Topband: Fine sigs from George, FO/AA7JV on 80 cw this morning
David Raymond
daraymond at iowatelecom.net
Tue Apr 4 13:32:20 EDT 2023
George has been QRV 160 cw most mornings NA time, sometimes earlier
rather than later. He's typically Q5 for the most part but not strong
here. . .usually S3 or S4 peak with QSB to virtually nil.
73. . . Dave, W0FLS
On 4/4/2023 12:09 PM, W3HKK at roadrunner.com wrote:
> I looked for George for the 3rd straight day on 160, but no copy.
> However there he was on 3527.5 at 1107z, with a very nice 579 sig and
> I quickly put him in the log. Well after my sunrise hr in Ohio I saw
> spots for him on 160 cw from several West Coast US stations.
>
> Havent heard a dx station on 160 at my SR for at least three days now,
> but had some nice short contacts with assorted VK's on 40 and 20 ssb
> around 1130z. Pulled 9U5RU out of the noise on 10m ssb shortly
> thereafter, so some sigs have been there for the taking.
>
> The VKs on 20 ssb were 5 S units stronger on the LP when I first
> contacted them, but at the end of the qso they were just 2 S units
> stronger LP. Wonder what else was coming through that I may have
> missed?
>
> -----------------------------------------From:
> topband-request at contesting.com
> To: topband at contesting.com
> Cc:
> Sent: Tuesday April 4 2023 12:00:44PM
> Subject: Topband Digest, Vol 244, Issue 4
>
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> Today's Topics:
>
> 1. Re: High Impedance RX Antennas (Dennis W0JX)
> 2. Re: High Impedance RX Antennas (Frank W3LPL)
> 3. Re: High Impedance RX Antennas (Tree)
> 4. Re: High Impedance RX Antennas (Don Moman VE6JY)
> 5. Re: High Impedance RX Antennas (John Kaufmann)
> 6. Re: [PVRC] 2-element receiving arrays (Dave Cuthbert)
> 7. Re: High Impedance RX Antennas (Jim Brown)
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 3 Apr 2023 16:42:37 +0000 (UTC)
> From: Dennis W0JX
> To: "topband at contesting.com"
> Subject: Re: Topband: High Impedance RX Antennas
> Message-ID:
> Content-Type: text/plain; charset=UTF-8
>
> There is an old saying "The enemy of good is perfect."? You will be
> driven crazy by chasing down every slight variance from the ideal.
> That being said, it is important to check out the obvious areas where
> flaws can create big problems. Indeed, the feedline coax, typically
> RG6 CATV line, is a major contributor to array performance problems.?
> The cheap, big box cable is covered with PVC and that stuff hardens
> and tightens up over the years. This allows water to enter the shield
> and the water easily migrates for long distances, creating a high
> resistance. Spend the money upfront and buy quality cable that is
> flooded.
> The idea of using cable that has a solid copper conductor has merit.
> But even with that, a bare copper conductor will oxidize over time. I
> find myself cleaning these conductors on an annual basis with the
> eraser end of a pencil (recommended by Lee K7TJR).
> I have also had F connector failures on my combiner box and on a
> common mode choke. Sometimes the imported female connector center
> contact just fails for no reason. The alternative Amphenol connectors
> are very expensive at about $8+ each but I am considering replacing
> the connectors with these higher grade parts.
> Also, the so-called "water-proof" compression connectors are often
> not. The connection must be waterproofed effectively.? Also,
> condensation from humidity can be a big problem. Here is northeast
> Ohio, the environment is humid for the majority of the year. I have
> poured water out of a 75 ohm preamp that was sheltered in a good
> enclosure!
> These complex phasing arrays are by no means plug and play. Each
> installation will be unique depending on layout and surrounding
> objects. There are three tools necessary to get them and keep them
> working:? 1.) a good portable signal source to feed the antenna
> preamps (I use an Elecraft XG-3 with a home brew impedance transformer
> at the input);? 2.) a portable transceiver to measure signal out of
> the system at various points (My KX3 does a great job); and an
> accurate antenna analyzer to measure impedances and to measure
> feedlines and phasing lines for the proper electrical lengths. N6RK is
> right. There can be considerable difference in RG6 impedance so you
> need to check it out.?
