[TenTec] TenTec Digest, Vol 148, Issue 18
Paul DeWitte
k9ot at yousq.net
Wed Apr 15 14:03:16 EDT 2015
Thanks for all of the replies and ideas. I am going to set up an
antenna here in my yard this spring/summer to try out some ideas
before field day.
My radio will probably be my Omni VI+, and the SSB station will be
some kind of Yaesu of the clubs (do not know the model). We also use
Dunestar band filters when using more than one radio.
Thanks,
73 Paul K9OT
On Wed, Apr 15, 2015 at 11:00 AM, <tentec-request at contesting.com> wrote:
> Send TenTec mailing list submissions to
> tentec at contesting.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://lists.contesting.com/mailman/listinfo/tentec
> or, via email, send a message with subject or body 'help' to
> tentec-request at contesting.com
>
> You can reach the person managing the list at
> tentec-owner at contesting.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of TenTec digest..."
>
>
> Today's Topics:
>
> 1. Re: Field day antennas (Ralph Matheny K8RYU)
> 2. field day antennas (Paul DeWitte)
> 3. Re: field day antennas (Jim Allen)
> 4. Re: field day antennas (Barry N1EU)
> 5. Re: field day antennas (Jim Allen)
> 6. Re: Field day antennas (Rick - DJ0IP / NJ0IP)
> 7. Re: field day antennas (Rick - DJ0IP / NJ0IP)
> 8. Re: Field day antennas (Jim Brown)
> 9. Re: Field day antennas (John Bescher via TenTec)
> 10. Re: Field day antennas (Jim Brown)
> 11. Re: Field day antennas (John Bescher via TenTec)
> 12. Re: Field day antennas (Jim Brown)
> 13. Re: Field day antennas (lciotti at lrlc.us)
> 14. Re: Field day antennas (Jim Brown)
> 15. Re: Field day antennas (Rick - DJ0IP / NJ0IP)
> 16. Re: Field day antennas (Rick - DJ0IP / NJ0IP)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 14 Apr 2015 12:07:44 -0400 (EDT)
> From: Ralph Matheny K8RYU <mathenyr at marietta.edu>
> To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
> Subject: Re: [TenTec] Field day antennas
> Message-ID:
> <1399845735.10431834.1429027664900.JavaMail.zimbra at marietta.edu>
> Content-Type: text/plain; charset=utf-8
>
>
>
> In my experience the 80M antenna on the higher bands will be a
> dud. If you must, use a loop rather than an dipole, and feed the
> loop with 300 (NOT 450) line via a true balanced link-coupled tuner,
> like the Johnson Matchbox of 60's fame. Both 80M antennas have just
> too many nulls on the higher bands. T or L network tuners with "baluns"
> at the input or output have not impressed me in this service, but that
> may be a personal prejudice.
>
> I think a short dipole for the higher bands is worth the trouble,
> say about 20 feet on a side, again with 300 ohm feed line.
>
> I stay away from the 450 stuff because one can end up with some
> VERY low or high Z at the tuner, and since the bands are harmonic
> related if it's good on one it will be bad on another to a much
> greater extent. If I could get 150 ohm open wire, I'd use it!
>
> One man's opinion.
>
> de K8RYU
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 14 Apr 2015 11:08:13 -0500
> From: Paul DeWitte <k9ot at yousq.net>
> To: tentec at contesting.com
> Subject: [TenTec] field day antennas
> Message-ID:
> <CAK=nnoGYbgvEcTHmxJfkjZF26A3PTgufYzFLjLf=FPj9A+XfpA at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> In my first post I asked if the 80m antenna was 60 ft instead of 66 ft
> would it tune easier on 40m.
>
> It should have read 60 ft on a side for an overall length of 120 ft,
> instead of an overall length of 132ft.
>
> I do all of my antenna calculations 234/freq which is one side of a
> dipole or the right formula for a vertical. Thus the 60 ft on a side.
>
> 73,Paul K9OT
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 14 Apr 2015 11:52:20 -0500
> From: Jim Allen <jim.allen at longhornband.net>
> To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
> Subject: Re: [TenTec] field day antennas
> Message-ID: <A14C2C24-F7B3-4FC8-BFC7-0AC710207871 at longhornband.net>
> Content-Type: text/plain; charset=us-ascii
>
> The 130' dipole I have at the moment has been a decent performer on all bands, better on 40 then 80, better on 20 than 40, etc. It is only 32' high at the center and slopes to ~15' at each end. It is fed with about 100' of 450 ohm ladder line and matched with a Icom AH-4. Thence RG-8X to the shack. It would be more effective if it were higher, of course.
