Re: Topband: Bowtie Flags

[JC]

Sorry, the invention was in 1938 and the patent issued 1941

-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of JC
Sent: Tuesday, December 13, 2016 6:28 PM
To: 'Don Kirk' <wd8...@gmail.com>; 'Mark Connelly' <markwa1...@aol.com>
Cc: 'topband' <topband@contesting.com>
Subject: Re: Topband: Bowtie Flags

Hi Mark

Terminated loops are very old, the first patent belongs to Harold Beverage 

Harold Beverage invented wide band receiver antenna, loaded loop in 1941

https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/
US2247743.pdf

Most variations of this kind of antennas like this was used by military
during WWII. Some commercial versions started to come up on the 60's, Tom
W8JI worked the first JA using a similar RX antenna with multiple loops
phased end fire.

You see, the loaded loop is a Beverage antenna too.

73
N4IS


-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Don Kirk
Sent: Tuesday, December 13, 2016 2:08 PM
To: Mark Connelly <markwa1...@aol.com>
Cc: topband <topband@contesting.com>
Subject: Re: Topband: Bowtie Flags

Hi Mark,

I had no idea a terminated bowtie previously existed, but does not surprise
me.

Thanks for posting.
Don

On Tue, Dec 13, 2016 at 2:00 PM, Mark Connelly via Topband <
topband@contesting.com> wrote:

> As Nick undoubtedly knows, Bowtie antennas have been in use by medium 
> wave broadcast band DXers for some time now.
>
> One I tested here in 2010 is shown in this sketch:
> http://www.qsl.net/wa1ion/pictures1/bowtie_s_yarmouth.gif
>
> Some use a dual feedline scheme so the pattern can be reversed.  This 
> would be implemented by 16:1 transformers at each end if 50-75 ohm 
> coaxial cable is used or 9:1 transformers if using 90-150 ohm balanced 
> feed (CAT-5, speaker wire, two conductor zip / lamp cord, twisted pair
> etc.) as recommended by Dallas Lankford and others.  In the balanced 
> feedline case, a 1.8:1 or 2:1 transformer (e.g. #73 binocular core 
> with 4 turns : 3 turns or 7 turns : 5 turns) is used in-shack to get 
> to unbalanced coaxial en route to the receiver / transceiver, RPA-1 or
similar amp, or phasing unit.
>
> Dual feedline split flag is another variant:
> http://www.qsl.net/wa1ion/pictures1/dual_feed_split_flag.gif
>
> Dual feedline antennas have a 4-pole 2-throw switch at the shack end 
> so either end can be switched to the receiver path and the opposite 
> end to a
> 250 or 500 ohm pot that facilitates in-shack null termination adjustment.
>
> Some people go with a single orientation antenna and put a preamp such 
> as the Wellbrook FLG100LN ( http://www.wellbrook.uk.com/FLG100LN-1 ) 
> right at the forward side.  This tends to overwhelm any feedline 
> pick-up (common-mode or otherwise) although common-mode choking is 
> still advisable near the antenna when longer runs (over 60m / 200 ft.) 
> of feedline are involved.
>
> In the case of a single orientation set-up, you then get to figure out 
> what termination end scheme is best.  These basically boil down to the 
> following options:
> (1) Fixed resistor in the 680-1200 ohm range either modelled / 
> guessed-at or determined by use of a potentiometer if it can somehow 
> be adjusted midway up the side of the antenna while monitoring a 
> target
station to null.
> (2) "Vactrol" termination: a photoresistor adjusted by a DC voltage 
> applied on a control line from the shack: see page 9 of 
> http://www.durenberger.com/documents/PRESBT2016.pdf
> (3) Potentiometer adjusted by a motor drive: see 
> http://www.bamlog.com/ remotepotbox.htm
>
> My experience with the Bowtie I installed in 2010 was that it was 
> about
> 10-12 dB less sensitive than a Flag or Kaz Delta occupying the same 
> rectangular "box" of air space.
>
> Nulling off the back could be wider than that of a Flag but the 
> bandwidth at which the null stayed optimum at a particular terminating 
> resistance was not as wide as with the Flag (or its SuperLoop base-fed
variation:
> http://www.bamlog.com/superloop.htm ).
>
> Seeing that the MW broadcast band 530-1710 kHz has a greater max/min 
> frequency range ratio than the 1800-2000 kHz of 160m, issues that 
> might be problematic for broadcast DXers could matter a lot less on 160.
>
> Some of the perceived problems of low gain and null bandwidth could 
> easily have been cured by a combination of rigorous common-mode 
> choking as done on the Waller Flag ( 
> http://www.kkn.net/dayton2011/N4ISWallerFlag.pdf ) and high gain
at-antenna amplification.
>
> Mark Connelly, WA1ION
> South Yarmouth, MA
>
> <<
> Nick,?
>
> ?
> Although I did not measure it, the front to back, and front to side is 
> better, over