>
> 73 Dennis W0JXMilan, OH
>
> ------------------------------
>
> Message: 2
> Date: Mon, 3 Apr 2023 13:11:27 -0400 (EDT)
> From: Frank W3LPL
> To: topband
> Subject: Re: Topband: High Impedance RX Antennas
> Message-ID:
>
> Content-Type: text/plain; charset=utf-8
>
> Another highly recommended tool is a Time Domain Reflectometer.
> Tt easily detects any abnormalities in my 8-circle and 4-square
> arrays and stacked HF Yagi arrays and switches.
>
> Other than my hand held antenna analyzer, my hand held TDR is my
> most often used and most valuable tool for proving that the
> performance
> of my antennas and feedlines has not changed from prior measurements
> and identifying and isolating faults before they cause partial or
> total failure. A TDR can detect, diagnose and locate feedline and
> antenna faults from the comfort of your ham shack.
>
> Affordable TDRs are often available on eBay. Some antenna
> analyzers have rudimentary TDR capabilities but I've never used
> an antenna analyzer with TDR capabilities comparable in
> performance to a TDR.
>
> Long before moisture causes coax failure, it causes the impedance
> of the coax to change, a potentially big problem in a phased array
> or stacked Yagis. A TDR easily detects and locates the problem
> before it causes a failure.
>
> An antenna analyzer can also detect that moisture has caused
> an impedance shift in coax cable. Place a dummy load (with the
> same impedance as the coax) at one end of the coax cable. Sweep
> the antenna analyzer frequency. As you do a frequency sweep the
> VSWR and impedance should not change. If it does, moisture is
> probably eating away inside your coax.
>
> 73
> Frank
> W3LPL
>
> ----- Original Message -----
> From: "Dennis W0JX via Topband"
> To: "topband"
> Sent: Monday, April 3, 2023 4:42:37 PM
> Subject: Re: Topband: High Impedance RX Antennas
>
> There is an old saying "The enemy of good is perfect."? You will be
> driven crazy by chasing down every slight variance from the ideal.
> That being said, it is important to check out the obvious areas where
> flaws can create big problems. Indeed, the feedline coax, typically
> RG6 CATV line, is a major contributor to array performance problems.?
> The cheap, big box cable is covered with PVC and that stuff hardens
> and tightens up over the years. This allows water to enter the shield
> and the water easily migrates for long distances, creating a high
> resistance. Spend the money upfront and buy quality cable that is
> flooded.
> The idea of using cable that has a solid copper conductor has merit.
> But even with that, a bare copper conductor will oxidize over time. I
> find myself cleaning these conductors on an annual basis with the
> eraser end of a pencil (recommended by Lee K7TJR).
> I have also had F connector failures on my combiner box and on a
> common mode choke. Sometimes the imported female connector center
> contact just fails for no reason. The alternative Amphenol connectors
> are very expensive at about $8+ each but I am considering replacing
> the connectors with these higher grade parts.
> Also, the so-called "water-proof" compression connectors are often
> not. The connection must be waterproofed effectively.? Also,
> condensation from humidity can be a big problem. Here is northeast
> Ohio, the environment is humid for the majority of the year. I have
> poured water out of a 75 ohm preamp that was sheltered in a good
> enclosure!
> These complex phasing arrays are by no means plug and play. Each
> installation will be unique depending on layout and surrounding
> objects. There are three tools necessary to get them and keep them
> working:? 1.) a good portable signal source to feed the antenna
> preamps (I use an Elecraft XG-3 with a home brew impedance transformer
> at the input);? 2.) a portable transceiver to measure signal out of
> the system at various points (My KX3 does a great job); and an
> accurate antenna analyzer to measure impedances and to measure
> feedlines and phasing lines for the proper electrical lengths. N6RK is
> right. There can be considerable difference in RG6 impedance so you
> need to check it out.?