>
> I'm in the process of upgrading to a delta loop for 40 and a rotating dipole for higher, but I have been satisfied with the dipole.
>
> 73 de W6OGC Jim Allen
>
> Sent from my iPad
>
>> On Apr 14, 2015, at 11:08 AM, Paul DeWitte <k9ot at yousq.net> wrote:
>>
>> In my first post I asked if the 80m antenna was 60 ft instead of 66 ft
>> would it tune easier on 40m.
>>
>> It should have read 60 ft on a side for an overall length of 120 ft,
>> instead of an overall length of 132ft.
>>
>> I do all of my antenna calculations 234/freq which is one side of a
>> dipole or the right formula for a vertical. Thus the 60 ft on a side.
>>
>> 73,Paul K9OT
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 14 Apr 2015 14:08:26 -0400
> From: Barry N1EU <barry.n1eu at gmail.com>
> To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
> Subject: Re: [TenTec] field day antennas
> Message-ID:
> <CAFmfzDv2jpESPncmUo8cCRU=kTWof-74t6_Bp0_O884iQzGPNQ at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> Not a big deal, but I'd consider bringing that doublet down to 88ft and it
> would probably be easier to match and have a better broadside pattern on
> 20M.
>
> Barry N1EU
>
> On Tue, Apr 14, 2015 at 12:52 PM, Jim Allen <jim.allen at longhornband.net>
> wrote:
>
>> The 130' dipole I have at the moment has been a decent performer on all
>> bands, better on 40 then 80, better on 20 than 40, etc. It is only 32'
>> high at the center and slopes to ~15' at each end. It is fed with about
>> 100' of 450 ohm ladder line and matched with a Icom AH-4. Thence RG-8X to
>> the shack. It would be more effective if it were higher, of course.
>>
>> I'm in the process of upgrading to a delta loop for 40 and a rotating
>> dipole for higher, but I have been satisfied with the dipole.
>>
>> 73 de W6OGC Jim Allen
>>
>> Sent from my iPad
>>
>> > On Apr 14, 2015, at 11:08 AM, Paul DeWitte <k9ot at yousq.net> wrote:
>> >
>> > In my first post I asked if the 80m antenna was 60 ft instead of 66 ft
>> > would it tune easier on 40m.
>> >
>> > It should have read 60 ft on a side for an overall length of 120 ft,
>> > instead of an overall length of 132ft.
>> >
>> > I do all of my antenna calculations 234/freq which is one side of a
>> > dipole or the right formula for a vertical. Thus the 60 ft on a side.
>> >
>> > 73,Paul K9OT
>> > _______________________________________________
>> > TenTec mailing list
>> > TenTec at contesting.com
>> > http://lists.contesting.com/mailman/listinfo/tentec
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 14 Apr 2015 13:18:42 -0500
> From: Jim Allen <jim.allen at longhornband.net>
> To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
> Subject: Re: [TenTec] field day antennas
> Message-ID:
> <CAO5v6iKVf3UbMQ=ULXET+hyao6cqCNDJP238=CxToReJEgQvQg at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> As I get the other two up and running, the dipole is coming down anyway,
> assuming the replacements described above are an improvement.
>
> The AH-4 has no issues with matching this at all, even on 6M. There are
> some lamentable nulls on some bands. It's not like having stacked
> monobanders at 120', that's for sure, but it has done nicely for what it is.
>
> Why do you refer to this as a "doublet?"
>
> 73 de W6OGC Jim Allen
>
> On Tue, Apr 14, 2015 at 1:08 PM, Barry N1EU <barry.n1eu at gmail.com> wrote:
>
>> Not a big deal, but I'd consider bringing that doublet down to 88ft and it
>> would probably be easier to match and have a better broadside pattern on
>> 20M.
>>
>> Barry N1EU
>>
>> On Tue, Apr 14, 2015 at 12:52 PM, Jim Allen <jim.allen at longhornband.net>
>> wrote:
>>
>> > The 130' dipole I have at the moment has been a decent performer on all
>> > bands, better on 40 then 80, better on 20 than 40, etc. It is only 32'
>> > high at the center and slopes to ~15' at each end. It is fed with about
>> > 100' of 450 ohm ladder line and matched with a Icom AH-4. Thence RG-8X to
>> > the shack. It would be more effective if it were higher, of course.
>> >
>> > I'm in the process of upgrading to a delta loop for 40 and a rotating
>> > dipole for higher, but I have been satisfied with the dipole.