Re: Topband: Bowtie Flags

[JC]

Hi Mark

Terminated loops are very old, the first patent belongs to Harold Beverage 

Harold Beverage invented wide band receiver antenna, loaded loop in 1941

https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/
US2247743.pdf

Most variations of this kind of antennas like this was used by military
during WWII. Some commercial versions started to come up on the 60's, Tom
W8JI worked the first JA using a similar RX antenna with multiple loops
phased end fire.

You see, the loaded loop is a Beverage antenna too.

73
N4IS


-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Don Kirk
Sent: Tuesday, December 13, 2016 2:08 PM
To: Mark Connelly <markwa1...@aol.com>
Cc: topband <topband@contesting.com>
Subject: Re: Topband: Bowtie Flags

Hi Mark,

I had no idea a terminated bowtie previously existed, but does not surprise
me.

Thanks for posting.
Don

On Tue, Dec 13, 2016 at 2:00 PM, Mark Connelly via Topband <
topband@contesting.com> wrote:

> As Nick undoubtedly knows, Bowtie antennas have been in use by medium 
> wave broadcast band DXers for some time now.
>
> One I tested here in 2010 is shown in this sketch:
> http://www.qsl.net/wa1ion/pictures1/bowtie_s_yarmouth.gif
>
> Some use a dual feedline scheme so the pattern can be reversed.  This 
> would be implemented by 16:1 transformers at each end if 50-75 ohm 
> coaxial cable is used or 9:1 transformers if using 90-150 ohm balanced 
> feed (CAT-5, speaker wire, two conductor zip / lamp cord, twisted pair 
> etc.) as recommended by Dallas Lankford and others.  In the balanced 
> feedline case, a 1.8:1 or 2:1 transformer (e.g. #73 binocular core 
> with 4 turns : 3 turns or 7 turns : 5 turns) is used in-shack to get 
> to unbalanced coaxial en route to the receiver / transceiver, RPA-1 or
similar amp, or phasing unit.
>
> Dual feedline split flag is another variant:
> http://www.qsl.net/wa1ion/pictures1/dual_feed_split_flag.gif
>
> Dual feedline antennas have a 4-pole 2-throw switch at the shack end 
> so either end can be switched to the receiver path and the opposite 
> end to a
> 250 or 500 ohm pot that facilitates in-shack null termination adjustment.
>
> Some people go with a single orientation antenna and put a preamp such 
> as the Wellbrook FLG100LN ( http://www.wellbrook.uk.com/FLG100LN-1 ) 
> right at the forward side.  This tends to overwhelm any feedline 
> pick-up (common-mode or otherwise) although common-mode choking is 
> still advisable near the antenna when longer runs (over 60m / 200 ft.) 
> of feedline are involved.
>
> In the case of a single orientation set-up, you then get to figure out 
> what termination end scheme is best.  These basically boil down to the 
> following options:
> (1) Fixed resistor in the 680-1200 ohm range either modelled / 
> guessed-at or determined by use of a potentiometer if it can somehow 
> be adjusted midway up the side of the antenna while monitoring a target
station to null.
> (2) "Vactrol" termination: a photoresistor adjusted by a DC voltage 
> applied on a control line from the shack: see page 9 of 