>
> 73 Dennis W0JXMilan, OH
> _________________
> Searchable Archives: http://www.contesting.com/_topband [1] - Topband
> Reflector
>
> ------------------------------
>
> Message: 3
> Date: Mon, 3 Apr 2023 10:20:26 -0700
> From: Tree
> To: Frank W3LPL
> Cc: topband
> Subject: Re: Topband: High Impedance RX Antennas
> Message-ID:
>
> Content-Type: text/plain; charset="UTF-8"
>
> I guess most people have some kind of small antenna analyzer that has
> a TDR
> kind of function.
>
> I have not warmed up to them yet as the results I see seem to be "all
> over
> the place". Maybe I just don't know how to use them yet.
>
> My goto TDR is homebrew - using an analog scope.
>
> Here is one design pretty similar to what I am using:
>
> A very simple TDR from W2AEW ? PierpaLab.com
> [2] I put a
> switch on it to slow down the rep rate as an option since some of my
> "stuff" is pretty long.
>
> It works wonderfully to check feedlines and beverages. I have one
> beverage
> that has transformers and feedlines on both ends and I can see the
> difference between open/short/terminate on the "far end" (which is
> physically in the shack).
>
> 73 Tree N6TR
>
> On Mon, Apr 3, 2023 at 10:11?AM Frank W3LPL wrote:
>
> > Another highly recommended tool is a Time Domain Reflectometer.
> > Tt easily detects any abnormalities in my 8-circle and 4-square
> > arrays and stacked HF Yagi arrays and switches.
> >
> > Other than my hand held antenna analyzer, my hand held TDR is my
> > most often used and most valuable tool for proving that the
> performance
> > of my antennas and feedlines has not changed from prior
> measurements
> > and identifying and isolating faults before they cause partial or
> > total failure. A TDR can detect, diagnose and locate feedline and
> > antenna faults from the comfort of your ham shack.
> >
> > Affordable TDRs are often available on eBay. Some antenna
> > analyzers have rudimentary TDR capabilities but I've never used
> > an antenna analyzer with TDR capabilities comparable in
> > performance to a TDR.
> >
> > Long before moisture causes coax failure, it causes the impedance
> > of the coax to change, a potentially big problem in a phased array
> > or stacked Yagis. A TDR easily detects and locates the problem
> > before it causes a failure.
> >
> > An antenna analyzer can also detect that moisture has caused
> > an impedance shift in coax cable. Place a dummy load (with the
> > same impedance as the coax) at one end of the coax cable. Sweep
> > the antenna analyzer frequency. As you do a frequency sweep the
> > VSWR and impedance should not change. If it does, moisture is
> > probably eating away inside your coax.
> >
> > 73
> > Frank
> > W3LPL
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "Dennis W0JX via Topband"
> > To: "topband"
> > Sent: Monday, April 3, 2023 4:42:37 PM
> > Subject: Re: Topband: High Impedance RX Antennas
> >
> > There is an old saying "The enemy of good is perfect." You will be
> driven
> > crazy by chasing down every slight variance from the ideal. That
> being
> > said, it is important to check out the obvious areas where flaws
> can create
> > big problems. Indeed, the feedline coax, typically RG6 CATV line,
> is a
> > major contributor to array performance problems. The cheap, big box
> cable
> > is covered with PVC and that stuff hardens and tightens up over the
> years.
> > This allows water to enter the shield and the water easily migrates
> for
> > long distances, creating a high resistance. Spend the money upfront
> and buy
> > quality cable that is flooded.
> > The idea of using cable that has a solid copper conductor has
> merit. But
> > even with that, a bare copper conductor will oxidize over time. I
> find
> > myself cleaning these conductors on an annual basis with the eraser
> end of
> > a pencil (recommended by Lee K7TJR).
> > I have also had F connector failures on my combiner box and on a
> common
> > mode choke. Sometimes the imported female connector center contact
> just
> > fails for no reason. The alternative Amphenol connectors are very
> expensive
> > at about $8+ each but I am considering replacing the connectors
> with these
> > higher grade parts.
