Can't comment on BOGs, but installed a JK BevFlex-4 COAX Beverage - 500 ft long
- a few yrs ago. It runs E-W and have found the performance to be
UNDERWHELMING! I use my K9AY Loop more often with my K3 in Diversity mode than
the JKBev when working DX!? Any comments welcome.
73 and HNY - Alan K9MBQ
-----Original Message-----
>From: Sam Josuweit <samjos@epix.net>
>Sent: Jan 3, 2021 5:48 PM
>To: W3HKK@roadrunner.com, topband@contesting.com
>Subject: Re: Topband: Topband Digest, Vol 217, Issue 5
>
>Hi Bob,
>
>I'm currently running 4 Bogs with a switching system. The lengths are
>220-250 feet, and I believe the optimal length really depends on your
>ground. With 700 feet of good quality coax RG6/RG11 and good transformers,
>the preamp in my rig is enough, but a preamp in field would not hurt. They
>are quiet and directional. I use them because my land is shaped like a long
>rectangle and in some directions I don't have enough room for a full length
>beverage. They are almost invisible, which makes the XYL happy. I take them
>down in the summer so I can mow the fields. They do not work as well as a
>normal full sized beverage, but they do work. Do some searching on youtube
>and you will see some A/B comparisons that are helpful.
>
>Sam(N3XZ)
>
>
>-----Original Message-----
>From: Topband [mailto:topband-bounces+samjos=epix.net@contesting.com] On
>Behalf Of W3HKK@roadrunner.com
>Sent: Sunday, January 03, 2021 3:01 PM
>To: 'topband@contesting.com'
>Subject: Re: Topband: Topband Digest, Vol 217, Issue 5
>
>anyone with experience using a 300' BOG? Suggestions based on your
>experience?
>
>ie are they worth it?
>
>I tried one before but without a preamp and found it worthless. (
>almost no signals heard)
>suggestions on best preamps? With all in good working order, what
>benefits do they provide? Comparable to a longer Beverage?
>
>Tnx
>
>Bob
>
> -----------------------------------------From:
>topband-request@contesting.com
>To: topband@contesting.com
>Cc:
>Sent: Sunday January 3 2021 11:59:27AM
>Subject: Topband Digest, Vol 217, Issue 5
>
> Send Topband mailing list submissions to
> topband@contesting.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
>http://lists.contesting.com/mailman/listinfo/topband
> /> or, via email, send a message with subject or body 'help' to
> topband-request@contesting.com
>
> You can reach the person managing the list at
> topband-owner@contesting.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Topband digest..."
>
> Today's Topics:
>
> 1. Influence of ground water level on vertical performance.
> (Henk Remijn PA5KT)
> 2. Need Ideas For "Fusing" Beverages From Falling Trees (Randy)
> 3. Re: (2wire) Beverage transformers (HA3LN)
> 4. Re: (2wire) Beverage transformers (HA3LN)
> 5. Re: (2wire) Beverage transformers (HA3LN)
> 6. Re: (2wire) Beverage transformers (HA3LN)
> 7. Re: Need Ideas For "Fusing" Beverages From Falling Trees
> (Glenn kd0q)
> 8. Re: Need Ideas For "Fusing" Beverages From Falling Trees
> (MU 4CX250B)
> 9. Re: Need Ideas For "Fusing" Beverages From Falling Trees
> (VE6WZ_Steve)
> 10. Need Ideas For "Fusing" Beverages From Falling Trees
> (Roger Parsons)
> 11. Re: Need Ideas For "Fusing" Beverages From Falling Trees
> (Mark Robinson)
> 12. Re: Need Ideas For "Fusing" Beverages From Falling Trees
> (Mark - N5OT)
> 13. Re: Need Ideas For "Fusing" Beverages From Falling Trees
> (CUTTER DAVID)
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 3 Jan 2021 11:03:14 +0100
> From: Henk Remijn PA5KT
> To: topband@contesting.com
> Subject: Topband: Influence of ground water level on vertical
> performance.
> Message-ID:
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> Hi,
>
> I am searching for info about influence of ground water level on
> vertical performance.
>
> Any info or references to articles is welcome.
>
> 73 Henk PA5KT
>
> ------------------------------
>
> Message: 2
> Date: Sun, 3 Jan 2021 11:54:30 +0000 (UTC)
> From: Randy
> To: topband@contesting.com
> Subject: Topband: Need Ideas For "Fusing" Beverages From Falling
>Trees
> Message-ID:
> Content-Type: text/plain; charset=UTF-8
>
> I have several 600 foot beverages made of WD-1A mil wire that run
>through heavy woods.? They can handle the random falling branch but
>when a large tree falls over them they break.? The wire is held in
>place with electric fence plastic insulators that are nailed to trees
>every 100 feet.?I would like to add a smaller diameter wire to each
>insulator to act as a "fuse" when a tree falls across them.? I am
>looking for ideas as to the best way to do this.? Maybe a number 26
>wire?? The wire size has to be heavy enough to support the wire in
>normal use but weak enough to break when hit by a
>tree.?Suggestions??73?Randy W9ZR
>
> ------------------------------
>
> Message: 3
> Date: Sun, 3 Jan 2021 14:52:11 +0100
> From: HA3LN
> To: Don Kirk , Lee STRAHAN
> Cc: Mike Waters , topband
> Subject: Re: Topband: (2wire) Beverage transformers
> Message-ID:
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> Hi All,
>
> Yes, I refer to this 2-wire design:
> http://ha3ln.hu/2wire.jpg
> />
> 73!
