Requesting "Off-Line" replies to a question I am strongly considering purchasing an Elecraft KPA-500 and KAT-500 amplifier and tuner combo. The KPA-1500 is probably too much for the neighbors around me (compact 80X100 foot city lots) to 'enjoy', so the 500-watt system best suits them AND my wallet!
Are there any horror stories about these units about which I should be informed ? I'd enjoy getting back on 160 from this city QTH. Any replies to -- dick.bing...@gmail.com 73 Dick/w7wkr at CN97uj On Fri, Jan 1, 2021 at 9:02 AM <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. SM5EDX 160m in KL7 December 31,2020 (uy0zg) > 2. Question about on ground radials field. (Jim Clymer) > 3. Re: Question about on ground radials field. (Artek Manuals) > 4. Re: Question about on ground radials field. (Jim Brown) > 5. Re: Question about on ground radials field. (Dave Cuthbert) > 6. Vertical choke needed? (Kenneth Silverman) > 7. Re: Question about on ground radials field. (donov...@erols.com) > 8. Re: Vertical choke needed? (Michael Walker) > 9. Re: Vertical choke needed? (Kenny Silverman) > 10. Re: Vertical choke needed? (Wes) > 11. Re: Vertical choke needed? (Artek Manuals) > 12. Re: Vertical choke needed? (Michael Walker) > 13. Re: Vertical choke needed? (Wes) > 14. Re: Vertical choke needed? (Jim Brown) > 15. Re: Vertical choke needed? (Jim Brown) > 16. Re: Vertical choke needed? (Jim Brown) > 17. Re: Vertical choke needed? (Artek Manuals) > 18. Choke Baluns etc (Roger Kennedy) > 19. Re: Vertical choke needed? (Michael Walker) > 20. Friday SSB DX Activity Night (Roger Kennedy) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 31 Dec 2020 21:20:17 +0200 > From: uy0zg <uy...@mksat.net> > To: Topband <topband@contesting.com> > Subject: Topband: SM5EDX 160m in KL7 December 31,2020 > Message-ID: <c3819b7f8c700c6d16fc6fdabed41...@mksat.net> > Content-Type: text/plain; charset=US-ASCII; format=flowed > > > > https://www.youtube.com/watch?v=7U-usMyfjzM > > -- > Nick, UY0ZG > http://www.topband.in.ua > > > ------------------------------ > > Message: 2 > Date: Thu, 31 Dec 2020 14:47:25 -0500 > From: Jim Clymer <ws6x....@gmail.com> > To: topband <topband@contesting.com> > Subject: Topband: Question about on ground radials field. > Message-ID: > <CAENrfzk08e+t9gcv-cgu9CpVGFT2gTVxxs8Sx= > mzjbrblbv...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Hello Gang, > This is somewhat related to the "Will radials on ground help?" thread. I > have poked around in various discussion groups but haven't found a specific > answer. > Assuming I have a fairly decent radial system on the ground (60 radials of > various lengths, some longer than 1/4 wave, many shorter), what happens if > I elevate the feedpoint of a quarter-wave, base-fed vertical? Let's say I > have an aluminum mounting post properly bonded to the radial plate, the top > of which will serve as the "radial system" connection for the vertical. Is > there some fractional part of a wavelength that the feedpoint could be > raised and not lose the effectiveness of the on ground radial system? > Thanks, and HNY to all! > Jim - WS6X > > > > > Today's Topics: > > 1. Re: Elevated Radials - will radials on ground help? > > ---------------------------------------------------------------------- > > Message: 1 > > Date: Wed, 30 Dec 2020 13:15:19 -0500 > > > > > I was under the impression that If you have elevated radials and if you > > > take even one to the ground you might as well move all to the > > > ground..??Fred KB4QZH > > > > > ------------------------------ > > Message: 3 > Date: Thu, 31 Dec 2020 15:18:40 -0500 > From: Artek Manuals <manu...@artekmanuals.com> > To: topband@contesting.com > Subject: Re: Topband: Question about on ground radials field. > Message-ID: <d74fed07-d65f-792e-73bd-32f13033d...@artekmanuals.com> > Content-Type: text/plain; charset=windows-1252; format=flowed > > Not a simple , on size fits all answer > > What happens depends on the frequency? you are talking about ??? ( I > assume 1.825 but if it is a multi band vertical ..then???) and how much > above the ground plane you are talking about > > And the approximate foot print of your radial systems ( square lot > filled in with radials ?) > > on 160M the raising of a few feet will likely have little affect if any > on the overall efficiency of the antenna if that was what you were hoping? > > Dave > NR1DX > > > On 12/31/2020 2:47 PM, Jim Clymer wrote: > > Hello Gang, > > This is somewhat related to the "Will radials on ground help?" thread. I > > have poked around in various discussion groups but haven't found