> > Also, the so-called "water-proof" compression connectors are often
> not.
> > The connection must be waterproofed effectively. Also, condensation
> from
> > humidity can be a big problem. Here is northeast Ohio, the
> environment is
> > humid for the majority of the year. I have poured water out of a 75
> ohm
> > preamp that was sheltered in a good enclosure!
> > These complex phasing arrays are by no means plug and play. Each
> > installation will be unique depending on layout and surrounding
> objects.
> > There are three tools necessary to get them and keep them working:
> 1.) a
> > good portable signal source to feed the antenna preamps (I use an
> Elecraft
> > XG-3 with a home brew impedance transformer at the input); 2.) a
> portable
> > transceiver to measure signal out of the system at various points
> (My KX3
> > does a great job); and an accurate antenna analyzer to measure
> impedances
> > and to measure feedlines and phasing lines for the proper
> electrical
> > lengths. N6RK is right. There can be considerable difference in RG6
> > impedance so you need to check it out.
> >
> > 73 Dennis W0JXMilan, OH
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [3] -
> Topband
> > Reflector
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [4] -
> Topband
> > Reflector
> >
>
> ------------------------------
>
> Message: 4
> Date: Mon, 3 Apr 2023 11:33:10 -0600
> From: Don Moman VE6JY
> To: "Topband at Contesting. Com"
> Subject: Re: Topband: High Impedance RX Antennas
> Message-ID:
>
> Content-Type: text/plain; charset="UTF-8"
>
> A used Tek 1502 TDR is the "gold standard" to me anyway and they can
> be
> quite cheap at flea markets etc. They are "arm held" and self
> contained
> portable so ideal for up to 1000' runs and have enough resolution
> that you
> can "see" defects that you don't really need to worry about. The
> advantage
> over some of the VNWA's that have a TDR function, is that the 1502 is
> real
> time so intermittents can easily be spotted. And it measures
> impedance so
> you can easily see how long and what Z that unknown roll of flea
> market
> coax is!
>
> I built the scope based TDR from the QST articles years ago, but that
> version isn't even close to the 1502. I also have a Tek 1503 for
> checking
> longer runs of control cable etc.
>
> 73 Don
> VE6JY
>
> On Mon, Apr 3, 2023 at 11:21?AM Tree wrote:
>
> > I guess most people have some kind of small antenna analyzer that
> has a TDR
> > kind of function.
> >
> > I have not warmed up to them yet as the results I see seem to be
> "all over
> > the place". Maybe I just don't know how to use them yet.
> >
> > My goto TDR is homebrew - using an analog scope.
> >
> > Here is one design pretty similar to what I am using:
> >
> > A very simple TDR from W2AEW ? PierpaLab.com
> > [5] I put a
> > switch on it to slow down the rep rate as an option since some of
> my
> > "stuff" is pretty long.
> >
> > It works wonderfully to check feedlines and beverages. I have one
> beverage
> > that has transformers and feedlines on both ends and I can see the
> > difference between open/short/terminate on the "far end" (which is
> > physically in the shack).
> >
> > 73 Tree N6TR
> >
> > On Mon, Apr 3, 2023 at 10:11?AM Frank W3LPL
> > wrote:
> >
> > > Another highly recommended tool is a Time Domain Reflectometer.
> > > Tt easily detects any abnormalities in my 8-circle and 4-square
> > > arrays and stacked HF Yagi arrays and switches.
> > >
> > > Other than my hand held antenna analyzer, my hand held TDR is my
> > > most often used and most valuable tool for proving that the
> performance
> > > of my antennas and feedlines has not changed from prior
> measurements
> > > and identifying and isolating faults before they cause partial or
> > > total failure. A TDR can detect, diagnose and locate feedline and
> > > antenna faults from the comfort of your ham shack.
> > >
> > > Affordable TDRs are often available on eBay. Some antenna
> > > analyzers have rudimentary TDR capabilities but I've never used
> > > an antenna analyzer with TDR capabilities comparable in
> > > performance to a TDR.