> Csaba
>
> On 2021-01-02 22:53, Don Kirk wrote:
> > Hi Lee,
> >
> > Csaba also refers to this transformer as T2 and based on what he
>has said
> > so far I suspect he is constructing something similar to the two
>direction
> > beverage shown in figure 7-115 in the 5th edition of Low-Band
>DXing. And
> > T2 is indeed a two winding transformer with center tap. This
>transformer
> > transforms the impedance of the open wire transmission line (745
>ohms in
> > Csabas case) to the coaxial feedline (75 or 50 ohm). The center tap
>is
> > used to feed another transformer (T1).
> >
> > I could be wrong but reading between the lines I probably am
>correct.
> >
> > Just FYI,
> > Don (wd8dsb)
> >
> > On Sat, Jan 2, 2021 at 4:09 PM Don Kirk wrote:
> >
> >> Hi Lee,
> >>
> >> Csaba said his transformer was " n1=3T/n2=12T tapped @6T ". This
>sure
> >> sounds like a transformer with two separate windings (3 Turns on
>the
> >> Primary, and 12 Turns on the Secondary and then it also has a
>center tap on
> >> the secondary), but I could be wrong. I think Csaba needs to
>clarify
> >> exactly what his transformer is, and his test circuit.
> >>
> >> Don (wd8dsb)
> >>
> >> On Sat, Jan 2, 2021 at 3:22 PM Lee STRAHAN wrote:
> >>
> >>> Hi Mike,
> >>> Assuming that you did not miss that this was a tapped winding and
>not
> >>> separate windings as Csaba mentioned. I see on reflection that he
>measured
> >>> 1:1.16 on one of his tests. In reality it wont likely get much
>better than
> >>> that. That test was likely the 3:12 he mentioned using. The high
>impedance
> >>> side of these transformers are a little unpredictable using
>simple formulas
> >>> with winding capacitance and magnetizing inductance added in the
>mix.
> >>> Sometimes I use wire wrap wire if it is not going to be used
>outside
> >>> otherwise I use #27 high temp motor winding class insulation wire
>which
> >>> helps keep from shorting the wires to the core. I have the
>benefit of many
> >>> part spools of motor winding wire scraps from a best friend and
>Ham in the
> >>> Motor rewinding business. By the way, Norton amplifiers require
>1:11:4
> >>> which is the same problem to solve as they are separate windings
>in the
> >>> ones I use. I also fit shrink tubing in the Norton amp cores for
>insulation
> >>> first. I don?t use Teflon because it has a dielectric constant
>around 5
> >>> which increases the capacitance from the wire to the core. Its
>tedious but
> >>> can be done easily. And in the case of the Norton amp it leaves
>room for a
> >>> larger wire on the 1 turn winding. Yes 4 AND16 for 20 total can
>be done but
> >>> yes it takes time and lots of patience. For those turns counts I
>go to # 75
> >>> material toroid cores which have slightly more winding room but
>require
> >>> more turns usually for 160 meter stuff. All this probably more
>than you
> >>> wanted to know. HNY
> >>> Lee K7TJR OR
> >>>
> >>> From: Mike Waters
> >>> Sent: Saturday, January 2, 2021 11:44 AM
> >>> To: Lee K7TJR
> >>> Cc: HA3LN ; topband
> >>> Subject: Re: Topband: (2wire) Beverage transformers
> >>>
> >>> Lee,
> >>>
> >>> What kind of wire do you use that allows that many turns (4t and
>16t)?
> >>>
> >>> 73 Mike
> >>> W0BTU
> >>>
> >>> On Sat, Jan 2, 2021, 1:37 PM Lee STRAHAN > k7tjr@msn.com>> wrote:
> >>> Hello Csaba,
> >>> I approach this problem this way your impedance ratio is 745/50
>ohms
> >>> or 14.9 . To get turns ratio use the square root of that which is
>3.86 . So
> >>> round that up to 4 as a good turns ratio.
> >>> On a BN73-202 core I usually use a minimum of 4 turns on the 50
>ohm
> >>> side for 160 meters, so the secondary would need 4 turns ratio
>times that
> >>> for 16 turns. Therefore 16 turns tapped at 4 turns should work
>for you.
> >>> Some will say the 3 turns on the 50 ohm side should work and the
>secondary
> >>> then would be turns ratio 4 times that or 12 turns. Therefore 12
>turns
> >>> tapped at 3 turns should work well also. Sorry, I do not follow
>your
> >>> formula as shown but you can use the above and it will work fine
>as an 800
> >>> ohm load to the 745 ohm source. This will reflect 745/16 or 46.6
>ohms to
> >>> your cable. SWR for that at the 50 ohm cable is 50/46.6 or 1.07
>using
> >>> resistance only for evaluation.
> >>> Lee K7TJR OR
> >>>
> >>> -----Original Message-----
> >>> From: Topband > msn.com@contesting.com>> On Behalf Of HA3LN
> >>> Sent: Saturday, January 2, 2021 4:59 AM
> >>> To: topband@contesting.com
> >>> Subject: Topband: (2wire) Beverage transformers
> >>>
> >>> Hi All and HNY for 2021.
> >>>
> >>> Preparing for the CQ160m with new (2 coax) 2-wire beverages to
>cover the
> >>> missing azimuthal gaps based on LBDX. The first 2x Bevs worked
>great back
> >>> in last Jan.
