Last edited:
Yagi antennas for under $5
- Thread starter kf4lne
- Start date
- Status
Sorry, this will be my first antenna I have ever built so I'm uncertain of how everything works- I'm new to all of it.
Also, in the instructions I downloaded it said that it should be oriented vertically for 800 mhz, is the antenna in post #64 oriented correctly?
And, am I understanding correctly that all of the elements except for the driven element can go all the way through as one piece, but the driven one needs to be cut in two? And then fed into the middle just far enough so the ends don't touch?
And, if I build this little antenna, will it be any good if I use it on my desk? I know it's not high or line of sight, but it should beat my rubber duck right?
Thanks in advance for any help, I'm really excited to build this.
Levi
Also, in the instructions I downloaded it said that it should be oriented vertically for 800 mhz, is the antenna in post #64 oriented correctly?
And, am I understanding correctly that all of the elements except for the driven element can go all the way through as one piece, but the driven one needs to be cut in two? And then fed into the middle just far enough so the ends don't touch?
And, if I build this little antenna, will it be any good if I use it on my desk? I know it's not high or line of sight, but it should beat my rubber duck right?
Thanks in advance for any help, I'm really excited to build this.
Levi
Quick question, why is the boom taken into consideration? I am going to be using PVC to construct my boom, I guess I don't understand what the diameter/width of the boom has to do with it.
Thanks,
Levi
Flatshovel
Member
I just built the 5 element 850mhz antenna with the dimensions found in the PDF file. However I cannot get the antenna to perform very well. I am trying to listen to a system that is about 40-50 miles away. Perhaps I don't have enough gain? It picks up the local town next to me about 20 miles out fine. I know the signal exists down here since I can somewhat pick it up on my Scantenna.
Here are the lengths that I used, I could have messed up in my calculations?
REF: L - 6.7 Inches
S - 0
Driven : L - 6.6 Inches
S - 6.3 Inches
DIR1: L - 6.2 Inches
S - 2.4 Inches
DIR2: L - 6.1 Inches
S - 2.5 Inches
DIR3: L - 5.9 Inches
S - 3.3 Inches
DIR4: L - 5.9 Inches
S - 3.1Inches
DIR5: L - 5.7 Inches
S - 3.4 Inches
Are these calculations correct? Any Ideas?
Here are the lengths that I used, I could have messed up in my calculations?
REF: L - 6.7 Inches
S - 0
Driven : L - 6.6 Inches
S - 6.3 Inches
DIR1: L - 6.2 Inches
S - 2.4 Inches
DIR2: L - 6.1 Inches
S - 2.5 Inches
DIR3: L - 5.9 Inches
S - 3.3 Inches
DIR4: L - 5.9 Inches
S - 3.1Inches
DIR5: L - 5.7 Inches
S - 3.4 Inches
Are these calculations correct? Any Ideas?
Attachments
N
N_Jay
Guest
how high is the scantenna and how high did you put the yagi?
Flatshovel
Member
The Scantenna is up about 25feet. I have not yet mounted the yagi on the pole, for testing purposes I walked around in my yard with the antenna held in my hand and tried to point it at the tower with no luck. I only have a short piece of coax on it at the moment for my testing. Do the calculations I have sound about right for the antenna? Do I have the elements to long or too short? Any suggestions or ideas on how to make it work better?
Thanks,
Joey
Thanks,
Joey
N
N_Jay
Guest
Trying to compare an 800 MHz antenna at near ground level to an antenna mounted at 25 feet is likely to give you misleading results.
Try comparing it to an antenna at the same height and see how it does.
If you followed the instructions, I would guess you have the lengths right.
Try comparing it to an antenna at the same height and see how it does.
If you followed the instructions, I would guess you have the lengths right.
guitarbrian30
Member
Where is the Drawings on the VHF police band 153 - 160?
I would like to attempt in building one of these!!
Nice job guys.
I would like to attempt in building one of these!!
Nice job guys.
kpoe_28
Member
Try here> 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) scroll down about halfway and click on the yellow yagi link, I used it to put together a 4 element for the 155mhz and my works great.
Mine doesn't work good at all
I used these lengths and spaces and mine doesn't work well at all. I have not soldered the coax shield/center yet... will this make a difference? I would like to know what the impedance of this antenna ends up being so I can maybe choose which coax to use.
Measurements (In Inches):
Reflector: 13.0
Driven Element: 12.5 inches (SEE NOTES!!!)
