John G0SNF

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

tony stokes

It is a simple math solution.  You know where it is resonant.    234/fMHz=length in feet(you would have to convert to cm/mm.
Just extrapolate the difference of where you want to be resonant and you can determine the length to cut.   Mine came in perfectly on the first try.  Only took it down the once.

On Tuesday, July 7, 2020, 09:51:49 AM EDT, John G0SNF via groups.io <g0snf@...> wrote:

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

John G0SNF

Tony
Thank you, I’m old enough to be happy with feet and inches.
Maybe that information could be on the Instruction leaflet.
If there is an easy answer,  what does the constant 234 represent?
Best wishes

John Culling

On 7 Jul 2020, at 18:16, tony stokes via groups.io <kn1mexico@...> wrote:

﻿
It is a simple math solution.  You know where it is resonant.    234/fMHz=length in feet(you would have to convert to cm/mm.
Just extrapolate the difference of where you want to be resonant and you can determine the length to cut.   Mine came in perfectly on the first try.  Only took it down the once.
On Tuesday, July 7, 2020, 09:51:49 AM EDT, John G0SNF via groups.io <g0snf@...> wrote:

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

John,
There are two things at play here.  The stub will determine the center of bandwidth while the lower point will determine the lowest SWR.  Remember that the antenna is a 3/4 wave but the stub is 1/4 wave.  I am right now at your same point and resonant at the same point.  However, I have nearly 4 MHz 2:1 bandwidth.  Since I have never worked any 6 meter activity, I am not going to move anything until I have a little more experience.  TV channel 2 (analog) was a big factor against 6 meter activity here in Chicago.
Al
WB9UVJ

VE9AA - Mike

234/49.73=4.71 feet...…...234/50.200=4.66 feet.

Make it .05feet longer---or about 5/8ths of an inch.

If I was a betting man, I'd say you're going to have to take it down more than once however. ;-)  That's just the way it is with these.

You should have enough wire left over at one end to just unravel the wire (you didn't clip it all off, right?) and lengthen it out a titch.

Myself, personally, I'd go another inch or even two longer, but that's just me ;-)

234 is just a constant that some math-whizz figured out if they took that # and divided it by the frequency in MHz, then the 1/4wave length would come out in feet.
Mike VE9AA

On Tue, Jul 7, 2020 at 10:51 AM, John G0SNF wrote:

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

--
Mike VE9AA

John G0SNF

Mike
I believe I need to shorten the wire in order to raise the resonant frequency ?

John Culling

On 7 Jul 2020, at 21:02, VE9AA - Mike <ve9aa@...> wrote:

﻿234/49.73=4.71 feet...…...234/50.200=4.66 feet.

Make it .05feet longer---or about 5/8ths of an inch.

If I was a betting man, I'd say you're going to have to take it down more than once however. ;-)  That's just the way it is with these.

You should have enough wire left over at one end to just unravel the wire (you didn't clip it all off, right?) and lengthen it out a titch.

Myself, personally, I'd go another inch or even two longer, but that's just me ;-)

234 is just a constant that some math-whizz figured out if they took that # and divided it by the frequency in MHz, then the 1/4wave length would come out in feet.
Mike VE9AA
On Tue, Jul 7, 2020 at 10:51 AM, John G0SNF wrote:

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

--
Mike VE9AA

VE9AA - Mike

Doh! Yes, you're correct John.  Wrote that in a rush and zigged instead of zagged.

So sorry !  Wasn't trying to lead you astray there.  Honest

mike

On Tue, Jul 7, 2020 at 06:21 PM, John G0SNF wrote:
Mike
I believe I need to shorten the wire in order to raise the resonant frequency ?

John Culling

--
Mike VE9AA

Gene W5GDP

I tweaked mine but it’s been over a year so don’t remember exact, but think somewhere around 6 inches. When you get on the air with it I’d be interested in how your results are. I’ve not had a lot of success on six compared to an attic antenna or now compared to my Hexbeam. Somewhat disappointing for me on six.

Gene Parker

On Jul 7, 2020, at 8:51 AM, John G0SNF via groups.io <g0snf@...> wrote:

﻿

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

Peter VA3PET

Gene,

You're probably not going to get 6m tuned without at least a few iterations of adjust and try.

You could try raising the lower 6m support 1" ,  folding the 6m wire back on itself to shorten it and then calculate how much of a frequency change 1" made. You should then should be able to accurately calculate the next adjustment.