> >>>
> >>> Now I have difficulties with reaching good imped match with the
> >>> T2 transformer (responsible to transform the 745 Ohms wire
>impedance to
> >>> 50 Ohm coax). I use n1=3T/n2=12T tapped @6T transformer (2m high,
>20cm wide
> >>> with 0.8mm wire)
> >>>
> >>> What can be the reason for the impedance transformation is rather
>off to
> >>> the calculated value?
> >>>
> >>> This is the T2 transformer from 2019:
> >>> http://ha3ln.hu/VNA_190116_230811.jpg
> /> >>> ...and this from yesterday:
> >>> http://ha3ln.hu/VNA_210101_153241.jpg
> /> >>>
> >>> I have
> >>> - same wire with the diam (even from the same roll)
> >>> - same BN73-202 cores (tried to use several cores from different
> >>> sources to eliminate the possible mix inconsistencies)
> >>> - same winding method (including n2 tapping)
> >>> - created a low inductance test resistor network for 744 Ohms
> >>>
> >>> ...tried to wind
> >>> - lousy, and precise (crossing windings vs. side-by-side, bunched
> >>> wires, etc.)
> >>> - n1 first and n2, after n2 first and n1, of course no
>difference.
> >>> - without the tapping, same as above.
> >>> - difference turning ratios (3/12, 2/12, 1/12, 3/11, etc.) to see
> >>> the change
> >>>
> >>>
> >>> The best I could reach now on 160m is
> >>> - SWR: 1:1.29 (Rs=40.4 Ohms, Xs=-5.4 Ohms) vs. in 2019:
> >>> - SWR: 1:1.16 (Rs=43.2 Ohms, Xs=-1.6 Ohms)
> >>>
> >>> I know, Beverages are really die hard antennas and this increased
> >>> mismatch might have zero effect on performance but still, the
>engineer part
> >>> of me...
> >>>
> >>> _________________
> >>> Searchable Archives: http://www.contesting.com/_topband [1] -
>Topband
> >>> Reflector
> >>>
> >>
> >
>
> ------------------------------
>
> Message: 4
> Date: Sun, 3 Jan 2021 15:44:42 +0100
> From: HA3LN
> To: topband@contesting.com
> Subject: Re: Topband: (2wire) Beverage transformers
> Message-ID:
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> Hi Lee,
>
> Thanks for the notes.
>
> Yes, the 1:1.16 measurement was from 2019 which I take as baseline.
>
> My aim was to have similar transformers for the new 2-wire directions
> but somehow I cannot wind them better than 1:1.29.
>
> I agree with Dave this is not something I could even observe on the
>air.
> As all the materials are exactly the same as last time I was
>interested
> if someone has experience on the reasoning.
>
> But I will use this versions.
>
> Thanks and 73!
> Csaba
>
> On 2021-01-02 23:15, Lee STRAHAN wrote:
> > Hi Don,
> > Regardless of the transformer whether it?s a tapped or separate. I
>gave him the tools that should make whatever he does correct.
>Personally I keep my Beverage when I make one at 450 ohms which makes
>the matching much easier for me. I just put up my first one yesterday
>in several years to test a new brainstorm antenna.
> > From what I saw he had a 1:1.16 SWR which could not get much better
>in my opinion. Apparently he thought it could be better.
> > All is good HNY
> > Lee K7TJR OR
> >
> >
> > From: Don Kirk
> > Sent: Saturday, January 2, 2021 1:54 PM
> > To: Lee STRAHAN
> > Cc: HA3LN ; Mike Waters ; topband
> > Subject: Re: Topband: (2wire) Beverage transformers
> >
> > Hi Lee,
> >
> > Csaba also refers to this transformer as T2 and based on what he
>has said so far I suspect he is constructing something similar to the
>two direction beverage shown in figure 7-115 in the 5th edition of
>Low-Band DXing. And T2 is indeed a two winding transformer with center
>tap. This transformer transforms the impedance of the open wire
>transmission line (745 ohms in Csabas case) to the coaxial feedline
>(75 or 50 ohm). The center tap is used to feed another transformer
>(T1).
> >
> > I could be wrong but reading between the lines I probably am
>correct.
> >
> > Just FYI,
> > Don (wd8dsb)
> >
> > On Sat, Jan 2, 2021 at 4:09 PM Don Kirk wrote:
> > Hi Lee,
> >
> > Csaba said his transformer was " n1=3T/n2=12T tapped @6T ". This
>sure sounds like a transformer with two separate windings (3 Turns on
>the Primary, and 12 Turns on the Secondary and then it also has a
>center tap on the secondary), but I could be wrong. I think Csaba
>needs to clarify exactly what his transformer is, and his test
>circuit.
> >
> > Don (wd8dsb)
> >
> > On Sat, Jan 2, 2021 at 3:22 PM Lee STRAHAN wrote:
> > Hi Mike,
> > Assuming that you did not miss that this was a tapped winding and
>not separate windings as Csaba mentioned. I see on reflection that he
>measured 1:1.16 on one of his tests. In reality it wont likely get
>much better than that. That test was likely the 3:12 he mentioned
>using. The high impedance side of these transformers are a little
>unpredictable using simple formulas with winding capacitance and
>magnetizing inductance added in the mix.