>> >
>> > 73 de W6OGC Jim Allen
>> >
>> > Sent from my iPad
>> >
>> > > On Apr 14, 2015, at 11:08 AM, Paul DeWitte <k9ot at yousq.net> wrote:
>> > >
>> > > In my first post I asked if the 80m antenna was 60 ft instead of 66 ft
>> > > would it tune easier on 40m.
>> > >
>> > > It should have read 60 ft on a side for an overall length of 120 ft,
>> > > instead of an overall length of 132ft.
>> > >
>> > > I do all of my antenna calculations 234/freq which is one side of a
>> > > dipole or the right formula for a vertical. Thus the 60 ft on a side.
>> > >
>> > > 73,Paul K9OT
>> > > _______________________________________________
>> > > TenTec mailing list
>> > > TenTec at contesting.com
>> > > http://lists.contesting.com/mailman/listinfo/tentec
>> > _______________________________________________
>> > TenTec mailing list
>> > TenTec at contesting.com
>> > http://lists.contesting.com/mailman/listinfo/tentec
>> >
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>
>
> ------------------------------
>
> Message: 6
> Date: Tue, 14 Apr 2015 20:33:40 +0200
> From: "Rick - DJ0IP / NJ0IP" <Rick at DJ0IP.de>
> To: "'Discussion of Ten-Tec Equipment'" <tentec at contesting.com>
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <00fd01d076e1$8864f020$992ed060$@de>
> Content-Type: text/plain; charset="us-ascii"
>
> Ralph,
>
> I really liked your post.
> I don't quite follow your bit about being against 450 Ohm feedline but the
> rest of your post was indeed impressive. Maybe you know something I don't
> know..
>
> Long low band antennas, used on the high bands, regardless of how good the
> SWR looks, are a waste. Less is better. A short dipole with maximum 6m (19
> ft.) per side is the longest the dipole should be. Otherwise the two major
> lobes will break up into several smaller lobes with multiple peaks and
> nulls. Not good.
>
> 20 ft. per side is borderline. I'm not sure. I would make it just 19 ft.
> per side to be on the safe side.
>
> I don't have a lot of experience with FD in USA. I have won outright, FD in
> Europe several times.
>
> Here in Europe, one of the best FD antennas one can have is a lazy loop (for
> 80m).
> This is basically a horizontal loop, 84 meters (21 meters per side), mounted
> about 30 to 40 ft. high. It is fed with 300 or 450 Ohm openwire and matched
> with a Johnson Viking matchbox (or Annecke). It may also be matched with
> other solutions.
>
> Ralph's statement about using an "L" or "T" matchbox is correct, though
> using a "Symmetrical L" such as Palstars BT-1500 or a "Symmetrical T" such
> as MFJ's MFJ-976 do work very good. The Link-Coupling of the JV Matchbox
> (or the Annecke, it's German successor) gives you about 20dB more of common
> mode impedance which is a great benefit. It is often quieter than the other
> technologies.
>
> There are some ways of using lesser matchboxes but for now I support what
> Ralph said.
>
> Categorically rejecting an OCFD is like shooting yourself in the foot.
> I would suggest you aren't up to date on the latest OCFD technology.
> Your information you have is probably sound, based on what we knew 15 years
> ago, but simply no longer true. (Not you Ralph, that bit was for the
> original OM that started the thread).
>
> Ralph's post was super.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Ralph
> Matheny K8RYU
> Sent: Tuesday, April 14, 2015 6:08 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Field day antennas
>
>
>
> In my experience the 80M antenna on the higher bands will be a dud. If you
> must, use a loop rather than an dipole, and feed the loop with 300 (NOT 450)
> line via a true balanced link-coupled tuner, like the Johnson Matchbox of
> 60's fame. Both 80M antennas have just too many nulls on the higher bands.
> T or L network tuners with "baluns"
> at the input or output have not impressed me in this service, but that may
> be a personal prejudice.
>
> I think a short dipole for the higher bands is worth the trouble, say about
> 20 feet on a side, again with 300 ohm feed line.
>
> I stay away from the 450 stuff because one can end up with some VERY low or
> high Z at the tuner, and since the bands are harmonic related if it's good
> on one it will be bad on another to a much greater extent. If I could get
> 150 ohm open wire, I'd use it!
>
> One man's opinion.
>
> de K8RYU
>
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
> ------------------------------
>
> Message: 7
> Date: Tue, 14 Apr 2015 20:44:32 +0200
> From: "Rick - DJ0IP / NJ0IP" <Rick at DJ0IP.de>
> To: "'Discussion of Ten-Tec Equipment'" <tentec at contesting.com>
> Subject: Re: [TenTec] field day antennas
> Message-ID: <00fe01d076e3$0c9e7770$25db6650$@de>
> Content-Type: text/plain; charset="us-ascii"
>
> Paul,
>
> The antenna you are looking at building is a complex antenna consisting of
> two parts that contribute to defining how easy/difficult it is to match:
> the dipole itself, and the length of the feedline.