a > specific > > answer. > > Assuming I have a fairly decent radial system on the ground (60 radials > of > > various lengths, some longer than 1/4 wave, many shorter), what happens > if > > I elevate the feedpoint of a quarter-wave, base-fed vertical? Let's say I > > have an aluminum mounting post properly bonded to the radial plate, the > top > > of which will serve as the "radial system" connection for the vertical. > Is > > there some fractional part of a wavelength that the feedpoint could be > > raised and not lose the effectiveness of the on ground radial system? > > Thanks, and HNY to all! > > Jim - WS6X > > > >> Today's Topics: > >> 1. Re: Elevated Radials - will radials on ground help? > >> ---------------------------------------------------------------------- > >> Message: 1 > >> Date: Wed, 30 Dec 2020 13:15:19 -0500 > >> > >>> I was under the impression that If you have elevated radials and if you > >>> take even one to the ground you might as well move all to the > >>> ground..??Fred KB4QZH > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > -- > Dave manu...@artekmanuals.com www.ArtekManuals.com > > -- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > > > ------------------------------ > > Message: 4 > Date: Thu, 31 Dec 2020 13:24:47 -0800 > From: Jim Brown <j...@audiosystemsgroup.com> > To: topband@contesting.com > Subject: Re: Topband: Question about on ground radials field. > Message-ID: > <136e19b7-62a4-7033-835e-df7f1ce63...@audiosystemsgroup.com> > Content-Type: text/plain; charset=utf-8; format=flowed > > On 12/31/2020 11:47 AM, Jim Clymer wrote: > > This is somewhat related to the "Will radials on ground help?" thread. I > > have poked around in various discussion groups but haven't found a > specific > > answer. > > The best way to learn technical things is to study them, and, and the > best recent work on radial systems has been published by Rudy Severns, > N6LF, an ARRL Handbook contributor. All of his work is published on his > website. > > > Assuming I have a fairly decent radial system on the ground (60 radials > of > > various lengths, some longer than 1/4 wave, many shorter), what happens > if > > I elevate the feedpoint of a quarter-wave, base-fed vertical? Let's say I > > have an aluminum mounting post properly bonded to the radial plate, the > top > > of which will serve as the "radial system" connection for the vertical. > Is > > there some fractional part of a wavelength that the feedpoint could be > > raised and not lose the effectiveness of the on ground radial system? > > Why do you want to do this? What are you trying to accomplish? > > 73, Jim K9YC > > > > > ------------------------------ > > Message: 5 > Date: Thu, 31 Dec 2020 11:37:27 -1000 > From: Dave Cuthbert <telegraph...@gmail.com> > To: Jim Clymer <ws6x....@gmail.com> > Cc: topband <topband@contesting.com> > Subject: Re: Topband: Question about on ground radials field. > Message-ID: > <CAHF5OZd-oSs4ZgZK=2ECHtSeHk= > vug5ub1eb56zzbzrsyga...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > The antenna becomes a ground mounted vertical having elevated feed. The > wire from the ground radial system to the base of the vertical becomes a > radiating portion of the vertical. The vertical has increased in length by > the wire length. > > Dave KH6AQ > > > On Thu, Dec 31, 2020 at 9:48 AM Jim Clymer <ws6x....@gmail.com> wrote: > > > Hello Gang, > > This is somewhat related to the "Will radials on ground help?" thread. I > > have poked around in various discussion groups but haven't found a > specific > > answer. > > Assuming I have a fairly decent radial system on the ground (60 radials > of > > various lengths, some longer than 1/4 wave, many shorter), what happens > if > > I elevate the feedpoint of a quarter-wave, base-fed vertical? Let's say I > > have an aluminum mounting post properly bonded to the radial plate, the > top > > of which will serve as the "radial system" connection for the vertical. > Is > > there some fractional part of a wavelength that the feedpoint could be > > raised and not lose the effectiveness of the on ground radial system? > > Thanks, and HNY to all! > > Jim - WS6X > > > > > > > > Today's Topics: > > > 1. Re: Elevated Radials - will radials on ground help? > > > ---------------------------------------------------------------------- > > > Message: 1 > > > Date: Wed, 30 Dec 2020 13:15:19 -0500 > > > > > > > I was under the impression that If you have elevated radials and if > you > > > > take even one to the ground you might as well move all to the > > > > ground..??Fred KB4QZH > > > > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > > > > ------------------------------ > > Message: 6 > Date: Thu, 31 Dec 2020 19:15:48 -0500 > From: Kenneth Silverman <kenny.k...