On Monday, July 18, 2011 4:07:09 PM UTC-5, amdx wrote:
On 7/18/2011 9:58 AM, wrote:
On Sunday, July 17, 2011 3:49:46 PM UTC-5, Sal wrote:


OK, so the final score is Dallas 3, Me 0. Game over. *sigh*

"Sal"

Now you see why I will not have anything to do with a
"group" that you must sign up for. Never have, and never will.

In trying to avoid such a simple request, you deny yourself
a great many sites.

I'll survive.. :/


Many of them seem to like to play their silly games, have
control over what is posted, banish the hecklers, etc..
No way to live as far as I'm concerned.

I don't see this as reason to deny yourself access to
hundreds or thousands of sites that have great information.

Who says it's all great information? Some may be. Some
may not. I'm not going to jump through hoops to find out
one way or the other.


And I don't need him to learn about phased broadcast
band antennas.

I want to learn, do you have any sites with good broadcast band antennas.

Well...Google is your friend.. He's not the only one to run
those ya know..
http://search.yahoo.com/search;_ylt=...8&fr=yfp-t-701

I'm sure I can gather some usable info without having
to jump through a hoop.


It's not like he invented them or anything.

He's not claiming invention, but he has made a nice
contribution to the hobby.

No problem with that. But I'm not going to be a
spectator if I have to jump through hoops, be censored,
moderated, vetted, etc, ad nausium.. :+


He's just tinkering with a few, and I presume posting his
results to the few that he deems worthy.. :/


Tinkering seems a little insincere, I'm sure he ha smany hundreds
of hours into his research.

He probably does. But what does that have to do with me?


Please post any websites you have regarding broadcast band antennas.
I have not found much other than resonant loops and beverages.
Mikek

Already gave one example above. I think W8JI was using
some sort of steerable verticals, and he might have some
info on his site. As I recall, they were pretty short,
and maybe not even resonant, but I don't recall how he
was steering them.
There is tons of stuff out there.. And there is always
that source many seem to ignore these days. Books.

Myself, I happen to like loops.. I'm more interested in
a good null, than I am a really directional pattern like a
flashlight. I don't have the room to run a decent beverage
here. I can do it at my dirt patch out in the sticks, but
I've never got around to stringing the wire up.
I intend to do it one of these days just to give em a try.
Anyway, I've been fairly satisfied just using the various
loops I have for general AM-BC use.
If I decide to build something a tad more exotic, I'll
dig up the info, and I won't be jumping through hoops to
get it. Plenty of other flag array users out there.
No need for me to bother Dallas about it.

On 7/18/2011 5:43 PM, wrote:
On Monday, July 18, 2011 4:07:09 PM UTC-5, amdx wrote:
On 7/18/2011 9:58 AM, wrote:
On Sunday, July 17, 2011 3:49:46 PM UTC-5, Sal wrote:


OK, so the final score is Dallas 3, Me 0. Game over. *sigh*

"Sal"

Now you see why I will not have anything to do with a
"group" that you must sign up for. Never have, and never will.

In trying to avoid such a simple request, you deny yourself
a great many sites.

I'll survive.. :/


Many of them seem to like to play their silly games, have
control over what is posted, banish the hecklers, etc..
No way to live as far as I'm concerned.

I don't see this as reason to deny yourself access to
hundreds or thousands of sites that have great information.

Who says it's all great information? Some may be. Some
may not. I'm not going to jump through hoops to find out
one way or the other.


And I don't need him to learn about phased broadcast
band antennas.

I want to learn, do you have any sites with good broadcast band antennas.

Well...Google is your friend.. He's not the only one to run
those ya know..
http://search.yahoo.com/search;_ylt=...8&fr=yfp-t-701


Interesting, out of the first 11 hits 9 of them are antennas from
Dallas's site, One is a site about 160 meter antennas and one is about
math (square arrays).


I'm sure I can gather some usable info without having
to jump through a hoop.

