eHam

eHam Forums => SWL (Shortwave Listening) => Topic started by: AUSSIE on August 12, 2012, 02:41:23 AM



Title: Youtube
Post by: AUSSIE on August 12, 2012, 02:41:23 AM
These are some of my youtube ndb end hf aero videos enjoy watching..

http://www.youtube.com/watch?feature=player_detailpage&v=NH_CngmaQoc
http://www.youtube.com/watch?feature=player_detailpage&v=3SPDzXCu6xs
http://www.youtube.com/watch?feature=player_detailpage&v=3Q4k_ZW_qwY
http://www.youtube.com/watch?feature=player_detailpage&v=oLvH3lzUBSg

Regards Lino..


Title: RE: Youtube
Post by: HFCRUSR on August 12, 2012, 05:35:51 PM
Man there is NO noise with those loops-good job Lino. I gotta get me a Wellbrook.


Title: RE: Youtube
Post by: AUSSIE on August 13, 2012, 03:15:10 PM
Hi thanks SNR is excellent on all my wellbrook loops there not cheap had plenty of hf receiving antennas but nothing comes close to the wellbrooks..
Regards Lino.


Title: RE: Youtube
Post by: KC4MOP on August 17, 2012, 04:22:09 AM
Same can be said for the PIXEL loops also. ANY MAGNETIC loop antenna will be quieter than a dipole and especially a vertical antenna.
As SWL's or Amateur radio operators we use Electro-Magnetic Radiation:

http://en.wikipedia.org/wiki/Electromagnetic_radiation

To be brief it has Magnetic and electrical components to it. The electrical component is the noise we hear on the radio. Static crashes, neighbors fish tank heaters, etc. A vertical antenna hears only the electrical component of the radio waves. Same for random wires and dipoles.
ANY magnetic loop antenna will only receive the magnetic portion of the radio wave which has much less of the static and trash and hence, much quieter.
Here is PIXEL's web site and video showing how much quieter their (magnetic loop antenna) is compared to a random wire antenna or a vertical antenna.
http://www.pixelsatradio.com/product/shortwave-magnetic-loop-antenna/

These MAG loop antennas are very popular in Europe, as the Hams there are really cramped for space and the electrical systems are much noisier than USA power distribution.
The beauty of MAG loop antennas are becoming very popular in the U.S.
WellBrook has been around for a long while and highly respected. The pricing between a WellBrook and Pixel are pretty close.
Fred

Fred


Title: RE: Youtube
Post by: K0OD on August 17, 2012, 06:09:55 AM
You guys need to tell ham low band DXers about this. They listen for stations a bit farther away than an NDB three counties away!

I've known quite a low band DXers who have tested loops on 160 and gone back to their conventional antennas for receiving. Stop falling for ad hype and follow what the guys use who win contests or are at the top of the 160 honor roll. Loops have a place in special situations. But they won't help many hams/swls to hear better.

If, for some reason, you value the illusion of low noise, you can often achieve that just by turning down the RF gain.


Title: RE: Youtube
Post by: KC4MOP on August 17, 2012, 06:53:15 AM
You guys need to tell ham low band DXers about this. They listen for stations a bit farther away than an NDB three counties away!

I've known quite a low band DXers who have tested loops on 160 and gone back to their conventional antennas for receiving. Stop falling for ad hype and follow what the guys use who win contests or are at the top of the 160 honor roll. Loops have a place in special situations. But they won't help many hams/swls to hear better.

If, for some reason, you value the illusion of low noise, you can often achieve that just by turning down the RF gain.


The mag loop antenna is a quick way to get over some interference problems.
The low band DX guys who are not plagued with electrical interference, can build or buy Flag antennas, EWES, K9AY steerable receiving antennas, four-squares, etc.
My post was to show that Well Brook was not the only game in town for an effective Magnetic loop antenna.
Low band DXers will have many choices for antennas to choose from to pick out that weak station.
And you are correct that turning down the RF gain achieves pretty much the same thing.
The noise can be really bad below 40M.

Fred


Title: RE: Youtube
Post by: K0OD on August 17, 2012, 07:38:47 AM
Quote
"The low band DX guys who are not plagued with electrical interference, can build or buy Flag antennas, EWES, K9AY steerable receiving antennas, four-squares, etc. "

Those can be great tools. I've had a 4-square. But some 160 meter big guns are on tiny lots and receive with their transmitting antenna, usually a vertical of some flavor. A couple do very well with big shunt fed towers. I'm sure some use a simple wire hanging from a tall tree. (that's $5 for wire and $10 for a slingshot)

Want to try a loop? Build one!


