Re: Topband: Balun Question

2013-10-27 Thread Gary Smith
Fellows,

Thanks for the on  off list replies, I just got back from a weekend 
away  read through them all. Part of me wants to just leave it as is 
but that's not practical, a good icing and the connections I made 
will fail. Since I need something to relieve stress from the 
copperweld and the weight of the coax, the W2DU 1:1 looks like it 
ought to cover the issues.

There's no telling when bad weather will hit and once there'ssnow on 
the roof I'm not going up to work on anything so I need to do it now. 
He only operates on 80M phone using a Viewstar PT-2500A amp so the 
W2DU 1:1 ought to be fine. Someday when I'm the one using the station 
I'll want to use it on 160 and I'm not sure how well that balun will 
do on 160 but that's for another time.

Thank you all for the thoughts and helpful suggestions.

73,

Gary
KA1J

 Unfortunately, optimum balun impedance and design really depends
 heavily on 
 the application,. There is no magic design that works best for all
 applications, and the issue is so complex that almost any article
 falls 
 short.
 
 For example, the 5000 ohms pure R will not work at 1500 watts with
 all 
 antennas. With a balanced feeder having a balun termination
 impedance of 
 2000 ohms, a balun would have 1732V RMS between conductors, and 866
 volts to 
 ground. CM voltage would be 866 across a perfect balun if the feeder
 were 
 perfectly balanced.  The 5000 ohm CM impedance balun would dissipate
 150 
 watts in the cores, far beyond what any reasonable core stack would
 tolerate. The fact the antenna comes out of balance reduces the heat
 somewhat, but this clearly is a case where we WANT a reactive
 isolation 
 impedance to reduce heat.
 
 Making things worse, a half wave antenna fed through 1/4 wave of
 open wire 
 might have an impedance of 6000 ohms or more. The above example was
 for 2000 
 ohms!
 
 Without much effort, we can see why simplistic always do this
 rules just 
 don't work in the real world.
 
 Every situation has to be case-by-case.
 
 73 Tom
 
 
 
 
 - Original Message - 
 From: Tom Boucher t...@telemetry.demon.co.uk
 To: 160 reflector topband@contesting.com
 Sent: Friday, October 25, 2013 10:49 AM
 Subject: Topband: Balun Question
 
 
  Gary KA1J - take a look at this excellent article on ferriste
 baluns by 
  GM3SEK:
 
  http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf
 
  73
  Tom G3OLB
  _
  Topband Reflector
 
 
  -
  No virus found in this message.
  Checked by AVG - www.avg.com
  Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date:
 10/20/13
  
 
 _
 Topband Reflector
 



_
Topband Reflector


Re: Topband: Balun Question

2013-10-27 Thread Charlie Cunningham
Hi, Gary

Should do fine!  The W2DU balun is a good current-mode design by someone who
knew what he was doing! 

As for 160, I do have a W2DU current mode balun, from Unadilla that is
longer that the 80-10m version (more beads) but I never really pushed it. I
did use it some n 80m. Actually on 160, I didn't really have need for a
balun with the inverted L antennas that I used. I expect that the
application for a 160 m balun is most likely for guy s with high dipoles and
inverted Vees, and really big delta loops. The w2DU balun will workat least
as well as, and probably better than, the W2AU balun that it woud be
replacing!

 Hope your dad enjoys it for many more years!  :-)

73,
Charlie, K4OTV



-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary
Smith
Sent: Sunday, October 27, 2013 7:45 PM
To: Topband@contesting.com
Subject: Re: Topband: Balun Question

Fellows,

Thanks for the on  off list replies, I just got back from a weekend 
away  read through them all. Part of me wants to just leave it as is 
but that's not practical, a good icing and the connections I made 
will fail. Since I need something to relieve stress from the 
copperweld and the weight of the coax, the W2DU 1:1 looks like it 
ought to cover the issues.

There's no telling when bad weather will hit and once there'ssnow on 
the roof I'm not going up to work on anything so I need to do it now. 
He only operates on 80M phone using a Viewstar PT-2500A amp so the 
W2DU 1:1 ought to be fine. Someday when I'm the one using the station 
I'll want to use it on 160 and I'm not sure how well that balun will 
do on 160 but that's for another time.