> > Sometimes I use wire wrap wire if it is not going to be used
>outside otherwise I use #27 high temp motor winding class insulation
>wire which helps keep from shorting the wires to the core. I have the
>benefit of many part spools of motor winding wire scraps from a best
>friend and Ham in the Motor rewinding business. By the way, Norton
>amplifiers require 1:11:4 which is the same problem to solve as they
>are separate windings in the ones I use. I also fit shrink tubing in
>the Norton amp cores for insulation first. I don?t use Teflon because
>it has a dielectric constant around 5 which increases the capacitance
>from the wire to the core. Its tedious but can be done easily. And in
>the case of the Norton amp it leaves room for a larger wire on the 1
>turn winding. Yes 4 AND16 for 20 total can be done but yes it takes
>time and lots of patience. For those turns counts I go to # 75
>material toroid cores which have slightly more winding room but
>require more turns usually for 160 meter stuf
> f. All this probably more than you wanted to know. HNY
> > Lee K7TJR OR
> >
> > From: Mike Waters
> > Sent: Saturday, January 2, 2021 11:44 AM
> > To: Lee K7TJR
> > Cc: HA3LN ; topband
> > Subject: Re: Topband: (2wire) Beverage transformers
> >
> > Lee,
> >
> > What kind of wire do you use that allows that many turns (4t and
>16t)?
> >
> > 73 Mike
> > W0BTU
> >
> > On Sat, Jan 2, 2021, 1:37 PM Lee STRAHAN wrote:
> > Hello Csaba,
> > I approach this problem this way your impedance ratio is 745/50
>ohms or 14.9 . To get turns ratio use the square root of that which is
>3.86 . So round that up to 4 as a good turns ratio.
> > On a BN73-202 core I usually use a minimum of 4 turns on the 50 ohm
>side for 160 meters, so the secondary would need 4 turns ratio times
>that for 16 turns. Therefore 16 turns tapped at 4 turns should work
>for you. Some will say the 3 turns on the 50 ohm side should work and
>the secondary then would be turns ratio 4 times that or 12 turns.
>Therefore 12 turns tapped at 3 turns should work well also. Sorry, I
>do not follow your formula as shown but you can use the above and it
>will work fine as an 800 ohm load to the 745 ohm source. This will
>reflect 745/16 or 46.6 ohms to your cable. SWR for that at the 50 ohm
>cable is 50/46.6 or 1.07 using resistance only for evaluation.
> > Lee K7TJR OR
> >
> > -----Original Message-----
> > From: Topband On Behalf Of HA3LN
> > Sent: Saturday, January 2, 2021 4:59 AM
> > To: topband@contesting.com
> > Subject: Topband: (2wire) Beverage transformers
> >
> > Hi All and HNY for 2021.
> >
> > Preparing for the CQ160m with new (2 coax) 2-wire beverages to
>cover the missing azimuthal gaps based on LBDX. The first 2x Bevs
>worked great back in last Jan.
> >
> > Now I have difficulties with reaching good imped match with the
> > T2 transformer (responsible to transform the 745 Ohms wire
>impedance to 50 Ohm coax). I use n1=3T/n2=12T tapped @6T transformer
>(2m high, 20cm wide with 0.8mm wire)
> >
> > What can be the reason for the impedance transformation is rather
>off to the calculated value?
> >
> > This is the T2 transformer from 2019:
> > http://ha3ln.hu/VNA_190116_230811.jpg
> /> > ...and this from yesterday:
> > http://ha3ln.hu/VNA_210101_153241.jpg
> /> >
> > I have
> > - same wire with the diam (even from the same roll)
> > - same BN73-202 cores (tried to use several cores from different
> > sources to eliminate the possible mix inconsistencies)
> > - same winding method (including n2 tapping)
> > - created a low inductance test resistor network for 744 Ohms
> >
> > ...tried to wind
> > - lousy, and precise (crossing windings vs. side-by-side, bunched
> > wires, etc.)
> > - n1 first and n2, after n2 first and n1, of course no difference.
> > - without the tapping, same as above.
> > - difference turning ratios (3/12, 2/12, 1/12, 3/11, etc.) to see
> > the change
> >
> >
> > The best I could reach now on 160m is
> > - SWR: 1:1.29 (Rs=40.4 Ohms, Xs=-5.4 Ohms) vs. in 2019:
> > - SWR: 1:1.16 (Rs=43.2 Ohms, Xs=-1.6 Ohms)
> >
> > I know, Beverages are really die hard antennas and this increased
>mismatch might have zero effect on performance but still, the engineer
>part of me...
> >
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [2] -
>Topband Reflector
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [3] -
>Topband Reflector
> >
>
> ------------------------------
>
> Message: 5
> Date: Sun, 3 Jan 2021 15:45:16 +0100
> From: HA3LN
> To: topband@contesting.com
> Subject: Re: Topband: (2wire) Beverage transformers
> Message-ID:
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> ...no problem Lee, actually each new idea helps.
> I'll give a try the n1=4T version with a 0.3mm (~AWG 28/29) wire to
>see
> if I can push a bit better matching.
>
> Sorry for the links I tried to avoid sending fairly large pics to the
> list directly.
>
> I have the same measurement setup as Don's sent yesterday, the
>loading
> resistors are similar too, soldered them from 2W metal oxide pieces,
> resulting 744 Ohms, which is within 1 Ohm to the open wire calculated
>value.
>
> What I see comparing the "old" transformer and the new ones that it
>has
> less linearity and as Don said it has significantly worse Z(s).
>@7MHz.
