[TowerTalk] TowerTalk Digest, Vol 138, Issue 48
Patrick Greenlee
patrick_g at windstream.net
Thu Jun 26 08:25:29 EDT 2014
Chuck, Thanks so much for sharing your interesting experience. The only
military antenna I ever personally deployed was multi-strand copper
alloy antenna wire intended to be lifted by a balloon inflated by the
supplied hydrogen generator or carried aloft by the included box kite.
Came with transmit only hand cranked low freq radio. Ground was a short
wire with attached copper plate which was to be tossed over the side of
the raft into the salt water.
73,
Patrick NJ5G
On 6/23/2014 3:56 PM, Chuck Smallhouse wrote:
> Gentlemen, and I do mean it as a compliment !
>
> I greatly appreciate your prompt answers to my questions regarding the
> B & W Dipole.
>
> Now for the rest of the story. Several years ago I purchased a new
> MIL Spec one of these, at almost a give away price, at a hamfest flea
> market, It's wire elements were of stainless steel and the overall
> length was about 90'. I installed it at my QTH over quite hilly
> terrain, the average height was > 40' above the average mean
> elevation, BTW, I live on the N facing slope of a 9K' mountain range
> at 5000 feet, with a negative horizon from about 280 degrees around
> through N to about 120 degrees. The B & W runs about due E and W.
>
> I tried using it on 160 and was not too impressed, on 80 M it seemed
> to perform quite well. Since I had plenty of acreage, I decided to
> extend it to 180 ', which the instructions that I received with it,
> indicated that was the length of one commercial type available model.
> Fortunately I was able to find the exact same diameter SS stranded
> cable at a local wire cable distributor. In doing the extension I was
> able to move the average height up another 5 + feet and supported the
> center on my 6M antenna tower. The Amateur version uses stranded
> copper cable, however my version was intended for Military (and
> probably Embassy deployments) so probably the SS stranded cable was
> specified and supplied (at a higher cost) for it's durability and
> longer life in extreme environments ?
>
> I've noticed a definite improvement on all bands and especially on
> 160M, However, I'm now exchanging my IC PW-1, for a QRO+ PA,
> and am concerned about the B & W's power handling capabilities . I've
> misplaced the original instructions, I think that they indicated that
> the max power should be < 1 KW (600 W ?). Also, as I recall, the
> Balun/impedance transformer is a 16:1 ratio and the center terminating
> (impedance/SWR leveling) resistance was about 800 ohms ? Are there
> any acknowledgements to my recollections, but more importantly any
> solutions ? I've even considered elimination of the resistance and
> the balun, and replacing it with short length of open wire line to a
> remote balanced auto ATU, an expensive solution, which would also make
> the conversion to my 50 ohm 7/8" Heliax feed line.
>
> There are always various, sometimes very biased, opinions about
> different types of antennas, which make for quite interesting reading
> and food for thought. However there are many that are not based on
> real life measurements and or based on interesting and questionable
> mathematical equations and formula. Some even on "known computer
> programs and analyses", so at times a bit of 'tongue in cheek' is
> required. The B & W resistive termination does not set a precedence,
> in antenna design and implementation, as evidenced by the ever admired
> and revered Rhombic. These were especially effective when being used
> by our military communicators, in overseas locations - WWII and Korea.
>
> Maybe due to my location and installation, but I seem to experience,
> better signal reports than most equally high or higher, full sized,
> mono-band wire dipoles. Here again a non-objective opinion ! I've
> not really seriously tried it much above 20M, as I have a M2 KT36 for
> the higher bands.
>
> Again thanks, es 73,
>
> Chuck, W7CS
>
>
>
>
> At 03:43 AM 6/23/2014, towertalk-request at contesting.com wrote:
>> Send TowerTalk mailing list submissions to
>> towertalk at contesting.com
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>> http://lists.contesting.com/mailman/listinfo/towertalk
>> or, via email, send a message with subject or body 'help' to
>> towertalk-request at contesting.com
>>
>> You can reach the person managing the list at
>> towertalk-owner at contesting.com
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of TowerTalk digest..."