Thank you all for the thoughts and helpful suggestions.

73,

Gary
KA1J

 Unfortunately, optimum balun impedance and design really depends
 heavily on 
 the application,. There is no magic design that works best for all
 applications, and the issue is so complex that almost any article
 falls 
 short.
 
 For example, the 5000 ohms pure R will not work at 1500 watts with
 all 
 antennas. With a balanced feeder having a balun termination
 impedance of 
 2000 ohms, a balun would have 1732V RMS between conductors, and 866
 volts to 
 ground. CM voltage would be 866 across a perfect balun if the feeder
 were 
 perfectly balanced.  The 5000 ohm CM impedance balun would dissipate
 150 
 watts in the cores, far beyond what any reasonable core stack would
 tolerate. The fact the antenna comes out of balance reduces the heat
 somewhat, but this clearly is a case where we WANT a reactive
 isolation 
 impedance to reduce heat.
 
 Making things worse, a half wave antenna fed through 1/4 wave of
 open wire 
 might have an impedance of 6000 ohms or more. The above example was
 for 2000 
 ohms!
 
 Without much effort, we can see why simplistic always do this
 rules just 
 don't work in the real world.
 
 Every situation has to be case-by-case.
 
 73 Tom
 
 
 
 
 - Original Message - 
 From: Tom Boucher t...@telemetry.demon.co.uk
 To: 160 reflector topband@contesting.com
 Sent: Friday, October 25, 2013 10:49 AM
 Subject: Topband: Balun Question
 
 
  Gary KA1J - take a look at this excellent article on ferriste
 baluns by 
  GM3SEK:
 
  http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf
 
  73
  Tom G3OLB
  _
  Topband Reflector
 
 
  -
  No virus found in this message.
  Checked by AVG - www.avg.com
  Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date:
 10/20/13
  
 
 _
 Topband Reflector
 



_
Topband Reflector

_
Topband Reflector


Re: Topband: Balun Question

2013-10-25 Thread Tom W8JI
Unfortunately, optimum balun impedance and design really depends heavily on 
the application,. There is no magic design that works best for all 
applications, and the issue is so complex that almost any article falls 
short.


For example, the 5000 ohms pure R will not work at 1500 watts with all 
antennas. With a balanced feeder having a balun termination impedance of 
2000 ohms, a balun would have 1732V RMS between conductors, and 866 volts to 
ground. CM voltage would be 866 across a perfect balun if the feeder were 
perfectly balanced.  The 5000 ohm CM impedance balun would dissipate 150 
watts in the cores, far beyond what any reasonable core stack would 
tolerate. The fact the antenna comes out of balance reduces the heat 
somewhat, but this clearly is a case where we WANT a reactive isolation 
impedance to reduce heat.


Making things worse, a half wave antenna fed through 1/4 wave of open wire 
might have an impedance of 6000 ohms or more. The above example was for 2000 
ohms!


Without much effort, we can see why simplistic always do this rules just 
don't work in the real world.


Every situation has to be case-by-case.

73 Tom




- Original Message - 
From: Tom Boucher t...@telemetry.demon.co.uk

To: 160 reflector topband@contesting.com
Sent: Friday, October 25, 2013 10:49 AM
Subject: Topband: Balun Question


Gary KA1J - take a look at this excellent article on ferriste baluns by 
GM3SEK:


http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf

73
Tom G3OLB
_
Topband Reflector


-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date: 10/20/13



_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Charlie Cunningham
Well, might work. Another idea though, check with Fair-Rite - I believe that
they have some cores that wil fit over .405 RG-8, and I know they have lots
that sill fit over RG-58 or RG-8X. If you don't  mind removing the
connector, you can just slip a bunch of them over the end of the cable and
use wire ties to keep them from sliding up and down the cable. I've left
them out in the weather for years with no adverse effects. They also have
snap-ons if you don't' want to remove the connector. About the only thing
that the PVC tube around that W2AU balun does is hold the connectors ( and
maybe trap moisture).

You didn't say what kind of cable, but winding RG-8 around a 1 form can be
sort of a pain!