>
> In general, a resonant 80m dipole (i.e. 132 to 138 ft.) will have an
> incredibly high feedpoint impedance on all even harmonic bands; somewhere in
> the range of 2500 Ohms.
>
> By reducing the size down to 120 ft., you will avoid these terribly high
> impedances and find it a bit easier to match on all bands. That was a
> correct assumption.
>
> Barry's suggestion for an 88' doublet is also a good one.
> It requires less space than full size and the reduction of signal strength
> on 80m is PEANUTS!
>
> I will also state that your absolute rejection of an OCFD is silly and
> unfounded.
> Perhaps we should do an off-line chat on this, even on the telephone at my
> cost.
> I have the time if you like.
> No problem if you're not interested. Your loss, not mine.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Paul
> DeWitte
> Sent: Tuesday, April 14, 2015 6:08 PM
> To: tentec at contesting.com
> Subject: [TenTec] field day antennas
>
> In my first post I asked if the 80m antenna was 60 ft instead of 66 ft would
> it tune easier on 40m.
>
> It should have read 60 ft on a side for an overall length of 120 ft, instead
> of an overall length of 132ft.
>
> I do all of my antenna calculations 234/freq which is one side of a dipole
> or the right formula for a vertical. Thus the 60 ft on a side.
>
> 73,Paul K9OT
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
> ------------------------------
>
> Message: 8
> Date: Tue, 14 Apr 2015 11:53:45 -0700
> From: Jim Brown <k9yc at audiosystemsgroup.com>
> To: tentec at contesting.com
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <552D6239.8090705 at audiosystemsgroup.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> On Tue,4/14/2015 11:33 AM, Rick - DJ0IP / NJ0IP wrote:
>> I don't have a lot of experience with FD in USA.
>
> FD antennas depend a lot on where you live. From Chicago, I used a pair
> of 20/15/10 fan dipoles -- one broadside E/W, the other N/S. They don't
> need to be very high -- 25-30 ft is good, and a bit lower still works.
> Likewise, a pair of 80/40 fans as high as we could get them. We ran
> three stations, so coax feed with resonant antennas and great radios
> matter. The group I went with there has been placing #1 - #3 for years.
> They're now using all K3s.
>
> From CA, we use a C3SS on a modular surplus military mast, usually
> about 25 ft, aimed at the east coast. We still manage to work AZ, WA and
> OR off the sides. For 80 and 40, one fan dipole as high as we can get
> it, broadside to 70 degrees, if we're running one TX. If two TX, one for
> each band. K3s the weapon of choice.
>
> 73, Jim K9YC
>
>
>
>
> ------------------------------
>
> Message: 9
> Date: Tue, 14 Apr 2015 15:36:49 -0400
> From: John Bescher via TenTec <tentec at contesting.com>
> To: tentec at contesting.com
> Cc: alan_wentzell at me.com, leepaulet at gmail.com, wd4rt at yahoo.com
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <14cb96f1f33-65f5-20a33 at webprd-m94.mail.aol.com>
> Content-Type: text/plain; charset=utf-8
>
> Adding another consideration for your Field Day antennas.....our club used a dipole on 40 m SSB last year and Yagi's on 20, 15, and 10. The 40 m station clobbered the other stations. One leg of the 40 m SSB dipole was secured on the mast for the tribander Yagi which was about 25 feet above the dipole. This year we will separate the antennas significantly and insure the dipole broadband pattern is not facing the Yagi.
>
>
> Another possibility to minimize interference is to use band pass filters. This year we will also use more modern rigs with better front ends. Coax stubs is another option.
>
>
> And for your comment on the OCFD, it's not what I've found using one on 80 and 40 at my home station....no problem working DX, better flexibility and SWR than my dipole.
>
>
> Good luck, let us know what you decide.
>
>
> 73....John Bescher, N4DXI
>
>
>
> -----Original Message-----
> From: Paul DeWitte <k9ot at yousq.net>
> To: tentec <tentec at contesting.com>
> Sent: Tue, Apr 14, 2015 1:08 am
> Subject: [TenTec] Field day antennas
>
>
> Not sure what is the correct forum to ask this on, but since at least
> one of
> the radios will be a TT here goes.