> http://www.durenberger.com/documents/PRESBT2016.pdf
> (3) Potentiometer adjusted by a motor drive: see 
> http://www.bamlog.com/ remotepotbox.htm
>
> My experience with the Bowtie I installed in 2010 was that it was 
> about
> 10-12 dB less sensitive than a Flag or Kaz Delta occupying the same 
> rectangular "box" of air space.
>
> Nulling off the back could be wider than that of a Flag but the 
> bandwidth at which the null stayed optimum at a particular terminating 
> resistance was not as wide as with the Flag (or its SuperLoop base-fed
variation:
> http://www.bamlog.com/superloop.htm ).
>
> Seeing that the MW broadcast band 530-1710 kHz has a greater max/min 
> frequency range ratio than the 1800-2000 kHz of 160m, issues that 
> might be problematic for broadcast DXers could matter a lot less on 160.
>
> Some of the perceived problems of low gain and null bandwidth could 
> easily have been cured by a combination of rigorous common-mode 
> choking as done on the Waller Flag ( 
> http://www.kkn.net/dayton2011/N4ISWallerFlag.pdf ) and high gain
at-antenna amplification.
>
> Mark Connelly, WA1ION
> South Yarmouth, MA
>
> <<
> Nick,?
>
> ?
> Although I did not measure it, the front to back, and front to side is 
> better, overall more quiet.
> ?
> It is receiving toward the Caribbean.?
> Europe, and USA stations, are lower in signal strength.
> ?
> Can often work?Caribbean and South American stations through a small 
> pile up when they are not working split.
> ?
> In my case it was a worth while change.
> ?
> The original plan was to be able to drive my car und

Re: Topband: Bowtie Flags

[wb6rse1]

Mark’s observation feeds my skepticism of a bowtie vs a flag in the specific 
circumstance where a ground independent RX antenna is your only option.

A bowtie would be about half the capture area of an equivalent “box” flag and 
consequently at a immediate disadvantage. If I was going to replace the flag 
with another ground independent design in about the same footprint, it would be 
a Waller flag.

73 - Steve WB6RSE

 
On Dec 13, 2016, at 11:00 AM, Mark Connelly via Topband 
 wrote:

My experience with the Bowtie I installed in 2010 was that it was about 10-12 
dB less sensitive than a Flag or Kaz Delta occupying the same rectangular "box" 
of air space.

_
Topband Reflector Archives - http://www.contesting.com/_topband

Topband: Bowtie Flags

[K1FZ-Bruce]

 
 
Earl, K6SE (sk)  advanced loop antennas on 160 meters. For 
information-See Page 34, July 2000 QST magazine. 
The small 160 meter bandwidth allows loop optimization k6SE gives 
dimensions. 
 
George Walter AA7JV  helped the TX3A Chesterfield DXpedition group 
with interconnected  two half delta loops. 
For more information  check "low Band DXing"  5th edition  page 7-106. 
 
Loop antennas optimized for the 160 meter band have been used in 
various folded loop   configurations for some time.. 
 

73
Bruce-k1fz
 


_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Bowtie Flags

[Don Kirk]

Hi Mark,

I had no idea a terminated bowtie previously existed, but does not surprise
me.