73,
Charlie, K4OTV

-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary
Smith
Sent: Thursday, October 24, 2013 7:25 PM
To: topband@contesting.com
Subject: Topband: Balun question

Though this reflector is for 160M I have an 80M question that might 
be best asked here. My father W1BML is on an 80 meter net nightly. 
His antenna in an inv-V with 40  80 elements though he never uses 40 
any more. I needed to fell a couple of trees to remove branches that 
were touching his copperweld and the W2AU balun he had broke in two 
during the process. (Don't ask, your imagination is probably correct) 
 :) And he would like it put back the way it was, with a balun. He's 
96 so I try to keep him happy.

I'm thinking 10 or so rolls of coax around 1' in diameter ought to be 
fine for a choke on 80. Any better suggestions?

Thanks,

Gary
KA1J
_
Topband Reflector

_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Charlie Cunningham
That would work as well. I used something similar, but  with less turns to
precede the 4:1 current balun feeding the drivers on my home brew 5-band
quad.

Charlie, K4OTV

-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim
Bennett
Sent: Thursday, October 24, 2013 7:41 PM
To: g...@ka1j.com
Cc: topband@contesting.com
Subject: Re: Topband: Balun question

I was just looking through the ARRL Antenna Book - if it's RG-8, then 8
turns would work if wound on an 8 inch PVC tube. However, that size PVC may
be difficult to find, and certainly wouldn't be to spiffy hung way up the
air. But then again, you were thinking about 10 turns on a 12 inch diameter
form...? I assume you were going to place it at the apex of the Inverted
Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch
OD and pass the coax through it six times. That ought to get about 5,000 ohm
impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80
meter Inverted L and it does a fine job. Mouser has those cores for $6-$7
each.

Jim / W6JHB


On   Thursday, Oct 24, 2013, at  Thursday, 4:25 PM, Gary Smith wrote:

 Though this reflector is for 160M I have an 80M question that might be 
 best asked here. My father W1BML is on an 80 meter net nightly.
 His antenna in an inv-V with 40  80 elements though he never uses 40 
 any more. I needed to fell a couple of trees to remove branches that 
 were touching his copperweld and the W2AU balun he had broke in two 
 during the process. (Don't ask, your imagination is probably correct)
 :) And he would like it put back the way it was, with a balun. He's
 96 so I try to keep him happy.
 
 I'm thinking 10 or so rolls of coax around 1' in diameter ought to be 
 fine for a choke on 80. Any better suggestions?
 
 Thanks,
 
 Gary
 KA1J
 _
 Topband Reflector

_
Topband Reflector

_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Randy Lake
Check this link out. It works flawlessly.
audiosystemsgroup.com/*RFI*-Ham.pdf


On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham 
charlie-cunning...@nc.rr.com wrote:

 That would work as well. I used something similar, but  with less turns to
 precede the 4:1 current balun feeding the drivers on my home brew 5-band
 quad.

 Charlie, K4OTV

 -Original Message-
 From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim
 Bennett
 Sent: Thursday, October 24, 2013 7:41 PM
 To: g...@ka1j.com
 Cc: topband@contesting.com
 Subject: Re: Topband: Balun question

 I was just looking through the ARRL Antenna Book - if it's RG-8, then 8
 turns would work if wound on an 8 inch PVC tube. However, that size PVC may
 be difficult to find, and certainly wouldn't be to spiffy hung way up the
 air. But then again, you were thinking about 10 turns on a 12 inch diameter
 form...? I assume you were going to place it at the apex of the Inverted
 Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch
 OD and pass the coax through it six times. That ought to get about 5,000
 ohm
 impedance at 3.5 MHz and would do the trick. I'm using exactly that on my
 80
 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7
 each.

 Jim / W6JHB


 On   Thursday, Oct 24, 2013, at  Thursday, 4:25 PM, Gary Smith wrote:

  Though this reflector is for 160M I have an 80M question that might be
  best asked here. My father W1BML is on an 80 meter net nightly.
  His antenna in an inv-V with 40  80 elements though he never uses 40
  any more. I needed to fell a couple of trees to remove branches that
  were touching his copperweld and the W2AU balun he had broke in two
  during the process. (Don't ask, your imagination is probably correct)
  :) And he would like it put back the way it was, with a balun. He's
  96 so I try to keep him happy.
 
  I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
  fine for a choke on 80. Any better suggestions?
 
