That's great news, Daryl. Thanks. Bill, K5WG
-----Original Message----- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of topband-requ...@contesting.com Sent: Monday, January 19, 2015 5:00 PM To: topband@contesting.com Subject: Topband Digest, Vol 145, Issue 19 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-requ...@contesting.com You can reach the person managing the list at topband-ow...@contesting.com When replying, please edit your Subject line so it is more specific than "Re: Contents of Topband digest..." Today's Topics: 1. Re: beverage on ice (Pete Millis) 2. Re: 160 VERT (Tom W8JI) 3. Re: Beverage on Ice (Tom W8JI) 4. Re: Beverage on Ice (Guy Olinger K2AV) 5. Re: Beverage on Ice (Mike Waters) 6. Beverage on Ice (Roger Parsons via Topband) ---------------------------------------------------------------------- Message: 1 Date: Sun, 18 Jan 2015 17:34:50 +0000 From: Pete Millis <pete.mil...@gmail.com> To: topband@contesting.com Subject: Re: Topband: beverage on ice Message-ID: <CAEf09xns-KStjdRZ74cid3RA6JPRr5u1nmVofFgKqPf-=kk...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Even a very thin wire shouldn't be left. Could easily slice a swimmer or get tangled around wildlife. Pete M3KXZ On 18 Jan 2015 17:01, <topband-requ...@contesting.com> wrote: > > 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-requ...@contesting.com > > You can reach the person managing the list at > topband-ow...@contesting.com > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Topband digest..." > > > Today's Topics: > > 1. Re: Beverage on Ice (Ron Feutz) > 2. Compact magnetic loop (Ignacy Misztal) > 3. Re: Compact magnetic loop (Bill Cromwell) > 4. Re: Compact magnetic loop (Arthur Delibert) > 5. Re: Compact magnetic loop (Tom W8JI) > 6. 160 VERT (Don) > 7. Beverage on Ice (Roger Parsons via Topband) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 17 Jan 2015 12:52:44 -0600 > From: "Ron Feutz" <fe...@wctc.net> > To: "Topband" <topband@contesting.com> > Subject: Re: Topband: Beverage on Ice > Message-ID: <012865CEF7284F718B9CAA230E728828@OwnerPC> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > > I did this about 10 years ago. I live on the Wisconsin River and it's about > a half-mile wide in front of the house. > > I laid out 1000' of #14 stranded, insulated wire. I terminated it with a > 200 ohm resistor to a 1/4 wave wire and several short radials running nearly > parallel to the antenna/grounding wires. At the feed end, I used a 4/1 > homebrew transformer using one of "Tom's" binocular cores. The transformer > was grounded to a conventional 8' ground rod. > > The antenna never worked at all, as far as I could tell. There was no > discernable, certainly not usable, directivity. Why, I don't have a clue. > The techniques chosen were the result of all the best advice I could get at > the time on the topband reflector. > > FWIW, the river averages about 10-15 feet deep under the antenna and is > sand/gravel/bedrock. I would love to try this again if someone can help > with an improved design. > > 73, > > Ron KK9K > > > -----Original Message----- > From: Roger Parsons via Topband > Sent: Friday, January 16, 2015 3:51 PM > To: Topband > Subject: Topband: Beverage on Ice > > I know that Beverages on Ground have been discussed on a number of > occasions, but: > > I live on the shores of a reasonably large lake, and at this time of year it > will be frozen to at least 2' and possibly 4' or 5' deep. I believe that ice > is a pretty good insulator, so I wonder about the effectiveness of a wire > just laid on the surface? It would be impossible to retrieve the wire in the > spring so it would have to be fine enameled copper. Even that may not be > very environmentally friendly? If the wire survived the first couple of days > it would be frozen into the ice - it would be at risk from snow machines > until that happened. > > This is just speculation from enforced idleness - I cleverly managed to > break my leg during a foolish last check of my receive antennas before > Christmas - so I can't even get into the shack, let alone onto the lake. I > was not very hopeful in any event that EP6T would be workable from here, but > I am determined somehow to get there for K1N... > > 73 Roger > VE3ZI > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband > > > > > ------------------------------ > > Message: 2 > Date: Sat, 17 Jan 2015 17:06:33 -0500 > From: Ignacy Misztal <n...