Thanks for posting.
Don

On Tue, Dec 13, 2016 at 2:00 PM, Mark Connelly via Topband <
topband@contesting.com> wrote:

> As Nick undoubtedly knows, Bowtie antennas have been in use by medium wave
> broadcast band DXers for some time now.
>
> One I tested here in 2010 is shown in this sketch:
> http://www.qsl.net/wa1ion/pictures1/bowtie_s_yarmouth.gif
>
> Some use a dual feedline scheme so the pattern can be reversed.  This
> would be implemented by 16:1 transformers at each end if 50-75 ohm coaxial
> cable is used or 9:1 transformers if using 90-150 ohm balanced feed (CAT-5,
> speaker wire, two conductor zip / lamp cord, twisted pair etc.) as
> recommended by Dallas Lankford and others.  In the balanced feedline case,
> a 1.8:1 or 2:1 transformer (e.g. #73 binocular core with 4 turns : 3 turns
> or 7 turns : 5 turns) is used in-shack to get to unbalanced coaxial en
> route to the receiver / transceiver, RPA-1 or similar amp, or phasing unit.
>
> Dual feedline split flag is another variant:
> http://www.qsl.net/wa1ion/pictures1/dual_feed_split_flag.gif
>
> Dual feedline antennas have a 4-pole 2-throw switch at the shack end so
> either end can be switched to the receiver path and the opposite end to a
> 250 or 500 ohm pot that facilitates in-shack null termination adjustment.
>
> Some people go with a single orientation antenna and put a preamp such as
> the Wellbrook FLG100LN ( http://www.wellbrook.uk.com/FLG100LN-1 ) right
> at the forward side.  This tends to overwhelm any feedline pick-up
> (common-mode or otherwise) although common-mode choking is still advisable
> near the antenna when longer runs (over 60m / 200 ft.) of feedline are
> involved.
>
> In the case of a single orientation set-up, you then get to figure out
> what termination end scheme is best.  These basically boil down to the
> following options:
> (1) Fixed resistor in the 680-1200 ohm range either modelled / guessed-at
> or determined by use of a potentiometer if it can somehow be adjusted
> midway up the side of the antenna while monitoring a target station to null.
> (2) "Vactrol" termination: a photoresistor adjusted by a DC voltage
> applied on a control line from the shack: see page 9 of
> http://www.durenberger.com/documents/PRESBT2016.pdf
> (3) Potentiometer adjusted by a motor drive: see http://www.bamlog.com/
> remotepotbox.htm
>
> My experience with the Bowtie I installed in 2010 was that it was about
> 10-12 dB less sensitive than a Flag or Kaz Delta occupying the same
> rectangular "box" of air space.
>
> Nulling off the back could be wider than that of a Flag but the bandwidth
> at which the null stayed optimum at a particular terminating resistance was
> not as wide as with the Flag (or its SuperLoop base-fed variation:
> http://www.bamlog.com/superloop.htm ).
>
> Seeing that the MW broadcast band 530-1710 kHz has a greater max/min
> frequency range ratio than the 1800-2000 kHz of 160m, issues that might be
> problematic for broadcast DXers could matter a lot less on 160.
>
> Some of the perceived problems of low gain and null bandwidth could easily
> have been cured by a combination of rigorous common-mode choking as done on
> the Waller Flag ( http://www.kkn.net/dayton2011/N4ISWallerFlag.pdf ) and
> high gain at-antenna amplification.
>
> Mark Connelly, WA1ION
> South Yarmouth, MA
>
> <<
> Nick,?
>
> ?
> Although I did not measure it, the front to back, and front to side is
> better, overall more quiet.
> ?
> It is receiving toward the Caribbean.?
> Europe, and USA stations, are lower in signal strength.
> ?
> Can often work?Caribbean and South American stations through a small
> pile up when they are not working split.
> ?
> In my case it was a worth while change.
> ?
> The original plan was to be able to drive my car under it.
> ?
> 73
> Bruce-K1FZ
> ?
>
> On Mon, 12 Dec 2016 16:35:14 +, Nick Hall-Patch wrote:
>
> What specific improvements did you note when the Delta was raised Bruce?
>
> Thanks,
>
> Nick
> VE7DXR
> >>
> _
> Topband Reflector Archives - http://www.contesting.com/_topband
>
_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Bowtie Flags

[Nick Hall-Patch]

Thanks Bruce.  Sounds like practical constraints led to a 
worthwhile outcome.


