Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
Search
cardioid loop antenna from Cross Country Wireless
If you want to go for the gold, have you thought of the Aziloop???https://quietradio.co.uk/
Nick ? On Sat, 19 Oct 2024 06:09:37 -0700, "Dave Martin" <kc7nj73@...> wrote: ? I am.? I don't need gain in any one direction,? I'm looking for a deep notch to be used for direction finding.? On the current loop I'm using the null is deep but no front to back ratio is sometimes a problem.? Dave
|
¿ªÔÆÌåÓýyou maybe could add a telescopic whip and phase loop and whip
together to have the null at the rear dg9bfc sigi Am 19.10.2024 um 15:09 schrieb Dave
Martin:
|
¿ªÔÆÌåÓýWould you or anyone else know where a schematic diagram could be found for such a phasing network that could be used from ~15 kHz to 150 kHz?Gedas, W8BYA EN70JT Light travels faster than sound..... This is why some people appear bright until you hear them speak. On 10/20/2024 1:39 PM, Siegfried
Jackstien wrote:
|
First derivative of frequency with respect to time is phase, so there are no analog wide bandwidth phase shifters, excepting for goniometers. Goniometers have an annoying amplitude variation with frequency, even in their capacitve form they are still tempermental. (Used to set the 3.579545 mhz carrier phase in RS-150 NTSC camera encoders and previously in WW2 radar sets.)
?
US2496920A - Phase shifter
?
If you are willing to create a matched pair of IF strips, with a +/- 45 degree difference at the IF freq, but with idetical phase matched RF front ends, it can work.
?
But cost as the over all limit, digital is another matter and an SDRplay duo, which has the ability of 90 degree diversity reception might be the useful wide band answer.
?
I would suspect that if you are willing to go "Non-Foster" then there is always an imaginary solution. . .
?
The pun was intentional.? Get it? "i" or "j"? ?
?
Jim/VEZ
?
?
?
?? |
It's not much different from a Wellbrook and rotator in terms of cost, but it is much more sophisticated, and a lot of thought has gone into it's design.
?
I think if you are interested in the LF bands, NDB or MW broadcast DXing, it's probably the best option, especially if you have limited space, or other restrictions.
?
Regards,
?
Martin
?
On Sun, Oct 20, 2024 at 10:05 PM, Dave Martin wrote:
That's a lot of money for an antenna I have to build.? |
I use an Aziloop located 400ft away from house at the bottom of a field in the clear and it works really well 1-10MHz,
Sharp nulls in loop mode from VLF to HF, but in K9AY mode it is limited by the performance of the size of K9AY.
My one is only 20ft across (diameter) and 15ft high and has up to 30dB groundwave f/b 1-4MHz.
A friend tried one close to his house and other antennas and understandably it did not work well in either s/n or bearing accuracy, a remote Wellbrook was better.
John |
to navigate to use esc to dismiss