Pete

va3pet va3hr

From: Butternut@groups.io <Butternut@groups.io> on behalf of Gene W5GDP <gparker5716@...>
Sent: Tuesday, July 7, 2020 8:33:15 PM
To: Butternut@groups.io <Butternut@groups.io>
Subject: Re: [butternut] HF6V adding 6 metres

I tweaked mine but it’s been over a year so don’t remember exact, but think somewhere around 6 inches. When you get on the air with it I’d be interested in how your results are. I’ve not had a lot of success on six compared to an attic antenna or now compared to my Hexbeam. Somewhat disappointing for me on six.

Gene Parker

On Jul 7, 2020, at 8:51 AM, John G0SNF via groups.io <g0snf@...> wrote:

﻿

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

Peter,
Raising the lower support will make the antenna look longer, lowering the resonant point.  By my calculations, the dimensions given should make the antenna resonant near the top end of the band.  The measured point indicates to me the effect of the inductance along the length of the antenna.  If i was going to move anything on my antenna at this point, I would move the whole assembly down 4"-6" and leave the stub length the same.  Remember that the antenna on 6M is a 3/4 wave so 6" is similar to a 2" move on a standard 1/4 wave radiator.  That is enough for a 2 MHz move according to my calculations.

Peter VA3PET

73

Pete

From: Butternut@groups.io <Butternut@groups.io> on behalf of Al WB9UVJ <markaren1@...>
Sent: Wednesday, July 8, 2020 11:55:20 AM
To: Butternut@groups.io <Butternut@groups.io>
Subject: Re: [butternut] HF6V adding 6 metres

Peter,
Raising the lower support will make the antenna look longer, lowering the resonant point.  By my calculations, the dimensions given should make the antenna resonant near the top end of the band.  The measured point indicates to me the effect of the inductance along the length of the antenna.  If i was going to move anything on my antenna at this point, I would move the whole assembly down 4"-6" and leave the stub length the same.  Remember that the antenna on 6M is a 3/4 wave so 6" is similar to a 2" move on a standard 1/4 wave radiator.  That is enough for a 2 MHz move according to my calculations.

Scott AC8DE

You'll also note that adding 6M throws 15M out of whack in most cases.  If you read the manual, it will mention having to work back and forth between the 6M and 15M adjustments.  The math won't work out sadly, due to all the capacitive reactance of the vertical resonator and wires.  While that was a fun exercise you guys went through, if you've now got it tuned, you probably found out it didn't work out as the math planned, but kinda-sorta got somewhat there.  It is covered in the current manual.

I've never gotten 15M and 6M to tune in one attempt.  It almost always take me 3ish attempts to get within band enough so I am happy on both 15M and 6M.

As far as taking the antenna up and down, if you remove the lower bolt and take off the fee line from the resonator, it's super easy and a one man job.  Less than about 2 minutes to take it down.  If it is an elevated installation... good luck, as it's going to take a while.

73,

Scott AC8DE

From: Butternut@groups.io On Behalf Of John G0SNF via groups.io
Sent: Tuesday, July 07, 2020 9:52 AM
To: Butternut@groups.io
Subject: [butternut] HF6V adding 6 metres

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

John G0SNF

Scott

Yes, adding 6 metres required changes to the 15 metre band as well. I really struggled to get the antenna to be resonant above 50 Mhz and it took a lot of ups and downs to get anywhere near it. None of the math suggested provided any help at all and, basically, I ended up making a lot of random moves relying on the Antenna Analyser for guidance. I think I could summerise as below just in case it helps anyone else, very unlikely I suspect !!

1. Installed as the Instruction sheet – tuning around 49Mhz
2. Raised the bottom connector by 5/8” calculated as advised – no change to tuning
3. Checked 15 metres which now requires adjustment to raise frequency.
4. Lowered the whole 6 metre assembly by 4” – tuning raised to ~50.1Mhz
5. Lowered lower end of 6 metre assembly by 5 “ – tuning raised to ~50.7 Mhz
6. Raised lower end of 6 metre assembly by ~ 2 1/2” – tuning at ~50.2+ Mhz
7. Re checked and adjusted 15 metre tuning.

No propagation currently on 6 metres but the FT101dxMP tuned at 50.2 so let’s wait and see.

Something of a drama one would have to say !!