> It might suggests that the core has different mix which gave the
>higher
> results. I wound as least 15 transformers with ~10 different BN73-202
> cores from different sources to avoid similar manufacturing batches
>but
> I could not see improvements, so I concluded this as core independent
> reason.
>
>http://ha3ln.hu/old_new.jpg
> /> (green=2020 version, white=2019 transformer version)
> Interesting that the SWR curve minimum inflection point is roughly
> halved, which was @850KHz, it is @400KHz in 2021.
>
> Tried Don's advise to twist the prim/sec ends of both n1 and n2.
> Interestingly enough if I twisted the one made from 0.3mm wire, I
>could
> reach the 1:1.16 measurement values again, but if I did the same to
>one
> made from 0.5mm diam wire it became worse.
>
> 73!
> Csaba
>
> On 2021-01-03 1:06, Lee STRAHAN wrote:
> > Sorry Guys, I miss interpreted Csaba?s transformer problem. My
>email program truncated the URL?s and most of the information past
>that point. What I did get I misread as a result so now I am curious
>also of his dilemma.
> > Lee K7TJR OR
> >
> > From: Don Kirk
> > Sent: Saturday, January 2, 2021 3:03 PM
> > To: Lee STRAHAN
> > Cc: HA3LN ; Mike Waters
> > Subject: Re: Topband: (2wire) Beverage transformers
> >
> > Hi Lee,
> >
> > I don?t think he needed any tools (formulas, etc.), he is just
>trying to figure out why his recently made transformer does match
>closer to one he made a year ago. He too agrees that the SWR with his
>new transformer is likely not an issue, he is just trying to figure
>out why his new transformer is different than his previous one, and
>that?s why I measured one of my own so he had another data point to
>work with.
> >
> > His transformer from a year ago was 1.16 to 1 whereas his new
>transformer measured 1.29 to 1 and that?s bugging him from an
>obsessive standpoint.
> >
> > The reason I mentioned 2 windings was because of how you responded
>to Mikes question. I'm really not familiar with reversible beverages
>and jumping into this topic helped me learn a bit about them (I love
>learning).
> >
> > Just FYI, and Happy New Year to you and yours too.
> > Don (wd8dsb)
> >
> >
> >
> > On Sat, Jan 2, 2021 at 5:15 PM Lee STRAHAN wrote:
> > Hi Don,
> > Regardless of the transformer whether it?s a tapped or separate. I
>gave him the tools that should make whatever he does correct.
>Personally I keep my Beverage when I make one at 450 ohms which makes
>the matching much easier for me. I just put up my first one yesterday
>in several years to test a new brainstorm antenna.
> > From what I saw he had a 1:1.16 SWR which could not get much better
>in my opinion. Apparently he thought it could be better.
> > All is good HNY
> > Lee K7TJR OR
> >
> >
> > From: Don Kirk
> > Sent: Saturday, January 2, 2021 1:54 PM
> > To: Lee STRAHAN
> > Cc: HA3LN ; Mike Waters ; topband
> > Subject: Re: Topband: (2wire) Beverage transformers
> >
> > Hi Lee,
> >
> > Csaba also refers to this transformer as T2 and based on what he
>has said so far I suspect he is constructing something similar to the
>two direction beverage shown in figure 7-115 in the 5th edition of
>Low-Band DXing. And T2 is indeed a two winding transformer with center
>tap. This transformer transforms the impedance of the open wire
>transmission line (745 ohms in Csabas case) to the coaxial feedline
>(75 or 50 ohm). The center tap is used to feed another transformer
>(T1).
> >
> > I could be wrong but reading between the lines I probably am
>correct.
> >
> > Just FYI,
> > Don (wd8dsb)
> >
> > On Sat, Jan 2, 2021 at 4:09 PM Don Kirk wrote:
> > Hi Lee,
> >
> > Csaba said his transformer was " n1=3T/n2=12T tapped @6T ". This
>sure sounds like a transformer with two separate windings (3 Turns on
>the Primary, and 12 Turns on the Secondary and then it also has a
>center tap on the secondary), but I could be wrong. I think Csaba
>needs to clarify exactly what his transformer is, and his test
>circuit.
> >
> > Don (wd8dsb)
> >
> > On Sat, Jan 2, 2021 at 3:22 PM Lee STRAHAN wrote:
> > Hi Mike,
> > Assuming that you did not miss that this was a tapped winding and
>not separate windings as Csaba mentioned. I see on reflection that he
>measured 1:1.16 on one of his tests. In reality it wont likely get
>much better than that. That test was likely the 3:12 he mentioned
>using. The high impedance side of these transformers are a little
>unpredictable using simple formulas with winding capacitance and
>magnetizing inductance added in the mix.
> > Sometimes I use wire wrap wire if it is not going to be used
>outside otherwise I use #27 high temp motor winding class insulation
>wire which helps keep from shorting the wires to the core. I have the
>benefit of many part spools of motor winding wire scraps from a best
>friend and Ham in the Motor rewinding business. By the way, Norton
>amplifiers require 1:11:4 which is the same problem to solve as they
>are separate windings in the ones I use. I also fit shrink tubing in
>the Norton amp cores for insulation first. I don?t use Teflon because
>it has a dielectric constant around 5 which increases the capacitance
>from the wire to the core. Its tedious but can be done easily. And in
>the case of the Norton amp it leaves room for a larger wire on the 1
>turn winding. Yes 4 AND16 for 20 total can be done but yes it takes
>time and lots of patience. For those turns counts I go to # 75
>material toroid cores which have slightly more winding room but
>require more turns usually for 160 meter stuf
> f. All this probably more than you wanted to know. HNY
> > Lee K7TJR OR
> >
> > From: Mike Waters
> > Sent: Saturday, January 2, 2021 11:44 AM
> > To: Lee K7TJR
> > Cc: HA3LN ; topband
> > Subject: Re: Topband: (2wire) Beverage transformers
> >
> > Lee,
> >
> > What kind of wire do you use that allows that many turns (4t and
>16t)?
