Navy Antennas (was Tilted Pinball Antenna Theory)
 

"Richard Clark" wrote in message
...
On Mon, 15 Sep 2008 12:01:10 GMT, "Jerry"
wrote:


"Sal M. Onella" wrote in message
...

"Richard Clark" wrote in message
...
On Sun, 14 Sep 2008 10:33:28 -0700, Richard Clark
wrote:

However, returning to my own recent shipboard experience and antennas
there, I will later today post a link to a dozen or so pictures. It
will include shots of Guss' Loops. I dare say several of these
pictures will provoke much head scratching (but only to those few
actually interested in antennas here in this forum).

http://home.comcast.net/~kb7qhc/antennas/navy/

I used to have the nomenclatures of all those antennas memorized, but,
alas,
having gotten away from EMI inspections in 2003 and having fully retired
last year, all I can call to mind is the AS-2815/SSR-1 (your "Drooped
Cross
Horizontal")

You zeroed in on some cryppie antennas. I rocognize the biconical
dipole,
an HFDF antenna and a Rubicon antenna. They're often found together on
an
Aegis cruiser. (Makes me want to put on my coveralls and get back out
there -- or maybe not.)

Hi "Sal"

I'd like to know more about the Drooped Cross
Horizontal"). Do you know the frequency it is designed for?

Jerry KD6JDJ


Hi Jerry,

I built a model of it, and from by guess and by golly, I presumed it
would be somewhere in the middle of the VHF/UHF Shipboard Band
(225-400 MHz) and made it resonant at 300 MHz (arbitrary selection,
mind you).

Let me know if you want a copy of that file.

73's
Richard Clark, KB7QHC

Hi Richard

That is an interesting antenna (AS-2815/SSR-1). I didnt know how to feed
it, but I see how you did it.
If that *is* used to communicate with polar orbiting satellites, I'd
expect the DCA to outperform it.
I have demonstrated fairly well that the DCA outperforms the Quad Helix
for reception from NOAA polar orbiting satellites. I'd be curious to know
what the Navy would think of the DCA for a replacement of that
AS-2815/SSR-1.

Jerry KD6JDJ

"zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz&q
 

Jerry wrote:

...
Hi John

You are right, this EZNEC antenna modeling program is like gold to anyone
interested in learning about antennas. You are additionally right about
the fact that all you need is a piece of paper (or monitor) to display
aspects of an antenna that would otherwise require thousands of dollars to
duplicate.

Jerry KD6JDJ

Jerry:

I certainly don't wish to invoke your anger by pointing out your
ignorance, but guy, eznec is only a front-end to eznec ... mmana-gal
does exactly the same thing, has no limitations and is free ...

Eznec does nothing but create an ascii text file and feed it to the nec
engine, and displays the results ...

Sorry guy, it just looks complicated to you ...

And, of course, no disrespect meant to Roy ... he did a nice job on the
front-end ...

Regards,
JS

"zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz&q
 

John Smith wrote:

...
Jerry:

I certainly don't wish to invoke your anger by pointing out your
ignorance, but guy, eznec is only a front-end to eznec ... mmana-gal
does exactly the same thing, has no limitations and is free ...

Eznec does nothing but create an ascii text file and feed it to the nec
engine, and displays the results ...

Sorry guy, it just looks complicated to you ...

And, of course, no disrespect meant to Roy ... he did a nice job on the
front-end ...

Regards,
JS

Just caught the error when I hit send:

Change "... eznec is only a front-end to eznec ..." TO "eznec is only a
front-end to the nec engine ..."

Regards,
JS

Navy Antennas (was Tilted Pinball Antenna Theory)
 

On Mon, 15 Sep 2008 23:31:31 GMT, "Jerry"
wrote:

Hi Richard

That is an interesting antenna (AS-2815/SSR-1). I didnt know how to feed
it, but I see how you did it.
If that *is* used to communicate with polar orbiting satellites, I'd
expect the DCA to outperform it.
I have demonstrated fairly well that the DCA outperforms the Quad Helix
for reception from NOAA polar orbiting satellites. I'd be curious to know
what the Navy would think of the DCA for a replacement of that
AS-2815/SSR-1.

Jerry KD6JDJ

Hi Jerry,

Well, I got most of the structural details down OK. However, the feed
is by guess and by golly. In the pictures you can catch a hint of it
(especially when you compare to my file), but this does not say if
there is a phasing harness hidden inside the stanchion tube.

As for the Navy being interested in your DCA, I've been on the vendor
list for years, and worked with their RFPs the same time. It is not
for someone who isn't ready to seriously commit a lot of time to
paperwork.