@arrl.net> > To: topband@contesting.com > Subject: Topband: Compact magnetic loop > Message-ID: > <CA+yG_kFJxjX09Z94ZTBcUjhKoPMHC= 0cirfgvx65b8kes5k...@mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in > K3. For perhaps up to 1000 miles the loop provides excellent separation > between signals from Hi-Z. But it hears distant stations poorly, much worse > than TX inv L. Based on earlier reports I expected the loop to be very good > for DX. > > The loop is made from coax, is tuned and has a transformer. About 50 KHz > 2:1 BW. A low-noise preamp does not improve S/N. > > Any experiences with the loop here? > > Ignacy, NO9E > > > ------------------------------ > > Message: 3 > Date: Sat, 17 Jan 2015 17:27:03 -0500 > From: Bill Cromwell <wrcromw...@gmail.com> > To: topband@contesting.com > Subject: Re: Topband: Compact magnetic loop > Message-ID: <54bae1b7.3070...@gmail.com> > Content-Type: text/plain; charset=windows-1252; format=flowed > > Hi, > > That small mag-loop has a small aperture and so all of the signals > delivered to your radio will be lower levels than from a bigger antenna > (in terms of wavelength. A preamp should improve the signal strength but > not improve the SNR over what you get with the loop and no preamp. The > mag-loop reduces the noise with it's high Q and decreased bandwidth and > those nulls contribute to reduced noise, too. I have excellent luck with > mine but there just isn't any silver bullet. The mag loop I use on 160 > meters is four and a half feet in diameter. The receiver I use on 160 is > easily overloaded without some attenuation so the reduced signal levels > from the mag-loop are *ideal*. > > 73, > > Bill KU8H > > On 01/17/2015 05:06 PM, Ignacy Misztal wrote: > > I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in > > K3. For perhaps up to 1000 miles the loop provides excellent separation > > between signals from Hi-Z. But it hears distant stations poorly, much worse > > than TX inv L. Based on earlier reports I expected the loop to be very good > > for DX. > > > > The loop is made from coax, is tuned and has a transformer. About 50 KHz > > 2:1 BW. A low-noise preamp does not improve S/N. > > > > Any experiences with the loop here? > > > > Ignacy, NO9E > > _________________ > > Topband Reflector Archives - http://www.contesting.com/_topband > > > > > > ------------------------------ > > Message: 4 > Date: Sat, 17 Jan 2015 18:30:33 -0500 > From: Arthur Delibert <radio7...@msn.com> > To: Ignacy Misztal <n...@arrl.net>, "topband@contesting.com" > <topband@contesting.com> > Subject: Re: Topband: Compact magnetic loop > Message-ID: <blu177-w144735cea64a4703b281fde4...@phx.gbl> > Content-Type: text/plain; charset="iso-8859-1" > > I've been playing with an amplified Wellbrook ALA 1530S+ loop antenna for about 10 days now. It does a very good job on both close-in and long-distance signals across the SW spectrum, and its ability to knock down the local noise is a great benefit in my dense suburban location. > > Compared to my two pennant antennas, which have DX Engineering amplifiers, both my ears and my display tell me that the Wellbrook signal is a few dB lower, although the better S/N ratio often makes the signal more readable on the Wellbrook. The difference in signal level is not surprising, given the larger size of the pennants; in fact, the surprising thing is that the difference isn't greater. > > Given my age and the continual loss of tall trees on the property, it's clear that I'm going to need a replacement for the pennants someday that doesn't require trees or ladder-climbing. The Wellbrook may be it. > > Art Delibert, KB3FJO > > > Date: Sat, 17 Jan 2015 17:06:33 -0500 > > From: n...