@gmail.com> > To: TopBand List <topband@contesting.com> > Subject: Topband: Vertical choke needed? > Message-ID: > <CAKw2SdwFrg3C=Qz8TieNWW-F5r= > njrxw1j+agishvqolqta...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Hello, I have an inverted-L and the radials are laying on the ground AND > the coax is on the ground too with radials right near the coax run. Do I > need a choke to stop any feedline coupling/radiation, and if so, where in > the feedline? > > The antenna is in the woods so burying either the radials or coax won't be > easy. > > Many thanks, Kenny K2KW > > > ------------------------------ > > Message: 7 > Date: Thu, 31 Dec 2020 19:17:15 -0500 (EST) > From: donov...@erols.com > To: topband <topband@contesting.com> > Subject: Re: Topband: Question about on ground radials field. > Message-ID: > <358044710.1690849.1609460235460.javamail.r...@starpower.net> > Content-Type: text/plain; charset=utf-8 > > > Hi Jim, > > > That simply makes the radiating part of the vertical taller and elevates > feed point. > > > Its known in professional antenna engineering circles as a sleeved > monopole with elevated feed point. The classic version is a vertical > with its feedline routed through a sleeve that is 1/2 the length of the > vertical above the feed point at the top of the sleeve. The bottom > of the sleeve is connected to radials laying on the ground or > slightly buried. > > > Its similar in concept to the off-center fed dipole. > > > 73 > Frank > W3LPL > > > > > On Thu, Dec 31, 2020 at 9:48 AM Jim Clymer <ws6x....@gmail.com> wrote: > > > Hello Gang, > > This is somewhat related to the "Will radials on ground help?" thread. I > > have poked around in various discussion groups but haven't found a > specific > > answer. > > Assuming I have a fairly decent radial system on the ground (60 radials > of > > various lengths, some longer than 1/4 wave, many shorter), what happens > if > > I elevate the feedpoint of a quarter-wave, base-fed vertical? Let's say > I > > have an aluminum mounting post properly bonded to the radial plate, the > top > > of which will serve as the "radial system" connection for the vertical. > Is > > there some fractional part of a wavelength that the feedpoint could be > > raised and not lose the effectiveness of the on ground radial system? > > Thanks, and HNY to all! > > Jim - WS6X > > > > > > > > Today's Topics: > > > 1. Re: Elevated Radials - will radials on ground help? > > > ---------------------------------------------------------------------- > > > Message: 1 > > > Date: Wed, 30 Dec 2020 13:15:19 -0500 > > > > > > > I was under the impression that If you have elevated radials and if > you > > > > take even one to the ground you might as well move all to the > > > > ground..??Fred KB4QZH > > > > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > > ------------------------------ > > Message: 8 > Date: Thu, 31 Dec 2020 20:01:16 -0500 > From: Michael Walker <va...@portcredit.net> > To: Kenneth Silverman <kenny.k...@gmail.com> > Cc: TopBand List <topband@contesting.com> > Subject: Re: Topband: Vertical choke needed? > Message-ID: <62cd13ad-e3c2-4579-9095-f1eca8cd3...@portcredit.net> > Content-Type: text/plain; charset=utf-8 > > Hi Ken > > Chokes at both ends of the feed line are always a good idea. > > I have a similar setup to you but with elevated radials and I have Mix 31 > chokes right at the base of the antenna with an UNUN since I am using 75 > ohm coax and then more chokes at the antenna switch. > > You can?t use enough chokes. > > Mike va3mw > > > On Dec 31, 2020, at 7:16 PM, Kenneth Silverman <kenny.k...@gmail.com> > wrote: > > > > ?Hello, I have an inverted-L and the radials are laying on the ground AND > > the coax is on the ground too with radials right near the coax run. Do I > > need a choke to stop any feedline coupling/radiation, and if so, where in > > the feedline? > > > > The antenna is in the woods so burying either the radials or coax won't > be > > easy. > > > > Many thanks, Kenny K2KW > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > ------------------------------ > > Message: 9 > Date: Thu, 31 Dec 2020 20:23:03 -0500 > From: Kenny Silverman <kenny.k...@gmail.com> > To: Michael Walker <va...@portcredit.net> > Cc: TopBand List <topband@contesting.com> > Subject: Re: Topband: Vertical choke needed? > Message-ID: <96efe78c-b4f3-4c71-b692-69011234c...