As for the others following this about crossed antennas, helical
antennas, there is one model the Navy uses that has interesting design
(Art will probably claim it proves what ever flavor theory he is
selling today) the AS-2227/SRN-9:
http://www.combatindex.com/hardware/...v/as-2227.html
http://www.combatindex.com/hardware/...as-2227_01.jpg

73's
Richard Clark, KB7QHC

Navy Antennas (was Tilted Pinball Antenna Theory)
 

"Richard Clark" wrote in message
...
On Mon, 15 Sep 2008 23:31:31 GMT, "Jerry"
wrote:

Hi Richard

That is an interesting antenna (AS-2815/SSR-1). I didnt know how to
feed
it, but I see how you did it.
If that *is* used to communicate with polar orbiting satellites, I'd
expect the DCA to outperform it.
I have demonstrated fairly well that the DCA outperforms the Quad Helix
for reception from NOAA polar orbiting satellites. I'd be curious to
know
what the Navy would think of the DCA for a replacement of that
AS-2815/SSR-1.

Jerry KD6JDJ

Hi Jerry,

Well, I got most of the structural details down OK. However, the feed
is by guess and by golly. In the pictures you can catch a hint of it
(especially when you compare to my file), but this does not say if
there is a phasing harness hidden inside the stanchion tube.

As for the Navy being interested in your DCA, I've been on the vendor
list for years, and worked with their RFPs the same time. It is not
for someone who isn't ready to seriously commit a lot of time to
paperwork.

As for the others following this about crossed antennas, helical
antennas, there is one model the Navy uses that has interesting design
(Art will probably claim it proves what ever flavor theory he is
selling today) the AS-2227/SRN-9:
http://www.combatindex.com/hardware/...v/as-2227.html
http://www.combatindex.com/hardware/...as-2227_01.jpg

73's
Richard Clark, KB7QHC

Hi Richard

You got good results from your "guess" at how to feed that Droop Cross
Navy antenna. I'm impressed. The fact is - I wouldnt advise the Navy to
change that antenna if it is functioning properly. It is simple and it is
rugged looking.
As you know, I am not on the selling end of anything, including antennas.
I do like to state that the DCA antenna design concept performs better for
horizon to horizon coverage of polar orbiting satellites than any other omni
azimuth antenna.

Jerry KD6JDJ

"zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz&q
 

On Sep 15, 7:50*pm, John Smith wrote:
John Smith wrote:

* ...





Jerry:

I certainly don't wish to invoke your anger by pointing out your
ignorance, but guy, eznec is only a front-end to eznec ... mmana-gal
does exactly the same thing, has no limitations and is free ...

Eznec does nothing but create an ascii text file and feed it to the nec
engine, and displays the results ...

Sorry guy, it just looks complicated to you ...

And, of course, no disrespect meant to Roy ... he did a nice job on the
front-end ...

Regards,
JS

Just caught the error when I hit send:

Change "... eznec is only a front-end to eznec ..." *TO "eznec is only a
front-end to the nec engine ..."

Regards,
JS- Hide quoted text -

- Show quoted text -

Glad to see you are coping, Mr. Anonymous "John". Good save chuckle

"zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz&q
 

Navy Antennas (was Tilted Pinball Antenna Theory)
 

"Jerry" wrote in message
...
..

Hi "Sal"

I'd like to know more about the Drooped Cross
Horizontal"). Do you know the frequency it is designed for?

Jerry KD6JDJ

Yes. Its nomenclature is AS-2815/SSR-1A. It was designed for the UHF
satellite "Fleet Broadcast," 240 - 315 MHz, but I have seen it used only in
a narrower range, more like 248 - 262 MHz. The pattern is semi-omni,
essentially taking in a view of the entire sky.

The system is receive-only and has been a mainstay of fleet comms for
decades. The version I grew up with had a 1200 bps digital mux of fifteen
74 baud TTY signals (100 WPM). It may have advanced since then; I don't
know the capabilities of the -A version. (I hope they made it more
idiot-proof.)

Ships are usually fitted with three or four antennas, strategically placed
so that at least one of them is clear of blockage. The system uses what is
called "pre-detection integration," whereby the strongest signal is
demodulated, on the presumption that it's the best quality. It's a form of
diversity reception.

The original AN/SSR-1 system downconverted the received signal to a 19.95
MHz first-IF out on deck, a few feet from the antenna. I believe the
AN/SSR-1A amplifies the received signal and it goes all the way to the radio
room at the d/l frequency. Maybe somebody will know for sure whether that's
right, but I think so.

"Sal"
(KD6VKW)

Navy Antennas (was Tilted Pinball Antenna Theory)
 

"Richard Clark" wrote in message
...


snip
As for the others following this about crossed antennas, helical
antennas, there is one model the Navy uses that has interesting design
(Art will probably claim it proves what ever flavor theory he is
selling today) the AS-2227/SRN-9:
http://www.combatindex.com/hardware/...v/as-2227.html
http://www.combatindex.com/hardware/...as-2227_01.jpg

Woo-hoo! I remember that beast! I had an interference study to do on it.

The SRN-9 and WRN-5 were used with the old Transit satnav system, a
precursor to GPS. It worked OK (usually) but the satellites were
sub-synchronous and you could only compute a fix during a pass, which
happened only a few times each day. Even then, you needed to get it during
rising Doppler, which really meant half a pass.