Promised Steve S that I would start a thread when I built my first antenna

[WSKY567]

And....

Turns out it's not that big of a thing.  Used 12 Gauge copper solid wire.  Used the following formula:

 

Used a drill and a vice to straighten the wire.  Ran into one problem, I don't have a hot enough soldering iron/gun for that large copper.  Have one on order but I did manage to get a solid solder connection although not pretty.  Left both legs of the antenna long and trimmed each by 1/8" increments.  Hit 1:1.03 at one point and should have left it alone.  It is now at 1:1.2 which is fine for my first build.  Used micrometers to measure spacing and feed points.  Still have a little work to do on it.  Want to re-melt the solder joints when the hotter gun get's here.  Want to make some "standoffs" out of plexiglass for between the elements for consistency.  Will pick up a chunk of PVC to wrap it in.  Used RGB 8X for pigtail which is fine with me as it is only 6" long with less than 1% loss.  Transceiver is putting out 9.9 out of 10 watts.  

Not sure what I will do with the thing but I just wanted to see if I could make one.  Measurements provided by above plan were very accurate with final build.  My bench is a mess right now but I will take some pictures when I clean up the antenna a little and get closer to finishing the build.  

[GreggInFL]

Pics?

[WSKY567]

Just now, GreggInFL said:

Pics?

Soon my friend.  As soon as I clean up my bench and the solder joints a little.  Probably sometime tomorrow.  It really doesn't look that special.  Just a bent copper wire with a chunk of coax soldered to it, lol.  

[Lscott]

25 minutes ago, WSKY567 said:

And....

Turns out it's not that big of a thing.  Used 12 Gauge copper solid wire.  Used the following formula:

 

Used a drill and a vice to straighten the wire.  Ran into one problem, I don't have a hot enough soldering iron/gun for that large copper.  Have one on order but I did manage to get a solid solder connection although not pretty.  Left both legs of the antenna long and trimmed each by 1/8" increments.  Hit 1:1.03 at one point and should have left it alone.  It is now at 1:1.2 which is fine for my first build.  Used micrometers to measure spacing and feed points.  Still have a little work to do on it.  Want to re-melt the solder joints when the hotter gun get's here.  Want to make some "standoffs" out of plexiglass for between the elements for consistency.  Will pick up a chunk of PVC to wrap it in.  Used RGB 8X for pigtail which is fine with me as it is only 6" long with less than 1% loss.  Transceiver is putting out 9.9 out of 10 watts.  

Not sure what I will do with the thing but I just wanted to see if I could make one.  Measurements provided by above plan were very accurate with final build.  My bench is a mess right now but I will take some pictures when I clean up the antenna a little and get closer to finishing the build.  

Wow! Those dimensions look close to what I used for a simple J-Pole antenna simulation a while back just from trial and error.

The performance should be pretty good.

Let use know how it works out. 

[SteveShannon]

32 minutes ago, WSKY567 said:

And....

Turns out it's not that big of a thing.  Used 12 Gauge copper solid wire.  Used the following formula:

 

Used a drill and a vice to straighten the wire.  Ran into one problem, I don't have a hot enough soldering iron/gun for that large copper.  Have one on order but I did manage to get a solid solder connection although not pretty.  Left both legs of the antenna long and trimmed each by 1/8" increments.  Hit 1:1.03 at one point and should have left it alone.  It is now at 1:1.2 which is fine for my first build.  Used micrometers to measure spacing and feed points.  Still have a little work to do on it.  Want to re-melt the solder joints when the hotter gun get's here.  Want to make some "standoffs" out of plexiglass for between the elements for consistency.  Will pick up a chunk of PVC to wrap it in.  Used RGB 8X for pigtail which is fine with me as it is only 6" long with less than 1% loss.  Transceiver is putting out 9.9 out of 10 watts.  

Not sure what I will do with the thing but I just wanted to see if I could make one.  Measurements provided by above plan were very accurate with final build.  My bench is a mess right now but I will take some pictures when I clean up the antenna a little and get closer to finishing the build.  

Very nice!!  How is the SWR on 467 MHz?

[WSKY567]

11 minutes ago, SteveShannon said:

Very nice!!  How is the SWR on 467 MHz?

I'll check that tomorrow when I go back to work on it and let you know.

[beerftw]

10 hours ago, WSKY567 said:

And....

Turns out it's not that big of a thing.  Used 12 Gauge copper solid wire.  Used the following formula:

 

Used a drill and a vice to straighten the wire.  Ran into one problem, I don't have a hot enough soldering iron/gun for that large copper.  Have one on order but I did manage to get a solid solder connection although not pretty.  Left both legs of the antenna long and trimmed each by 1/8" increments.  Hit 1:1.03 at one point and should have left it alone.  It is now at 1:1.2 which is fine for my first build.  Used micrometers to measure spacing and feed points.  Still have a little work to do on it.  Want to re-melt the solder joints when the hotter gun get's here.  Want to make some "standoffs" out of plexiglass for between the elements for consistency.  Will pick up a chunk of PVC to wrap it in.  Used RGB 8X for pigtail which is fine with me as it is only 6" long with less than 1% loss.  Transceiver is putting out 9.9 out of 10 watts.  