>>
>>
>> Today's Topics:
>>
>> 1. Re: Comments by K9YC (Dan Hearn)
>> 2. Re: Comments by K9YC (Joe Subich, W4TV)
>> 3. B & W Folded Dipole (Chuck Smallhouse)
>> 4. Re: Comments by K9YC (Steve Hunt)
>> 5. Re: B & W Folded Dipole (Jim Lux)
>> 6. Re: B & W Folded Dipole (w5gn at mxg.com)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Sun, 22 Jun 2014 20:28:40 -0700
>> From: Dan Hearn <n5ardxcc at gmail.com>
>> To: "Joe Subich, W4TV" <lists at subich.com>
>> Cc: towertalk reflector <towertalk at contesting.com>
>> Subject: Re: [TowerTalk] Comments by K9YC
>> Message-ID:
>> <CAHU7KER2eVc1o+5uz2Pr_Leu2OFoMxacMJ9FZeWEebkoo=asAw at mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> Thanks for your comments guys. I am very confused. There have been a
>> number
>> of things in QST saying that the current from the center conductor goes
>> into one half of the dipole DE and the remaining current goes partiallly
>> into the other half of the dipole and some of it goes down the outside
>> shield surface. I have never questioned that. There are commercial
>> antennas
>> which use a quarter wave line with the top near the DE and the bottom
>> connected to the feedline outer shield a quarter wave down the feed
>> line.
>> This should develop a high Z at the spillover point if there is one, Hi.
>> Here is what G0ksc says about it and he is a highly respected antenna
>> modeler
>> http://www.g0ksc.co.uk/creatingabalun.html
>> Frankly, I do not know what to believe. I have a rf current clamp on
>> meter which I may use to explore this further.
>>
>> 73, Dan, N5AR
>>
>>
>> On Sun, Jun 22, 2014 at 7:36 PM, Joe Subich, W4TV <lists at subich.com>
>> wrote:
>>
>> >
>> > On 2014-06-22 10:12 PM, Dan Hearn wrote:
>> >
>> >> The coax saw many places on the 3 bands where the feed point
>> >> impedance was not 52 ohms. That will result in spill over of current
>> >> from the inside of the shield to the outside at the attachment point
>> >> and ultimately radiation which screws up the beam pattern and sends
>> >> rf into your shack.
>> >>
>> >
>> > The fact that the feedline is not working into a matched load does
>> *not*
>> > create common mode current. Common mode on a feedline is created
>> *only*
>> > when the impedance to ground is different on each leg of the antenna.
>> > If the impedance is the same - even if it does not match the feedline
>> > impedance - the current into each leg of the antenna is the same, the
>> > antenna is balanced and there can be no common mode current.
>> >
>> > Mosley used to connect one side of the driven element to the boom with
>> > a strap. Grounding one half of the driven element and connecting the
>> > shield of the coax to the junction of the half-element and strap is
>> > guaranteed to seriously unbalance the antenna, causing beam skew,
>> feed-
>> > line radiation, and common mode current. In addition, if the boom
>> plus
>> > end elements happened to be a multiple of a half wave, the 1/4 wave
>> > each side of the feed point along the boom could easily cause all
>> kinds
>> > of strange behavior.
>> >
>> > It is unbalance *not SWR* that causes common mode current to flow in
>> > a feedline. In a properly balanced system, the currents on the center
>> > conductor and inside the coax are equal and opposite regardless of
>> > their level or their phase relationship to the voltage and no current
>> > appears on the *outside* of the shield.
>> >
>> > 73,
>> >
>> > ... Joe, W4TV
>> >
>> >
>> >
>> > On 2014-06-22 10:12 PM, Dan Hearn wrote:
>> >
>> >> I recently sent the following to towertalk reflector. It appears
>> that K9YC
>> >> does not understand it.
>> >> _________________________________________________________________
>> >> On 6/21/2014 3:23 PM, Dan Hearn wrote:
>> >>
>> >> It is interesting to note that the Mosley claimed gain is about 2db
>> >>> greater than other tri band beams. They use dbd reference instead
>> of dbi
>> >>> while I think their claims would be about right if they used dbi
>> >>> reference.