> > >
> > > Long before moisture causes coax failure, it causes the impedance
> > > of the coax to change, a potentially big problem in a phased
> array
> > > or stacked Yagis. A TDR easily detects and locates the problem
> > > before it causes a failure.
> > >
> > > An antenna analyzer can also detect that moisture has caused
> > > an impedance shift in coax cable. Place a dummy load (with the
> > > same impedance as the coax) at one end of the coax cable. Sweep
> > > the antenna analyzer frequency. As you do a frequency sweep the
> > > VSWR and impedance should not change. If it does, moisture is
> > > probably eating away inside your coax.
> > >
> > > 73
> > > Frank
> > > W3LPL
> > >
> > >
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "Dennis W0JX via Topband"
> > > To: "topband"
> > > Sent: Monday, April 3, 2023 4:42:37 PM
> > > Subject: Re: Topband: High Impedance RX Antennas
> > >
> > > There is an old saying "The enemy of good is perfect." You will
> be
> > driven
> > > crazy by chasing down every slight variance from the ideal. That
> being
> > > said, it is important to check out the obvious areas where flaws
> can
> > create
> > > big problems. Indeed, the feedline coax, typically RG6 CATV line,
> is a
> > > major contributor to array performance problems. The cheap, big
> box
> > cable
> > > is covered with PVC and that stuff hardens and tightens up over
> the
> > years.
> > > This allows water to enter the shield and the water easily
> migrates for
> > > long distances, creating a high resistance. Spend the money
> upfront and
> > buy
> > > quality cable that is flooded.
> > > The idea of using cable that has a solid copper conductor has
> merit. But
> > > even with that, a bare copper conductor will oxidize over time. I
> find
> > > myself cleaning these conductors on an annual basis with the
> eraser end
> > of
> > > a pencil (recommended by Lee K7TJR).
> > > I have also had F connector failures on my combiner box and on a
> common
> > > mode choke. Sometimes the imported female connector center
> contact just
> > > fails for no reason. The alternative Amphenol connectors are very
> > expensive
> > > at about $8+ each but I am considering replacing the connectors
> with
> > these
> > > higher grade parts.
> > > Also, the so-called "water-proof" compression connectors are
> often not.
> > > The connection must be waterproofed effectively. Also,
> condensation from
> > > humidity can be a big problem. Here is northeast Ohio, the
> environment is
> > > humid for the majority of the year. I have poured water out of a
> 75 ohm
> > > preamp that was sheltered in a good enclosure!
> > > These complex phasing arrays are by no means plug and play. Each
> > > installation will be unique depending on layout and surrounding
> objects.
> > > There are three tools necessary to get them and keep them
> working: 1.) a
> > > good portable signal source to feed the antenna preamps (I use an
> > Elecraft
> > > XG-3 with a home brew impedance transformer at the input); 2.) a
> > portable
> > > transceiver to measure signal out of the system at various points
> (My KX3
> > > does a great job); and an accurate antenna analyzer to measure
> impedances
> > > and to measure feedlines and phasing lines for the proper
> electrical
> > > lengths. N6RK is right. There can be considerable difference in
> RG6
> > > impedance so you need to check it out.
> > >
> > > 73 Dennis W0JXMilan, OH
> > > _________________
> > > Searchable Archives: http://www.contesting.com/_topband [6] -
> Topband
> > > Reflector
> > > _________________
> > > Searchable Archives: http://www.contesting.com/_topband [7] -
> Topband
> > > Reflector
> > >
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [8] -
> Topband
> > Reflector
> >
>
> ------------------------------
>
> Message: 5
> Date: Mon, 3 Apr 2023 14:09:32 -0400
> From: "John Kaufmann"
> To: "'Topband at Contesting. Com'"
> Subject: Re: Topband: High Impedance RX Antennas
> Message-ID:
> Content-Type: text/plain; charset="utf-8"
>
> Another tool I've found indispensable for setting up and
> troubleshooting phased vertical RX arrays is a two-port VNA. I use an
> Array Solutions VNA-2180 (now discontinued) for critical measurements.
