How directional are people finding the Pixel Loop?

Roy Laufer

I purchased a Pixel Technologies Pro-1B during the winter and was waiting for the spring thaw to set it up (at about 10 feet) in my backyard. I've only had it working for a few hours, but it seems to beat the heck out of my Alpha-Delta DX-CC fan dipole. The noise floor has plummeted and transmissions I could barely hear are fully intelligible. It's almost like magic, for something so small and not needing high altitude (if only it could transmit too, I'd know I imagined it).

I got a G450 rotor for it, which is probably overkill for such a light loop. I really cannot tell any difference when I rotate it. I've played with it on 80 M, 40 M, 20 M and 10 M. I can't hear any additional noise nulling, or any signal level variations that aren't just normal QSB.

Do the directional benefits "come and go" like propagation anomalies or am I missing something. Is it just much more directional at LF and MWL and not that much at HF?

I'd appreciate any insight from people that have had more than my half a day's experience with is 'miracle antenna'!

Thanks!

Roy, AC2GS

K6OZY

I love my Waldo and have it permanently attached to my RX B on the 6700.   I picked up a used one that I keep in the closet for portable demos.  I don't rotate it, but did test the best reception for my area before tightening it down.   It works great with Diversity on the 6700 for many uses and sounds great when I put it on my right ear and my Windom in my left ear.   It also gets rid of my neighbors noises when he decides to turn on his grow lamp.

Larry _ NY8T

It has directivity and for me I tend to turn it so the noise nulls rather than the direction someone's signal rises, although  I tweak it a tad for best reception. Its all about pulling them out of the noise rather than how big their signal is.  I ran mine about 12 feet off the ground most of the winter then last weekend I put it on my roof and it made it very usable on the higher bands as well as the low bands that were working fine 12 feet off the ground. I would have to say at any given time I can turn it and raise or lower the noise level on any band, at least here at my location.

http://s707.photobucket.com/user/llavaseur/media/loop_zps793d6f11.jpg.html 

http://s707.photobucket.com/user/llavaseur/media/DSC_0177_zpszdiay45b.jpg.html

WA2SQQ

You will find that the directivity diminishes with sky wave. When used to null out local noise, and reception using ground wave, the nulls are much sharper. On the BCB, when using it with my 5000, I was able to null the signal of a local 50kw station by about 20db, more than enough to alleviate a problem I had on 160. I now use it with my 6500 for receiving below the BCB. I CANT BELIEVE THE STUFF IM RECEIVING!

Jeffrey Kerber, N3VE

I love my pixel and can't wait to see the 8 foot version.  I hope they have it at Dayton!  I first mounted it on my roof top at approx. 30 feet and did not like the reception.  After a call to the manufacturer I mounted it 10 feet off the ground in my back yard.  I think that antenna freaked out the neighbors more than the others.  I hear nulls on occasion but mostly not.  It is a great addition to the 6700 setup and I use it most of the time.

Jeff

KY6LA_Howard

i had mine at 10' .. did not hear as well as I would like.. mainly because it was blocked by the 50' hill in my backyard... Now its at 25'... hears significantly better

Yes there are definite nulls and peaks....

https://community.flexradio.com/flexradio/topics/pixel-loop-on-the-roof

Here are pictures..

Ken - NM9P

Does anyone have a link to a design for a homemade version of a Pixel or similar loop? I have been thinking of trying one using a MAR-6 or similar amp chip. ( I have a dozen of them I bought at Dayton many years ago). I want to see if I can get better performance than I get out of the 20 ft. Shielded magnetic loop I built last winter.

K4SC

I've had my Pixel Loop about six months now.  I purchased it because my temporary QTH apartment is located ten feet from a sports bar with multiple Plasma TVs which made HF unbearable for my Flex 6500 and analog radios.  Best $500 bucks I've ever spent, well maybe second best to a good divorce lawer in 1969.

I have an Armstrong rotor arrangement on mine but have given up adjusting it because it just doesn't make enough difference to be worthwhile.  Once I nulled the Plasma noise it's pretty much stayed put.  Mine is mounted on the fire escape railing on my 2nd floor apartment and is just above the roof line.  Interesting to hear there is an 8' loop coming?  I wonder what the advantage to the bigger diameter will be?

When I bought mine, I did so with the thought that I could resell it if it didn't really help;  I intend to move it with me on my next jon in Corvallis Oregon this summer.  They are very well built. BTW I use mine on the Loop A receiver input of the 6500.

SteveM

Re: the 8' loop. Yeah, if you watch the 'How it's made" video on InLogis' website they mention this. The XYL in the video is something else. Notice how she smiles and strokes the tube while stating "... Because we all know size matters". Shameless marketing display.

Roy Laufer

I would think that making it 8 feet wide would defeat the purpose of the Pro-1B. It would require much more space, it would be significantly heavier and need a heftier rotator.

I assume that the primary benefit will be a boost in signal strength - I just wonder if the boost is worth the additional costs (in money and non-monetary costs).

I hope that they show it off at Dayton (but then I also wish there was some website that covered Dayton like other sites cover things like than annual CES in Las Vegas). W5KUB tries to do this, but he is mostly a one man operation.

Roy, AC2GS

ka7gzr

I have two Pixel loops. They are ~ 70 feet apart and phased 90 degrees apart. They are mounted~ 10 feet above the ground.They are connected to my 6700 RXA and RXB inputs. In "Div" mode I often hear and see (s meter) differences dependent on the signal arrival path. They usually out-perform my R8 vertical from a noise floor standpoint. Actual signal strength is about the same. I often use them to receive and then I transmit on the R8. I use the PTT blanking inputs to inhibit the preamp when I transmit.

Great little antennas for the broad banded Flex spectrum scope.

Jim

ka7gzr 

Jerry WA9UKB

I have two loops also to a DX NCC-1 on my Flex 6500, I wonder if it would be beneficial to go to a flex 6700 like your setup to null out interference over the NCC-1

maybe a smoother approach, My loops are 65 feet spaced.

Jerry,

WA9UKB

K6OZY

It is a bit directional for DX, but not much.  It is directional for local AM stations that are ground wave range.