> >
> > 73 Mike
> > W0BTU
> >
> > On Sat, Jan 2, 2021, 1:37 PM Lee STRAHAN wrote:
> > Hello Csaba,
> > I approach this problem this way your impedance ratio is 745/50
>ohms or 14.9 . To get turns ratio use the square root of that which is
>3.86 . So round that up to 4 as a good turns ratio.
> > On a BN73-202 core I usually use a minimum of 4 turns on the 50 ohm
>side for 160 meters, so the secondary would need 4 turns ratio times
>that for 16 turns. Therefore 16 turns tapped at 4 turns should work
>for you. Some will say the 3 turns on the 50 ohm side should work and
>the secondary then would be turns ratio 4 times that or 12 turns.
>Therefore 12 turns tapped at 3 turns should work well also. Sorry, I
>do not follow your formula as shown but you can use the above and it
>will work fine as an 800 ohm load to the 745 ohm source. This will
>reflect 745/16 or 46.6 ohms to your cable. SWR for that at the 50 ohm
>cable is 50/46.6 or 1.07 using resistance only for evaluation.
> > Lee K7TJR OR
> >
> > -----Original Message-----
> > From: Topband On Behalf Of HA3LN
> > Sent: Saturday, January 2, 2021 4:59 AM
> > To: topband@contesting.com
> > Subject: Topband: (2wire) Beverage transformers
> >
> > Hi All and HNY for 2021.
> >
> > Preparing for the CQ160m with new (2 coax) 2-wire beverages to
>cover the missing azimuthal gaps based on LBDX. The first 2x Bevs
>worked great back in last Jan.
> >
> > Now I have difficulties with reaching good imped match with the
> > T2 transformer (responsible to transform the 745 Ohms wire
>impedance to 50 Ohm coax). I use n1=3T/n2=12T tapped @6T transformer
>(2m high, 20cm wide with 0.8mm wire)
> >
> > What can be the reason for the impedance transformation is rather
>off to the calculated value?
> >
> > This is the T2 transformer from 2019:
> > http://ha3ln.hu/VNA_190116_230811.jpg
> /> > ...and this from yesterday:
> > http://ha3ln.hu/VNA_210101_153241.jpg
> /> >
> > I have
> > - same wire with the diam (even from the same roll)
> > - same BN73-202 cores (tried to use several cores from different
> > sources to eliminate the possible mix inconsistencies)
> > - same winding method (including n2 tapping)
> > - created a low inductance test resistor network for 744 Ohms
> >
> > ...tried to wind
> > - lousy, and precise (crossing windings vs. side-by-side, bunched
> > wires, etc.)
> > - n1 first and n2, after n2 first and n1, of course no difference.
> > - without the tapping, same as above.
> > - difference turning ratios (3/12, 2/12, 1/12, 3/11, etc.) to see
> > the change
> >
> >
> > The best I could reach now on 160m is
> > - SWR: 1:1.29 (Rs=40.4 Ohms, Xs=-5.4 Ohms) vs. in 2019:
> > - SWR: 1:1.16 (Rs=43.2 Ohms, Xs=-1.6 Ohms)
> >
> > I know, Beverages are really die hard antennas and this increased
>mismatch might have zero effect on performance but still, the engineer
>part of me...
> >
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [4] -
>Topband Reflector
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [5] -
>Topband Reflector
> >
>
> ------------------------------
>
> Message: 6
> Date: Sun, 3 Jan 2021 15:51:56 +0100
> From: HA3LN
> To: topband@contesting.com
> Subject: Re: Topband: (2wire) Beverage transformers
> Message-ID:
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> ...thanks Luke, then I stop gold plating... ;-)
>
> One of the new directions is pointing dedicated to VK/ZL
> hope I can catch you in the CQ160m.
>
> 73!
> Csaba
>
> On 2021-01-03 1:39, List Mail wrote:
> > "The best I could reach now on 160m is
> > - SWR: 1:1.29 (Rs=40.4 Ohms, Xs=-5.4 Ohms)
> > vs. in 2019:
> > - SWR: 1:1.16 (Rs=43.2 Ohms, Xs=-1.6 Ohms)"
> >
> >
> > If I can get those matches on a *transmitting* antenna, I am very
> > satisfied!
> >
> > I built three 2-wire beverages using W0BTU's design (single coax)
>and
> > measured best SWR around 1.5:1 and didn't give it a second thought.
>They
> > are all 269 m long, using 2.5 mm galvanised high-tensile fencing
>wire.
> > They work!
> >
> > 73, Luke VK3HJ
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [6] -
>Topband Reflector
>
> ------------------------------
>
> Message: 7
> Date: Sun, 3 Jan 2021 08:59:52 -0600
> From: Glenn kd0q
> To: Randy
> Cc: Top Band Contesting
> Subject: Re: Topband: Need Ideas For "Fusing" Beverages From Falling
> Trees
> Message-ID:
>
> Content-Type: text/plain; charset="UTF-8"
>
> Hi Randy,
>
> I have the same situation here and I use 20 GA solid hookup wire for
>the
> "fuse" with about 10 turns wrapped around itself at the insulators.
