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Homemade Antennas!!


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Greetings!!!

 

Anyone make their own antennas for the field or for home?  I cut an old homemade dipole down to 470mhz and am using it as a scanner/gmrs antenna in my shop (stapled to the outside of my shop) right now but am gathering materials to make a copper pipe/pvc vertical dipole that I can raise over my roof.

 

WRMQ982

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Greetings!!!
 
Anyone make their own antennas for the field or for home?  I cut an old homemade dipole down to 470mhz and am using it as a scanner/gmrs antenna in my shop (stapled to the outside of my shop) right now but am gathering materials to make a copper pipe/pvc vertical dipole that I can raise over my roof.
 
WRMQ982

Yes, for the education and fun of it. I have made a few different 1/4 wave ground planes that I can use in a pinch on different services. But I am using commercially made antennas on the home and vehicle.


Michael
WRHS965
KE8PLM
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Forgive me but I'm so lazy and old.  I was at HamFest in NC and for $35 could get a great antenna without looking for all the parts...  I do like the guy who makes his own and gets into it... I'm just an 74 yo and do not have the time...  That is why I can respect Lscott doing it himself.

MacJack

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3 hours ago, kb2ztx said:

Sorry this isn't ham radio. Many manufacturers sell commercial gear for GMRS. Its in the business LMR spectrum and parts can be very reasonably purchased. I respect those who like to build stuff but to me its no for this service.

So, in your opinion those who can should not build functional antennae for GMRS? 

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3 hours ago, kb2ztx said:

Sorry this isn't ham radio. Many manufacturers sell commercial gear for GMRS. Its in the business LMR spectrum and parts can be very reasonably purchased. I respect those who like to build stuff but to me its no for this service.

For some people it isn’t about the cost. It’s the satisfaction of building something yourself and the knowledge gained doing it. 
 

I’ve picked up cheap magnet mounts at swaps along with some generic whip elements that screw in to them. I wanted a cheap and quick 1/4 wave antenna for the Ham 1.25M band. Didn’t take much to trim one down using the antenna analyzer. 
 

Also doing some simulations it looks like a 1/4 wave could be made to cover the Ham 2M band and the MURS channels.

The same with the Ham 70cm band and GMRS. The later I built using a cheap BNC circuit board socket and stiff bus wire. I can cover the frequency range of 430 MHz to 470 MHz with under a 2:1 SWR with a nearly 1:1 match at 450 MHz. I have one I use at the office on the top of a bookcase. Another one I used tie-wraped on the top of an old baseball type hat at the Dayton Hamvention a few years ago. Worked much better than the rubber duck antenna with the radio hanging on the waist.
 

Sure I could have purchased them, but where’s the fun in that? 

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17 hours ago, MacJack said:

Forgive me but I'm so lazy and old.  I was at HamFest in NC and for $35 could get a great antenna without looking for all the parts...  I do like the guy who makes his own and gets into it... I'm just an 74 yo and do not have the time...  That is why I can respect Lscott doing it himself.

MacJack

I can commiserate with you Jack. I have twiddled with antennas off and on through the years. But when you need an antenna, and you need it now, it's way too easy to pick one up at a hamfest or off ebay!

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On 7/24/2021 at 2:51 PM, mbrun said:


Yes, for the education and fun of it. I have made a few different 1/4 wave ground planes that I can use in a pinch on different services. But I am using commercially made antennas on the home and vehicle.


Michael
WRHS965
KE8PLM

Very nice!  I think it is more fun than talking on the radios!  If I could find a job in an antenna factory I would be in Heaven!

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On 7/24/2021 at 6:15 PM, Lscott said:

If you like to experiment and design antennas some good simulation software helps.

I’ve used various versions of EZNEC+  up to V6 for a number of years. The software will be free starting in 2022. The guy who wrote it explains why, he’s turning 76 and wants to retire and doesn’t want to deal with it anymore.

https://www.eznec.com/

Wow!  That software looks way over my head!  I am studying for my Ham license, but am not that far along LOL.  I will look into it though, I think it is good to understand radiation patterns and all of that good stuff. 

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On 7/25/2021 at 7:51 AM, Lscott said:

For some people it isn’t about the cost. It’s the satisfaction of building something yourself and the knowledge gained doing it. 
 

I’ve picked up cheap magnet mounts at swaps along with some generic whip elements that screw in to them. I wanted a cheap and quick 1/4 wave antenna for the Ham 1.25M band. Didn’t take much to trim one down using the antenna analyzer. 
 

Also doing some simulations it looks like a 1/4 wave could be made to cover the Ham 2M band and the MURS channels.