John Culling (G0SNF)

Tel: 01844 275152

Mob: 07748 335155

From: Butternut@groups.io <Butternut@groups.io> On Behalf Of Scott AC8DE
Sent: 13 July 2020 18:25
To: Butternut@groups.io
Subject: Re: [butternut] HF6V adding 6 metres

You'll also note that adding 6M throws 15M out of whack in most cases.  If you read the manual, it will mention having to work back and forth between the 6M and 15M adjustments.  The math won't work out sadly, due to all the capacitive reactance of the vertical resonator and wires.  While that was a fun exercise you guys went through, if you've now got it tuned, you probably found out it didn't work out as the math planned, but kinda-sorta got somewhat there.  It is covered in the current manual.

I've never gotten 15M and 6M to tune in one attempt.  It almost always take me 3ish attempts to get within band enough so I am happy on both 15M and 6M.

As far as taking the antenna up and down, if you remove the lower bolt and take off the fee line from the resonator, it's super easy and a one man job.  Less than about 2 minutes to take it down.  If it is an elevated installation... good luck, as it's going to take a while.

73,

Scott AC8DE

From: Butternut@groups.io On Behalf Of John G0SNF via groups.io
Sent: Tuesday, July 07, 2020 9:52 AM
To: Butternut@groups.io
Subject: [butternut] HF6V adding 6 metres

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

Artie KD0GY

For what little it's worth, depending on what you wish to accomplish, I have a stock HF6-V on a chain link fence, with a ground rod well bonded. Using a tuner, I have worked 39 states, Mexico, Canada, Panama, and Costa Rica, so far on FT-8, and 31, Mexico, Canada and Alaska on CW. When the band really opens, what's left of 100 watts with the tuner goes coast to coast and border to border on PSK reporter, if that's anyone's interest. I don't personally care about SSB that much on 6M, and would rather have best resonance on 15M if I had to choose. I can dependably hit a 6M FM repeater 30 miles away. Eventually, I hope to get a small beam up on the roof for 6M.

Artie KD0GY

On Mon, Jul 13, 2020 at 12:48 PM John G0SNF via groups.io <g0snf=aol.com@groups.io> wrote:

Scott

Yes, adding 6 metres required changes to the 15 metre band as well. I really struggled to get the antenna to be resonant above 50 Mhz and it took a lot of ups and downs to get anywhere near it. None of the math suggested provided any help at all and, basically, I ended up making a lot of random moves relying on the Antenna Analyser for guidance. I think I could summerise as below just in case it helps anyone else, very unlikely I suspect !!

1. Installed as the Instruction sheet – tuning around 49Mhz
2. Raised the bottom connector by 5/8” calculated as advised – no change to tuning
3. Checked 15 metres which now requires adjustment to raise frequency.
4. Lowered the whole 6 metre assembly by 4” – tuning raised to ~50.1Mhz
5. Lowered lower end of 6 metre assembly by 5 “ – tuning raised to ~50.7 Mhz
6. Raised lower end of 6 metre assembly by ~ 2 1/2” – tuning at ~50.2+ Mhz
7. Re checked and adjusted 15 metre tuning.

No propagation currently on 6 metres but the FT101dxMP tuned at 50.2 so let’s wait and see.

Something of a drama one would have to say !!

John Culling (G0SNF)

Tel: 01844 275152

Mob: 07748 335155

From: Butternut@groups.io <Butternut@groups.io> On Behalf Of Scott AC8DE
Sent: 13 July 2020 18:25
To: Butternut@groups.io
Subject: Re: [butternut] HF6V adding 6 metres

You'll also note that adding 6M throws 15M out of whack in most cases.  If you read the manual, it will mention having to work back and forth between the 6M and 15M adjustments.  The math won't work out sadly, due to all the capacitive reactance of the vertical resonator and wires.  While that was a fun exercise you guys went through, if you've now got it tuned, you probably found out it didn't work out as the math planned, but kinda-sorta got somewhat there.  It is covered in the current manual.

I've never gotten 15M and 6M to tune in one attempt.  It almost always take me 3ish attempts to get within band enough so I am happy on both 15M and 6M.

As far as taking the antenna up and down, if you remove the lower bolt and take off the fee line from the resonator, it's super easy and a one man job.  Less than about 2 minutes to take it down.  If it is an elevated installation... good luck, as it's going to take a while.