> Sometimes the wire breaks, sometimes it comes unwrapped. I use butt
>splice
> crimp connectors on the WD-1A at the "fuse" as they are quick and
>easy to
> replace. One size smaller wire might be good too but I haven't had to
> splice the WD-1A yet. We had a derecho here last August that
>basically
> flattened my timber. The WD-1A is still good but buried under
>countless
> blown down trees.
>
> 73, Glenn KD0Q
>
> On Sun, Jan 3, 2021 at 5:54 AM Randy via Topband
> wrote:
>
> >
> > I have several 600 foot beverages made of WD-1A mil wire that run
>through
> > heavy woods. They can handle the random falling branch but when a
>large
> > tree falls over them they break. The wire is held in place with
>electric
> > fence plastic insulators that are nailed to trees every 100 feet. I
>would
> > like to add a smaller diameter wire to each insulator to act as a
>"fuse"
> > when a tree falls across them. I am looking for ideas as to the
>best way
> > to do this. Maybe a number 26 wire? The wire size has to be heavy
>enough
> > to support the wire in normal use but weak enough to break when hit
>by a
> > tree. Suggestions? 73 Randy W9ZR
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [7] -
>Topband
> > Reflector
> >
>
> ------------------------------
>
> Message: 8
> Date: Sun, 3 Jan 2021 10:21:06 -0500
> From: MU 4CX250B
> To: Randy
> Cc: topband@contesting.com
> Subject: Re: Topband: Need Ideas For "Fusing" Beverages From Falling
> Trees
> Message-ID:
>
> Content-Type: text/plain; charset="UTF-8"
>
> Hi Randy,
> My 720ft beverages (also made of WD1a strung between ceramic
> insulstors) have short lengths (12 inches or so) of 26 AWG wire that
> act as fuses. Each end of the wire is stapled to the 4 x 4 post at
>the
> vertex of the beverages. This fuse wire is recommended by DX
> Engineerimg to protect the front end of receivers from induced
> currents caused by nearby lightning strikes. It does not provide
> protection from falling branches or, here in New Mexico, from falling
> cacti or wandering bobcats.
>
> However, to me, a mechanical fuse link seems reasonable. As I recall,
> WD1a is a twisted pair of wires with a rated breaking strength
>greater
> than 200 lbs. A short conveniently placed segment of just one of the
> conductors would have half the breaking strength, and would be the
> likely breaking point if a tree or large branch fell on the antenna.
> 73,
> Jim w8zr
> Sent from my iPhone
>
> > On Jan 3, 2021, at 4:54 AM, Randy via Topband wrote:
> >
> > ?
> > I have several 600 foot beverages made of WD-1A mil wire that run
>through heavy woods. They can handle the random falling branch but
>when a large tree falls over them they break. The wire is held in
>place with electric fence plastic insulators that are nailed to trees
>every 100 feet. I would like to add a smaller diameter wire to each
>insulator to act as a "fuse" when a tree falls across them. I am
>looking for ideas as to the best way to do this. Maybe a number 26
>wire? The wire size has to be heavy enough to support the wire in
>normal use but weak enough to break when hit by a tree. Suggestions?
>73 Randy W9ZR
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [8] -
>Topband Reflector
>
> ------------------------------
>
> Message: 9
> Date: Sun, 3 Jan 2021 09:02:33 -0700
> From: VE6WZ_Steve
> To: Randy
> Cc: topband@contesting.com
> Subject: Re: Topband: Need Ideas For "Fusing" Beverages From Falling
> Trees
> Message-ID:
> Content-Type: text/plain; charset=utf-8
>
> Randy,
>
> I have 15 Beverage wires that average about 900? long. About 2.5
>miles of wire. All the wires are in dense, old growth forest.
> I have trees falling ALL the time. Every wire has a counterweight
>concrete block pulley system to prevent breakage.
> When a tree falls on a wire (about twice a month), the wire does not
>break, and a quick trip with the chain saw to remove the tree recovers
>the wire.
>
> You may not be a ?video guy? but I made a YouTube that shows the
>detail of how I install it and how they work:
>https://youtu.be/l91JL2ImEbk [9]
> />
> And here is a short video showing it in action:
> https://youtu.be/GEkA9Hzrwas [10]
> />
> Also, for those that have larger Beverage installations, this video
>explains how I use my antenna analyzer to sweep my wires at any time
>(even remotely) and by comparing the seep to saved files, I know if a
>wire is down.
> This is NOT a trivial problem. With my Beverage field, to walk and
>check all the wires, I would need to walk about 8 miles through heavy
>bush! This would take the better part of a day.
> Before a contest, in 5 minutes, I can check all 15 wires and know if
>there is a tree down or broken term or feed.
> https://youtu.be/PA67Tz-1TO4 [11]
> />
>
> 73, de steve ve6wz
>
> > On Jan 3, 2021, at 4:54 AM, Randy via Topband wrote:
> >
> >
> > I have several 600 foot beverages made of WD-1A mil wire that run
>through heavy woods. They can handle the random falling branch but
>when a large tree falls over them they break. The wire is held in
>place with electric fence plastic insulators that are nailed to trees
>every 100 feet. I would like to add a smaller diameter wire to each
>insulator to act as a "fuse" when a tree falls across them. I am
>looking for ideas as to the best way to do this. Maybe a number 26
>wire? The wire size has to be heavy enough to support the wire in
>normal use but weak enough to break when hit by a tree. Suggestions?