>
> To make things simpler for us guys that
> set things up, we want to
> minimize the number of antennas for field day. We
> will be 2A, one SSB
> and one CW station.
>
> If we put up an 80m dipole fed with
> plastic window ladder line, how
> will it play on 20m and up?
> How about putting
> a 20m dipole at 90 degrees to the 80m ant with a
> common feed point with the 80m
> ant?
>
> Would separate antennas on separate supports for 80/40, and
> 20/15/10m
> be better? Thus 2 supports 2 antennas for each station.
>
> If I make
> the 80m ant 60ft instead of 66 will it tune easier on 40m?
>
> We will not use an
> OCFD so do not even suggest it.
>
> Thanks,73
> Paul
> K9OT
> _______________________________________________
> TenTec mailing
> list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
>
> ------------------------------
>
> Message: 10
> Date: Tue, 14 Apr 2015 13:30:17 -0700
> From: Jim Brown <k9yc at audiosystemsgroup.com>
> To: tentec at contesting.com
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <552D78D9.5030206 at audiosystemsgroup.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> On Tue,4/14/2015 12:36 PM, John Bescher via TenTec wrote:
>> And for your comment on the OCFD,
>
> Off-center fed antennas put lots of common mode RF on the feedline,
> which is bad news for interaction between stations.
>
> Yes, stubs and bandpass filters can help reduce interference between
> stations. So can a better rig -- cleaner TX and more bulletproof RX.
> That's why K3s are the current weapon of choice, with rigs like the KX3
> and TS590 a decent second place.
>
> Don't even think about bringing an el-cheapo do-everything wonder like
> an IC706, FT100D, or newer equivalent Yaesus to FD -- you'll be spewing
> trash into all the other stations!
>
> 73, Jim K9YC
>
>
> ------------------------------
>
> Message: 11
> Date: Tue, 14 Apr 2015 17:50:50 -0400
> From: John Bescher via TenTec <tentec at contesting.com>
> To: k9yc at arrl.net, tentec at contesting.com
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <14cb9e9d008-144c-1d5dd at webprd-m99.mail.aol.com>
> Content-Type: text/plain; charset=utf-8
>
> My club of 150 members, a lot of 2 m repeater hams, seem to have a lot of older rigs, which, of course they want to use for Field Day.
>
>
> The opposite seems also to be true: the hams who have the newest rigs do not want to risk damage lugging them to Field Day or having 'strangers' operate them.
>
>
> Is there a way, besides on site testing, to tell whether a rig is suitable for multiple station Field Day?
>
>
> I presume Orion II is ok but that falls into the category of not wanting it get scratched up or knocked around for Field Day. I was going to use a Tentec Eagle for the GOTA station, easy to operate and fairly simple with a half decent front end. My backup is an old but reliable Icom 735...but that's ancient, full of scratches, a hardened veteran of many Field Days and probably not much of a front end.
>
>
> Maybe I can look up some of the specs on the transceivers that members are offering for Field Day....should I look for anything special to eliminate the major interference offenders?
>
>
> I guess there would be two issues: impure transmitting signals and permissive receiving front ends.
>
>
> Sure wish I had a dozen K3's for Field Day, but that's not in the offering.
>
>
> John Bescher, N4DXI
>
>
>
>
> -----Original Message-----
> From: Jim Brown <k9yc at audiosystemsgroup.com>
> To: tentec <tentec at contesting.com>
> Sent: Tue, Apr 14, 2015 4:38 pm
> Subject: Re: [TenTec] Field day antennas
>
>
> On Tue,4/14/2015 12:36 PM, John Bescher via TenTec wrote:
>> And for your
> comment on the OCFD,
>
> Off-center fed antennas put lots of common mode RF on
> the feedline,
> which is bad news for interaction between stations.
>
> Yes,
> stubs and bandpass filters can help reduce interference between
> stations. So
> can a better rig -- cleaner TX and more bulletproof RX.
> That's why K3s are the
> current weapon of choice, with rigs like the KX3
> and TS590 a decent second
> place.
>
> Don't even think about bringing an el-cheapo do-everything wonder like
>
> an IC706, FT100D, or newer equivalent Yaesus to FD -- you'll be spewing
>
> trash into all the other stations!
>
> 73, Jim
> K9YC
> _______________________________________________
> TenTec mailing
> list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
>
> ------------------------------
>
> Message: 12
> Date: Tue, 14 Apr 2015 15:48:20 -0700
> From: Jim Brown <k9yc at audiosystemsgroup.com>
> To: tentec at contesting.com
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <552D9934.6080205 at audiosystemsgroup.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> On Tue,4/14/2015 2:50 PM, John Bescher via TenTec wrote:
>> Is there a way, besides on site testing, to tell whether a rig is suitable for multiple station Field Day?