73

Nick
VE7DXR




At 17:21 12-12-16, K1FZ-Bruce wrote:

Nick,



Although I did not measure it, the front to back, and front to side 
is better, overall more quiet.




It is receiving toward the Caribbean.

Europe, and USA stations, are lower in signal strength.



Can often work Caribbean and South American stations through a small 
pile up when they are not working split.




In my case it was a worth while change.



The original plan was to be able to drive my car under it.



73

Bruce-K1FZ



On Mon, 12 Dec 2016 16:35:14 +, Nick Hall-Patch  wrote:


What specific improvements did you note when the Delta was raised Bruce?

Thanks,


Nick
VE7DXR





At 16:23 12-12-16, K1FZ-Bruce wrote:

Dennis,

Is there a photo or sketch available of your antenna anywhere by email ?

Note: Height above ground helped a lot when my receiving Delta
antenna was re-installed higher. The bottom wire went from 3 feet up
to ~6 feet at my QTH.
73
Bruce-k1fz

http://www.qsl.net/k1fz/flag_antennas.html

_

Nick Hall-Patch
Victoria, BC
Canada

_
Topband Reflector Archives - http://www.contesting.com/_topband



Nick Hall-Patch
Victoria, BC
Canada

_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Bowtie Flags

[K1FZ-Bruce]

Nick, 

 
Although I did not measure it, the front to back, and front to side is 
better, overall more quiet. 
 

It is receiving toward the Caribbean. 
Europe, and USA stations, are lower in signal strength. 
 
Can often work Caribbean and South American stations through a small 
pile up when they are not working split. 
 
In my case it was a worth while change. 
 
The original plan was to be able to drive my car under it. 
 

73
Bruce-K1FZ
 

On Mon, 12 Dec 2016 16:35:14 +, Nick Hall-Patch  wrote:

What specific improvements did you note when the Delta was raised Bruce?

Thanks,

Nick
VE7DXR



At 16:23 12-12-16, K1FZ-Bruce wrote:

Dennis,

Is there a photo or sketch available of your antenna anywhere by email ?

Note: Height above ground helped a lot when my receiving Delta
antenna was re-installed higher. The bottom wire went from 3 feet up
to ~6 feet at my QTH. 
73

Bruce-k1fz

http://www.qsl.net/k1fz/flag_antennas.html

_

Nick Hall-Patch
Victoria, BC
Canada

_
Topband Reflector Archives - http://www.contesting.com/_topband


_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Bowtie Flags

[Nick Hall-Patch]

What specific improvements did you note when the Delta was raised Bruce?

Thanks,


Nick
VE7DXR





At 16:23 12-12-16, K1FZ-Bruce wrote:

Dennis,

Is there a photo or sketch available of your antenna anywhere by email ?

Note: Height above ground helped a lot when my receiving Delta 
antenna was re-installed higher.  The bottom wire went from 3 feet up 
to  ~6 feet at my QTH.

73
Bruce-k1fz

http://www.qsl.net/k1fz/flag_antennas.html

_

Nick Hall-Patch
Victoria, BC
Canada

_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Bowtie Flags

[K1FZ-Bruce]

Dennis,
 
Is there a photo or sketch available of your antenna anywhere by email ?
 
Note: Height above ground helped a lot when my receiving Delta antenna 
was re-installed higher.  The bottom wire went from 3 feet up to  ~6 
feet at my QTH. 
 

73
Bruce-k1fz
 
http://www.qsl.net/k1fz/flag_antennas.html

On Sun, 11 Dec 2016 22:00:12 + (UTC), Dennis W0JX via Topband  wrote:

  Mike and Don,

I have been using an expanded version of a DHDL here since November 
2011. I was forced into going this way because the neighborhood around 
me has become very noisy and the antenna seems to be less susceptible 
to noise than my other antennas. I call it the Dual Flag array. I 
essentially expanded the DHDL deltas into the shape of a flag. My flags 
are large, approximately 24.5 feet tall and 32.5 feet long and 
separated by three feet. The wires cross in the middle rather than at 
the bottom so the flags are 180 degrees out of phase. They are similar 
to a Waller Flag antenna in some respects. 