> I also have a NanoVNA H4 (https://nanovna.com/) [9] which is a very
> "affordable" VNA that can be used as a portable, handheld, standalone
> instrument and that you can take out in the field. In most cases, the
> NanoVNA H4 is more than good enough.
>
> There is a learning curve to using a VNA. However, once you learn it,
> you'll be able to make very accurate measurements of delay line
> lengths, preamplifier gain and phase, phase combiner gain and phase.
> Most VNA's also have a TDR function, although it is usually based on
> frequency domain measurements that are transformed to the time domain.
>
> I'm running a homebrew RX array and it would have been almost
> impossible to get it running as well as it is now without a VNA.
>
> 73, John W1FV
>
> ------------------------------
>
> Message: 6
> Date: Mon, 3 Apr 2023 09:04:26 -1000
> From: Dave Cuthbert
> To: Frank W3LPL
> Cc: topband , PVRC
> Subject: Re: Topband: [PVRC] 2-element receiving arrays
> Message-ID:
>
> Content-Type: text/plain; charset="UTF-8"
>
> It seems that padding the element capacitance as needed for equal
> capacitance would help.
>
> Dave KH6AQ
>
> On Thu, Mar 30, 2023 at 4:48?PM Frank W3LPL wrote:
>
> > Hi Dave,
> >
> > Anyone who has experimented with a high impedance antenna such
> > as an end fed half wave has experienced the extreme environmental
> > influence on the feedpoint impedance of a high impedance feed.
> >
> > The required spacing to trees and buildings is very difficult to
> predict
> > with any confidence. The impedance of a high impedance element
> > -- and hence the amount of voltag if feeds into the preamp --
> > is heavily influenced by its immediate environment.
> >
> > If all of the high impedance verticals in an array do not produce
> the
> > same voltages from the signals received by the array, the pattern
> > of the array and especially its nulls are significantly degraded.
> >
> > 73
> > Frank
> > W3LPL
> >
> >
> >
> >
> >
> >
> >
> > From: "K3ZJ David Siddall"
> > To: "Frank W3LPL"
> > Cc: "topband" , "PVRC" ,
> > "Pete N4ZR N4ZR"
> > Sent: Friday, March 31, 2023 12:34:28 AM
> > Subject: Re: [PVRC] Topband: 2-element receiving arrays
> >
> > Frank,
> > " wrt to-negative effects of nearby trees and buildings." for high
> > impedance verticals:
> >
> > Is there any data measuring how much loss if placed in the woods?
> Minimum
> > distance from a tree to minimize the loss? Are their other effects
> too,
> > such as less directionality?
> >
> > 73, Dave K3ZJ
> >
> >
> >
> > On Thu, Mar 30, 2023 at 1:38 PM Frank W3LPL < [ mailto:
> > donovanf at starpower.net | donovanf at starpower.net ] > wrote:
> >
> >
> > Hi Pete,
> >
> > For a monoband receiving array, you might consider using low
> impedance
> > resonant verticals rather than high impedance verticals.
> >
> > The primary advantages of high impedance verticals are
> > - very short verticals (but taller verticals produce stronger
> signals)
> > - multi-band operation
> > - no radials
> >
> > The primary disadvantages are
> > - reliability issues with outdoor electronics
> > - lightning susceptibility of outdoor electronics
> > - higher cost
> > - much lower signal levels
> > - extreme care required to suppress common mode signals (buried
> feedlines
> > are highly recommended)
> > - negative effects of nearby trees and buildings.
> >
> > The primary advantages of low impedance verticals are
> > - much stronger signal levels
> > - much less criticality of common mode signal suppression,
> > - much lower cost
> > - much higher reliability
> > - immunity to lightning damage
> > - much less affected by nearby trees and buildings
> >
> > The primary disadvantages are
> > - taller verticals (typically about 24 feet)
> > - radials (they can be very short if many radials are used)
> > - mono band operation (switchable matching networks can be used for
> > multi-band operation).