>> >>>
>> >>> ------------------------------------------------------------
>> >> -------------------------------------------------
>> >> Maybe I should have used a few more words to explain. In the fine
>> Yagi
>> >> tests described by K7LXC and N0AX in their book on tri band
>> Yagis. each
>> >> companies reference for their gain ratings is given. Mosley gave
>> dbd as
>> >> their reference. That implies that they have about 2db greater
>> gain than
>> >> other companies who use dbi. People who do antenna modeling get
>> their gain
>> >> answers referred to dbi, an isotropic model. If this is confusing,
>> You can
>> >> go to our clubs web page, www.sdxa.org and look under Articals to
>> find a
>> >> clear discussion of dbi,dbd, and db gains.
>> >> ------------------------------------------------------------
>> >> -------------------------------------------------
>> >> K9YC comment.
>> >>
>> >> "Exactly the opposite. The peak gain of a dipole is 2.2 dBi. So a
>> gain
>> >> specification of 4 dBd is equivalent to 6.2 dBi."
>> >> ------------------------------------------------------------
>> >> ----------------------------------------------
>> >> This is true but I fail to see what it has to do with my note.
>> >> ------------------------------------------------------------
>> >> -----------------------------------------------
>> >>
>> >> My second comment
>> >>>
>> >>
>> >>
>> >>
>> >> I suspect if you used a good line choke at the coax feed point and
>> >>> subtract
>> >>> 2.1db from their claimed gain you would have a typical triband beam.
>> >>>
>> >>> ------------------------------------------------------------
>> >> ------------------------------------------------
>> >>
>> >>
>> >> I don't agree with that logic or that statement. A simple common mode
>> >> choke
>> >> simply reduces common mode current, which mostly prevents RF
>> received on
>> >> the feedline from filling in the nulls in the pattern.
>> >> ------------------------------------------------------------
>> >> -----------------------------------------------
>> >> Here I do not believe Jim understands the problem. The choke will
>> do what
>> >> he says ON RECEIVING but that is not the problem we are trying to
>> solve
>> >> with understanding the lousy test results for the Mosley tri
>> bander. They
>> >> connected the coax directly to the driven element as Mosley said.
>> The coax
>> >> saw many places on the 3 bands where the feed point impedance was
>> not 52
>> >> ohms. That will result in spill over of current from the inside of
>> the
>> >> shield to the outside at the attachment point and ultimately
>> radiation
>> >> which screws up the beam pattern and sends rf into your shack.
>> That is why
>> >> you need a good line choke at the coax attachment point.
>> >>
>> >> I have a lot of respect for Jim and his work on line chokes and
>> other
>> >> things. I have built and measured many of his designs with excellent
>> >> results. I do not understand why he went on such a rampage over my
>> post.
>> >> ------------------------------------------------------------
>> >> ----------------------------------------------
>> >>
>> >>
>> >> In his book, "Array of Light," N6BT shows optimized designs of
>> 2-element,
>> >> 3-element, and 4-element MONOBAND Yagis. He put these IDEAL gain
>> figures
>> >> in
>> >> a table with the CLAIMED gains of a dozen or so competing
>> products. In
>> >> nearly all cases, the advertised gains were 2-3 dB better than the
>> best
>> >> monoband beam. In other words, they claimed impossible gains.
>> After the
>> >> first edition of "Array of Light" was published, nearly all of those
>> >> manufacturers revised their gain claimed downward by several dB.
>> >>
>> >> 73, Jim K9YC
>> >>
>> >> _______________________________________________
>> >
>> >
>> >
>> > _______________________________________________
>> > TowerTalk mailing list
>> > TowerTalk at contesting.com
>> > http://lists.contesting.com/mailman/listinfo/towertalk
>> >
>>
>>
>>
>> --
>> Dan Hearn
>> N5AR
>>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Mon, 23 Jun 2014 00:03:27 -0400
>> From: "Joe Subich, W4TV" <lists at subich.com>
>> To: Dan Hearn <n5ardxcc at gmail.com>
>> Cc: towertalk reflector <towertalk at contesting.com>
>> Subject: Re: [TowerTalk] Comments by K9YC
>> Message-ID: <53A7A70F.2050506 at subich.com>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>>
>> > There are commercial antennas which use a quarter wave line with the
>> > top near the DE and the bottom connected to the feedline outer shield
>> > a quarter wave down the feed line. This should develop a high Z at
>> > the spillover point if there is one, Hi.
