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k6sti
06-19-2010, 08:41 PM
Some time ago I posted information about an earlier version of this FM Yagi design by Peter Körner. The 19.3 is an update with even better performance. It came to life this weekend at VHF Teknik AB in Sweden.

The 19.3 is the best high-performance FM design I've ever seen. Testing isn't yet complete, but I'm sure VHF Teknik will be offering the antenna as a commercial product before long. Peter, who does not work for VHF Teknik, encourages home construction and has been very helpful with builders in the past. Today he reported receiving several signals from Berlin at 500 km with the antenna low to the ground and tilted toward the sky on its test trolley under poor tropo conditions.

My writeup is here with a photo and the SWR curve they measured today:

http://ham-radio.com/k6sti/korn193.htm

You can see how the performance compares with other antennas here:

http://ham-radio.com/k6sti/curves.htm

Brian

John Wilke K9RZZ
07-05-2010, 01:35 PM
Wow - neat graphs.

I'm sure happy with my stacked 6065p's. Can't imagine anything better - except perhaps ... dare I say it ... a box of FOUR! :cool:

I know, they don't make 'em anymore. Maybe four Körner 19.3's ?

Hey, if they sponsor me, I'll put 'em up! :laughing:

k6sti
07-06-2010, 11:01 AM
I'm sure happy with my stacked 6065p's. Can't imagine anything better

See the attached comparison curves. The HD6065P curve does not include the pattern degradation due to vertical stacking, which always detunes the elements.

Brian

k6sti
07-06-2010, 03:45 PM
John, I modeled a pair of HD6065Ps stacked in the vertical plane with 72" spacing so you can see what the mutual coupling does to the pattern. The curve plots the worst backlobe in the rear half-plane (90° to 270°). Gain for the stack includes 0.3 dB loss for a power combiner.

Brian

John Wilke K9RZZ
07-08-2010, 02:04 AM
Thanks for the graphs. That Körner looks impressive. I certainly can't complain about my stack of 6065p's. They hear where I aim 'em and hear quite well. :)

k6sti
07-08-2010, 11:03 AM
The HD6065P stack has very good gain, John. It's about equal to that of the 19.3, which uses 19 elements on a 200" boom. The problem with the HD6065P is that the rear lobes are not that far down, especially when stacked vertically. If you don't have much co-channel or adjacent-channel interference, this doesn't matter. But here in Southern California I receive at least one station on every FM channel, with two or more stations on many channels. For me, co-channel interference limits reception quality for many signals. I believe the situation is even worse on the east coast where there are many short-spaced stations, where two or more stations on the same or adjacent frequencies are closer in distance than current FCC rules allow, permitted I believe for historical reasons (grandfathered). I have inserted a 20-dB attenuator in my feedline with no difference in reception on nearly every channel! In my situation, rear attenuation is much more important than forward gain. I think the opposite often is true in the boondocks.

Incidentally, twice I've had to take down my HD6065P to reseat the push-on connection between the matching network and the parallel feeder wires. It had become intermittent. I don't know why this happens because the connection is protected from the weather and I'm not near the ocean with its corrosive salt air. If you ever notice intermittent signal strength, especially when starting or stopping antenna rotation, this may the cause.

Brian

John Wilke K9RZZ
07-08-2010, 09:16 PM
I actually did have an intermittent connection all last winter. Spring check up showed a bad coax connector though (commercial - not one of mine ;) ) Back rejection is always good, but so far the Winegard gives me plenty unless the band is dead and I'm trying to make something from nothing in which case I should just turn the radio off and do something else anyway. :)

Has anyone done any work with box arrays of four antennas that you know of? I recall seeing a web page from Sweden where the guy did some stuff like that. A box of four wouldn't be so big that it couldn't be done reasonably.

:cool:

k6sti
07-08-2010, 10:33 PM
The best configuration of four antennas is a diamond array. For a given sidelobe rejection, you can get much more gain. Conversely, for a given gain the sidelobes are much further down. For details, see the February 1996 issue of QST. I can e-mail you a copy of the article if you don't have that issue.

Brian

konrad
08-30-2010, 06:22 PM
I finished building this great antenna few days ago!

http://img822.imageshack.us/img822/9537/korner2.jpg (http://img651.imageshack.us/img651/8919/kornerf.jpg)

My both antenna masts (Körner 19.3 H and 2x Yagi 5-el V) are supplied with 360° rotators.
Take a look at this short video that shows rotating 19.3 http://www.youtube.com/watch?v=trFlAOgCvl4 :)

I'm really impressed with its gain and f/r. I recorded some videos of distant stations lately (during poor tropo conditions):