> >
> > I highly recommend the DX Engineering Receiving Antenna Phasing
> System.
> > Its expensive but well worth the investment especially for a small
> array.
> >
> > [ https://www.dxengineering.com/parts/dxe-ncc-2 [10] |
> > https://www.dxengineering.com/parts/dxe-ncc-2 [11] ]
> >
> > If you have 120 feet for a three element array, the YCCC array is a
> great
> > choice
> > It can use high impedance or low impedance verticals
> > Unfortunately its no longer available from DX Engineering
> > The nine element YCCC array uses only three active elements at any
> time,
> > so its really a three element array switchable in many directions.
> >
> > [
> >
> https://static.dxengineering.com/global/images/instructions/dxe-yccc-switch.pdf?_gl=1*1cv0fc9*_ga*MjEyMDA1Nzc3MS4xNjUyMzAyMjc0*_ga_NZB590FMHY*MTY4MDE5NTk1OC40My4xLjE2ODAxOTYwNTYuNTAuMC4w
> /> > |
> >
> https://static.dxengineering.com/global/images/instructions/dxe-yccc-switch.pdf?_gl=1*1cv0fc9*_ga*MjEyMDA1Nzc3MS4xNjUyMzAyMjc0*_ga_NZB590FMHY*MTY4MDE5NTk1OC40My4xLjE2ODAxOTYwNTYuNTAuMC4w
> /> > ]
> >
> > [ https://www.youtube.com/watch?v=dl-crM5Kb6A [12] |
> > https://www.youtube.com/watch?v=dl-crM5Kb6A [13] ]
> >
> > [ https://www.youtube.com/watch?v=lVW1CmrzP7c [14] |
> > https://www.youtube.com/watch?v=lVW1CmrzP7c [15] ]
> >
> > A two element array occupies only 60 feet or even a little less.
> >
> > 73
> > Frank
> > W3LPL
> >
> >
> > ----- Original Message -----
> > From: "Pete N4ZR N4ZR" < [ mailto:pete.n4zr at gmail.com |
> > pete.n4zr at gmail.com ] >
> > To: "topband" < [ mailto:Topband at contesting.com |
> Topband at contesting.com
> > ] >
> > Sent: Thursday, March 30, 2023 12:54:30 PM
> > Subject: Topband: 2-element receiving arrays
> >
> > Thinking ahead to next winter on 160, I'm interested in replacing
> my
> > K9AY Loop with a 2-vertical phased array. I'd like to homebrew the
> > antennas and just buy or build the remote control unit for the
> shack.
> > I'm looking for sources of components (antenna-located preamps and
> an
> > in-shack controller), and would prefer not to completely homebrew
> them,
> > but the prices at the usual suspects are awfully high. Any ideas?
> >
> > I have pretty reasonably-priced access to 25 and 31-foot fiberglass
> > poles (used for wind-socks by model airplane enthusiasts). I'm
> thinking
> > that one relatively low-cost approach might be to attach, say, #14
> wire
> > to the poles, with preamps at the base, but wonder if there is a
> > downside to using such small-diameter antenna elements rather than
> 1 or
> > 1.5 inch tubing? Alternatively, are clones of the DX Engineering 8'
> > short verticals with preamps a good alternative?