@arrl.net > > To: topband@contesting.com > > Subject: Topband: Compact magnetic loop > > > > I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in > > K3. For perhaps up to 1000 miles the loop provides excellent separation > > between signals from Hi-Z. But it hears distant stations poorly, much worse > > than TX inv L. Based on earlier reports I expected the loop to be very good > > for DX. > > > > The loop is made from coax, is tuned and has a transformer. About 50 KHz > > 2:1 BW. A low-noise preamp does not improve S/N. > > > > Any experiences with the loop here? > > > > Ignacy, NO9E > > _________________ > > Topband Reflector Archives - http://www.contesting.com/_topband > > > ------------------------------ > > Message: 5 > Date: Sat, 17 Jan 2015 18:32:19 -0500 > From: "Tom W8JI" <w...@w8ji.com> > To: "Bill Cromwell" <wrcromw...@gmail.com>, <topband@contesting.com> > Subject: Re: Topband: Compact magnetic loop > Message-ID: <91BC8F7FDFE34CFDB4E8BBA738D1CF1C@MAIN> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=response > > Effective aperture is not size related. > Effective aperture is exclusively tied to wavelength and gain. > > The only time effective aperture means anything for receiving is when > external noise no longer significantly influences noise floor. Other than > that, effective aperture is meaningless for S/N or hearing DX. > > The real issue with a small loop is it only has two very sharp nulls through > the axis. It all other directions, even straight up and below, it has > response. This means the only points where it significantly discriminates > against external noise are two points through the axis. > > Making it worse, many or most loops have terrible feedpoint designs. I > measured a very popular expensive loop, and the pattern had considerable > skewing because of feedline common mode response. While I had the loop > thousands of feet from noise sources, the pattern told me the feedline was a > major part of the "antenna". > > That same antenna, near my house, was nearly dominated by conducted noise > along the feedline. I determined the common mode "noise" sensitivity was > only down 5-10 dB from the loop pickup when a 50 foot feedline was used. > > It could only be three things: > > 1.) The feedpoint or loop design was poor, resulting in local conducted > noise dominating the background > > 2.) An inherent lack of directivity that comes with the wide peak response > and narrow axis nulls of the loop > > 3.) The loop efficiency is too low for the noise floor of the preamps, and > internal noise is limiting weak signal response (even a 3 foot loop has > enough theoretical gain for use in a reasonably quiet location) > > All of those are reasonably easy to test. > > 73 Tom > > > > > ----- Original Message ----- > From: "Bill Cromwell" <wrcromw...@gmail.com> > To: <topband@contesting.com> > Sent: Saturday, January 17, 2015 5:27 PM > Subject: Re: Topband: Compact magnetic loop > > > > Hi, > > > > That small mag-loop has a small aperture and so all of the signals > > delivered to your radio will be lower levels than from a bigger antenna > > (in terms of wavelength. A preamp should improve the signal strength but > > not improve the SNR over what you get with the loop and no preamp. The > > mag-loop reduces the noise with it's high Q and decreased bandwidth and > > those nulls contribute to reduced noise, too. I have excellent luck with > > mine but there just isn't any silver bullet. The mag loop I use on 160 > > meters is four and a half feet in diameter. The receiver I use on 160 is > > easily overloaded without some attenuation so the reduced signal levels > > from the mag-loop are *ideal*. > > > > 73, > > > > Bill KU8H > > > > On 01/17/2015 05:06 PM, Ignacy Misztal wrote: > >> I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in > >> K3. For perhaps up to 1000 miles the loop provides excellent separation > >> between signals from Hi-Z. But it hears distant stations poorly, much > >> worse > >> than TX inv L. Based on earlier reports I expected the loop to be very > >> good > >> for DX. > >> > >> The loop is made from coax, is tuned and has a transformer. About 50 KHz > >> 2:1 BW. A low-noise preamp does not improve S/N. > >> > >> Any experiences with the loop here? > >> > >> Ignacy, NO9E > >> _________________ > >> Topband Reflector Archives - http://www.contesting.com/_topband > >> > > > > _________________ > > Topband Reflector Archives - http://www.contesting.com/_topband > > > > > > ----- > > No virus found in this message. > > Checked by AVG - www.avg.com > > Version: 2014.0.4800 / Virus Database: 4257/8945 - Release Date: 01/17/15 > > > > > > ------------------------------ > > Message: 6 > Date: Sat, 17 Jan 2015 20:49:57 -0500 > From: "Don" <w4...