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 <[email protected]> >Sent: Jan 3, 2021 5:48 PM >To: [email protected], [email protected] >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:[email protected]] On >Behalf Of [email protected] >Sent: Sunday, January 03, 2021 3:01 PM >To: '[email protected]' >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: >[email protected] >To: [email protected] >Cc: >Sent: Sunday January 3 2021 11:59:27AM >Subject: Topband Digest, Vol 217, Issue 5 > > Send Topband mailing list submissions to > [email protected] > > 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 > [email protected] > > You can reach the person managing the list at > [email protected] > > 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: [email protected] > 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: [email protected] > 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 > [email protected]>> 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 > [email protected]>> On Behalf Of HA3LN > >>> Sent: Saturday, January 2, 2021 4:59 AM > >>> To: [email protected] > >>> 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: [email protected] > 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: [email protected] > > 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: [email protected] > 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: [email protected] > > 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: [email protected] > 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: [email protected] > 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: [email protected] > 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 > [email protected] >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 _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