>
> Yes. Study my summary of ARRL Lab Tests of the TX cleanliness of a dozen
> or so medium to high priced modern rigs.
>
> k9yc.com/TXNoise.pdf
>
> Look for rigs with very low TX phase noise in the wide plots. I haven't
> added the new Flex 6000-series rigs yet, but the 6500 and 6700 are good
> performers for phase noise. Also study Rob Sherwood's comparison of
> receivers for handling strong signals.
>
> http://www.sherweng.com/table.html
>
> Phase noise is that "rushing" sound you hear off frequency when a strong
> signal is being keyed. Both TX and RX have it -- we hear it because the
> other guy is TXing it, and also because our RX contributes its own phase
> noise. :) You want rigs that score well both ways.
>
> 73, Jim K9YC
>
>
> ------------------------------
>
> Message: 13
> Date: Tue, 14 Apr 2015 21:41:41 -0400
> From: "lciotti at lrlc.us" <lciotti at lrlc.us>
> To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <12276E93-D5C8-4683-9D0B-440914EAAF66 at lrlc.us>
> Content-Type: text/plain; charset=us-ascii
>
> All this field day antenna talk has me wondering... In multi setups, I know distance helps, but is it true that keeping the antenna parallel also helps? We are considering going from three stations this year to 4 so that is going to complicate our antenna setup. We typically have run two band fan dipoles.
>
>
>
> Sent from my iPhone
>
>> On Apr 14, 2015, at 2:38 PM, Rick - DJ0IP / NJ0IP <Rick at DJ0IP.de> wrote:
>>
>> Ralph,
>>
>> I really liked your post.
>> I don't quite follow your bit about being against 450 Ohm feedline but the
>> rest of your post was indeed impressive. Maybe you know something I don't
>> know..
>>
>> Long low band antennas, used on the high bands, regardless of how good the
>> SWR looks, are a waste. Less is better. A short dipole with maximum 6m (19
>> ft.) per side is the longest the dipole should be. Otherwise the two major
>> lobes will break up into several smaller lobes with multiple peaks and
>> nulls. Not good.
>>
>> 20 ft. per side is borderline. I'm not sure. I would make it just 19 ft.
>> per side to be on the safe side.
>>
>> I don't have a lot of experience with FD in USA. I have won outright, FD in
>> Europe several times.
>>
>> Here in Europe, one of the best FD antennas one can have is a lazy loop (for
>> 80m).
>> This is basically a horizontal loop, 84 meters (21 meters per side), mounted
>> about 30 to 40 ft. high. It is fed with 300 or 450 Ohm openwire and matched
>> with a Johnson Viking matchbox (or Annecke). It may also be matched with
>> other solutions.
>>
>> Ralph's statement about using an "L" or "T" matchbox is correct, though
>> using a "Symmetrical L" such as Palstars BT-1500 or a "Symmetrical T" such
>> as MFJ's MFJ-976 do work very good. The Link-Coupling of the JV Matchbox
>> (or the Annecke, it's German successor) gives you about 20dB more of common
>> mode impedance which is a great benefit. It is often quieter than the other
>> technologies.
>>
>> There are some ways of using lesser matchboxes but for now I support what
>> Ralph said.
>>
>> Categorically rejecting an OCFD is like shooting yourself in the foot.
>> I would suggest you aren't up to date on the latest OCFD technology.
>> Your information you have is probably sound, based on what we knew 15 years
>> ago, but simply no longer true. (Not you Ralph, that bit was for the
>> original OM that started the thread).
>>
>> Ralph's post was super.
>>
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt am Main)
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Ralph
>> Matheny K8RYU
>> Sent: Tuesday, April 14, 2015 6:08 PM
>> To: Discussion of Ten-Tec Equipment
>> Subject: Re: [TenTec] Field day antennas
>>
>>
>>
>> In my experience the 80M antenna on the higher bands will be a dud. If you
>> must, use a loop rather than an dipole, and feed the loop with 300 (NOT 450)
>> line via a true balanced link-coupled tuner, like the Johnson Matchbox of
>> 60's fame. Both 80M antennas have just too many nulls on the higher bands.
>> T or L network tuners with "baluns"
>> at the input or output have not impressed me in this service, but that may
>> be a personal prejudice.
>>
>> I think a short dipole for the higher bands is worth the trouble, say about
>> 20 feet on a side, again with 300 ohm feed line.