>>
>> Yes, the quarter wave stub (Pawsley stub) raises the impedance seen
>> by the "grounded" side of the antenna. It does not change the SWR
>> on the antenna or effect any mismatch between the impedance of the
>> feedline and the antenna. The only thing it does is reduce the shunt
>> impedance from the outside of the coax shield.
>>
>> The shield of the coax is directly analogous to the grounding strap
>> Mosley used on one side of its antennas - it's just a little longer.
>> If one were to correctly model a dipole fed with coax, one would
>> include *a third wire* the length of the feedline running from one
>> side of the feedpoint to ground. With that third wire, one no longer
>> has a *balanced* antenna.
>>
>> In fact, get EZNEC or another modeling program that will show you the
>> currents in each segment. Then play with the length of that third
>> wire to see what happens to those currents at various lengths of
>> wire ... what happens to "feedline radiation" and how beam patterns
>> can become corrupted/skewed. It's quite interesting and educational.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 2014-06-22 11:28 PM, Dan Hearn wrote:
>> > Thanks for your comments guys. I am very confused. There have been
>> a number
>> > of things in QST saying that the current from the center conductor
>> goes
>> > into one half of the dipole DE and the remaining current goes
>> partiallly
>> > into the other half of the dipole and some of it goes down the outside
>> > shield surface. I have never questioned that. There are commercial
>> antennas
>> > which use a quarter wave line with the top near the DE and the bottom
>> > connected to the feedline outer shield a quarter wave down the feed
>> line.
>> > This should develop a high Z at the spillover point if there is
>> one, Hi.
>> > Here is what G0ksc says about it and he is a highly respected antenna
>> > modeler
>> > http://www.g0ksc.co.uk/creatingabalun.html
>> > Frankly, I do not know what to believe. I have a rf current
>> clamp on
>> > meter which I may use to explore this further.
>> >
>> > 73, Dan, N5AR
>> >
>> >
>> > On Sun, Jun 22, 2014 at 7:36 PM, Joe Subich, W4TV
>> <lists at subich.com> wrote:
>> >
>> >>
>> >> On 2014-06-22 10:12 PM, Dan Hearn wrote:
>> >>
>> >>> The coax saw many places on the 3 bands where the feed point
>> >>> impedance was not 52 ohms. That will result in spill over of current
>> >>> from the inside of the shield to the outside at the attachment point
>> >>> and ultimately radiation which screws up the beam pattern and sends
>> >>> rf into your shack.
>> >>>
>> >>
>> >> The fact that the feedline is not working into a matched load does
>> *not*
>> >> create common mode current. Common mode on a feedline is created
>> *only*
>> >> when the impedance to ground is different on each leg of the antenna.
>> >> If the impedance is the same - even if it does not match the feedline
>> >> impedance - the current into each leg of the antenna is the same, the
>> >> antenna is balanced and there can be no common mode current.
>> >>
>> >> Mosley used to connect one side of the driven element to the boom
>> with
>> >> a strap. Grounding one half of the driven element and connecting the
>> >> shield of the coax to the junction of the half-element and strap is
>> >> guaranteed to seriously unbalance the antenna, causing beam skew,
>> feed-
>> >> line radiation, and common mode current. In addition, if the boom
>> plus
>> >> end elements happened to be a multiple of a half wave, the 1/4 wave
>> >> each side of the feed point along the boom could easily cause all
>> kinds
>> >> of strange behavior.
>> >>
>> >> It is unbalance *not SWR* that causes common mode current to flow in
>> >> a feedline. In a properly balanced system, the currents on the
>> center
>> >> conductor and inside the coax are equal and opposite regardless of
>> >> their level or their phase relationship to the voltage and no current
>> >> appears on the *outside* of the shield.
