2 meter yagi
 

"Ian White GM3SEK" wrote in message
...
Ralph Mowery wrote:

"Scott" wrote in message
...
Depends what you want. Are you going to use a small Yagi for FM work or
a
long boom Yagi for SSB/CW? If you want something fairly simple, a
homemade 6 or 8 element Yagi is fairly simple. Otherwise, for some
serious weak signal work, the K1FO designs are quite commonly used.
Directive Systems sell them...
http://www.directivesystems.com/antenna4.htm

Hope that helps!

Scott
N0EDV

Now you tell me. I just ordered 2 beams from M-Square, one for 432 and
one
for 144. Wish I had the K1FO antennas as I had one for 432 and it worked
very well. I did not know anyone had picked up the K1FO design after he
became a SK.

Important correction: Steve Powlishen, K1FO, is NOT an SK! (W9GB had it
correct: the person who died was the co-developer W1EJ.)

W9GB is also correct that they are excellent yagis, and have been
published in several editions of the ARRL Handbook. The most extensive
write-up is in the ARRL Microwave Experimenter's Handbook Volume 1.


Big mistake on my part. I was thinking of Rutland Arrays. The owner of
that company (small one man shop mostly) is the one that is a SK. He sold
the K1FO type antennas. He used to show up at the Shelby, NC hamfest and
that is where I bought the 432 antenna about 10 years ago . I really liked
the way it was made and it seemed to work very well. I have a handbook or
two that have the K1FO designs in them. Just don't have time or equipment
to put one together.

I may be wrong, but was thinking the M2 antennas were based on the K1FO
designs also. That was my reason for going with them.

2 meter yagi
 

"Ralph Mowery" wrote in message
link.net...

"Ian White GM3SEK" wrote in message
...
Ralph Mowery wrote:

"Scott" wrote in message
t...
Depends what you want. Are you going to use a small Yagi for FM work
or
a
long boom Yagi for SSB/CW? If you want something fairly simple, a
homemade 6 or 8 element Yagi is fairly simple. Otherwise, for some
serious weak signal work, the K1FO designs are quite commonly used.
Directive Systems sell them...
http://www.directivesystems.com/antenna4.htm

Hope that helps!

Scott
N0EDV

Now you tell me. I just ordered 2 beams from M-Square, one for 432 and
one
for 144. Wish I had the K1FO antennas as I had one for 432 and it
worked
very well. I did not know anyone had picked up the K1FO design after he
became a SK.

Important correction: Steve Powlishen, K1FO, is NOT an SK! (W9GB had it
correct: the person who died was the co-developer W1EJ.)

W9GB is also correct that they are excellent yagis, and have been
published in several editions of the ARRL Handbook. The most extensive
write-up is in the ARRL Microwave Experimenter's Handbook Volume 1.


Big mistake on my part. I was thinking of Rutland Arrays. The owner of
that company (small one man shop mostly) is the one that is a SK. He sold
the K1FO type antennas. He used to show up at the Shelby, NC hamfest and
that is where I bought the 432 antenna about 10 years ago . I really
liked the way it was made and it seemed to work very well. I have a
handbook or two that have the K1FO designs in them. Just don't have time
or equipment to put one together.

I may be wrong, but was thinking the M2 antennas were based on the K1FO
designs also. That was my reason for going with them.

Can't remember the name, but The "M" in KLM (antennas) is the same guy as
one of the "M"s in M2.

Tam/WB2TT

2 meter yagi
 

Scott wrote:

If you don't mind having a little less gain than is ultimately possible
by using an antenna modeling program, the NBS (Nation Bureau of
Standards) designs are pretty straight-forward. For a 6 element Yagi,
here is element lengths and spacings for building with insulated
elements (insulated from the boom, so I would use wood, 1" X 2" X 8.5')

Lengths:
Reflector = 3' 4"
Driven = 3' 2-3/16"
Dir 1 = 3' 7/8"
Dir 2 = 3' 7/16"
Dir 3 = 3' 7/16"
Dir 4 = 3' 7/8"

Spacing:
Ref to Driven = (187.2/Fc) X 12
Spacing between all other elements = (234/Fc) X 12
where Fc is the design center frequency in MHz, ie 146 for the center of
the FM portion). The spacing calculations give the answer in inches.

Then you need to feed it. I use delta matches. Are you good at
qrz.com? If so I can send you a drawing of the feed to get you started
(but you would need an SWR meter that works at 2M to get it adjusted).

Scott
N0EDV

NBS yagis were quite horrible actually. Not good gain, horrid
bandwidth, high sensitivity to build errors , crummy patterns compared
to anything since the early 90's. Don't bother.

tom
K0TAR

2 meter yagi
 

Scott wrote:

If you don't mind having a little less gain than is ultimately possible
by using an antenna modeling program, the NBS (Nation Bureau of
Standards) designs are pretty straight-forward. For a 6 element Yagi,
here is element lengths and spacings for building with insulated
elements (insulated from the boom, so I would use wood, 1" X 2" X 8.5')

Lengths:
Reflector = 3' 4"
Driven = 3' 2-3/16"
Dir 1 = 3' 7/8"
Dir 2 = 3' 7/16"
Dir 3 = 3' 7/16"
Dir 4 = 3' 7/8"

Spacing:
Ref to Driven = (187.2/Fc) X 12
Spacing between all other elements = (234/Fc) X 12
where Fc is the design center frequency in MHz, ie 146 for the center of
the FM portion). The spacing calculations give the answer in inches.