@gmail.com> > Content-Type: text/plain; charset=utf-8 > > Thanks Mike. I wasn?t sure if one was needed where the coax exits the > radial field > > Regards , Kenny K2KW > > > On Dec 31, 2020, at 8:01 PM, Michael Walker <va...@portcredit.net> > wrote: > > > > ?Hi Ken > > > > Chokes at both ends of the feed line are always a good idea. > > > > I have a similar setup to you but with elevated radials and I have Mix > 31 chokes right at the base of the antenna with an UNUN since I am using 75 > ohm coax and then more chokes at the antenna switch. > > > > You can?t use enough chokes. > > > > Mike va3mw > > > >> On Dec 31, 2020, at 7:16 PM, Kenneth Silverman <kenny.k...@gmail.com> > wrote: > >> > >> ?Hello, I have an inverted-L and the radials are laying on the ground > AND > >> the coax is on the ground too with radials right near the coax run. Do > I > >> need a choke to stop any feedline coupling/radiation, and if so, where > in > >> the feedline? > >> > >> The antenna is in the woods so burying either the radials or coax won't > be > >> easy. > >> > >> Many thanks, Kenny K2KW > >> _________________ > >> Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > ------------------------------ > > Message: 10 > Date: Thu, 31 Dec 2020 19:49:43 -0700 > From: Wes <wes_n...@triconet.org> > To: topband@contesting.com > Subject: Re: Topband: Vertical choke needed? > Message-ID: <96aac1ee-fdce-7983-c046-58c0af936...@triconet.org> > Content-Type: text/plain; charset=utf-8; format=flowed > > I have the same situation and no choke.? IMHO the transmission line is > just > another random length radial.? I don't have chokes on any of the others > either. > > Wes? N7WS > > > On 12/31/2020 5:15 PM, Kenneth Silverman wrote: > > Hello, I have an inverted-L and the radials are laying on the ground AND > > the coax is on the ground too with radials right near the coax run. Do I > > need a choke to stop any feedline coupling/radiation, and if so, where in > > the feedline? > > > > The antenna is in the woods so burying either the radials or coax won't > be > > easy. > > > > Many thanks, Kenny K2KW > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > > > ------------------------------ > > Message: 11 > Date: Thu, 31 Dec 2020 22:09:33 -0500 > From: Artek Manuals <manu...@artekmanuals.com> > To: topband@contesting.com > Subject: Re: Topband: Vertical choke needed? > Message-ID: <cfba0a80-0299-8731-bf84-b6979e45b...@artekmanuals.com> > Content-Type: text/plain; charset=UTF-8; format=flowed > > Kenny > > My personal experience with radials on the ground is that with a fair > number (16 or more) that I end up with little if any common mode > currents on the coax . Smaller (numbers of)? ground mounted radial > counts could benefit somewhat from a choke, depends on other factors? > besides the number of radials like relative ground conductivity. > > Not hard to measure see > > https://forums.qrz.com/index.php?threads/measuring-common-mode-current.623054/page-2. > > you can make a simple common mode choke and do a before and after to see > the relative change..if any > > Elevated radial systems NEED a choke ..PERIOD. Been there , done that, > got the RF burns to prove it...8^( > > Dave > NR1DX > > > > On 12/31/2020 7:15 PM, Kenneth Silverman wrote: > > Hello, I have an inverted-L and the radials are laying on the ground AND > > the coax is on the ground too with radials right near the coax run. Do I > > need a choke to stop any feedline coupling/radiation, and if so, where in > > the feedline? > > > > The antenna is in the woods so burying either the radials or coax won't > be > > easy. > > > > Many thanks, Kenny K2KW > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > -- > Dave manu...@artekmanuals.com www.ArtekManuals.com > > > -- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > > > ------------------------------ > > Message: 12 > Date: Thu, 31 Dec 2020 22:22:27 -0500 > From: Michael Walker <va...@portcredit.net> > To: Wes <wes_n...@triconet.org> > Cc: topband <topband@contesting.com> > Subject: Re: Topband: Vertical choke needed? > Message-ID: > <CA+33ts6Z5vPrX5uPSwaDwdWd= > pod80i2aj9q8nfu+dbftsw...