>> >>
>> >> 73,
>> >>
>> >> ... Joe, W4TV
>> >>
>> >>
>> >>
>> >> On 2014-06-22 10:12 PM, Dan Hearn wrote:
>> >>
>> >>> I recently sent the following to towertalk reflector. It appears
>> that K9YC
>> >>> does not understand it.
>> >>> _________________________________________________________________
>> >>> On 6/21/2014 3:23 PM, Dan Hearn wrote:
>> >>>
>> >>> It is interesting to note that the Mosley claimed gain is about
>> 2db
>> >>>> greater than other tri band beams. They use dbd reference
>> instead of dbi
>> >>>> while I think their claims would be about right if they used dbi
>> >>>> reference.
>> >>>>
>> >>>> ------------------------------------------------------------
>> >>> -------------------------------------------------
>> >>> Maybe I should have used a few more words to explain. In the fine
>> Yagi
>> >>> tests described by K7LXC and N0AX in their book on tri band
>> Yagis. each
>> >>> companies reference for their gain ratings is given. Mosley gave
>> dbd as
>> >>> their reference. That implies that they have about 2db greater
>> gain than
>> >>> other companies who use dbi. People who do antenna modeling get
>> their gain
>> >>> answers referred to dbi, an isotropic model. If this is
>> confusing, You can
>> >>> go to our clubs web page, www.sdxa.org and look under Articals to
>> find a
>> >>> clear discussion of dbi,dbd, and db gains.
>> >>> ------------------------------------------------------------
>> >>> -------------------------------------------------
>> >>> K9YC comment.
>> >>>
>> >>> "Exactly the opposite. The peak gain of a dipole is 2.2 dBi. So a
>> gain
>> >>> specification of 4 dBd is equivalent to 6.2 dBi."
>> >>> ------------------------------------------------------------
>> >>> ----------------------------------------------
>> >>> This is true but I fail to see what it has to do with my note.
>> >>> ------------------------------------------------------------
>> >>> -----------------------------------------------
>> >>>
>> >>> My second comment
>> >>>>
>> >>>
>> >>>
>> >>>
>> >>> I suspect if you used a good line choke at the coax feed point and
>> >>>> subtract
>> >>>> 2.1db from their claimed gain you would have a typical triband
>> beam.
>> >>>>
>> >>>> ------------------------------------------------------------
>> >>> ------------------------------------------------
>> >>>
>> >>>
>> >>> I don't agree with that logic or that statement. A simple common
>> mode
>> >>> choke
>> >>> simply reduces common mode current, which mostly prevents RF
>> received on
>> >>> the feedline from filling in the nulls in the pattern.
>> >>> ------------------------------------------------------------
>> >>> -----------------------------------------------
>> >>> Here I do not believe Jim understands the problem. The choke will
>> do what
>> >>> he says ON RECEIVING but that is not the problem we are trying to
>> solve
>> >>> with understanding the lousy test results for the Mosley tri
>> bander. They
>> >>> connected the coax directly to the driven element as Mosley said.
>> The coax
>> >>> saw many places on the 3 bands where the feed point impedance was
>> not 52
>> >>> ohms. That will result in spill over of current from the inside
>> of the
>> >>> shield to the outside at the attachment point and ultimately
>> radiation
>> >>> which screws up the beam pattern and sends rf into your shack.
>> That is why
>> >>> you need a good line choke at the coax attachment point.
>> >>>
>> >>> I have a lot of respect for Jim and his work on line chokes
>> and other
>> >>> things. I have built and measured many of his designs with excellent
>> >>> results. I do not understand why he went on such a rampage over
>> my post.
>> >>> ------------------------------------------------------------
>> >>> ----------------------------------------------
>> >>>
>> >>>
>> >>> In his book, "Array of Light," N6BT shows optimized designs of
>> 2-element,
>> >>> 3-element, and 4-element MONOBAND Yagis. He put these IDEAL gain
>> figures
>> >>> in
>> >>> a table with the CLAIMED gains of a dozen or so competing
>> products. In
>> >>> nearly all cases, the advertised gains were 2-3 dB better than
>> the best
>> >>> monoband beam. In other words, they claimed impossible gains.