89.9 Radio Wien 530km RDS
Austria, Wien
http://www.youtube.com/watch?v=FSJ_MZWXw_0

105.8 Kronehit 530km RDS
Austria, Wien
http://www.youtube.com/watch?v=DRCXM5ocBQA

89.4 OE 3 Hitradio 565km RDS
Austria, Sankt Polten
http://www.youtube.com/watch?v=1JMtn2SLM3o

97.0 OE 1 565km RDS
Austria, Sankt Polten
http://www.youtube.com/watch?v=S9ksbxgLlEk

105.8 Lumen 360km RDS (erp only 9.5kW)
Slovakia, Namestovo
http://www.youtube.com/watch?v=OXj5cZ1HO2I

105.5 Evropa 2 - 485km RDS
Czech Republic, Votice
http://www.youtube.com/watch?v=n2IYvHpEblk

And the farthest DX, that comes every day:
89.5 hr3 710km (Germany, Hoher Meißner)
http://www.youtube.com/watch?v=b86Db8xrMiA
Such quality was impossible with my old 9-element Yagi.

I'm also able to receive Sweden, Germany, Lithuania, Latvia, Denmark, Czech Republic (lots from here!), Slovakia with RDS, and some countries without (Russia (Kaliningrad), Hungary or Romania) with normal propagation conditions.

BTW, I'm using 18dB (NF 4dB) amplifier to avoid audio volume fadings by XDR-F1HD while signal is lower than 1 bar.

Thank you, Peter Körner and k6sti, very much for this great antenna design! :cool:

http://img839.imageshack.us/img839/1451/kornernoc2.jpg (http://img839.imageshack.us/img839/5518/kornernoc.jpg)

Greetings from Płock, Poland.
Konrad

Damon Hill
08-31-2010, 04:50 AM
Antenna envy. :(

k6sti
08-31-2010, 08:02 AM
Peter deserves all the credit for designing this great antenna. All I did was tell people about it. I believe a commercial version of the design is now available from VHF Teknik in Sweden.

Glad to hear you're using a preamp with the XDR-F1HD. Its adaptive noise reduction greatly reduces noise in stereo, but it doesn't function in mono and can't benefit mono DXing. The tuner does not have an RF amplifier stage so its noise figure is rather high (8.5 dB, about the same as a Technics ST-9030). Adding a low-noise preamp can really improve S/N for weak signals. As you note, the preamp gain covers up the soft-muting, which can be annoying at low signal levels. It also holds off the high-cut noise filter and this can improve intelligibility when trying to ID a weak station.

Brian

Boško Igić
09-01-2010, 07:16 AM
Konrad, you have great equipement. You can also try to catch radio-stations from Serbia:
Radios from Crveni Čot near Novi Sad (824 km to Plock):
94.5 RTS - Radio Beograd 1
96.5 Beograd 2
101.8 Beograd 202
Radios from Avala near Belgrade (876 km to Plock):
95.3 Beograd 1
97.6 Beograd 2
104.0 Beograd 202

Todd Emslie
09-18-2010, 02:03 AM
Konrad,

A 4 dB RF preamplifier contributes too much noise considering you are living in a semi-rural environment. Rural or semi-rural environments often (but not always) feature relatively low ambient noise levels. I know of two DXers who are receiving significant S/N improvement when using the following 87-108 MHz PHEMT design LNA with their Sony XDR-F1HD tuners:

http://cgi.ebay.com/LNA-FM-Radio-UKW-88-108-MHz-super-low-noise-amplifier-/110584424818?pt=LH_DefaultDomain_0&hash=item19bf586972

The AMIWINA PHEMT FM LNA is rated as having ~ 0.5 dB noise figure, which is competitive with other high-end EME installations. Use RG6 (or ideally RG11) type low loss 75-ohm coax when the RF LNA is used near the XDR-F1HD tuner.

With the AMIWIMA LNA in line, you may be able to hear out to 800 km FM on a daily basis using aircraft reflection.

DXers living in metro / city areas will not benefit from this preamp, unless they are situated at least 20-25 km (12-15 miles) from high powered band 2 FM transmitters. For example, Peter Korner and myself both tried one AMIWIMA LNA, but IMD / overload was excessive.

Regards,

Todd

Danny
09-19-2010, 12:07 PM
Welcome to WTFDA Forums, Todd.

k6sti
09-24-2010, 12:24 PM
Peter has made some very minor changes to the 19.3 design and I've updated my writeup and performance curves:

http://ham-radio.com/k6sti/korn193.htm

http://ham-radio.com/k6sti/curves.htm

I include a photo of the prototype installed well above ground for testing with broadcast signals. Peter reports improved reception of difficult signals as far away as 520 km. He says distant weak signals that previously suffered interference from the rear are now free of it.

Brian

k6sti
09-29-2010, 10:22 PM
Peter has measured F/B for the prototype 19.3 Yagi in a city environment. I've added his measurements to my writeup. I also included a model of a distant unwanted reflection to see how it might affect F/B. The results astonished me.

http://ham-radio.com/k6sti/korn193.htm

Brian

k6sti
10-08-2010, 09:58 AM
Below is a message I received from VHF Teknik AB. Looks like I was a bit premature thinking the 19.3 might be commercially available. I was surprised how many of the smaller 15.11 design they have sold.