I still want to learn, do you have a specific site with a good
broadcast band receiving antenna. Preferably with a null I can rotate
and that will fit in 150 ft.
Thanks, Mikek

On 7/18/2011 6:50 PM, amdx wrote:


I still want to learn, do you have a specific site with a good broadcast
band receiving antenna. Preferably with a null I can rotate
and that will fit in 150 ft.


how deep a null, how narrow/wide?

One of the noise canceling boxes with two antennas will do quite well.
Timewave ANC-4 is one possibility
MFJ 1026 is another.
DX engineering NCC-1


For BC band, almost any antenna will work.

If you want physically small you could use any of the active antennas..
You could use a MFJ1020C,1022,1024, Ameco TPA, DX Engineering ARAV3-1P, etc.
The MFJ 1026 canceller includes an antenna.

A whole bunch of kits out there..
Ramsey AA7B, the Amrad antenna, ..


If you want to get more sophisticated, some sort of software receiver
might be better approach (you could use more than 2 antennas, for
instance). There's not much off the shelf, but if you're ambitious you
might look at K1LT's array using softrock receivers.http://www.k1lt.com/

On Tue, 19 Jul 2011 12:12:52 -0700, Jim Lux wrote:
On 7/18/2011 6:50 PM, amdx wrote:

I still want to learn, do you have a specific site with a good broadcast
band receiving antenna. Preferably with a null I can rotate
and that will fit in 150 ft.

how deep a null, how narrow/wide?

One of the noise canceling boxes with two antennas will do quite well.
Timewave ANC-4 is one possibility
MFJ 1026 is another.
DX engineering NCC-1

In BCB SWLing you want the null(s) deep (and steerable)
to kill the strong, unwanted station.

Jonesy

On 19 Jul 2011 20:55:42 GMT, Allodoxaphobia
wrote:

In BCB SWLing you want the null(s) deep (and steerable)
to kill the strong, unwanted station.

This characteristic demands the SAME considerations as required for a
sharp beam of high directionality.

If we were to select the antenna that matches your quoted specs above,
it would be called the Cardiod (example available in EZNEC). Problem
there is the 30dB null isn't steerable (not enough elements). And it
is large (too large for the back yard):
1. Too tall for most to build.
2. Elements too far apart (out of necessity for, dare I say it?
Phasing).

As it is designed as a transmit antenna, too tall is quickly
dismissed. You can use as short of one as proves useful.

The first element, now being shorter, also allows us to add any number
of shorter elements in an array around (or mixed in with) the first.
This brings steerability. The more elements, the better angle
resolution and null depth control.

You can pull the additional elements (if only one more to build a
proof of concept Cardiod) closer to the first (dismissing the large
spacing objection), and introduce the necessary time/phase control
through:
1. cabling;
2. analog delay circuits;
3. digital delay circuits.

Moving to a digital solution controls all variables.

If none of this is covered in the "Dallas Files," it would be best to
leave them in the File Cabinet. Jim has provided adequate links to
fill in the gaps and no one was injured in the process of obtaining
the information.

73's
Richard Clark, KB7QHC

On 7/19/2011 3:47 PM, Richard Clark wrote:
On 19 Jul 2011 20:55:42 GMT, Allodoxaphobia
wrote:

In BCB SWLing you want the null(s) deep (and steerable)
to kill the strong, unwanted station.

This characteristic demands the SAME considerations as required for a
sharp beam of high directionality.


Actually, no.
You can form a deep null with a much simpler antenna system than for
high directionality.

All you need is to "cancel" the signal from the undesired direction.

If you had two verticals spaced some distance apart, fed by equal length
transmission lines, and one is polarity reversed, you get a fairly sharp
null on the line perpendicular to the line between the antennas.
(e.g. a signal coming from broadside will exactly cancel in the combining)

A loopstick antenna on a ferrite core or a multiturn loop, as popular in
direction finding, is another example with a fairly sharp null.



