Bill's- HomeBrewed Pan Cake - 40 Meter TAK-tenna or Tak Antenna

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http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=21075

Project Overview:

So I've been reading about this Small Space antenna (Small Space HF Antenna) that is being sold as the TAK-Tenna. Really neat idea - Has a 30 inch boom and Spiral Coils on the ends. See a picture at http://www.taktenna.com/

Looks easy to build - Right ?

So I Built my version out of wood - Mine is very ugly as compared to the store bought one (See Pictures).

Materials and Tools • Parts:

1.)    3 - Wooden sections - 1 1/2 in X 1/2 in X 8 ft - Cost 92 Cents each - Home Depot

2.)    1 - 100' Spool of Steel Guide/fence Wire - Cost - $7 - Home Depot - The purchased version uses some type of "Special" patented wire, but this seemed fine.     I tried Copper, but it was not stiff enough to make the Spiral Coils.    Again from quick test it did not seem critical - From what I read larger gauge wire is better for improved band width.

3.)    1 - 25 foot RG8 coax with PL259 - Radio Shack - Close Out - $5

4.)     2 - Packages - Nuts/Bolts - $2 - Home Depot

5.)      2 - Aligator Clips - Free from my junk Box.

6.)      Few Feet of Electrical Tape - Free from my junk Box.

Total Material Cost: $16.76

The commercial version uses PVC and tie wraps, which would have been much easier.

Tools:

a.) Saw - I just used a simple hand saw.

b.) Drill with wood bits - I just used a simple hand electric drill.

c.)  Flat Screw Driver and Rubber Malet.

d.)  Wire Cutters.

e.)  Gloves and Eye Protection.

Fab Time:

For my version was about 4 hours - Drilling Lots of Holes and feeding the wire in to make the Spiral Coils was most of the work.

Testing:

However - Test wise it isn't bad I got it tuned up on 40 meters at about 8 feet off the ground and it has an SWR 1:2 to 1:5 from 7.30 to 7.175 MHZ (Without a Transmatch). Also does ok on 15 meter - Tune up wise. Bad news the performance is not Great - Signal pick up is several S units below my Dipole, but it does work. From what I have read the Antenna has problems in that most of the performance is based on feedline radiation (See the links below).

http://groups.google.ie/group/rec.radio.amateur.antenna/browse_thread/thread/167fb7a34305cf3e

http://lists.contesting.com/_antennaware/2008-04/msg00021.html

Summary of Results:

I'm still testing and it was an interesting experiment. The Antenna fits into a small space 25 inch X 30 inch. Hey it works. If you have no space it might be worth $20 and a few hours of your time or If you aren't a Homebrewer Buy one. If you make your own one point - I needed more wire than the 468/7.2 MHZ = 65 Feet Total or 32.5 Feet per side - I had to add wire after the fact. So I would make it about 33.5 per side.

Measurements: 

One more added item - Someone had a question about my dimensions:

Boom = 30 inches meaning Cross Pieces are about 30 inches a part.

Cross Pieces = 25 Inches Across or 12.5 Inches from center

Hole Spacing from Center, but this did not seem critical, but I used:

12 in
11 in
10 in
9 in
8 in
7 in
6 in
5 in
4 in
3 in

Total Turns = 10

Tuning:

a.)   Put the antenna in the expected operating position (Mine was about 8 feet in the air).

b.)   Conect the Coax via the Aligator Clips about 2 inches from the end of the smallest inner Spiral Coils.

c.)    Measure SWR in the Center of the 40 Meter Band (SSB or CW) you intend to use most.    If the SWR is too high move to Step d.

d.)    Move the Aligator Clips/Coax out evenly about 2 inches on each Spiral Coil.

e.)     Repeat Step c. 

I was able to acheive acceptable SWR after about 3 cycles of adjustment without a Transmatch.   

73's

Bill - KA6KBC