DIY HD antenna questions - Page 3

EscapeVelocity · 10-26-2009, 11:02 AM

BTW, your link isnt working anymore.

highdefjeff · 10-26-2009, 12:55 PM

Just finished uploading after change in hosting.

Sorry. It's up now.

Refresh pages if needed.

Ooops! Somehow lost home page!

http://www.wowvision.tv/grabitears.htm

Grabbit Ears Link worked for me.

highdefjeff · 10-26-2009, 01:02 PM

My bad!

I mispelled wowvision on the signature.

Should be fixed!!!

IDRick · 10-26-2009, 05:11 PM

Hi Jeff,

I have some questions relative to the grabbitears antenna:

1) The distance between the phase lines (feed lines) is 1-3/4", correct?

2) The phase lines are 7 inches long and the whiskers + fractals are 14", correct?

3) It appears that you have varying connections between the phase line and fractals. On one side, the feed line is bolted to the inside of the phase line and the other side is bolted to the outside of the phase line. This orientation changes between the top fractal pair and bottom fractal pair, correct?

4) On a different forum, I saw where you stated that you made a loop at the middle connections and at the fractal connections. Are you still making the antenna the same way? Could you show a picture of your loops prior to attaching the phase line to the fractals/whiskers?

5) If your making loops in the phase line, what is the actual distance between fractal pairs in the vertical direction?

Thanks and God Bless!

Rick

highdefjeff · 10-26-2009, 06:13 PM

Quote:

Originally Posted by IDRick

Hi Jeff,

I have some questions relative to the grabbitears antenna:

1) The distance between the phase lines (feed lines) is 1-3/4", correct? (Yes)

2) The phase lines are 7 inches long and the whiskers + fractals are 14", correct? (Whiskers and fractals both start with a 14" piece. Length of the phase line is 7" end to end, after loops.)

3) It appears that you have varying connections between the phase line and fractals. On one side, the feed line is bolted to the inside of the phase line and the other side is bolted to the outside of the phase line. This orientation changes between the top fractal pair and bottom fractal pair, correct? (I don't think it matters which way they are bolted. You may have seen that arrangement, but I bolt them for looks and flatness. If I'm putting them on a stick, I do it one way, and if I am putting them on sticky paper, I think I do them another.)

4) On a different forum, I saw where you stated that you made a loop at the middle connections and at the fractal connections. Are you still making the antenna the same way? (Yes) Could you show a picture of your loops prior to attaching the phase line to the fractals/whiskers? (Yes)

5) If your making loops in the phase line, what is the actual distance between fractal pairs in the vertical direction? (End to end, fractal to fractal is 7".)

Thanks and God Bless!

Rick

Rick,

Gotta make another one anyway. I gave away my last one and the 4220 I'm using is cumbersome and doesn't work as well inside, anyway. I will photo document the phase lines with loops and I will include a ruler in the pictures. That should help.

Be back in a few...

highdefjeff · 10-26-2009, 08:19 PM

Here's some pics

IDRick · 10-26-2009, 08:45 PM

Thanks for taking the time to shoot these pictures Jeff! Really helps alot! Looks like you lose approximately 3/8 inch of length with each loop at the end and the center loop. I based this on a quick test at the work bench with some scrap 12 gauge wire. If my quick test is right, I need to start out with piece of wire that is 8-1/2 inches long to have a total of 7 inch spacing between the two fractals. Or am I misunderstanding and the actual distance between is something less than 7 inches when constructed?

Are the loops critical? I have a way to construct antennas using 3/4" pvc pipe and 3/4" pvc strap. There is natural gap of 1-3/4" between the mounting holes. If I use the strap, it's not necessary to make loops. My plan is to compare the grabbitears with my 2-bay and 4-bay mclapp. I can also test with and without a reflector (24 inches wide x 20 inches tall 1"x1" hardware cloth). I'll have to take a picture of my 2-bay so you can see my construction technique. I'll try to post it tomorrow evening.

All the best and God bless!

Rick

IDRick · 10-26-2009, 09:45 PM

Jeff,

I have attached pictures of my 2-bay mclapp DIY antenna. The whiskers are 10" long and the bay spacing is 9.5". I constructed the antenna using pvc electrical conduit (3/4" diameter) and carlon pvc straps from Home Depot. Would this technique work for mounting the grabbitears antenna? Should work well in my estimation...

Best,

Rick

highdefjeff · 10-27-2009, 11:39 AM

Quote:

Originally Posted by IDRick

Thanks for taking the time to shoot these pictures Jeff! Really helps alot! Looks like you lose approximately 3/8 inch of length with each loop at the end and the center loop. I based this on a quick test at the work bench with some scrap 12 gauge wire. If my quick test is right, I need to start out with piece of wire that is 8-1/2 inches long to have a total of 7 inch spacing between the two fractals. (Correct) Or am I misunderstanding and the actual distance between is something less than 7 inches when constructed? (7")

Are the loops critical? (I added the loops so that I would have a way to hold the pieces together. I have no idea whether they are critical or not. I tried soldering and welding with no success.) I have a way to construct antennas using 3/4" pvc pipe and 3/4" pvc strap. There is natural gap of 1-3/4" between the mounting holes. If I use the strap, it's not necessary to make loops. (I pray it works, especially if it makes construction more user friendly.) My plan is to compare the grabbitears with my 2-bay and 4-bay mclapp. (Cool!) I can also test with and without a reflector (24 inches wide x 20 inches tall 1"x1" hardware cloth). (I made one or two feeble attempts at adding a reflector - to no avail.) I'll have to take a picture of my 2-bay so you can see my construction technique. I'll try to post it tomorrow evening.

All the best and God bless!

Rick

Sounds awesome Rick!

I DON'T THINK that the loops are critical. Initially, they were much bigger since I used satellite dish nuts and bolts that I had on hand for the first couple.

I now use smaller ones from big box hardware stores.

One thing that I found out is that the type of washers in the third picture do the best job of "trapping" and securely holding the parts together. They are not flat and they squash around the wires. I chose the smaller size and cap nuts for aesthetic reasons. In my experience, the size of hardware wasn't a factor, and the cap nuts are strictly optional.

I've included a picture of my brother's apartment balcony with a comparison of what he's using and Grabbit Ears. In this very tough reception area, signal readings are the same with either antenna.

God bless you Rick!
I look forward to hearing your results!
Jeff

highdefjeff · 10-28-2009, 03:34 PM

Rick,

As the Lord would have it, I am just about to put a set of Grabbit Ears in the mail to Eagle, Idaho. (83616).

Their deployment should give us some additional usage data.

Here are a couple more photos.


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