@truvista.net> > To: <topband@contesting.com> > Subject: Topband: 160 VERT > Message-ID: <4E51229DF1534843B607936FD9304406@DonPC> > Content-Type: text/plain; charset="UTF-8" > > I put up on of K6MM?s helically Wound 160 vert can not get SWR down > I put up k6mm Helically wound vert for 160 but can not get SWR below 3:1 I have 8 - 1/4 wave radials of 16 awg wire out . Any suggestions you can offer would be appreciated > > W4DEE > > ------------------------------ > > Message: 7 > Date: Sun, 18 Jan 2015 15:02:49 +0000 (UTC) > From: Roger Parsons via Topband <topband@contesting.com> > To: Topband <topband@contesting.com> > Subject: Topband: Beverage on Ice > Message-ID: > < 818909102.2891473.1421593369343.javamail.ya...@jws106124.mail.bf1.yahoo.com> > > Content-Type: text/plain; charset=UTF-8 > > Many thanks for the comments received on this reflector and privately. A few points: > I don't think that the proposed antenna is just another BOG - there is a large non-conductive layer of ice before there is anything conductive. However, here on the Canadian Shield normal ground is not very conductive either. > > It would be essential to build the antenna from a very thin wire for environmental reasons. A thicker wire could cause all sorts of problems when the ice melts in the spring. > There is not that much snow machine activity on this lake - I would be unlucky for the wire to be broken, particularly if I installed it on a Monday - it would be well frozen into the ice long before the next weekend. > Perhaps the most interesting observation was from KK9K - what Ron did was pretty close to my intentions. Hopefully I will be able to corroberate or otherwise next season. > 73 RogerVE3ZI > > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Topband mailing list > Topband@contesting.com > http://lists.contesting.com/mailman/listinfo/topband > > > ------------------------------ > > End of Topband Digest, Vol 145, Issue 18 > **************************************** ------------------------------ Message: 2 Date: Sun, 18 Jan 2015 12:39:09 -0500 From: "Tom W8JI" <w...@w8ji.com> To: "Don" <w4...@truvista.net>, <topband@contesting.com> Subject: Re: Topband: 160 VERT Message-ID: <8BBDEE6B30D54A68B801D082776B50FC@MAIN> Content-Type: text/plain; format=flowed; charset="UTF-8"; reply-type=original There is no matching system at the base, and the antenna is pretty short. The SWR should be higher than 3:1 except losses are involved. System loss will tend to lower the SWR. The worse antenna efficiency becomes (within limits), the lower SWR will become. You could add a shunt capacitor from the feedpoint to ground (directly across the coax) or an inductor across the coax. You probably are going to need 35 ohms of capacitive or inductive reactance shunting the coax, and to retune the antenna with that reactance there. That would be a 2400 pF capacitor or a 3.1 uH inductor shunting the coax. The inductor would be about 10 turns 2 inches in diameter, and might be easiest. Then you just retune it to resonance. ----- Original Message ----- From: "Don" <w4...@truvista.net> To: <topband@contesting.com> Sent: Saturday, January 17, 2015 8:49 PM Subject: Topband: 160 VERT >I put up on of K6MM?s helically Wound 160 vert can not get SWR down > I put up k6mm Helically wound vert for 160 but can not get SWR below 3:1 I > have 8 - 1/4 wave radials of 16 awg wire out . Any suggestions you can > offer would be appreciated > > W4DEE > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4800 / Virus Database: 4257/8948 - Release Date: 01/17/15 > ------------------------------ Message: 3 Date: Sun, 18 Jan 2015 14:57:25 -0500 From: "Tom W8JI" <w...@w8ji.com> To: "Ron Feutz" <fe...