  Thanks,
 
  Gary
  KA1J
  _
  Topband Reflector

 _
 Topband Reflector

 _
 Topband Reflector




-- 
Randy Lake N1KWF
73 Gunn Rd.
Keene,NH
_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Charlie Cunningham
What works flawlessly, Randy? The link?  J

 

73,

Charlie, K4OTV

 

From: Randy Lake [mailto:randyn1...@gmail.com] 
Sent: Thursday, October 24, 2013 7:51 PM
To: Charlie Cunningham
Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com
Subject: Re: Topband: Balun question

 

Check this link out. It works flawlessly.

audiosystemsgroup.com/RFI-Ham.pdf

 

On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham
charlie-cunning...@nc.rr.com wrote:

That would work as well. I used something similar, but  with less turns to
precede the 4:1 current balun feeding the drivers on my home brew 5-band
quad.

Charlie, K4OTV


-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim
Bennett
Sent: Thursday, October 24, 2013 7:41 PM
To: g...@ka1j.com
Cc: topband@contesting.com
Subject: Re: Topband: Balun question

I was just looking through the ARRL Antenna Book - if it's RG-8, then 8
turns would work if wound on an 8 inch PVC tube. However, that size PVC may
be difficult to find, and certainly wouldn't be to spiffy hung way up the
air. But then again, you were thinking about 10 turns on a 12 inch diameter
form...? I assume you were going to place it at the apex of the Inverted
Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch
OD and pass the coax through it six times. That ought to get about 5,000 ohm
impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80
meter Inverted L and it does a fine job. Mouser has those cores for $6-$7
each.

Jim / W6JHB


On   Thursday, Oct 24, 2013, at  Thursday, 4:25 PM, Gary Smith wrote:

 Though this reflector is for 160M I have an 80M question that might be
 best asked here. My father W1BML is on an 80 meter net nightly.
 His antenna in an inv-V with 40  80 elements though he never uses 40
 any more. I needed to fell a couple of trees to remove branches that
 were touching his copperweld and the W2AU balun he had broke in two
 during the process. (Don't ask, your imagination is probably correct)
 :) And he would like it put back the way it was, with a balun. He's
 96 so I try to keep him happy.

 I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
 fine for a choke on 80. Any better suggestions?

 Thanks,

 Gary
 KA1J
 _
 Topband Reflector

_
Topband Reflector

_
Topband Reflector





 

-- 
Randy Lake N1KWF
73 Gunn Rd.
Keene,NH 

_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Randy Lake
I am sorry! That was not very clear.
The info on chokes worked wonderfully for me on 80m and 160m using the Big
31 snap-ons.
Not only that but lots of good info other than chokes.
Randy


On Thu, Oct 24, 2013 at 7:55 PM, Charlie Cunningham 
charlie-cunning...@nc.rr.com wrote:

 What “works flawlessly”, Randy? The link?  J

 ** **

 73,

 Charlie, K4OTV

 ** **

 *From:* Randy Lake [mailto:randyn1...@gmail.com]
 *Sent:* Thursday, October 24, 2013 7:51 PM
 *To:* Charlie Cunningham
 *Cc:* Jim Bennett; g...@ka1j.com; topband@contesting.com
 *Subject:* Re: Topband: Balun question

 ** **

 Check this link out. It works flawlessly.

 audiosystemsgroup.com/*RFI*-Ham.pdf

 ** **

 On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham 
 charlie-cunning...@nc.rr.com wrote:

 That would work as well. I used something similar, but  with less turns to
 precede the 4:1 current balun feeding the drivers on my home brew 5-band
 quad.

 Charlie, K4OTV


 -Original Message-
 From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim
 Bennett
 Sent: Thursday, October 24, 2013 7:41 PM
 To: g...@ka1j.com
 Cc: topband@contesting.com
 Subject: Re: Topband: Balun question

 I was just looking through the ARRL Antenna Book - if it's RG-8, then 8
 turns would work if wound on an 8 inch PVC tube. However, that size PVC may
 be difficult to find, and certainly wouldn't be to spiffy hung way up the
 air. But then again, you were thinking about 10 turns on a 12 inch diameter
 form...? I assume you were going to place it at the apex of the Inverted
 Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch
 OD and pass the coax through it six times. That ought to get about 5,000
 ohm
 impedance at 3.5 MHz and would do the trick. I'm using exactly that on my
 80
 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7
 each.