Some of these SWL posts sound like ads hyping specific very costly antennas (ala the Zero-Five cult). You don't need a specific brand of 43' aluminum "stick" and you don't need a specific brand of loop. 



Title: RE: Youtube
Post by: W1AEX on August 17, 2012, 11:25:45 AM
Lino, your videos are the best demonstrations of the Wellbrook broadband loop on VLF and HF that I have seen so far. It's amazing what can be done with such a small capture area and a low noise preamp. I live in a reasonably quiet area for reception, but have been very impressed with the ability of receive loops to reduce static crashes and other atmospheric disturbances when compared to what my transmit antennas pick up on receive. I have no doubt that a Wellbrook or Pixel loop will show up in my backyard at some point, but the price still makes me flinch a little bit. For the fun of it, I've been playing around with a pair of very simple 85 foot vertically oriented loops for receive. They are based upon the K9AY design, but I use them without terminating resistors to allow them to receive with a bi-directional pattern. Recently, I built and installed broadband preamps for the feedpoint of each loop (based upon the design by W7IUV) and that has really made them come alive, especially on 40 meters and above. They are cheap to build, easy to install, and they're very quiet when compared to my dipoles. I have details, pictures, and a few embedded YouTube videos here: 

http://www.w1aex.com/loop/loop.html

Thanks for sharing your results with the Wellbrook. The SNR below 500 KHz is especially impressive.

73,

Rob W1AEX


Title: RE: Youtube
Post by: AUSSIE on August 17, 2012, 12:04:56 PM
Hi Fred the wellbrook active loops are very popular in australia this year at least 15 of of my friends both them and very happy with the results do have a pixel loop at dads works just as good 6 of my uncles also use the wellbrooks together we got 20 wellbrook,4 pixel,7 Rf system
i got 4 myself and very happy with results due for another one towards the end of the year..

Hi Rob been getting intrested in chasing ndb furthest i got so far has been new zealand that was a few days ago my area is flat with underground powerlines in fact a friend of mine got the ALA1530L seems it works a little better in his place and his in a ditch i live in a double storey and did an experiment buy putting them at 10 metres high did work as good as 5 metres high took me a while to get the right height and direction in the next few eeks picking up a Yaesu-G250 rotator that will probably on the ALA1530L and thanks for watching my videos will make more as soon as i get some time radio room is getting pulled a part building a new hutch and have to fix all my cables ,wires bit of a mess at the moment..

Regards Lino..


Title: RE: Youtube
Post by: HFCRUSR on August 17, 2012, 03:50:07 PM
Lino I gotta laugh every time you rattle off how many loops your family has! You alone have what-close to $2000 just in loops with the 4-I think I have between the PAR, tripod, and 100' wire, about $90 haha!
I gotta get one for sure!


Title: RE: Youtube
Post by: KC4MOP on August 17, 2012, 03:58:32 PM
Quote
"The low band DX guys who are not plagued with electrical interference, can build or buy Flag antennas, EWES, K9AY steerable receiving antennas, four-squares, etc. "

Those can be great tools. I've had a 4-square. But some 160 meter big guns are on tiny lots and receive with their transmitting antenna, usually a vertical of some flavor. A couple do very well with big shunt fed towers. I'm sure some use a simple wire hanging from a tall tree. (that's $5 for wire and $10 for a slingshot)

Want to try a loop? Build one!


Some of these SWL posts sound like ads hyping specific very costly antennas (ala the Zero-Five cult). You don't need a specific brand of 43' aluminum "stick" and you don't need a specific brand of loop. 



I knew a low bander guy who worked a lot of DX, 160M on a small lot with an inverted "L". The secret to good success is CW. Digital modes are cool but some are non-exciting, but interesting, such as JT 65 HF.


Title: RE: Youtube
Post by: K0OD on August 18, 2012, 07:15:03 AM
Quote
I knew a low bander guy who worked a lot of DX, 160M on a small lot with an inverted "L".

I'm a little puny in that heart pounding NDB SWL category, but I've WORKED everything but about 10 countries on 40 meters. I've won the Zero District in the CQWW or ARRL DX tests many times on 40, a few times on 80 and perhaps once or twice on 160 with an inverted L, a wire shot over a 50' high tree, plus a decent radial system. 

160 is a tough band, no doubt. Much tougher than 80 or 40. But for most of us antenna restricted suburbanites, an inverted L is the only decent DX option. Even from Missouri I had little trouble working DXCC with my L years ago. Yes, KW and of course CW. 160 big guns always got thru the pileups first, but I usually snagged the Q eventually.