Now.. if you want one null, and one null only, that gets a bit trickier
in a small space. I don't know that you can do it with only two
elements (haven't thought about it much).

And if you want to steer the null.

One traditional approach in direction finding is to use a goniometer or
an adcock array.


If we were to select the antenna that matches your quoted specs above,
it would be called the Cardiod (example available in EZNEC). Problem
there is the 30dB null isn't steerable (not enough elements). And it
is large (too large for the back yard):
1. Too tall for most to build.
2. Elements too far apart (out of necessity for, dare I say it?
Phasing).

that's the "one null and one null only" problem.

On Tue, 19 Jul 2011 17:45:01 -0700, Jim Lux
wrote:

On 7/19/2011 3:47 PM, Richard Clark wrote:
On 19 Jul 2011 20:55:42 GMT, Allodoxaphobia
wrote:

In BCB SWLing you want the null(s) deep (and steerable)
to kill the strong, unwanted station.

This characteristic demands the SAME considerations as required for a
sharp beam of high directionality.


Actually, no.
You can form a deep null with a much simpler antenna system than for
high directionality.

Simpler does not invalidate SAME consideration.

All you need is to "cancel" the signal from the undesired direction.

If you had two verticals spaced some distance apart, fed by equal length
transmission lines, and one is polarity reversed, you get a fairly sharp
null on the line perpendicular to the line between the antennas.
(e.g. a signal coming from broadside will exactly cancel in the combining)

Hence my referenced Cardiod antenna available for modeling with EZNEC.

A loopstick antenna on a ferrite core or a multiturn loop, as popular in
direction finding, is another example with a fairly sharp null.

Mike has explicitly rejected loop solutions.

Now.. if you want one null, and one null only, that gets a bit trickier
in a small space. I don't know that you can do it with only two
elements (haven't thought about it much).

And if you want to steer the null.

One traditional approach in direction finding is to use a goniometer or
an adcock array.

Something I've already offered (Bellini Tosi Antenna, as well as
Wullenweber) - and has been rejected/ignored. Repetition doesn't seem
to stand much chance against the ongoing cult examination in trying to
parse the entrance qualifications for the Dallas Files.


If we were to select the antenna that matches your quoted specs above,
it would be called the Cardiod (example available in EZNEC). Problem
there is the 30dB null isn't steerable (not enough elements). And it
is large (too large for the back yard):
1. Too tall for most to build.
2. Elements too far apart (out of necessity for, dare I say it?
Phasing).

that's the "one null and one null only" problem.

Which loops (as in recurse, not a pun) us back to the top.

73's
Richard Clark, KB7QHC

On 7/19/2011 8:08 PM, Richard Clark wrote:

If you had two verticals spaced some distance apart, fed by equal length
transmission lines, and one is polarity reversed, you get a fairly sharp
null on the line perpendicular to the line between the antennas.
(e.g. a signal coming from broadside will exactly cancel in the combining)

Hence my referenced Cardiod antenna available for modeling with EZNEC.

Cardioid has only a single null and is a "end fire" configuration. I
don't think (esp with short spacing) you can get as deep or narrow a
null as with a W8JK style antenna(short spacing, out of phase).

two 180 degree out of phase antennas can be very narrow, even with small
physical extent.



A loopstick antenna on a ferrite core or a multiturn loop, as popular in
direction finding, is another example with a fairly sharp null.

Mike has explicitly rejected loop solutions.

Perhaps big loops were rejected.. what about physically small loops.


Now.. if you want one null, and one null only, that gets a bit trickier
in a small space. I don't know that you can do it with only two
elements (haven't thought about it much).

And if you want to steer the null.

On 7/20/2011 8:01 PM, Jim Lux wrote:
On 7/19/2011 8:08 PM, Richard Clark wrote:


After reading too many postings from this thread I wonder why anyone,
excepting myself just for this once, bothers to comment.

Who bleeping cares about this thread? This is not a great debate even
if you consider any of the the best ones here "great debates".

Which they mostly aren't.

tom
K0TAR