 Jim / W6JHB


 On   Thursday, Oct 24, 2013, at  Thursday, 4:25 PM, Gary Smith wrote:

  Though this reflector is for 160M I have an 80M question that might be
  best asked here. My father W1BML is on an 80 meter net nightly.
  His antenna in an inv-V with 40  80 elements though he never uses 40
  any more. I needed to fell a couple of trees to remove branches that
  were touching his copperweld and the W2AU balun he had broke in two
  during the process. (Don't ask, your imagination is probably correct)
  :) And he would like it put back the way it was, with a balun. He's
  96 so I try to keep him happy.
 
  I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
  fine for a choke on 80. Any better suggestions?
 
  Thanks,
 
  Gary
  KA1J
  _
  Topband Reflector

 _
 Topband Reflector

 _
 Topband Reflector



 

 ** **

 --
 Randy Lake N1KWF
 73 Gunn Rd.
 Keene,NH 




-- 
Randy Lake N1KWF
73 Gunn Rd.
Keene,NH
_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Charlie Cunningham
Just teasin' you, Randy! J  I think the snap-ons would be  quick, simple and
very effective and should outlast the antenna, I expect!

 

From: Randy Lake [mailto:randyn1...@gmail.com] 
Sent: Thursday, October 24, 2013 7:58 PM
To: Charlie Cunningham
Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com
Subject: Re: Topband: Balun question

 

I am sorry! That was not very clear.

The info on chokes worked wonderfully for me on 80m and 160m using the Big
31 snap-ons. 

Not only that but lots of good info other than chokes.

Randy

 

On Thu, Oct 24, 2013 at 7:55 PM, Charlie Cunningham
charlie-cunning...@nc.rr.com wrote:

What works flawlessly, Randy? The link?  J

 

73,

Charlie, K4OTV

 

From: Randy Lake [mailto:randyn1...@gmail.com] 
Sent: Thursday, October 24, 2013 7:51 PM
To: Charlie Cunningham
Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com
Subject: Re: Topband: Balun question

 

Check this link out. It works flawlessly.

audiosystemsgroup.com/RFI-Ham.pdf

 

On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham
charlie-cunning...@nc.rr.com wrote:

That would work as well. I used something similar, but  with less turns to
precede the 4:1 current balun feeding the drivers on my home brew 5-band
quad.

Charlie, K4OTV


-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim
Bennett
Sent: Thursday, October 24, 2013 7:41 PM
To: g...@ka1j.com
Cc: topband@contesting.com
Subject: Re: Topband: Balun question

I was just looking through the ARRL Antenna Book - if it's RG-8, then 8
turns would work if wound on an 8 inch PVC tube. However, that size PVC may
be difficult to find, and certainly wouldn't be to spiffy hung way up the
air. But then again, you were thinking about 10 turns on a 12 inch diameter
form...? I assume you were going to place it at the apex of the Inverted
Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch
OD and pass the coax through it six times. That ought to get about 5,000 ohm
impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80
meter Inverted L and it does a fine job. Mouser has those cores for $6-$7
each.

Jim / W6JHB


On   Thursday, Oct 24, 2013, at  Thursday, 4:25 PM, Gary Smith wrote:

 Though this reflector is for 160M I have an 80M question that might be
 best asked here. My father W1BML is on an 80 meter net nightly.
 His antenna in an inv-V with 40  80 elements though he never uses 40
 any more. I needed to fell a couple of trees to remove branches that
 were touching his copperweld and the W2AU balun he had broke in two
 during the process. (Don't ask, your imagination is probably correct)
 :) And he would like it put back the way it was, with a balun. He's
 96 so I try to keep him happy.

 I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
 fine for a choke on 80. Any better suggestions?

 Thanks,

 Gary
 KA1J
 _
 Topband Reflector

_
Topband Reflector

_
Topband Reflector





 

-- 
Randy Lake N1KWF
73 Gunn Rd.
Keene,NH 





 

-- 
Randy Lake N1KWF
73 Gunn Rd.
Keene,NH 

_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Tom W8JI

Though this reflector is for 160M I have an 80M question that might
be best asked here. My father W1BML is on an 80 meter net nightly.
His antenna in an inv-V with 40  80 elements though he never uses 40
any more. I needed to fell a couple of trees to remove branches that
were touching his copperweld and the W2AU balun he had broke in two
during the process. (Don't ask, your imagination is probably correct)
:) And he would like it put back the way it was, with a balun. He's
96 so I try to keep him happy.