@wctc.net>, "Topband" <topband@contesting.com> Subject: Re: Topband: Beverage on Ice Message-ID: <3738775A41544F02818CC4E5D687C475@MAIN> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response > I laid out 1000' of #14 stranded, insulated wire. I terminated it with a > 200 ohm resistor to a 1/4 wave wire and several short radials running > nearly parallel to the antenna/grounding wires. At the feed end, I used a > 4/1 homebrew transformer using one of "Tom's" binocular cores. The > transformer was grounded to a conventional 8' ground rod. > > The antenna never worked at all, as far as I could tell. There was no > discernable, certainly not usable, directivity. Why, I don't have a clue. > The techniques chosen were the result of all the best advice I could get > at the time on the topband reflector. > I'm afraid antennas like that are severely length constrained, because they are slow wave structures. The velocity factor of an antenna laying on or surrounded by ice is pretty slow. This will limit how long you can make an antenna before the pattern falls apart. Insulation will not mitigate this problem, because the issue is the proportion of electric field in the media (ice) around the antenna compared to other dielectrics. If we consider the dielectric constant 3, maximum length would be 250 feet and it would be quite length critical. Too short or too long and pattern would fall apart. The impedance is also a lot higher than you might expect. It is nothing like a BOG laid on normal dirt. It doesn't even act like a Beverage because of the extremely slow wave velocity. 73 Tom ------------------------------ Message: 4 Date: Sun, 18 Jan 2015 16:27:18 -0500 From: Guy Olinger K2AV <k2av....@gmail.com> To: Tom W8JI <w...@w8ji.com> Cc: Ron Feutz <fe...@wctc.net>, Topband <topband@contesting.com> Subject: Re: Topband: Beverage on Ice Message-ID: <canckpc1njy4exbcca244svfmu6fas2oxlhep-ge-z3yxwq-...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 The 1000 feet of wire trenched in ice was doomed from the start. 160m BOG's longer than 220 feet start to not model well, and start to not perform well. One can easily model a BOG that has a pattern *reversal*. The various serious quirks of BOG's make them unpopular. And so they are not well-researched. Based on BOG-related measurements and experience (not modeling) I can pretty well guarantee that an Ice-BOG of 1000 feet would not work well. It has been interesting to figure out how to model a BOG so that the model agrees with reality. The most accurate results require NEC4, which can handle wires which are slightly underground. The beverage technique of terminating the far end of a wire in what amounts to a characteristic impedance, to zero the standing wave on the wire, does not produce an optimum BOG. As Tom has stated, the antenna is dominated by the fact that signals on the wire and incoming from the air move at vastly different speeds. Understanding the velocity factor on a BOG wire in its *individual* setting is key to success. The best modeled patterns USE that difference to advantage, to optimize pattern. Not at all like a beverage. To that end, "beverage on ground" is a misnomer. What is called a BOG is really a ground mounted low velocity factor RX antenna, which has its own set of rules. For just one, notching the BOG into the ground at installation prevents a large change in velocity factor as over seasons the wire gradually works itself through the grass and into the dirt. To get the BOG adjusted and with a somewhat constant behavior really requires that the BOG be UNDER ground, notched into the actual dirt, not up in the grass. In truth, both "beverage" and "on" the ground, the "B" and "O" of BOG, are misnomers for optimal installations. If you want the acronym to actually mean something correct, what we call a BOG is a GLVF ( Ground installed Low Velocity Factor) antenna, following its own set of rules. Doing a GLVF antenna in ice would imply possible issues, also correct, reference Tom's commentary. The BOG's pattern will also vary with the ground's water content, which is in turn varying the velocity factor and the best termination strategy. This IMHO, along with the wire gradually growing down into the grass, is mainly responsible for the difficulty in obtaining repeatable results and unsatisfactory results. This implies setting up the BOG in wet conditions anywhere other than desert. At contest time, a dried out BOG can be brought back to the setup performance with a garden hose. Try doing that in reverse. I stand by my original statement of 220 feet for an Ice-BOG. And for mechanical reasons, notched into the ice, using insulated flexweave. 