>> After the
>> >>> first edition of "Array of Light" was published, nearly all of those
>> >>> manufacturers revised their gain claimed downward by several dB.
>> >>>
>> >>> 73, Jim K9YC
>> >>>
>> >>> _______________________________________________
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> TowerTalk mailing list
>> >> TowerTalk at contesting.com
>> >> http://lists.contesting.com/mailman/listinfo/towertalk
>> >>
>> >
>> >
>> >
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Mon, 23 Jun 2014 00:32:59 -0700
>> From: Chuck Smallhouse <w7cs at theriver.com>
>> To: towertalk at contesting.com
>> Subject: [TowerTalk] B & W Folded Dipole
>> Message-ID: <20140623004903.B81DF507 at sj1-dm103.mta.everyone.net>
>> Content-Type: text/plain; charset="us-ascii"; format=flowed
>>
>> Recently I saw an ad, in maybe QST, by a company selling a dipole
>> that looked like the B & W one. Maybe they bought the rights from B
>> & W ? Does anyone recall the ad and where I saw it ? I've looked
>> through two or three recent QSTs and can't seem to find it .
>>
>> Also two or three years ago someone wrote a not too complimentary
>> article, in QST, about the B & W folded dipole . Does anyone recall
>> what issue that was ?
>>
>> Thanks & 73,
>>
>> Chuck, W7CS
>>
>>
>>
>> ------------------------------
>>
>> Message: 4
>> Date: Mon, 23 Jun 2014 10:18:26 +0100
>> From: Steve Hunt <steve at karinya.net>
>> Cc: towertalk reflector <towertalk at contesting.com>
>> Subject: Re: [TowerTalk] Comments by K9YC
>> Message-ID: <53A7F0E2.1040408 at karinya.net>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> You can then try inserting a choke at the feedpoint in the EZNEC model
>> and see how it does indeed change the SWR on the feedline!
>>
>> The SWR is bound to change under those conditions. If you have a low CM
>> impedance back along the coax braid outer surface, which is shunting one
>> side of the antenna to ground, the impedance "seen" at the end of the
>> feedline is bound to change when you then use a choke to make that shunt
>> CM path a much higher impedance.
>>
>> Steve G3TXQ
>>
>>
>>
>> On 23/06/2014 05:03, Joe Subich, W4TV wrote:
>> >
>> > In fact, get EZNEC or another modeling program that will show you the
>> > currents in each segment. Then play with the length of that third
>> > wire to see what happens to those currents at various lengths of
>> > wire ... what happens to "feedline radiation" and how beam patterns
>> > can become corrupted/skewed. It's quite interesting and educational.
>> >
>> > 73,
>> >
>> > ... Joe, W4TV
>> >
>> >
>>
>>
>>
>> ------------------------------
>>
>> Message: 5
>> Date: Mon, 23 Jun 2014 11:24:55 +0100
>> From: Jim Lux <jimlux at earthlink.net>
>> To: Chuck Smallhouse <w7cs at theriver.com>
>> Cc: "towertalk at contesting.com" <towertalk at contesting.com>
>> Subject: Re: [TowerTalk] B & W Folded Dipole
>> Message-ID: <B46602FC-827A-40A1-84F9-2BC2E8D8845E at earthlink.net>
>> Content-Type: text/plain; charset=us-ascii
>>
>> I doubt the B&W design is patented (or that the patent is in force)
>>
>> Anyone can make and sell a terminated folded dipole
>>
>> It's not inherently a bad design, although not popular for amateur
>> radio, which tends to put a premium on radiation efficiency, and
>> which doesn't do fast frequency changes and uses narrow band
>> signals. However, if you've got power to burn, and don't want to
>> fool with tuners, etc( e.g. You're doing ALE at an embassy or NGO or
>> doing millisecond frequency hopping) it works fairly well.
>>
>> One can probably do as well with a 3 - 6 dB pad at the feed point of
>> a standard dipole of similar length.