I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
fine for a choke on 80. Any better suggestions?


Gary,

The W2AU balun he was happy with isn't a balun at all...it basically has NO 
common mode suppression.


The impedance of a few turns of coax is also next to nothing on 80 meters, 
but almost everyone is happy with them.


As a matter of fact, if the feedline from the antenna to the ground point of 
the coax is 30-45 feet long, it would need no balun at all for good common 
mode suppression.


This illustrates some of the ridiculous overkill we are all caught up in.

Since he was happy with his non-suppression balun, just use anything he 
thinks is a balun. He will be just as happy.  A sting of beads of any 
impedance, a few turns of coax, a big coil of coax, if he didn't notice the 
W2AU balun causing a problem anything you put there will make him happy. 
:)


73 Tom

73 Tom 


_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Charlie Cunningham
True!  

-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI
Sent: Thursday, October 24, 2013 8:41 PM
To: g...@ka1j.com; topband@contesting.com
Subject: Re: Topband: Balun question

 Though this reflector is for 160M I have an 80M question that might
 be best asked here. My father W1BML is on an 80 meter net nightly.
 His antenna in an inv-V with 40  80 elements though he never uses 40
 any more. I needed to fell a couple of trees to remove branches that
 were touching his copperweld and the W2AU balun he had broke in two
 during the process. (Don't ask, your imagination is probably correct)
 :) And he would like it put back the way it was, with a balun. He's
 96 so I try to keep him happy.

 I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
 fine for a choke on 80. Any better suggestions?

Gary,

The W2AU balun he was happy with isn't a balun at all...it basically has NO 
common mode suppression.

The impedance of a few turns of coax is also next to nothing on 80 meters, 
but almost everyone is happy with them.

As a matter of fact, if the feedline from the antenna to the ground point of

the coax is 30-45 feet long, it would need no balun at all for good common 
mode suppression.

This illustrates some of the ridiculous overkill we are all caught up in.

Since he was happy with his non-suppression balun, just use anything he 
thinks is a balun. He will be just as happy.  A sting of beads of any 
impedance, a few turns of coax, a big coil of coax, if he didn't notice the 
W2AU balun causing a problem anything you put there will make him happy. 
:)

73 Tom

73 Tom 

_
Topband Reflector

_
Topband Reflector


Re: Topband: Balun question

2013-10-24 Thread Charlie Cunningham
A W2DU balun, however is another story!  Walt knew what he was doing!

73,
Charlie, K4OTV

-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI
Sent: Thursday, October 24, 2013 8:41 PM
To: g...@ka1j.com; topband@contesting.com
Subject: Re: Topband: Balun question

 Though this reflector is for 160M I have an 80M question that might
 be best asked here. My father W1BML is on an 80 meter net nightly.
 His antenna in an inv-V with 40  80 elements though he never uses 40
 any more. I needed to fell a couple of trees to remove branches that
 were touching his copperweld and the W2AU balun he had broke in two
 during the process. (Don't ask, your imagination is probably correct)
 :) And he would like it put back the way it was, with a balun. He's
 96 so I try to keep him happy.

 I'm thinking 10 or so rolls of coax around 1' in diameter ought to be
 fine for a choke on 80. Any better suggestions?

Gary,

The W2AU balun he was happy with isn't a balun at all...it basically has NO 
common mode suppression.

The impedance of a few turns of coax is also next to nothing on 80 meters, 
but almost everyone is happy with them.

As a matter of fact, if the feedline from the antenna to the ground point of

the coax is 30-45 feet long, it would need no balun at all for good common 
mode suppression.

This illustrates some of the ridiculous overkill we are all caught up in.

Since he was happy with his non-suppression balun, just use anything he 
thinks is a balun. He will be just as happy.  A sting of beads of any 
impedance, a few turns of coax, a big coil of coax, if he didn't notice the 
W2AU balun causing a problem anything you put there will make him happy. 
:)

73 Tom

73 Tom 

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Topband Reflector

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Topband Reflector