The same with the Ham 70cm band and GMRS. The later I built using a cheap BNC circuit board socket and stiff bus wire. I can cover the frequency range of 430 MHz to 470 MHz with under a 2:1 SWR with a nearly 1:1 match at 450 MHz. I have one I use at the office on the top of a bookcase. Another one I used tie-wraped on the top of an old baseball type hat at the Dayton Hamvention a few years ago. Worked much better than the rubber duck antenna with the radio hanging on the waist.
 

Sure I could have purchased them, but where’s the fun in that? 

Exactly!!!!  That is where I am at!  I have no one to talk to and am studying to get my Ham license so why not play with antennas!  I love creating things and experimenting with design (also design and print 3D objects).  I have a magnet mount antenna for my car and a fender mount as well, but nothing for my home yet, that is why I am playing with building them.  My girlfriend probably would not let me hang a big antenna on the house so I have to be discreet. 

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On 7/25/2021 at 4:31 AM, kb2ztx said:

parts can be very reasonably purchased.

It doesn't get much more reasonably priced than a panel mount SO239 and some old copper wire.

diy_so239_quarterwave.jpg.a0297fd273037a65827f2d86bf38aaa2.jpg

20 hours ago, maddogrecurve said:

Exactly!!!!  That is where I am at!  I have no one to talk to and am studying to get my Ham license so why not play with antennas!  I love creating things and experimenting with design (also design and print 3D objects).  I have a magnet mount antenna for my car and a fender mount as well, but nothing for my home yet, that is why I am playing with building them.  My girlfriend probably would not let me hang a big antenna on the house so I have to be discreet. 

Not withstanding the "this isn't ham radio" aspect in a couple of ham radio classes I've taught we built these 5/8λ mobile antennas in a morning as a group.  The attendees got a kick out it and most of them ended up being put into actual service on trucks, this being members of my 4WD club, with good results.  They aren't quite Larsen or Laird commercial but they're not bad and there's pride in being able to say "I built that" kicking tires around a campfire.

http://www.arrl.org/files/file/Technology/tis/info/pdf/8009022.pdf

Although for a home installation a J-pole makes more sense IMO.  If you can find - and afford - enough copper pipe anyway.

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11 minutes ago, WRNA236 said:

It doesn't get much more reasonably priced than a panel mount SO239 and some old copper wire.

diy_so239_quarterwave.jpg.a0297fd273037a65827f2d86bf38aaa2.jpg

Not withstanding the "this isn't ham radio" aspect in a couple of ham radio classes I've taught we built these 5/8λ mobile antennas in a morning as a group.  The attendees got a kick out it and most of them ended up being put into actual service on trucks, this being members of my 4WD club, with good results.

This goes to show that usable antennas do not need to be complicated. I see an antenna like this one being quite useful when attached to a handheld transceiver. You could even place it on a very simple mast by using 3/4" PVC, running the coax through it, and placing the antenna on top (with the connector sitting just inside the top of the conduit).

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8 hours ago, WyoJoe said:

This goes to show that usable antennas do not need to be complicated. I see an antenna like this one being quite useful when attached to a handheld transceiver. You could even place it on a very simple mast by using 3/4" PVC, running the coax through it, and placing the antenna on top (with the connector sitting just inside the top of the conduit).

I think every ham should at least try building a 1/4λ ground plane like this and cut some dipoles.  GMRS users are obviously not in the hobby to experiment but I think being able to use stand alone antennas there seems value in understanding how they work and see first hand what impacts performance and issues.

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8 hours ago, WyoJoe said:

This goes to show that usable antennas do not need to be complicated. I see an antenna like this one being quite useful when attached to a handheld transceiver. You could even place it on a very simple mast by using 3/4" PVC, running the coax through it, and placing the antenna on top (with the connector sitting just inside the top of the conduit).

I built almost exactly the same thing using some old PCB type BNC connectors. All the wires were soldered on, no screws. Surprising how well a 1/4 works, and the bandwidth I got was from 430 MHz to 470 MHz at the 2:1 SWR points.

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LScott, 

 

That is cool that you did this type of antenna with BNC connectors!  I would have never thought of using anything other than SO-239.  

I am not an Amateur operator, I have always been interested in it, and have been into C.B off and on for 34 years and antennas have always fascinated me.  I am finally getting serious about getting my Tech license and after that may progress through the ranks, we shall see.  

I have been listening to a couple of "nets", one at night and one in the morning and I love how disciplined they are ran and how polite everyone is!  So much better than C.B.  

