October 29th 06, 01:31 AM
posted to rec.radio.amateur.antenna
|
|
external usenet poster
|
|
First recorded activity by RadioBanter: Oct 2006
Posts: 9
|
|
Timewave ANC-4 question!
Jan Simons PA0SIM wrote:
"Sun Tzu" schreef in bericht
news:ruCdnermL6SEDd_YnZ2dnUVZ_uydnZ2d@hawaiiantel. net...
Jan Simons PA0SIM wrote:
"Sun Tzu" schreef in bericht
...
Jan Simons PA0SIM wrote:
Reading the schematics it is possible that the ANC-4 does not
fully cover the 360 degrees phase shift, just like the MFJ-1025.
But it is also possible that you experience more than one noise
source on 75 mtrs. A noise canceller (with two inputs/antennas)
can cancel only one noise source.
I have written about noise cancelling on my site, e.g.:
http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm
May be it can help.
73 es gl de Jan PA0SIM
Nice website, have you considered modifying the existing units (MFJ &
ANC)
to do what you have shown? Your idea would make either of these 2 units
much
better.
By the way, I took the sense antenna which is a short dipole and I made
one
leg vertical and the other horizontal. Now I have almost no noise on 75
meters. I haqve been playing around with this for awhile and it was
either all vertical or all horizontal. Now with this configuration the
weak signals can be heard.
Stan
AH6JR
Hi Stan,
I have considered it, but sometimes it is easier and better to start
fresh. First question is always: what phaser/noise canceller do you
really
want? What do you expect from it?
Looking at the design of the MFJ-1025, it would take to much mods to
realize my needs.
When one of the antennas doesnt hear the noise source, you dont need
a phaser. But of course that antenna still has to hear your wanted
signals. Using a small loop antenna it is sometimes possible to null the
noise source.
I think playing with a short dipole, as you did, is the same as nulling
with small loops.
73 de Jan PA0SIM
I have the ANC-4 which works well. This new sense antenna is really good,
as
I can hear signals down to S-2 on 75 meters. I guess if I had to do it I
would prefer to modify the ANC-4 as its a quality unit, not perfect but
it is built well.
If you would have any ideas as to modifying the ANC-4 I would'nt mind
working with you on this project. But I will leave that one up to you.
Hopefully I will be able to hear you in the contest this weekend on 75
meters!
Good Luck in the contest my friend!
Sri, I prefer my Digital Signal Processing route with the two Elecraft K2
receivers.
DSP makes an ideal phaser. So no need here for a "better" analog one.
And DSP gives me a lot more tricks to reduce interference and noise.
73 es gl de Jan PA0SIM
May I ask what the tricks are?
|