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Scatter Forager

The Scatter Forager is a newer antenna design that is based on the typical radar antenna.  More info on the antenna can be found here: http://www.digitalhome.ca/forum/showthread.php?t=127205

For my design, I decided to go with a wider mesh to concentrate on the VHF spectrum, and maybe use this antenna to replace the Stealth Hawk.

My basic design is using examples from the above link, but making my antenna wider to pickup better on the VHF-Hi frequencies...or so my thinking.  Here is my design:


The mesh is 1"x2" grid 16AWG galvanized steel.  This is fencing wire that I purchased from a local TSC.  I've used this mesh for all the reflectors on my current antennas.  Of all my antenna builds, this one was by far the easiest.


Below is  my  first rendition of this antenna.






Unfortunately this design didn't work so well. One of the DHC members noted that the balun used affected the antenna to much.  So I ended up switching to a conventional balun, that I have used in all my other designs.

After that, I setup a test in my livingroom and was surprised at what I picked up.  The way my livingroom is situated, my garage wall blocks any signals from Toronto.  Using this antenna, I was able to not just pick up a signal, but it was a pretty clean, watchable signal from analog CTV RF9.  I don't recall any other antenna have the abilities to pick up this station from this location.

I then tested it out at my in-laws, and picked up most of the Toronto stations like usual.

This was a few weeks back, and I haven't worked on it too much since.  Now that the weather has cooled a little, I may just take this up into the attic and do the shootout between this antenna and the Stealth Hawk.

*22/09/10*

I haven't really been updating this thread lately as I've had too many other things on the go, mainly a huge home project and trying to fix up the music-server.  But I did get a second chance to run this from the living room, directly connected to the TV.  I compared the results to my existing antenna farm on the same TV.  The big difference was overall cable length.  This antenna was connected to the TV via 25' RG59 cable.  My actual setup goes through a pre-amp+60' of cable from the attic to the basement, then an additional 25' to the TV.

This particular night of testing was clear and calm, and using this antenna I was actually able to pickup RF38, RF39, pixilated RF33, RF32, and the local digitals RF18, 15, and 35.  Again CTV analog on RF9 (VHF-hi) came through more clear than when using my setup, even though this antenna is blocked from signals in that direction by the garage.

This just increases my high hopes that this antenna will outperform the current Stealth Hawk in the attic, once I have the time to get it up there.

*26/09/10*

Here is the Scatter Forager with updated feed points:

Location of testing.  I took this shot to show the garage wall that blocks the Toronto signals:

I used  the LCD in the living room to perform the tests.  The first image is of CTV analog, using the attic mounted Stealth Hawk:

I then replaced the feed to the Scatter Forager:

CKCO (RF13)


So in picture comparison to the Stealth Hawk, which is up higher, and pointing better in the direction of CTV Toronto, it would appear that the capabilities of the Scatter Forager are excellent in picking up weak and blocked signals.  I don't think I will have too many problems post transition.  I will follow up with more photos after the install in the attic.

*22/10/10*

So after testing this antenna to the Stealth Hawk and 2-Bay Bowtie, this is where it stands:

The STEALTH HAWK
The Stealth Hawk's excels in its small size compared to its competitors.  It is very compact and can easily be pointed in any direction without too much issue.  It's downfall is not really a fault of this antenna, but it doesn't seem to like the enclosed space of the attic.  I didn't really notice this with the first SH design, but really notice it with the new version.  As talked about on the digitalhome.ca site, this antenna I think really needs to be in the open, with very little obstacles around it.  Even though it did receive the primary channel aimed at (CFTO), it was very snowy as compared to the Scatter Forager or the Bowtie.  It did also failed at even picking up CKCO one night...and when it did pick it up, it was too snowy to watch.  To me, this may not bold well for the post transition period.  WICU and WNGS were no-shows, though it did top the SNR meter on the HTPC to around 10db one evening on WNGS.  To this end, I am not going to use this antenna in my setup.

The 2-BAY BOWTIE
I quickly assembled this antenna, and though I've only tested it for one afternoon, I did notice that this antenna was by far the best one at picking up CFTO analog.  It was a very clear picture.  Though CKCO didn't fare as well, it was still a better picture than the SH.  This bowtie, as the graphs indicate, would appear to be very directional.  So far this antenna to has failed to pickup on WNGS or WICU.  The big downfall to this antenna is the size of it.  It is not very easily movable in a confined space like the attic.  The element and phase wire is 10AWG, but even at that gauge, with the elements as long as they were, the antenna is very flimsy.  Unless something miraculous happens, I will most likely tear this antenna down and use the wiring for some other antenna fun in the future. 

The SCATTER FORAGER
So this antenna seems to offer the best reception of what I'm gearing up for, and is more easily movable to be able to point in the directions I want to best my reception.  It picked up CFTO very well when pointed in that direction.  CKCO took a bit of a hit, but I think if I can rotate it, it will be able to capture both CFTO and CKCO, and aimed better in picking up WNGS...which currently is a no go, though I was able to pick up some signal...it was no where near strong enough to lock.  WICU, like with the other antennas, is a no-show, and I may just have to forget about try to get that channel.  As I stated above, for its ablilties, this antenna was by far the easiest one to build out of all my builds.  This antenna may not top the 2-Bay in reception, and may not be as small and compact as the Stealth Hawk, but it is a little of everything, which is why I'm giving it two thumbs up.





Disclaimer:

I am not an electrical/electronics engineer, nor am I claiming to be a professional at designing electronic circuits, I am, though, an Electronics Technologist, and have a firm understanding of all the circuits that I have built.  If you choose to try some of the projects that I have done, I take no responsibility to your lose of personal health or property.  All projects are performed at your own risk.