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Hi Wes > > The chokes do a few things. For transmitting, they keep the RF off the > feedline. It is critical for RX and TX. > > Just as importantly, they keep RF and Noise off the feedline while > receiving, and this is what you want. The quieter you are, the more you > can hear. > > Common Mode Currents can raise make it harder to hear weak signals and I > have seen and heard this with my own ears, as many others have. How about > I reduced my 80M noise floor from S9 to lower than S6. I'm not sure on > 160M as I didn't really get going on 160 until after I was loving chokes. > I now buy them in lots of 50 in bulk from Digikey. > > Read these pages. This is where I started a long time ago > http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf. > Well worth the read. > > Next, read Jim's stuff http://k9yc.com/2018Cookbook.pdf > > He is part of this group, and I know he will comment at some point. > > Mike va3mw > > > On Thu, Dec 31, 2020 at 9:50 PM Wes <wes_n...@triconet.org> wrote: > > > I have the same situation and no choke. IMHO the transmission line is > > just > > another random length radial. I don't have chokes on any of the others > > either. > > > > Wes N7WS > > > > > > On 12/31/2020 5:15 PM, Kenneth Silverman wrote: > > > Hello, I have an inverted-L and the radials are laying on the ground > AND > > > the coax is on the ground too with radials right near the coax run. > Do I > > > need a choke to stop any feedline coupling/radiation, and if so, where > in > > > the feedline? > > > > > > The antenna is in the woods so burying either the radials or coax won't > > be > > > easy. > > > > > > Many thanks, Kenny K2KW > > > _________________ > > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > > > > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > > > > ------------------------------ > > Message: 13 > Date: Thu, 31 Dec 2020 23:21:25 -0700 > From: Wes <wes_n...@triconet.org> > To: Michael Walker <va...@portcredit.net> > Cc: topband <topband@contesting.com> > Subject: Re: Topband: Vertical choke needed? > Message-ID: <3aa56882-37f0-073a-325b-4b480c8a6...@triconet.org> > Content-Type: text/plain; charset=utf-8; format=flowed > > Hi Mike, > > I've read all of that stuff and more many times.? Frankly, I'm not > motivated to > put a 10 pound lump of ferrite on every wire into or out of my shack.? It > appears that common-mode chokes and articles about them, have become a > cottage > industry.? I will leave my opinion of the topic at that. > > Back to the actual case at hand, a ground-mounted, inherently unbalanced > antenna, with a bunch of radials.? I contend that the coax outer conductor > is > just another radial.? As an approximation the currents in the radials will > divide by the number of radials.? Because of its different length, there > will be > asymmetry in the coax "radial" current but it could go either way.? So > tell me > where exactly do I choke this "radial" and why? > > Wes? N7WS > > On 12/31/2020 8:22 PM, Michael Walker wrote: > > Hi Wes > > > > The chokes do a few things.? ?For transmitting, they keep the RF off the > > feedline.? ?It is critical for RX and TX. > > > > Just as importantly, they keep RF and Noise off the feedline while > receiving, > > and this is what you want.? The quieter you are, the more you can hear. > > > > Common Mode Currents can raise make it harder to hear weak signals and I > > have?seen and heard this with my own ears, as many others have.? How > about I > > reduced my 80M noise floor from S9 to lower than S6.? I'm not sure on > 160M as > > I didn't really get going on 160 until after I was loving chokes.? I now > buy > > them in lots of 50 in bulk from Digikey. > > > > Read these pages.? This is where I started a long time ago > > http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf > > <http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf>. > Well > > worth the read. > > > > Next, read Jim's stuff http://k9yc.com/2018Cookbook.pdf > > <http://k9yc.com/2018Cookbook.pdf> > > > > He is part of this group, and I know he will comment at some point. > > > > Mike va3mw > > > > > > On Thu, Dec 31, 2020 at 9:50 PM Wes <wes_n...@triconet.org > > <mailto:wes_n...@triconet.org>> wrote: > > > > I have the same situation and no choke.? IMHO the transmission line > is just > > another random length radial.? I don't have chokes on any of the > others > > either. > > > > Wes? N7WS > > > > > > On 12/31/2020 5:15 PM, Kenneth Silverman wrote: > > > Hello, I have an inverted-L and the radials are laying on the > ground AND > > > the coax is on the ground too with radials right near the coax > run.? Do I > > > need a choke to stop any feedline coupling/radiation, and if so, > where in > > > the feedline? > > > > > > The antenna is in the woods so burying either the radials or coax > won't be > > > easy. > > > > > > Many thanks, Kenny K2KW > > > _________________ > > > Searchable Archives: http://www.contesting.com/_topband > > <http://www.contesting.com/_topband> - Topband Reflector > > > > > > _________________ > > Searchable Archives: http://www.contesting.com/_topband > > <http://www.contesting.com/_topband> - Topband Reflector > > > > > > ------------------------------ > > Message: 14 > Date: Fri, 1 Jan 2021 01:19:38 -0800 > From: Jim Brown <j...