Antenna Database

VHF/UHF,   K1FO Yagi Designs


Directive Systems  K1FO style yagis all employ high strength 6063-T832 aluminum alloy booms of 1 3/8" and 1 1/4" and will survive in harsh winter environments.  Elements are made of 3/16" 6061-T6 CF rod and are electrically insulated from the boom as originally done by K2RIW. Black machined delrin spacers and stainless steel fasteners are used throughout for excellent UV protection and long service life. The brass driven element is T-match fed with a teflon semi rigid coax balun for high power operation. All T-match connections are soldered upon assembly for trouble free operation year after year.

The DS50-5 50 MHz antenna utilizes a 1 1/2" and 1 3/8" tapered boom for added strength. Elements are 3/4" diameter at the center and 1/2" on the ends for best ice loading performance. The feed is a balanced dipole with T-match, teflon coax balun, and N (UG-58) connector for high power and trouble free operation. All components are of the highest grade with machined parts rather than formed or molded parts.  Despite it's modest size, the DS50-5 is a thoroughbred antenna! It combines very good gain with an excellent pattern in E and H planes for crowded band conditions. Stacked patterns are excellent over wide spacing variables from 13 to 19 ft.

All antennas except the short boom ones,(some 6' models take 1 1/2" masts), are designed to accept a 2" maximum mast size. All U-bolts and hardware are stainless steel for long life. All of these yagis combine very high gain with the best patterns possible to date. Low sidelobes mean better signal to noise ratios and wider main lobes for easy aiming. These antennas are the culmination of thousands of hours of optimization on computers and in the real world, resulting in a rugged design with flawless performance!


VHF/UHF & K1FO Yagi Specifications

The highlighted links will connect you with more detailed information about each antenna including PDF files of the individual instruction sheets.

This portion of the website is under construction. New material is being added often.

 

Model #
Frequency MHz
Gain dBd
Length
Half PWR. Beamwidth: E, (H)
F/B ratio
Wind Area: SQ.FT.
Shipping Weight
DS50-4
50-54
8.3 
12' 0" 
50
20
1.3
12
DS50-5
50-51.5
9.1
17' 4" 
45 (60)
24
1.9
19
DS144-6RS
144-145.5
10.1
8'
44 (52)
21
.67
7
DPM144-5LVA
144-148
9.1
68"
52 (57)
20
0.50
5
DSFO144-12
144-148
12.6 
17' 4" 
34 (37)
23
1.5
9.5
DS144-5SC
144-148
9.0
6'0"
46 (61)
20
0.5
5
DSFO222-10RS
222-225
11.4
8'
39 (42)
20
0.69
7
DSFO222-16
222-225 
13.9
17' 3" 
31 (33)
23
1.4
9.5
DS224-8R
222-225
10.0
6' 0" 
42(49) 
20
0.6
5
DSFO432-15RS
428-436
13.5
8'
30 (32)
21
0.67
6
DSFO432-25
428-435 
16.5 
17' 3" 
22 (23)
24
1.4
8.5
DSFO432-11R
430-440 
12.0 
6" 0" 
38 (43)
20
0.7
5
DSFO446-11R
438-450 
12.0 
6' 0" 
38 (43)
20
0.7
5
DSFOATV-25
420-440
16.2-16.5
17'3"
22 (23)
24
1.4
8.5

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