recently suspected that the 17M kit might actually be in the wrong place on my antenna.  I plan to perform some experiments when I get my analyzer back from MFJ.  I did see a resonance dip in band while I adjusted the coil section but it was a very low base impedance at resonance.
--
Al
WB9UVJ

 


--
Charles  WB4X

 


--
Charles  WB4X


Brent WB4X
 

That’s your opinion. I got mine to. It sure will bring antenna weaknesses to light.

 

Sent from Mail for Windows 10

 

From: Tom Parkinson
Sent: Tuesday, August 25, 2020 2:47 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

400 watts on FT8........ there is the real problem.......

 

-------- Original message --------

From: Brent WB4X <bsutphin@...>

Date: 8/25/20 14:26 (GMT-05:00)

To: Butternut@groups.io

Subject: Re: [butternut] HF9V-X rebuild completed.

 

I think I found the problem with high SWR on 17 meters.  The Lowest I could get the SWR on 17 meters was 2.8-1. I was able to tune that out easily with my antenna tuner. So I decided to put sum power to it just to see what happed. (smoke test). So I put 400 watts on FT8. After several CQs and contacts, I noticed that the swr had drifted higher. I better go check. Went to the antenna and sure enough the insulator at the top of the 17 meter coil had heated to the point that it had burned and melted the insulator. So now I need and insulator, I think glass or ceramic would be better.  Your thoughts please. Did I read on this reflector about someone replacing there insulator with one made of ceramic?

 

Charles

WB4X

 

Sent from Mail for Windows 10

 

From: Brent WB4X
Sent: Monday, August 24, 2020 10:19 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

Hi Al, thanks for the reply. I do have a dip in the SWR on 17 but 2.8 was as low as it would go. I made a few ft8 contacts using it with my tuner. Seems to work ok even with the high swr. On thing interesting is that it just rained here and 17 meter swr came down. All other bands did not change.  Over all this antenna seems to work really good.

 

Charles

WB4X

 

Sent from Mail for Windows 10

 

From: Al WB9UVJ
Sent: Monday, August 24, 2020 8:22 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

[Edited Message Follows]

Charles,
The better the radial system the more difficult it is to get a low SWR on 17M.  My antenna measured about 10+j0 on 17M and I have 64 radials.  A long time ago, I talked with the design engineer who gave me that little tidbit.  I had that feedback that the 17M kit adds resonance that sums with low impedance from the 30M kit and the wide 20M bandwidth.  If you think about it, a poor radial system would increase the radiation resistance to the point where it might actually achieve 30 ohms. 
I have recently suspected that the 17M kit might actually be in the wrong place on my antenna.  I plan to perform some experiments when I get my analyzer back from MFJ.  I did see a resonance dip in band while I adjusted the coil section but it was a very low base impedance at resonance.
--
Al
WB9UVJ

 


--
Charles  WB4X

 


--
Charles  WB4X

 


--
Charles  WB4X


 

OK, You said it had just rained, was the insulator wet and that was the cause of the heating?  My insulator appears to be delrin or some other dark grey
polycarbonate, not porous,
--
Al
WB9UVJ


Brent WB4X
 

It rained yesterday, when it rained the swr went down. The antenna was dry today in full sun and the swr was back up to 2.8-1. I tuned swr out with the tuner.  Then I put some power to it. At first swr was great. Gradually as I was transmitting the swr went up. Made me think something was heating up, sort of like when a toroidal inductor saturates. So I went to the antenna and the insulator was really hot and distorted on the coil end.  My antenna is a very old one. (HF9V-X) The insulator is made of a gray plastic looking materal.

 

Sent from Mail for Windows 10

From: Al WB9UVJ
Sent: Tuesday, August 25, 2020 7:14 PM
To: Butternut@groups.io
Subject: Re: [butternut] HF9V-X rebuild completed.

 

OK, You said it had just rained, was the insulator wet and that was the cause of the heating?  My insulator appears to be delrin or some other dark grey
polycarbonate, not porous,
--
Al
WB9UVJ

 


--
Charles  WB4X


 

My guess is the insulator has become resistive and once you applied power, some of it went into heating the insulator.  That is not uncommon, but you also mentioned it was hotter near the coil end.  I would immediately suspect a poor or high resistance contact at that point.  High resistance and high current don't play well with each other.
--
Al
WB9UVJ