@audiosystemsgroup.com> > To: topband@contesting.com > Subject: Re: Topband: Vertical choke needed? > Message-ID: > <e23f6d0f-da57-0039-c71d-ed99e01e3...@audiosystemsgroup.com> > Content-Type: text/plain; charset=utf-8; format=flowed > > On 12/31/2020 5:01 PM, Michael Walker wrote: > > Hi Ken > > > > Chokes at both ends of the feed line are always a good idea. > > At the base of the antenna, yes, so that the feedline doesn't become a > radial. More are probably wasted money. See my latest Cookbook at > k9yc.com/publish.htm > > > > I have a similar setup to you but with elevated radials and I have Mix > 31 chokes right at the base of the antenna with an UNUN since I am using 75 > ohm coax and then more chokes at the antenna switch. > > > > You can?t use enough chokes. > > The only good reasons I've discovered for using chokes on feedlines > anywhere but at the feedpoint are 1) to break up the feedline into > lengths that won't be parasitic becoming parasitic elements to other > verticals; and 2) to prevent noise pickup by a mechanism quantified as > the Transfer Impedance of the cable, whereby shield current is converted > to a differential voltage inside the cable. > > W3LPL has observed that #2 should not be an issue with coax laying on > the ground. I am not so optimistic with the CATV RG6 we often use for RX > antennas, whose shields are VERY flimsy at MF, but I always value > Frank's observations. > > As to chokes at the station -- if they solve problems, they're putting a > band-aid on badly done (or missing) grounding and bonding. See N0AX's > ARRL book on the topic, and/or the slide deck for my talks about it. > > http://k9yc.com/GroundingAndAudio.pdf > > 73, Jim K9YC > > > > > > ------------------------------ > > Message: 15 > Date: Fri, 1 Jan 2021 01:23:44 -0800 > From: Jim Brown <j...@audiosystemsgroup.com> > To: topband@contesting.com > Subject: Re: Topband: Vertical choke needed? > Message-ID: > <772288b5-7ee9-0d02-2054-8ab4587c3...@audiosystemsgroup.com> > Content-Type: text/plain; charset=utf-8; format=flowed > > Hi Wes, > > The chokes in my latest Cookbook weigh a LOT less than that. I won't > debate your engineering judgement about whether one is needed on your > antenna. You're as good an engineer as anyone on this reflector! > > 73, Jim > > On 12/31/2020 10:21 PM, Wes wrote: > > Frankly, I'm not motivated to put a 10 pound lump of ferrite on every > > wire into or out of my shack. > > > > ------------------------------ > > Message: 16 > Date: Fri, 1 Jan 2021 01:29:28 -0800 > From: Jim Brown <j...@audiosystemsgroup.com> > To: topband@contesting.com > Subject: Re: Topband: Vertical choke needed? > Message-ID: > <e045e285-e382-e3b0-182d-5f25ae2d8...@audiosystemsgroup.com> > Content-Type: text/plain; charset=utf-8; format=flowed > > On 12/31/2020 7:09 PM, Artek Manuals wrote: > > Not hard to measure see > > > https://forums.qrz.com/index.php?threads/measuring-common-mode-current.623054/page-2. > > > you can make a simple common mode choke and do a before and after to see > > the relative change..if any > > I haven't read the link, but common mode current follows the behavior of > the feedline as an antenna, so common mode current distribution along > the feedline will vary as with a piece of wire having the dielectric > properties and dimensions of the feedline, and connected as the feedline > is. In other words, that feedline is part of the antenna. > > So the obvious question is, how many measurements along that feedline > are you willing to make? :) > > 73, Jim K9YC > > > ------------------------------ > > Message: 17 > Date: Fri, 1 Jan 2021 05:19:36 -0500 > From: Artek Manuals <manu...@artekmanuals.com> > To: topband@contesting.com > Subject: Re: Topband: Vertical choke needed? > Message-ID: <ca80ca93-af20-6959-7a86-710ef2262...@artekmanuals.com> > Content-Type: text/plain; charset=UTF-8; format=flowed > > Jim/ K9YC > > I am with you 100% on your comments below > > my 80/ 160 verticals all run "10 lbs of ferrite" at the feed points but > that is because I run elevated non resonant radials these days. 5lbs of > ferrites just got to warm to touch, but that is fodder for a whole > different thread.? My "jungle" makes running ground mounted radial > systems unpractical. > > Among other things? with my wire T's and L's I also avoid coax runs that > are multiples of odd 1/4 waves at the frequency of interest which helps > ( how much ?)