73,

Scott AC8DE

From: Butternut@groups.io On Behalf Of John G0SNF via groups.io
Sent: Tuesday, July 07, 2020 9:52 AM
To: Butternut@groups.io
Subject: [butternut] HF6V adding 6 metres

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.

Artie KD0GY

I might have mentioned, the antenna matches very well on the 6 bands it's designed for, and no 160 kit installed, and no need for a tuner. I believe the last time I checked, it also seems to resonate at about 47 Mhz, so this may be why the tuner is able to match 1:1 and work after a fashion on 6M.

Artie KD0GY

On Mon, Jul 13, 2020 at 2:50 PM Artie KD0GY via groups.io <artielangston=gmail.com@groups.io> wrote:
For what little it's worth, depending on what you wish to accomplish, I have a stock HF6-V on a chain link fence, with a ground rod well bonded. Using a tuner, I have worked 39 states, Mexico, Canada, Panama, and Costa Rica, so far on FT-8, and 31, Mexico, Canada and Alaska on CW. When the band really opens, what's left of 100 watts with the tuner goes coast to coast and border to border on PSK reporter, if that's anyone's interest. I don't personally care about SSB that much on 6M, and would rather have best resonance on 15M if I had to choose. I can dependably hit a 6M FM repeater 30 miles away. Eventually, I hope to get a small beam up on the roof for 6M.

Artie KD0GY

On Mon, Jul 13, 2020 at 12:48 PM John G0SNF via groups.io <g0snf=aol.com@groups.io> wrote:

Scott

Yes, adding 6 metres required changes to the 15 metre band as well. I really struggled to get the antenna to be resonant above 50 Mhz and it took a lot of ups and downs to get anywhere near it. None of the math suggested provided any help at all and, basically, I ended up making a lot of random moves relying on the Antenna Analyser for guidance. I think I could summerise as below just in case it helps anyone else, very unlikely I suspect !!

1. Installed as the Instruction sheet – tuning around 49Mhz
2. Raised the bottom connector by 5/8” calculated as advised – no change to tuning
3. Checked 15 metres which now requires adjustment to raise frequency.
4. Lowered the whole 6 metre assembly by 4” – tuning raised to ~50.1Mhz
5. Lowered lower end of 6 metre assembly by 5 “ – tuning raised to ~50.7 Mhz
6. Raised lower end of 6 metre assembly by ~ 2 1/2” – tuning at ~50.2+ Mhz
7. Re checked and adjusted 15 metre tuning.

No propagation currently on 6 metres but the FT101dxMP tuned at 50.2 so let’s wait and see.

Something of a drama one would have to say !!

John Culling (G0SNF)

Tel: 01844 275152

Mob: 07748 335155

From: Butternut@groups.io <Butternut@groups.io> On Behalf Of Scott AC8DE
Sent: 13 July 2020 18:25
To: Butternut@groups.io
Subject: Re: [butternut] HF6V adding 6 metres

You'll also note that adding 6M throws 15M out of whack in most cases.  If you read the manual, it will mention having to work back and forth between the 6M and 15M adjustments.  The math won't work out sadly, due to all the capacitive reactance of the vertical resonator and wires.  While that was a fun exercise you guys went through, if you've now got it tuned, you probably found out it didn't work out as the math planned, but kinda-sorta got somewhat there.  It is covered in the current manual.

I've never gotten 15M and 6M to tune in one attempt.  It almost always take me 3ish attempts to get within band enough so I am happy on both 15M and 6M.

As far as taking the antenna up and down, if you remove the lower bolt and take off the fee line from the resonator, it's super easy and a one man job.  Less than about 2 minutes to take it down.  If it is an elevated installation... good luck, as it's going to take a while.

73,

Scott AC8DE

From: Butternut@groups.io On Behalf Of John G0SNF via groups.io
Sent: Tuesday, July 07, 2020 9:52 AM
To: Butternut@groups.io
Subject: [butternut] HF6V adding 6 metres

I have added the BUT-A-6 6 metre kit to my HF6V this morning. Using my MFJ 259B analyser the antenna is showing 1.1 SWR at 49.73 MHz.
The single page Instruction sheet which came with the kit says, ‘...In general the wire may be lengthened to lower resonance or shortened a slight amount to raise it...’
As I need to raise the resonance point by ~550Khz to give ~50.250can anyone suggest how much ‘a slight amount’ might be ?

I really only want to take it down once to make the adjustment rather than making several random guessed alterations.