73, Guy. On Sun, Jan 18, 2015 at 2:57 PM, Tom W8JI <w...@w8ji.com> wrote: > I laid out 1000' of #14 stranded, insulated wire. I terminated it with a >> 200 ohm resistor to a 1/4 wave wire and several short radials running >> nearly parallel to the antenna/grounding wires. At the feed end, I used a >> 4/1 homebrew transformer using one of "Tom's" binocular cores. The >> transformer was grounded to a conventional 8' ground rod. >> >> The antenna never worked at all, as far as I could tell. There was no >> discernable, certainly not usable, directivity. Why, I don't have a clue. >> The techniques chosen were the result of all the best advice I could get at >> the time on the topband reflector. >> >> > I'm afraid antennas like that are severely length constrained, because > they are slow wave structures. > > The velocity factor of an antenna laying on or surrounded by ice is pretty > slow. This will limit how long you can make an antenna before the pattern > falls apart. > > Insulation will not mitigate this problem, because the issue is the > proportion of electric field in the media (ice) around the antenna compared > to other dielectrics. > > If we consider the dielectric constant 3, maximum length would be 250 feet > and it would be quite length critical. Too short or too long and pattern > would fall apart. > > The impedance is also a lot higher than you might expect. It is nothing > like a BOG laid on normal dirt. It doesn't even act like a Beverage because > of the extremely slow wave velocity. > > 73 Tom > > > > > > > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband > ------------------------------ Message: 5 Date: Sun, 18 Jan 2015 16:36:58 -0600 From: Mike Waters <mikew...@gmail.com> To: Topband <topband@contesting.com> Subject: Re: Topband: Beverage on Ice Message-ID: <ca+fxyxiypekxjg7kgfrphjg4ibvojen5x9v-2quowzfzlpv...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 IIRC, the dielectric constant of pure ice is over 80. :-) While looking it up, I found that it varies with frequency, temperature, and any dissolved content. http://nvlpubs.nist.gov/nistpubs/jres/64D/jresv64Dn4p357_A1b.pdf This begs the question, Exactly how much might the performance of a Beverage vary between summer (the ground under a Beverage completely thawed) and winter with a frost depth of several feet? 73, Mike www.w0btu.com On Sun, Jan 18, 2015 at 1:57 PM, Tom W8JI <w...@w8ji.com> wrote: > > The velocity factor of an antenna laying on or surrounded by ice is pretty > slow. ... > ------------------------------ Message: 6 Date: Sun, 18 Jan 2015 23:58:35 +0000 (UTC) From: Roger Parsons via Topband <topband@contesting.com> To: Topband <topband@contesting.com> Subject: Topband: Beverage on Ice Message-ID: <712418824.3036606.1421625515559.javamail.ya...@jws106113.mail.bf1.yahoo.com > Content-Type: text/plain; charset=UTF-8 I think I give up on this project. Firstly, I can think of no way to reliably retrieve the wire in the spring, no matter what gauge it is and as has been pointed out that could be hazardous to wildlife. Secondly, it would seem unlikely that it will work very well, and as I have plenty of space for real Beverages I will concentrate on those. 73 RogerVE3ZI ------------------------------ Subject: Digest Footer _______________________________________________ Topband mailing list Topband@contesting.com http://lists.contesting.com/mailman/listinfo/topband ------------------------------ End of Topband Digest, Vol 145, Issue 19 **************************************** _________________ Topband Reflector Archives - http://www.contesting.com/_topband