Director 1: 12.1 inches or about 12 1/8
Director 2: 11.75 In
Director 3: 11.75 In
Director 4: 10.75 In
Spacing
Driven Element: 2.5in
Director 1: 5.5in
Director 2: 11.0in
Director 3: 18.0in
Director 4: 28.5in
I used these lengths and spaces and mine doesn't work well at all. I have not soldered the coax shield/center yet... will this make a difference? I would like to know what the impedance of this antenna ends up being so I can maybe choose which coax to use.
k8tmk
Member
Just build the one of the 800 MHz yagis described in Pop Comm a couple of years ago (maybe June or July 2007 issue). It works great. There were three different designs described, and the largest had 10 elements and was only about 3 feet long. I got all of the parts at my local Ace Hardware.
Randy, K8TMK
Randy, K8TMK
k8tmk
Member
More on my previous response.
I finally found the Pop Comm article. It is the May 2007 issue. There are plans for 4-, 6-, and 10-element 800 MHz yagis.
More elements provides more gain, but also a narrower reception pattern.
I fed mine with 9913 coaxial cable I had and mounted it about 40 feet up on the side of a TV tower.
Randy, K8TMK
I finally found the Pop Comm article. It is the May 2007 issue. There are plans for 4-, 6-, and 10-element 800 MHz yagis.
More elements provides more gain, but also a narrower reception pattern.
I fed mine with 9913 coaxial cable I had and mounted it about 40 feet up on the side of a TV tower.
Randy, K8TMK
HiIf you want me to build them and pay me for parts and labor I can. The 800MHz antenna works great, I used my cordless phone to test it and it performed great. The UHF antenna can hit a 70cm amateur repeater 16 air miles away with good reports at 1/2 watts in mountainous terrain. If you are serious about $15+shipping then by all means lets do it
Just came across your antenna and was wondering if you are still building and selling them. I would be very interested in buying a couple of them.
I live in Oswego County, NY and get get limited reception on the P25 system. 453.000 thru 461.000 frequency.
Thanks in advance
Bob
br0adband
Member
Holy thread necrophilia, Batman!
Not to disappoint you, rwsvjm, but seeing as the last post before yours was 6 years ago in October of 2009, I'm not sure you're going to get any response at this time so, don't hold out any hopes - it also appears the last post made by the creator of this thread, kf4lne, was in February of 2007 and he/she hasn't been seen from since that post.
Based on reading the OP (the original or first post in this thread) I'd say it looks like a fairly simple project one - I mean, the whole idea for the creator of this thread was to create something cheap and functional and he/she apparently did just that and had good success with it.
That's part of the fun of this kind of hobby: experimentation can sometimes prove incredibly useful even with a handful of spare or very cheap parts. A lot of us hobbyists and even quite a few professionals regularly build our own antennas with great success using whatever we happen to have around us: electrical wire - and yes even coat hangers - cut as required for the elements of a Yagi, a piece of wood or PVC that can be used as the boom, etc and sometimes the results can be quite surprising and even perform just as a very expensive commercial antenna of the same or similar design would be but obviously for a lot less out of pocket cost, if any at all.
As that was your very first post, I'll finish by saying welcome to RadioReference aka RR and I hope you find this hobby of ours and this community a great experience.
Not to disappoint you, rwsvjm, but seeing as the last post before yours was 6 years ago in October of 2009, I'm not sure you're going to get any response at this time so, don't hold out any hopes - it also appears the last post made by the creator of this thread, kf4lne, was in February of 2007 and he/she hasn't been seen from since that post.
Based on reading the OP (the original or first post in this thread) I'd say it looks like a fairly simple project one - I mean, the whole idea for the creator of this thread was to create something cheap and functional and he/she apparently did just that and had good success with it.
That's part of the fun of this kind of hobby: experimentation can sometimes prove incredibly useful even with a handful of spare or very cheap parts. A lot of us hobbyists and even quite a few professionals regularly build our own antennas with great success using whatever we happen to have around us: electrical wire - and yes even coat hangers - cut as required for the elements of a Yagi, a piece of wood or PVC that can be used as the boom, etc and sometimes the results can be quite surprising and even perform just as a very expensive commercial antenna of the same or similar design would be but obviously for a lot less out of pocket cost, if any at all.
As that was your very first post, I'll finish by saying welcome to RadioReference aka RR and I hope you find this hobby of ours and this community a great experience.
See post 17 on page 1
http://forums.radioreference.com/sc...45999-yagi-antennas-under-5-a.html#post344796
He just wrapped the center conductor around the one side and the shielding around the other. When I did mine, I wrapped like mentioned but soldered it as well.
And check out the pdf
http://forums.radioreference.com/at...1-yagi-antennas-under-5-5-dollar-antennas.pdf
http://forums.radioreference.com/sc...45999-yagi-antennas-under-5-a.html#post344796
He just wrapped the center conductor around the one side and the shielding around the other. When I did mine, I wrapped like mentioned but soldered it as well.
And check out the pdf
http://forums.radioreference.com/at...1-yagi-antennas-under-5-5-dollar-antennas.pdf
- Status
Similar threads