>>
>> 73, Jim
>>
>> On Jun 23, 2014, at 8:32, Chuck Smallhouse <w7cs at theriver.com> wrote:
>>
>> > Recently I saw an ad, in maybe QST, by a company selling a dipole
>> that looked like the B & W one. Maybe they bought the rights from B
>> & W ? Does anyone recall the ad and where I saw it ? I've looked
>> through two or three recent QSTs and can't seem to find it .
>> >
>> > Also two or three years ago someone wrote a not too complimentary
>> article, in QST, about the B & W folded dipole . Does anyone recall
>> what issue that was ?
>> >
>> > Thanks & 73,
>> >
>> > Chuck, W7CS
>> >
>> > _______________________________________________
>> >
>> >
>> >
>> > _______________________________________________
>> > TowerTalk mailing list
>> > TowerTalk at contesting.com
>> > http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>> ------------------------------
>>
>> Message: 6
>> Date: Mon, 23 Jun 2014 05:43:25 -0500
>> From: <w5gn at mxg.com>
>> To: <towertalk at contesting.com>
>> Cc: 'Jim Lux' <jimlux at earthlink.net>
>> Subject: Re: [TowerTalk] B & W Folded Dipole
>> Message-ID: <002b01cf8ecf$f803b240$e80b16c0$@mxg.com>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> I didn't write the QST article, but I did post some years ago,
>> probably on the Contest ListServer, about my NEGATIVE experience
>> when I tested the antenna on 80 meters in an NAQP Contest,
>> and incrementally increased my power to find that I could only
>> make marginal QSOs at 700 watts, but that at 1200 watts I was
>> getting the same success as I had with 100 watts to a 135 foot
>> longwire at the same elevation.
>>
>> (I remember a subsequent posting about my exceeding the 100 watt
>> power limit in the NAQP, and I pointed out that only applied
>> if I had submitted my log for score - I submitted as a CheckLog.)
>>
>> 73
>>
>> Barry, EI/W5GN
>>
>> -----Original Message-----
>> From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf
>> Of Jim Lux
>> Sent: Monday, June 23, 2014 5:25 AM
>> To: Chuck Smallhouse
>> Cc: towertalk at contesting.com
>> Subject: Re: [TowerTalk] B & W Folded Dipole
>>
>> I doubt the B&W design is patented (or that the patent is in force)
>>
>> Anyone can make and sell a terminated folded dipole
>>
>> It's not inherently a bad design, although not popular for amateur
>> radio, which tends to put a premium on radiation efficiency, and
>> which doesn't do fast frequency changes and uses narrow band
>> signals. However, if you've got power to burn, and don't want to
>> fool with tuners, etc( e.g. You're doing ALE at an embassy or NGO or
>> doing millisecond frequency hopping) it works fairly well.
>>
>> One can probably do as well with a 3 - 6 dB pad at the feed point of
>> a standard dipole of similar length.
>>
>> 73, Jim
>>
>> On Jun 23, 2014, at 8:32, Chuck Smallhouse <w7cs at theriver.com> wrote:
>>
>> > Recently I saw an ad, in maybe QST, by a company selling a dipole
>> that looked like the B & W one. Maybe they bought the rights from B
>> & W ? Does anyone recall the ad and where I saw it ? I've looked
>> through two or three recent QSTs and can't seem to find it .
>> >
>> > Also two or three years ago someone wrote a not too complimentary
>> article, in QST, about the B & W folded dipole . Does anyone recall
>> what issue that was ?
>> >
>> > Thanks & 73,
>> >
>> > Chuck, W7CS
>> >
>> > _______________________________________________
>> >
>> >
>> >
>> > _______________________________________________
>> > TowerTalk mailing list
>> > TowerTalk at contesting.com
>> > http://lists.contesting.com/mailman/listinfo/towertalk
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>>
>> ------------------------------
>>
>> Subject: Digest Footer
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>> ------------------------------
>>
>> End of TowerTalk Digest, Vol 138, Issue 48
>> ******************************************
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
More information about the TowerTalk
mailing list