>>
>> I stay away from the 450 stuff because one can end up with some VERY low or
>> high Z at the tuner, and since the bands are harmonic related if it's good
>> on one it will be bad on another to a much greater extent. If I could get
>> 150 ohm open wire, I'd use it!
>>
>> One man's opinion.
>>
>> de K8RYU
>>
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>
>
> ------------------------------
>
> Message: 14
> Date: Tue, 14 Apr 2015 21:08:19 -0700
> From: Jim Brown <k9yc at audiosystemsgroup.com>
> To: tentec at contesting.com
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <552DE433.3030004 at audiosystemsgroup.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> On Tue,4/14/2015 6:41 PM, lciotti at lrlc.us wrote:
>> In multi setups, I know distance helps, but is it true that keeping the antenna parallel also helps?
>
> In line is good, but still separate as much as possible. Distance is the
> biggest help.
>
> 73, Jim K9YC
>
>
> ------------------------------
>
> Message: 15
> Date: Wed, 15 Apr 2015 09:45:52 +0200
> From: "Rick - DJ0IP / NJ0IP" <Rick at DJ0IP.de>
> To: "'Discussion of Ten-Tec Equipment'" <tentec at contesting.com>
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <003501d07750$33833430$9a899c90$@de>
> Content-Type: text/plain; charset="us-ascii"
>
> Jim, your comment is both accurate and inaccurate.
> In general it is accurate but does not have to be like that.
> Things have changed.
>
> The amount of common mode current on the feedline of an OCFD is determined
> by many factors. One of them is "how far off center" the feedpoint is. The
> closer to the center, the less CMC gets onto the feedpoint. OLD OCFD's have
> used 33% (from one end) as their feedpoint.
> Recently other splits have shown up, some of which are closer to the center.
> These newer ones have inherently less common mode current.
>
> ALL commercial OCFD antennas of the past have used a single-core 4:1
> Guanella balun (no exceptions that I know of). These not only do a lousy
> job of impeding common mode current, they actually generate common mode
> current, as Steve Hunt (G3TXQ) has mathematically shown us and then shown us
> the lab measurements to prove it.
>
> Bottom line there: everything we know of to date was of poor design.
>
> Finally, I have spent several hundred hours in the field measuring common
> mode current on all sorts of OCFD antennas, strung in various configurations
> and using both types of baluns. I've bent the coax all over the place and
> re-measured, each time comparing the amount measured common mode current to
> its impact on the SWR curve across each ham band.
>
> I have over 500 sets of measured data.
> About half of these are posted on my web site.
>
> If you use a single core balun like all the US commercial vendors are
> selling, then you are correct Jim. You do get CMC onto the feedline.
>
> But if you use a well designed dual-core balun, then you are incorrect. You
> must do some really dumb things to it (like running the coax just a few feet
> away from one leg) before you get significant amounts of common mode
> current.
>
> BTW, I tried that on a dipole too and it also got common mode current on the
> coax, albeit, not as much as the OCFD did. However surely nobody would ever
> erect an antenna like that!
>
> So in practice you are 100% correct if a person goes out and buys a
> Buckmaster or Carolina Windom. However it is possible to build one
> yourself, or buy one from Scott W4PA, which does not have this problem.
>
> DISCLOSURE: I have a commercial interest in the antenna products Scott is
> selling.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Jim Brown
> Sent: Tuesday, April 14, 2015 10:30 PM
> To: tentec at contesting.com
> Subject: Re: [TenTec] Field day antennas
>
> On Tue,4/14/2015 12:36 PM, John Bescher via TenTec wrote:
>> And for your comment on the OCFD,
>
> Off-center fed antennas put lots of common mode RF on the feedline, which is
> bad news for interaction between stations.
>
> Yes, stubs and bandpass filters can help reduce interference between
> stations. So can a better rig -- cleaner TX and more bulletproof RX.
> That's why K3s are the current weapon of choice, with rigs like the KX3 and
> TS590 a decent second place.
>
> Don't even think about bringing an el-cheapo do-everything wonder like an
> IC706, FT100D, or newer equivalent Yaesus to FD -- you'll be spewing trash
> into all the other stations!
>
> 73, Jim K9YC
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
> ------------------------------
>
> Message: 16
> Date: Wed, 15 Apr 2015 11:41:34 +0200
> From: "Rick - DJ0IP / NJ0IP" <Rick at DJ0IP.de>
> To: "'Discussion of Ten-Tec Equipment'" <tentec at contesting.com>
> Subject: Re: [TenTec] Field day antennas
> Message-ID: <004201d07760$5d9a8d80$18cfa880$@de>
> Content-Type: text/plain; charset="us-ascii"
>
> Jim has given some good advice.