? didn't measure it a the time, but the Winkeyer stopped > locking up ......:) > > Dave > NR1DX > > On 1/1/2021 4:19 AM, Jim Brown wrote: > > On 12/31/2020 5:01 PM, Michael Walker wrote: > >> Hi Ken > >> > >> Chokes at both ends of the feed line are always a good idea. > > > > At the base of the antenna, yes, so that the feedline doesn't become a > > radial. More are probably wasted money. See my latest Cookbook at > > k9yc.com/publish.htm > >> > >> I have a similar setup to you but with elevated radials and I have > >> Mix 31 chokes right at the base of the antenna with an UNUN since I > >> am using 75 ohm coax and then more chokes at the antenna switch. > >> > >> You can?t use enough chokes. > > > > The only good reasons I've discovered for using chokes on feedlines > > anywhere but at the feedpoint are 1) to break up the feedline into > > lengths that won't be parasitic becoming parasitic elements to other > > verticals; and 2) to prevent noise pickup by a mechanism quantified as > > the Transfer Impedance of the cable, whereby shield current is > > converted to a differential voltage inside the cable. > > > > W3LPL has observed that #2 should not be an issue with coax laying on > > the ground. I am not so optimistic with the CATV RG6 we often use for > > RX antennas, whose shields are VERY flimsy at MF, but I always value > > Frank's observations. > > > > As to chokes at the station -- if they solve problems, they're putting > > a band-aid on badly done (or missing) grounding and bonding. See > > N0AX's ARRL book on the topic, and/or the slide deck for my talks > > about it. > > > > http://k9yc.com/GroundingAndAudio.pdf > > > > 73, Jim K9YC > > > > > > > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > -- > Dave manu...@artekmanuals.com www.ArtekManuals.com > > > -- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > > > ------------------------------ > > Message: 18 > Date: Fri, 1 Jan 2021 12:19:56 -0000 > From: "Roger Kennedy" <ro...@wessexproductions.co.uk> > To: <topband@contesting.com> > Subject: Topband: Choke Baluns etc > Message-ID: <F706EB65348447299EB00DF3595E30DF@Packard> > Content-Type: text/plain; charset="us-ascii" > > > I think if I had a vertical with just a few Radials lying on the ground, I > wouldn't use a Common Mode Choke either . . . to me, any RF on the outer of > the coax would just mean it acts as another radial. > > I've actually NEVER had any issues with RF in the shack . . . I used > Dipoles > fed with co-ax on several bands for decades, without any Chokes at the > feedpoint. However, in an effort to reduce Received Noise, I DID install > decent Ferrite Choke Baluns on my 160m & 80m Dipoles about 4 years ago . . > . > however, it made no difference to anything ! (neither the noise level or > the > resonant frequency of the antennas) > > Here's something else that many people find surprising . . . > > At 3 different QTHs I have had over the decades, it wasn't possible to put > up a Dipole for Top Band . . . so I had an End-Fed Half Wave. At all 3 > locations the shack was in an attic room on the third floor . . . so the > end > of the 260ft of wire came into the attic window, straight to an ATU on the > windowsill. The only ground I had was the Mains Wiring around the house, > plus the central-heating system (copper pipes all over). > > Even running an Amplifier, I never had any RF Feedback issues . . . and > those End-Fed Half Waves seemed to work just as well as the Dipoles I used > at other QTHs. > > (I do, however, suspect that with all the RF Noise rubbish around these > days > that the noise level would be worse than a Dipole!) > > 73 Roger G3YRO > > > > ------------------------------ > > Message: 19 > Date: Fri, 1 Jan 2021 08:52:21 -0500 > From: Michael Walker <va...@portcredit.net> > To: Wes <wes_n...@triconet.org> > Cc: topband <topband@contesting.com> > Subject: Re: Topband: Vertical choke needed? > Message-ID: > < > ca+33ts4u+udsyogusdu-fbv4swxdg-7tnhib1yukn3k1vyw...@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Wes > > That is an option you have and no one is making anything do anything. It > is 100% up to you. > > Happy New Year > > On Fri, Jan 1, 2021 at 1:21 AM Wes <wes_n...