> >
> > --
> > 73, Pete N4ZR
> > _________________
> > Searchable Archives: [ http://www.contesting.com/_topband [16] |
> > http://www.contesting.com/_topband [17] ] - Topband Reflector
> > ______________________________________________________________
> > PVRC mailing list
> > Home: [ http://mailman.qth.net/mailman/listinfo/pvrc [18] |
> > http://mailman.qth.net/mailman/listinfo/pvrc [19] ]
> > Help: [ http://mailman.qth.net/mmfaq.htm [20] |
> > http://mailman.qth.net/mmfaq.htm [21] ]
> > Post: mailto: [ mailto:PVRC at mailman.qth.net | PVRC at mailman.qth.net
> ]
> > Message delivered to [ mailto:davek3zj at gmail.com |
> davek3zj at gmail.com ]
> >
> > This list hosted by: [ http://www.qsl.net/ [22] |
> http://www.qsl.net [23] ]
> > Please help support this email list: [
> http://www.qsl.net/donate.html [24] |
> > http://www.qsl.net/donate.html [25] ]
> >
> >
> >
> > _________________
> > Searchable Archives: http://www.contesting.com/_topband [26] -
> Topband
> > Reflector
> >
>
> ------------------------------
>
> Message: 7
> Date: Mon, 3 Apr 2023 12:18:02 -0700
> From: Jim Brown
> To: topband at contesting.com
> Subject: Re: Topband: High Impedance RX Antennas
> Message-ID:
>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> On 4/3/2023 10:20 AM, Tree wrote:
> > I guess most people have some kind of small antenna analyzer that
> has a TDR
> > kind of function.
>
> In my professional life in pro audio, I started doing Time Domain
> Spectrometry in 1982, so I have a pretty good handle on how it works.
> There is a mathematical relationship between the frequency response
> of a
> system and its time response -- one is the inverse of the other. The
> Fourier Transform of the time response yields the frequency response,
> and the Inverse Fourier of the frequency response yields the time
> response. Modern antenna analyzers produce a swept frequency
> response,
> and associated software running on the computer does the Inverse
> Fourier
> Transform of a sweep to produce the TDR.
>
> For more than 10 years, the best of the low cost Vector Network
> Analyzers has been the VNWA3SE, built and sold as a finished and
> tested
> unit, by SDR Kits, run by hams in UK. The unit, its firmware, and
> associated software, was designed by DG8SAQ, an EE prof. Support from
> both DG8SAQ and SDR Kits is excellent -- both read and respond to
> their
> support email reflector. Current cost with shipping is about $560
> (depending on currency).
>
> https://www.sdr-kits.net/introducing-DG8SAQ-VNWA3
> />
> Greatest precision (ability to see small things) is provided by a
> sweep
> over a very wide frequency range. I usually sweep from 50-500 MHz.
> Once
> the sweep is done, the TDR is simply a few more button pushes in the
> menu system.
>
> 73, Jim K9YC
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> Topband mailing list
> Topband at contesting.com
> http://lists.contesting.com/mailman/listinfo/topband
> />
>
> ------------------------------
>
> End of Topband Digest, Vol 244, Issue 4
> ***************************************
>
>
> Links:
> ------
> [1] http://www.contesting.com/_topband
> [2] https://pierpalab.com/2022/04/30/a-very-simple-tdr-from-w2aew/%3E
> [3] http://www.contesting.com/_topband
> [4] http://www.contesting.com/_topband
> [5] https://pierpalab.com/2022/04/30/a-very-simple-tdr-from-w2aew/%3E
> [6] http://www.contesting.com/_topband
> [7] http://www.contesting.com/_topband
> [8] http://www.contesting.com/_topband
> [9] https://nanovna.com/)
> [10] https://www.dxengineering.com/parts/dxe-ncc-2
> [11] https://www.dxengineering.com/parts/dxe-ncc-2
> [12] https://www.youtube.com/watch?v=dl-crM5Kb6A
> [13] https://www.youtube.com/watch?v=dl-crM5Kb6A
> [14] https://www.youtube.com/watch?v=lVW1CmrzP7c
> [15] https://www.youtube.com/watch?v=lVW1CmrzP7c
> [16] http://www.contesting.com/_topband
> [17] http://www.contesting.com/_topband
> [18] http://mailman.qth.net/mailman/listinfo/pvrc
> [19] http://mailman.qth.net/mailman/listinfo/pvrc
> [20] http://mailman.qth.net/mmfaq.htm
> [21] http://mailman.qth.net/mmfaq.htm
> [22] http://www.qsl.net/
> [23] http://www.qsl.net
> [24] http://www.qsl.net/donate.html
> [25] http://www.qsl.net/donate.html
> [26] http://www.contesting.com/_topband
>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
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