>
> Another thing that helps when running 2 transmitters on the same band (i.e.
> 40m or 20m) is to use different polarities of antennas; one horizontally
> polarized and one vertically polarized.
>
> Then separate as far as possible.
> It's better to have 1 or 2 dB of additional loss in the coax than to have 10
> or 20 dB of intermodulation or broadband noise on receive all the time.
>
> Running them in parallel is the worst thing that you can do.
> For me, parallel means the wires are in parallel just as the elements of a
> beam are in parallel.
>
> Instead, mount them end-to-end or rotated 90 degrees and of course separate
> as far as possible.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of
> lciotti at lrlc.us
> Sent: Wednesday, April 15, 2015 3:42 AM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Field day antennas
>
> All this field day antenna talk has me wondering... In multi setups, I
> know distance helps, but is it true that keeping the antenna parallel also
> helps? We are considering going from three stations this year to 4 so
> that is going to complicate our antenna setup. We typically have run two
> band fan dipoles.
>
>
>
> Sent from my iPhone
>
>> On Apr 14, 2015, at 2:38 PM, Rick - DJ0IP / NJ0IP <Rick at DJ0IP.de> wrote:
>>
>> Ralph,
>>
>> I really liked your post.
>> I don't quite follow your bit about being against 450 Ohm feedline but
>> the rest of your post was indeed impressive. Maybe you know something
>> I don't know..
>>
>> Long low band antennas, used on the high bands, regardless of how good
>> the SWR looks, are a waste. Less is better. A short dipole with
>> maximum 6m (19
>> ft.) per side is the longest the dipole should be. Otherwise the two
>> major lobes will break up into several smaller lobes with multiple
>> peaks and nulls. Not good.
>>
>> 20 ft. per side is borderline. I'm not sure. I would make it just 19 ft.
>> per side to be on the safe side.
>>
>> I don't have a lot of experience with FD in USA. I have won outright,
>> FD in Europe several times.
>>
>> Here in Europe, one of the best FD antennas one can have is a lazy
>> loop (for 80m).
>> This is basically a horizontal loop, 84 meters (21 meters per side),
>> mounted about 30 to 40 ft. high. It is fed with 300 or 450 Ohm
>> openwire and matched with a Johnson Viking matchbox (or Annecke). It
>> may also be matched with other solutions.
>>
>> Ralph's statement about using an "L" or "T" matchbox is correct,
>> though using a "Symmetrical L" such as Palstars BT-1500 or a
>> "Symmetrical T" such as MFJ's MFJ-976 do work very good. The
>> Link-Coupling of the JV Matchbox (or the Annecke, it's German
>> successor) gives you about 20dB more of common mode impedance which is
>> a great benefit. It is often quieter than the other technologies.
>>
>> There are some ways of using lesser matchboxes but for now I support
>> what Ralph said.
>>
>> Categorically rejecting an OCFD is like shooting yourself in the foot.
>> I would suggest you aren't up to date on the latest OCFD technology.
>> Your information you have is probably sound, based on what we knew 15
>> years ago, but simply no longer true. (Not you Ralph, that bit was for
>> the original OM that started the thread).
>>
>> Ralph's post was super.
>>
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt am Main)
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Ralph
>> Matheny K8RYU
>> Sent: Tuesday, April 14, 2015 6:08 PM
>> To: Discussion of Ten-Tec Equipment
>> Subject: Re: [TenTec] Field day antennas
>>
>>
>>
>> In my experience the 80M antenna on the higher bands will be a dud.
>> If you must, use a loop rather than an dipole, and feed the loop with
>> 300 (NOT 450) line via a true balanced link-coupled tuner, like the
>> Johnson Matchbox of 60's fame. Both 80M antennas have just too many nulls
> on the higher bands.
>> T or L network tuners with "baluns"
>> at the input or output have not impressed me in this service, but that
>> may be a personal prejudice.
>>
>> I think a short dipole for the higher bands is worth the trouble, say
>> about
>> 20 feet on a side, again with 300 ohm feed line.
>>
>> I stay away from the 450 stuff because one can end up with some VERY
>> low or high Z at the tuner, and since the bands are harmonic related
>> if it's good on one it will be bad on another to a much greater
>> extent. If I could get
>> 150 ohm open wire, I'd use it!
>>
>> One man's opinion.
>>
>> de K8RYU
>>
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
> ------------------------------
>
> End of TenTec Digest, Vol 148, Issue 18
> ***************************************
More information about the TenTec
mailing list