@triconet.org> wrote: > > > Hi Mike, > > > > I've read all of that stuff and more many times. Frankly, I'm not > > motivated to put a 10 pound lump of ferrite on every wire into or out of > my > > shack. It appears that common-mode chokes and articles about them, have > > become a cottage industry. I will leave my opinion of the topic at that. > > > > Back to the actual case at hand, a ground-mounted, inherently unbalanced > > antenna, with a bunch of radials. I contend that the coax outer > conductor > > is just another radial. As an approximation the currents in the radials > > will divide by the number of radials. Because of its different length, > > there will be asymmetry in the coax "radial" current but it could go > either > > way. So tell me where exactly do I choke this "radial" and why? > > > > Wes N7WS > > > > On 12/31/2020 8:22 PM, Michael Walker wrote: > > > > Hi Wes > > > > The chokes do a few things. For transmitting, they keep the RF off the > > feedline. It is critical for RX and TX. > > > > Just as importantly, they keep RF and Noise off the feedline while > > receiving, and this is what you want. The quieter you are, the more you > > can hear. > > > > Common Mode Currents can raise make it harder to hear weak signals and I > > have seen and heard this with my own ears, as many others have. How > about > > I reduced my 80M noise floor from S9 to lower than S6. I'm not sure on > > 160M as I didn't really get going on 160 until after I was loving chokes. > > I now buy them in lots of 50 in bulk from Digikey. > > > > Read these pages. This is where I started a long time ago > > http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf. > > Well worth the read. > > > > Next, read Jim's stuff http://k9yc.com/2018Cookbook.pdf > > > > He is part of this group, and I know he will comment at some point. > > > > Mike va3mw > > > > > > On Thu, Dec 31, 2020 at 9:50 PM Wes <wes_n...@triconet.org> wrote: > > > >> I have the same situation and no choke. IMHO the transmission line is > >> just > >> another random length radial. I don't have chokes on any of the others > >> either. > >> > >> Wes N7WS > >> > >> > >> On 12/31/2020 5:15 PM, Kenneth Silverman wrote: > >> > Hello, I have an inverted-L and the radials are laying on the ground > AND > >> > the coax is on the ground too with radials right near the coax run. > Do > >> I > >> > need a choke to stop any feedline coupling/radiation, and if so, where > >> in > >> > the feedline? > >> > > >> > The antenna is in the woods so burying either the radials or coax > won't > >> be > >> > easy. > >> > > >> > Many thanks, Kenny K2KW > >> > _________________ > >> > Searchable Archives: http://www.contesting.com/_topband - Topband > >> Reflector > >> > >> > >> _________________ > >> Searchable Archives: http://www.contesting.com/_topband - Topband > >> Reflector > >> > > > > > > > ------------------------------ > > Message: 20 > Date: Fri, 1 Jan 2021 13:58:09 -0000 > From: "Roger Kennedy" <ro...@wessexproductions.co.uk> > To: <topband@contesting.com> > Subject: Topband: Friday SSB DX Activity Night > Message-ID: <6640D7CE4E84427EA41D6C7992364FFF@Packard> > Content-Type: text/plain; charset="us-ascii" > > > Happy New Year to all Top Band DXers ! > > Following on from the continued success of the Wednesday CW Nights (Great > to > have lots of stations on again this week!) . . . I'd like to suggest an SSB > DX Night, and think Friday Night/Saturday Morning might be a good time. > > Years ago (when conditions seemed much better) I used to work lots of DX > Stations on SSB . . . but there seems to be very few stations on these > days. > I know conditions aren't so good . . . but signals ARE often strong enough > to have an SSB QSO. I do usually have several SSB contacts on 160 during > the various Contests, but unlike CW it's often hard to copy weak signals > due > to the splatter from strong Europeans ! > > However, this would not be a problem when there's not a Contest. And one of > the advantages of a Phone contact (over CW) is that it's easy to have lots > of stations from both sides of the Pond in the same QSO, all getting > reports > from each other (which in itself is interesting, comparing signals) > > Here in Britain we're only allowed to run high power below 1850 kHz . . . > so > I'm suggesting around 1850 as the best frequency. Best propagation to NA > for me is currently around 0100Z . . . so I will be on tonight on SSB to > see > who's around, hopefully other EU stations will join in too. > > 73 Roger G3YRO > > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Topband mailing list > Topband@contesting.com > http://lists.contesting.com/mailman/listinfo/topband > > > ------------------------------ > > End of Topband Digest, Vol 217, Issue 1 > *************************************** > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector