1. Rochester VHF Group 09 February 2007
“Cheap” Yagis
Rochester VHF Group
09 February 2007

2. “Cheap” Yagis Presenters: Mark Adams, K2QO Bill Rogers, K2TER
11/23/2018
Rochester VHF Group

3. Introduction
“This year, I just scraped together enough ‘bottle and can’ money to buy my VHF radio equipment. Do I have to wait till next year for the antennas I need to put a decent signal on the air?”
11/23/2018
Rochester VHF Group

4. Introduction
“Having never homebrewed an antenna other than a HF dipole, I don’t think I have the skills or experience to replicate the NBS yagis in the ARRL Antenna handbook. Now what?”
11/23/2018
Rochester VHF Group

5. Introduction
“I’d like to try roving on the bottom 6 bands but I don’t want to spend an arm and a leg on another set of antennas that are 6 feet or less in length. What’s an avid VHFer to do?”
11/23/2018
Rochester VHF Group

6. Introduction The Answer… You need “Cheap” yagis.
Cheap yagis were originally conceived by Kent Britain, WA5VJB, in an effort to assist Cuban operators in getting on the VHF bands. Cheap yagi construction plans are readily available for all bands from 144 MHz to 1296 MHz. These designs are scalable for use at other frequencies, as well.
11/23/2018
Rochester VHF Group

7. Why “Cheap” Yagis?
Simplicity – Mechanical construction and Feed point impedance matching.
Availability – Common materials can be obtained with one stop to a hardware store. No special tools needed. Plans are in public domain.
Repeatability – It’s hard to mess these up.
Time efficiency – You could build a set of these antennas in a Saturday afternoon.
Affordability – Less than $10/antenna at retail rates.
11/23/2018
Rochester VHF Group

8. The “Cheap” Yagi Driven Element
No balun req’d
11/23/2018
Rochester VHF Group

9. Cheap Yagi Stack
11/23/2018
Rochester VHF Group

10. 144 MHz Yagi dimensions 11/23/2018 Rochester VHF Group
144 MHz Driven El. = 38.5" and H = 1.0" - All 1/8" dia. elements
Reflector
Driven
Director 1
Director 2
Director 3
Director 4
3 Element 
Length 41 37
3 Element
Spacing
8.5 20
4 Element 42
37.5 33
19.25
40.5
6 Element
36.5
32.75
7.5
16.5 34 52 70
11/23/2018
Rochester VHF Group

11. 222 MHz Yagi dimensions 11/23/2018 Rochester VHF Group
222 MHz Driven El. = 24.5" and H = 1" - All 3/16" dia. Elements
Reflector
Driven
Director 1
Director 2
Director 3
Director 4
3 Element 
Length 26
23.75
3 Element
Spacing
5.5
13.5
4 Element
26.25
24.1 22 5
11.75
23.5
6 Element 21
10.75
33.75
45.5
144 MHz Driven El. = 38.5" and H = 1.0" - All 1/8" dia. elements
Reflector
Driven
Director 1
Director 2
Director 3
Director 4
3 Element 
Length 41 37
3 Element
Spacing
8.5 20
4 Element 42
37.5 33
19.25
40.5
6 Element
36.5
32.75
7.5
16.5 34 52 70
11/23/2018
Rochester VHF Group

12. 432 MHz Yagi dimensions 11/23/2018 Rochester VHF Group
432 MHz Driven El. = 13.0" and H = 3/8" - all 1/8" dia. Elements
Reflector
Driven
Dir 1
Dir 2
Dir 3
Dir 4
Dir 5
Dir 6
Dir 7
Dir 8
Dir 9
6 Element 
Length
13.5
12.5 12 11
6 Element
Spacing
2.5
5.5
11.25
17.5 24
8 Element
 12.00
30.75 38
11 Element
11.75
45.5 53
59.5
11/23/2018
Rochester VHF Group

13. 903 MHz Yagi dimensions 11/23/2018 Rochester VHF Group 902/903 MHz
Reflector
Driven
Director 1
Director 2
Director 3
Director 4
Director 5
Director 6
Director 7
Director 8
Length
6.2
   *
5.6
5.5
5.4
5.3
5.2
5.1
Spacing
2.4
3.9
5.8 9
12.4
17.4
22.4
27.6 33
11/23/2018
Rochester VHF Group

14. 1296 MHz Yagi dimensions Measured gain: 12.5 dBd
The driven element is small enough to allow semi-rigid coax to be used instead of RG-58. Silicon Bronze welding rod was used for the elements but any material can be used. Driven element dimensions are L = 4.0" and H = 1/2" Elements are 1/8" diameter.
Measured gain: 12.5 dBd 
1296 MHz
Reflector
Driven
Dir 1
Dir 2
Dir 3
Dir 4
Dir 5
Dir 6
Dir 7
Dir 8
10 Element
Length
4.3
3.9
3.8
3.75
3.65
3.6
3.5
Spacing
1.7
2.8 4
6.4
8.7
12.2
15.6
19.3 23
11/23/2018
Rochester VHF Group

15. K2QO/R Antenna Setup
11/23/2018
Rochester VHF Group

16. K2QO Rover We use Cheap Yagis on 2, 222, 432 and 903!
1296 is a Quagi from the Handbook. This is an easy to make antenna too.
Performance of 6-el 2M Yagi same as driven section of my FO-12.
11/23/2018
Rochester VHF Group

17. Construction Notes:
Start with the exact dimensions as published by Kent
Use a file to remove any sharp edges
Consider plastic caps for element tips
11/23/2018
Rochester VHF Group

18. More Tips
Consider surplus patch cables. Cut off one end and attach to feed.
Best if connection at antenna is a female.
Use $2.99/Gal Redwood stain.
Radio Shack mast clamps are FB.
Wind loads are virtually nil.
11/23/2018
Rochester VHF Group

19. Closing
11/23/2018
Rochester VHF Group