Brian

------------------------------------------------

> By the way, I've been telling people that VHF Teknik AB would probably
> be offering the 19.3 for sale. Is that true?


We haven't decided yet Brian it is quite costly to make a kit and no one
have been asking for it, 26 of the 15.11 are mounted around the globe
mostly Europe but also Canada, Australia and Brazil is on the map.
Sven

Mike-CT
10-08-2010, 11:10 AM
There's not much of a demand for FM antennas these days, I guess. Ed Hanlon found that out. He sold as many of his APS9bs and 13s as he could and now he's out of business.

What I heard was that Ed dumped his remaining antennas on eBay and got what he could for them. VHF Teknik is probably wise to not offer it commercially.

FWIW, anyway.

k6sti
10-11-2010, 12:52 PM
Peter made some additional F/B measurements on the 19.3 over the weekend. I've added them to my writeup here:

http://ham-radio.com/k6sti/korn193.htm

Here are some comments from Peter:

"In practical tests, which is what counts, like when receiving the 420 km distant BFBS in Germany, the 19.3 gets it cleanly, whereas with the old 14 element antenna there is considerable breakthrough from a Swedish transmitter from behind, often taking over completely.
So when switching antennas, a new transmitter is heard although both antennas point in the same direction! - Thanks to the improved F/B.

Going by car to the summer house yesterday afternoon, I could get BBC from the UK on the car radio!
Having arrived I turned the 15.9 west, and easily got BBC on 13 frequencies, most of which achieved three signal strength bars with RDS on the XDR-F1HD. Distances are around 980km across the North Sea. Also from Germany some 500km distant stations produced similar levels."

The 15.9 is an earlier version of the 15.11 described here:

http://ham-radio.com/k6sti/korn1511.htm

I've attached a photo showing the 19.3 and the 14-element antenna, both aimed south toward Germany. The four guy wires on the mast are made of nonconductive, pre-stretched polyester (what we call Phillystran).

Brian

Mike-CT
10-11-2010, 01:31 PM
Going by car to the summer house yesterday afternoon, I could get BBC from the UK on the car radio!
Having arrived I turned the 15.9 west, and easily got BBC on 13 frequencies, most of which achieved three signal strength bars with RDS on the XDR-F1HD. Distances are around 980km across the North Sea. Also from Germany some 500km distant stations produced similar levels."

Those receptions are because there's a HUGE tropo opening going on over there from the UK to Germany and all points in between as I type this.

Gary Hickerson
10-11-2010, 02:18 PM
Does anyone, know, how the Magnum Dynalab MD-10, compares to the Korner 19.3 or the Winegard 6065? The MD-10 is said to have 12 db forward gain !

Gary H.

k6sti
10-11-2010, 02:47 PM
12 dB average gain with decent F/B is impossible on a 142" boom regardless of whether the gain reference is a dipole or an isotropic radiator, which isn't specified. I doubt it's possible even if you try to maximize gain only, which will obliterate F/B. Any time the gain reference is missing, be skeptical. Beyond that, there is so much BS in the description of their ST-2 whip that it's clear they don't know what they're talking about. I distrust anything the company says and wouldn't take any of their performance claims seriously.

Brian

John Wilke K9RZZ
10-12-2010, 12:06 AM
Looks cool, but I still love my stack of 6065p's. :cool:

Been up there, I think, for 3 years and still working great. :rolleyes:

Gary Hickerson
10-13-2010, 03:17 PM
Does anuone, know, how the MD-10, compares, to the Korner or HD 6065?
It has 12 db forward gain !

Gary H.

W1VLF
03-31-2011, 05:44 PM
Brian,

Thanks for all the work you have done in modeling all the antennas at your site.
A lot of work went into all that information.

Concerning the 19.3 antenna. I would like to model it using EZNEC.
I was able to glean the dimension I needed to do the 88 to 92 Mhz yagi on your site, but I am having trouble with the 19.3

Having used AO.xxx many years ago, I am not familiar enough with the dimensioning conventions anymore.

Do you know if there is a dimensions list somewhere?

I have made and sold a few of my heavy duty 8 element logs for FM but its just not worth the time.

But I would like to think about building 2 for myself
pauLC
W1VLF

Romy The Cat
10-07-2011, 02:11 PM
Hi, Brian,

I wonder what people at the East Cost of US can get this antenna? I am in Boston, doing FM, have 6065P on 50 tower mast but I need one more comparable gain antenna to implement a have phase-cancelation form one near-spaced station in upper New Hampshire. I was thinking about 6065P but your antenna does look sexy, not to mention that 6065P nowadays have 8 segments. So, can you pitch a place where to get your antenna?

Rgs, Romy the Cat

Octavio
11-18-2011, 05:11 PM
Any chance to get the construction layout ? ,I would like to build it ..
Please advise