My dual flag antenna is supported in the middle by a 31 foot pole made 
up of military fiberglas poles and the ends are supported by two trees. 
The bottom wire is 6 feet above ground. The feed transformer was wound 
on a binocular core with two turns on the primary and 7 turns secondary 
giving 918 ohms when fed with 75 ohm cable. I think my load resistor is 
1290 ohms at the back of the second flag. You can put a variable pot 
there and tune for best F/B but that is not necessarily the best RDF. 

I have found my dual flag array to be the quietest RX antenna in my RX 
system. It works very well on 160 through 40 although the pattern turns 
broadside on 40 meters. It beats all my 450 foot beverages hands down 
and is a great compliment to my HiZ 4 square which is now on the main 
RX of the K3 with the dual flag on the sub RX. You can also build a 
switching system to reverse directions but the circuit is rather 
complicated so I have two of these dual flag antennas pointed in 
different directions. I manually switch directions by moving the 
transformers and loads around using banana jacks when really need to 
grab a new country. 

As with all antennas of this type, an effective common mode choke at 
the feed point is an absolute must.SInce a rotatable version would be 
very difficult to build and support on a tower, the next logical step 
would be a smaller true Waller Flag like NX4D's Big Waller. 

I must give credit to George AA7JV who modeled this antenna for me and 
provided the inspiration through his TX3A DHDL RX antenna. 


73, Dennis W0JX
_
Topband Reflector Archives - http://www.contesting.com/_topband


_
Topband Reflector Archives - http://www.contesting.com/_topband

Topband: Bowtie Flags

[Dennis W0JX via Topband]

Mike and Don,

I have been using an expanded version of a DHDL here since November 2011. I was 
forced into going this way because the neighborhood around me has become very 
noisy and the antenna seems to be less susceptible to noise than my other 
antennas. I call it the Dual Flag array. I essentially expanded the DHDL deltas 
into the shape of a flag. My flags are large, approximately 24.5 feet tall and 
32.5 feet long and separated by three feet. The wires cross in the middle 
rather than at the bottom so the flags are 180 degrees out of phase. They are 
similar to a Waller Flag antenna in some respects.

My dual flag antenna is supported in the middle by a 31 foot pole made up of 
military fiberglas poles and the ends are supported by two trees. The bottom 
wire is 6 feet above ground. The feed transformer was wound on a binocular core 
with two turns on the primary and 7 turns secondary giving 918 ohms when fed 
with 75 ohm cable. I think my load resistor is 1290 ohms at the back of the 
second flag. You can put a variable pot there and tune for best F/B but that is 
not necessarily the best RDF.

I have found my dual flag array to be the quietest RX antenna in my RX system. 
It works very well on 160 through 40 although the pattern turns broadside on 40 
meters. It beats all my 450 foot beverages hands down and is a great compliment 
to my HiZ 4 square which is now on the main RX of the K3 with the dual flag on 
the sub RX. You can also build a switching system to reverse directions but the 
circuit is rather complicated so I have two of these dual flag antennas pointed 
in different directions. I manually switch directions by moving the 
transformers and loads around using banana jacks when really need to grab a new 
country.

As with all antennas of this type, an effective common mode choke at the feed 
point is an absolute must.SInce a rotatable version would be very difficult to 
build and support on a tower, the next logical step would be a smaller true 
Waller Flag like NX4D's Big Waller.

I must give credit to George AA7JV who modeled this antenna for me and provided 
the inspiration through his TX3A DHDL RX antenna.

73, Dennis W0JX 
_
Topband Reflector Archives - http://www.contesting.com/_topband