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6 hours ago, maddogrecurve said:

LScott, 

 

That is cool that you did this type of antenna with BNC connectors!  I would have never thought of using anything other than SO-239.  

I am not an Amateur operator, I have always been interested in it, and have been into C.B off and on for 34 years and antennas have always fascinated me.  I am finally getting serious about getting my Tech license and after that may progress through the ranks, we shall see.  

I have been listening to a couple of "nets", one at night and one in the morning and I love how disciplined they are ran and how polite everyone is!  So much better than C.B.  

I used a BNC connector since I can find adapters to just about any other connector type. Plus BNC’s are constant impedance types. You can easily find BNC to SMA that screws into the antenna port on handheld radios. I also find heaps of short jumper cables at swaps with BNC connectors on the end. 

You want your Tech Class license the test is very easy with just a little bit of study. 

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On 7/28/2021 at 8:04 PM, WRNA236 said:

It doesn't get much more reasonably priced than a panel mount SO239 and some old copper wire.

diy_so239_quarterwave.jpg.a0297fd273037a65827f2d86bf38aaa2.jpg

Not withstanding the "this isn't ham radio" aspect in a couple of ham radio classes I've taught we built these 5/8λ mobile antennas in a morning as a group.  The attendees got a kick out it and most of them ended up being put into actual service on trucks, this being members of my 4WD club, with good results.  They aren't quite Larsen or Laird commercial but they're not bad and there's pride in being able to say "I built that" kicking tires around a campfire.

http://www.arrl.org/files/file/Technology/tis/info/pdf/8009022.pdf

Although for a home installation a J-pole makes more sense IMO.  If you can find - and afford - enough copper pipe anyway.

image.thumb.png.9fce77fd05f1a0b4e806c15492b08fdc.pngI just made this one!  GMRS resonant!  ugly, unlike yours, but it works!!!

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On 8/4/2021 at 11:33 PM, maddogrecurve said:

image.thumb.png.9fce77fd05f1a0b4e806c15492b08fdc.pngI just made this one!  GMRS resonant!  ugly, unlike yours, but it works!!!

Looks fine to me for Mk.1.  If you use solid 12 or 14 AWG electrical wire like that one I showed you can work it to be straight-ish but for more permanent antennas you might experiment with welding filler rod, coat hangers, metal rods you find at a hardware or hobby shop.

Oh, also, you should test it with insulation on and off, you might see if it makes any difference (it should).

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  • 3 weeks later...
On 8/9/2021 at 5:15 PM, WRNA236 said:

Looks fine to me for Mk.1.  If you use solid 12 or 14 AWG electrical wire like that one I showed you can work it to be straight-ish but for more permanent antennas you might experiment with welding filler rod, coat hangers, metal rods you find at a hardware or hobby shop.

Oh, also, you should test it with insulation on and off, you might see if it makes any difference (it should).

I just made a dual band antenna out of two coat hangers  Ended up scrapping it due to over-trimming the 150mhz band portion.   I the video I saw had the coax connected directly to the coat hangers via the terminal strip, but when I remake mine I am going to use jumpers and connect an SMA male connector onto it for my SMA female coax connector.

 

Anyhow, I just welded the stinger onto another groundplane antenna using brass rod that I bought to make tumbler pins for locks.  They are 12 inches long and I am going to install them full length, and run my analyzer on it and see where it resonates and trim it from there.  Just curious..

 

I do not know how well brass will work, but I have plenty of brass, so/239's, and coat hangers, so I can play..

 

WRMQ982

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The brass rod will work just fine. Being rather stiff it won’t bend out of shape from handling the antenna, that’s the advantage.

One other thing, the larger diameter wire or rod tends to increase the bandwidth too. That means you might get away with an antenna the works over the range of two services, like Ham 70cm and GMRS, or Ham 2M and MURS.

Manufactures typically spec the usable bandwidth of their antennas at the 1.5:1 SWR points. Practically most radios are OK up to a 2:1 SWR. The higher the SWR of course results in a larger usable bandwidth.

Go ahead build some antennas, experiment, do some reading and ask questions. It’s a great way to learn, and you can end up with a usable design that you hand crafted yourself!

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On 7/25/2021 at 6:31 AM, kb2ztx said:

Sorry this isn't ham radio. Many manufacturers sell commercial gear for GMRS. Its in the business LMR spectrum and parts can be very reasonably purchased. I respect those who like to build stuff but to me its no for this service.

Can you explain how a home brew antenna causes interference/noise/splatter in the business spectrum, and why it should not be used?  The type accepance applies to the radio.  Other than FRS, I have not seen anything in the regulations that mentions any type of antenna that is permitted or prohibited for GMRS.

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