Bow Tie TV Antenna Designs (mclapp's M4 featured)

[j3d]

Originally Posted by stampeder

• CM4221 is the original Channel Master 4-bay bowtie reflector (data from HDTVPrimer site)
• CM4221HD is the new Channel Master 4-bay bowtie reflector (data provided by CM to videobruce - a DHC member. Assumed to have been in dBd)
• PR-4400 is a 4-bay bowtie reflector made by Winegard (data from HDTVPrimer site)
• DB-4 is a 4-bay bowtie reflector made by Antennas Direct (data from HDTVPrimer site)
• SBGH is a Single Bay Gray Hoverman Gold Standard (GH10 data from j3d - a DHC member)
• * antenna not designed for 52 and higher
• M-4 is a DIY 4 Bay 40x44 14 inch Reflector spacing fwd ele & refl (data from mclapp - a DHC member)
• ^ is the listed gain on the next highest channel since tables did not match all channels

Hi Stampeder,

I think that it would be nice to have links in the table for these
antennas or their computer models. For example I have been unable to
find the M-4.

Thanks,
--John

[stampeder]

Originally Posted by j3d

I have been unable to find the M-4.

That's a good point, j3d - mclapp and I were discussing how several of his 4-bay bowtie reflector variants fared very well in comparisons so I downloaded a spreadsheet of his and took the net gain numbers from it.

I used the terms M-4 and M-8 because he had not given them names, so I just used mclapp 4 and mclapp 8.

Today I'll put his spreadsheet up for you folks to check out. Hopefully mclapp will drop in today too.

[stampeder]

Here's a comparison chart of some of mclapp's designs:

[stampeder]

Originally Posted by mclapp

Here is an excel chart with some numbers for some computer modeled DIY collinear antennas, there is a early design GH in the chart which has been improved upon a few db since I made this chart

http://www.frontiernet.net/~mclapp/A...re11-23-08.xls

[zjts]

What does the "x" mean in the spreadsheet such as in the last column of the 4 Bay 40x44 14 inch space flat Reflector fwd swept ele.?

[mclapp]

The x means nothing it was just a marker to remind me that I had filled in that table with the latest data after I made a tweek to the computer model.

[mclapp]

Originally Posted by j3d

Hi Stampeder,

I think that it would be nice to have links in the table for these
antennas or their computer models. For example I have been unable to
find the M-4.

Thanks,
--John

Are you looking for the model or the data? A bunch of models can be found here http://www.frontiernet.net/~mclapp/A...uter%20Models/ most are in .ez format, the spreadsheet stampeder posted already.

The one Stampeder is calling M-4 is a 4 bay with a 14" reflector spacing, that one has the highest peak but a narrower band width, the 4 - 5" reflector spacings are more consistant across the UHF band but with 1 db or so less peak.

I've got a 8 bay vertical stack that's up to 19dbi net but have yet to test it other than computer modeling. A version of it is in the computer models folder in the link above, look for 8 bay vert stack.

[Frost55]

Mclapp,any chance of putting your 8 bay vert stack" 19dbi " on the graph above
??

[mclapp]

If you have a way to read excel spread sheets I have one on my web space called "4 bay compare 11-23-08" It has the computer simulated gain info on that antenna and many others I've modeled.
http://www.frontiernet.net/~mclapp/Antennas/plots/
Sorry, I see stampeder already posted a link to that spreadsheet. If you can't do excel I could post a gain curve of that antenna.

I'll give a quick run down here. The UHF gain peaks at about 19.1dbi net around channel 41, the gain at channel 14 is 16.5dbi net and at ch 50 it's 17.5dbi net. I've found from my field testing on the antennas I've built that the gain curve is shifted downward on UHF a few channels compared to the computer models .

For VHF-HI the peak gain is 10.8dbi net on channel 8 and drops to 9.5dbi. net on channel 7 and 5.3 dbi net on channel 13.

[mlord]

If there exist some detailed measurements for construction, I might be able to insert this antenna into a test lab equipped with a Spectrum Analyzer and Tracking Generator.. the output of which would be a plot of *actual* frequency response across the UHF band..

Need the measurements in easy-to-digest form, though.

Cheers

[Frost55]

Well I started building one of these but I already had my whiskers made up so it won't be exact. 9.5"whiskers with 9.25 spacing.I give update when done.

[peekaboo]

Originally Posted by mclapp

Are you looking for the model or the data? A bunch of models can be found here http://www.frontiernet.net/~mclapp/A...uter%20Models/ most are in .ez format, the spreadsheet stampeder posted already.

The one Stampeder is calling M-4 is a 4 bay with a 14" reflector spacing, that one has the highest peak but a narrower band width, the 4 - 5" reflector spacings are more consistant across the UHF band but with 1 db or so less peak.

I've got a 8 bay vertical stack that's up to 19dbi net but have yet to test it other than computer modeling. A version of it is in the computer models folder in the link above, look for 8 bay vert stack.

Are there any plans available in an image format or PDF?
TIA

[300ohm]

Are there any plans available in an image format or PDF?

Just click on the Parent Directory in the above link and look in the 4 Bay Stuff directory.

[peekaboo]

Originally Posted by 300ohm

Just click on the Parent Directory in the above link and look in the 4 Bay Stuff directory.

Hmm I can't find the "4-bay stuuf directory" you mention when I click on eitheer the parent OTA or Antenna research directories up top.

[300ohm]

Its here : http://www.frontiernet.net/~mclapp/Antennas/