Railroad Band Yagi Beam

[1998]

I fould the plans for a handheld yagi beam made from tape measure for 3 elements on a pvc beam. I wanted it tuned for the railroad band. I punched in 161 MHz on a yagi calculator and it said the element spacing should be 1 ft. 2 in. Does this mean the elements are spaced equally? On another website it said the reflector to the driven element are spaced 10 in. and the driven element to the director are spaced 14 in. Is there any way to determine which way is correct? I am fairly new to the world of antennas and any help would be greatly appreciated. Thanks in advance

 

[dgoodnough]

Try this guys website. Many different antenna design programs you can download, including yagis. I have made 2 beams from his program, 1 for the RR at 161mhz and another for 461 with the local PD's. The 161 I made a 3 element, and the 461 a 5 element. Both out of PVC and threaded rod. Both work very nice, and I haven't had the chance to mount up on the house due to the lovely winter weather here. If you would like I can PM the program to you.

Antenna, VE3SQB Ham radio antenna design software programs and sstv,qha, amateur radio,sstv,antennas,j-pole,quad,dipole,discone,antenna program, super scanner, pdl, omni, rhcp, bazooka, coaxial dipole,skyhopper)

 

[1998]

Thanks for the program. The element spacing is the right column, correct?

 

[WQFM513]

a great one i use, Martin E. Meserve - K7MEM - VHF/UHF Yagi Antenna Quick Designer i have made several out of aluminum, brass, and stainless rod. seem to work well. even the one i made out of a metal clothes hanger for 2.4ghz worked.

 

[majoco]

You can design a Yagi to do one thing well but at the expense of others! You may adjust the reflector/director spacing for best forward gain, but find that the sidelobe performance or front/back ratio is poor. The reflector spacing will change the feedpoint impedance too.

Go for a design that has best front/back ratio and low sidelobes. You may have to put up with slightly less gain (and therefore a broader front beam) but that will give you the best compromise. For 160Mhz an old Band 2 TV antenna should work ok if you have them available in the US.

 

[dgoodnough]

Correct, the right side is the spacing, left is length of the elements. Don't know if you noticed, there is a calculator for decimal to feet in inches to make things a bit easier.

Hope you have fun and good luck. Nice project to do.

I just mounted the 461 mhz outside today. Works wonders pulling in Rochester PD and Monroe county sheriff at about 30 miles from me. All law dispatches went p25 last year, this antenna pulls the signal in so much better. RPD was choppy / in and out at best but now comes in with 3 to 5 bars on 996xt scanner.

 

[1998]

Thanks for all the help. I just finished the antenna tonight and so far it works great. Im picking up stuff i would of never got before with the rubber duck and whip. Thanks again

 

[dgoodnough]

Glad it is working out for you. Just curious, how many elements did you include on your beam?

Happy scanning!!