>73 Randy W9ZR
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [12] -
>Topband Reflector
>
> ------------------------------
>
> Message: 10
> Date: Sun, 3 Jan 2021 16:14:57 +0000 (UTC)
> From: Roger Parsons
> To: Topband
> Subject: Topband: Need Ideas For "Fusing" Beverages From Falling
>Trees
> Message-ID:
> Content-Type: text/plain; charset=UTF-8
>
> I have had good success (mostly) following W8JI's recommendations in
>a similar situtation with over 30000 ft of Beverages in very rough
>woodland:
>
> Use electric fence insulators nailed to trees, but allow the wire to
>pass freely through them;
> Fix only at the extremes of the antenna;
> Use a very strong wire - this is where I diverge from Tom because I
>find that WD1A is perfect for Beverages - but not bidirectional ones.
>Electric fence wire is probably OK too - and that is W8JI's
>recommendation.
>
> At the end points I use an egg insulator and a length of thin Dacron
>rope.
> WD1A has a major advantage for testing purposes - I make each wire
>off separately to a single connection point, and this? allows
>resistance measurements to be made from either end of the run to
>confirm its continuity.
>
> This arrangement allows the wire to withstand several large trees
>falling along its length (1000 ft) - and the antennas keep working.
>
> 73 Roger
> VE3ZI
>
> ------------------------------
>
> Message: 11
> Date: Sun, 3 Jan 2021 11:38:03 -0500
> From: Mark Robinson
> To: Randy , 'topband'
> Subject: Re: Topband: Need Ideas For "Fusing" Beverages From Falling
> Trees
> Message-ID:
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> I use 1/4 inch AMP spade connectors , male and female as a breakaway
> point on my open wire feeder. I greased them up with dielectric
>grease
> to keep the water out.?? Automotive bullet connectors might be a
>tighter fit
>
> 73 Mark N1UK
>
> On 03-Jan-21 6:54 AM, Randy via Topband wrote:
> > I have several 600 foot beverages made of WD-1A mil wire that run
>through heavy woods.? They can handle the random falling branch but
>when a large tree falls over them they break.? The wire is held in
>place with electric fence plastic insulators that are nailed to trees
>every 100 feet.?I would like to add a smaller diameter wire to each
>insulator to act as a "fuse" when a tree falls across them.? I am
>looking for ideas as to the best way to do this.? Maybe a number 26
>wire?? The wire size has to be heavy enough to support the wire in
>normal use but weak enough to break when hit by a
>tree.?Suggestions??73?Randy W9ZR
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [13] -
>Topband Reflector
>
> ------------------------------
>
> Message: 12
> Date: Sun, 3 Jan 2021 10:52:57 -0600
> From: Mark - N5OT
> To: TopBand List
> Subject: Re: Topband: Need Ideas For "Fusing" Beverages From Falling
> Trees
> Message-ID:
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> > This arrangement allows the wire to withstand several large trees
> falling along its length (1000 ft) - and the antennas keep working.
>
> Strange as it sounds, (living where I live and all that), sometimes
> during an ice storm all you really want to do is get on the air and
>play
> radio.? Can't really go out with the chainsaw while it's happening.?
> That's for later.
>
> I am liking the counterweight approach as what I may use if I put up
> long wires like that.
>
> 73 - Mark N5OT
>
> ------------------------------
>
> Message: 13
> Date: Sun, 3 Jan 2021 16:57:30 +0000 (GMT)
> From: CUTTER DAVID
> To: Mark Robinson , Randy ,
> topband
> Subject: Re: Topband: Need Ideas For "Fusing" Beverages From Falling
> Trees
> Message-ID:
> Content-Type: text/plain; charset=UTF-8
>
> Mark
> I like that idea the best. I would tie the parts together with a long
>piece of rot-proof cord so they don't get lost.
>
> David G3UNA/G6CP
>
> > On 03 January 2021 at 16:38 Mark Robinson wrote:
> >
> >
> > I use 1/4 inch AMP spade connectors , male and female as a
>breakaway
> > point on my open wire feeder. I greased them up with dielectric
>grease
> > to keep the water out.?? Automotive bullet connectors might be a
>tighter fit
> >
> > 73 Mark N1UK
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> Topband mailing list
> Topband@contesting.com
>http://lists.contesting.com/mailman/listinfo/topband
> />
>
> ------------------------------
>
> End of Topband Digest, Vol 217, Issue 5
> ***************************************
>
>
>Links:
>------
>[1] http://www.contesting.com/_topband
>[2] http://www.contesting.com/_topband
>[3] http://www.contesting.com/_topband
>[4] http://www.contesting.com/_topband
>[5] http://www.contesting.com/_topband
>[6] http://www.contesting.com/_topband
>[7] http://www.contesting.com/_topband
>[8] http://www.contesting.com/_topband
>[9] https://youtu.be/l91JL2ImEbk
>[10] https://youtu.be/GEkA9Hzrwas
>[11] https://youtu.be/PA67Tz-1TO4
>[12] http://www.contesting.com/_topband
>[13] http://www.contesting.com/_topband
>
>_________________
>Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
>
>
>_________________
>Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
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