Then you need to feed it. I use delta matches. Are you good at
qrz.com? If so I can send you a drawing of the feed to get you started
(but you would need an SWR meter that works at 2M to get it adjusted).

Scott
N0EDV


Sorry, I didn't give an alternatives in my previous email. Please see
the K1FO series in the ARRL antenna books. They are among absolutely
the best possible, very replicable,, low build sensitivity, and fairly
short to very long boom plans are available.

If you do not have one of the ARRL Antenna books available, I, or others
here, have copies as needed.

tom
K0TAR

2 meter yagi
 

I won't debate the differences in patterns, as I have no data on the
patterns for the NBS designs. In the ones I've built, gains measured
were pretty close to what they claimed and the claimed gains of the K1FO
style antennas from Directive Systems
http://www.directivesystems.com/antenna4.htm (for the same number of
elements) is usually within a quarter to a half of a dB of the claimed
gains of the NBS designs. I didn't notice a high sensitivity to build
errors. I used the design lengths and diameters of the elements on a
wood boom. On my 222 version, I used the T match (same thing as the
K1FO designs) and all I had to do was shorten the driven element to get
zero reflected power (which was expected since you need to make the
driven capacitive to tune out the inductance of the matching rods). Not
sure what you mean by horrid bandwidth...are the NBS designs too narrow
or too wide? Again, I've never noticed that as being a problem because
I only use my (222 for example) antenna from about 222.100 to 222.150.

Scott
N0EDV

Tom Ring wrote:
Scott wrote:

If you don't mind having a little less gain than is ultimately
possible by using an antenna modeling program, the NBS (Nation Bureau
of Standards) designs are pretty straight-forward.


NBS yagis were quite horrible actually. Not good gain, horrid
bandwidth, high sensitivity to build errors , crummy patterns compared
to anything since the early 90's. Don't bother.

tom
K0TAR

2 meter yagi
 

Thanks for all the information everyone...
The only ARRL antenna book I have is the one on wire antennas, If you could
suggest one that covers yagi antennas in detail, I am sure they still sell
it. I think that I could build one a lot cheaper than buying one and learn
something at the same time.

I would like the best gain possible (who wouldn't) However, I need
something that has the smallest lobe(s) off the sides and back. (I know the
two more or less coincide with each to a large degree.

To give you an idea of what I am trying to do...I have some land in
Richlands NC. I am a member of several ham clubs in the Charleston,SC area
that has repeaters fairly close to the SC,NC state lines. I would like to be
able to make it into one of those repeaters from Richlands, NC. (that may
only work when the bands open up every now and again)
I do not want to key up every repeater on the same freq. to the sides or
the back of the antenna.
So I bow down to the elmers and those who can point me in the right
direction. BTW. the antenna will be at least 60' high but possibley up to
110' high depending on tower funds when I move.

Im good at QRZ and ARRL
Thanks again
Joe KI4ILB
Solar powered ham radio


"Tom Ring" wrote in message
.. .
Scott wrote:

If you don't mind having a little less gain than is ultimately possible
by using an antenna modeling program, the NBS (Nation Bureau of
Standards) designs are pretty straight-forward. For a 6 element Yagi,
here is element lengths and spacings for building with insulated
elements (insulated from the boom, so I would use wood, 1" X 2" X 8.5')

Lengths:
Reflector = 3' 4"
Driven = 3' 2-3/16"
Dir 1 = 3' 7/8"
Dir 2 = 3' 7/16"
Dir 3 = 3' 7/16"
Dir 4 = 3' 7/8"

Spacing:
Ref to Driven = (187.2/Fc) X 12
Spacing between all other elements = (234/Fc) X 12
where Fc is the design center frequency in MHz, ie 146 for the center of
the FM portion). The spacing calculations give the answer in inches.

Then you need to feed it. I use delta matches. Are you good at
qrz.com? If so I can send you a drawing of the feed to get you started
(but you would need an SWR meter that works at 2M to get it adjusted).

Scott
N0EDV


Sorry, I didn't give an alternatives in my previous email. Please see
the K1FO series in the ARRL antenna books. They are among absolutely
the best possible, very replicable,, low build sensitivity, and fairly
short to very long boom plans are available.

If you do not have one of the ARRL Antenna books available, I, or others
here, have copies as needed.

tom
K0TAR

2 meter yagi
 

"Merlin-7 KI4ILB" wrote in message
...
Thanks for all the information everyone...
The only ARRL antenna book I have is the one on wire antennas, If you
could
suggest one that covers yagi antennas in detail, I am sure they still sell
it. I think that I could build one a lot cheaper than buying one and learn
something at the same time.

I would like the best gain possible (who wouldn't) However, I need
something that has the smallest lobe(s) off the sides and back. (I know
the
two more or less coincide with each to a large degree.

To give you an idea of what I am trying to do...I have some land in
Richlands NC. I am a member of several ham clubs in the Charleston,SC area
that has repeaters fairly close to the SC,NC state lines. I would like to
be
able to make it into one of those repeaters from Richlands, NC. (that may
only work when the bands open up every now and again)
I do not want to key up every repeater on the same freq. to the sides or
the back of the antenna.
So I bow down to the elmers and those who can point me in the right
direction. BTW. the antenna will be at least 60' high but possibley up to
110' high depending on tower funds when I move.

Im good at QRZ and ARRL
Thanks again
Joe KI4ILB
Solar powered ham radio


For high gain and vertical polarization, you might want to consider two
antennas stacked horizontally. This will get the antennas away from the
metal of the mast and tower. Somewhere betwee 6 and 8 feet should work.

Tam/WB2TT