Not sure what I will do with the thing but I just wanted to see if I could make one.  Measurements provided by above plan were very accurate with final build.  My bench is a mess right now but I will take some pictures when I clean up the antenna a little and get closer to finishing the build.  

I solder massive wire at work, my soldering iron does not work either for big copper. My simple fix is a small butane torch and precision heat control, if you already know how to draw solder to the heat you can make it work. Of course most of my soldering is ground and power cables for car batteries, and I solder them because most aftermarket crimp connectors are terrible and sometimes cars come in configurations where no pre made option works.

[WSKY567]

7 hours ago, beerftw said:

I solder massive wire at work, my soldering iron does not work either for big copper. My simple fix is a small butane torch and precision heat control, if you already know how to draw solder to the heat you can make it work. Of course most of my soldering is ground and power cables for car batteries, and I solder them because most aftermarket crimp connectors are terrible and sometimes cars come in configurations where no pre made option works.

Appreciate this.  I do have one I use for cooking.  I have always enjoyed sweating copper pipe of all things. I'll have to practice a little to make sure I don't melt or burn off the insulation in the coax.  

[SteveShannon]

1 hour ago, WSKY567 said:

Appreciate this.  I do have one I use for cooking.  I have always enjoyed sweating copper pipe of all things. I'll have to practice a little to make sure I don't melt or burn off the insulation in the coax.  

Use Messi and Paloni connectors.  They aren’t inexpensive but they don’t require solder for the braid.  The center conductor is still soldered.

Or switch to crimped or crimp/solder connectors.  If you do this you must have a good ratcheting crimper and the right crimp die.  I use a Klein brand crimper and die set. This has become my preferred method:

 

[WSKY567]

27 minutes ago, SteveShannon said:

Use Messi and Paloni connectors.

Thanks!  I like these.  Trying to avoid the expense of the crimp and die set although I'm starting to rack up some expense trying to get a soldering gun/iron that will provide enough heat for the mass I'm trying to heat.  

[WRYZ926]

I have a good Weller soldering station and I still have problems trying to solder PL-259 connectors to the coax shield. 

I can solder 30-32 gauge wires to tiny solder pads on my N Scale locomotive digital control boards without an issue. Plus I have welded for years as apart of my job as a machinist/tool and die maker. And I've sweated enough copper over the years. But coax cables gives me fits.

I have switched over to crimp on connectors and have a Powerwerx crimper set that works well. Having a good crimper makes things easier. Also making sure the crimper uses a common style of crimp dies so that you can swap them out is important. 

[HHD1]

I have heard several people claim that soldering large wires to connectors of any sort is less superior than a mechanically crimped connection.  I learned this while researching to build my solar battery bank.  Some claimed that the reason crimped is superior to solder is the addition of dissimilar metals being added to the connection. And that copper wire with a high-quality crimped copper lug introduced less loss and made for a physically stronger connection.

Does anyone have input on that idea?  And how it may translate to coax connections?  My friend that sets up towers and equipment for Wisconsin's WISCOM system seems to only use crimp ons for coax.  maybe that's just easier out in the field.

[WSKY567]

Ok, so I decided to start over.  OooooPs.  This time trimmed too much and ended up around 1:2 .  I promised a pic.  It doesn't look like much, but here it is:

Have electrical tape on the bottom to keep the coax from moving around and electrical tape holding the plexiglass stand-off while the glue dries.  Probably will just leave it on.  

 

On a brighter note have the soldering problem solved.  Got a monster Weller D650 with 300 Watts of heating power.  Solder is flowing like water.  Beautiful soldering job.  Might try a 3rd build just to see if I can do better but this one is solid.  

[SteveShannon]

1 hour ago, WSKY567 said:

Ok, so I decided to start over.  OooooPs.  This time trimmed too much and ended up around 1:2 .  I promised a pic.  It doesn't look like much, but here it is:

Have electrical tape on the bottom to keep the coax from moving around and electrical tape holding the plexiglass stand-off while the glue dries.  Probably will just leave it on.  

 

On a brighter note have the soldering problem solved.  Got a monster Weller D650 with 300 Watts of heating power.  Solder is flowing like water.  Beautiful soldering job.  Might try a 3rd build just to see if I can do better but this one is solid.  

In the metals section of well stocked hardware stores there are sometimes small brass tubes.  If you buy a piece that just slides onto the wire you’re using you can slide it longer or shorter to tune your antenna. 

[WSKY567]

41 minutes ago, SteveShannon said:

In the metals section of well stocked hardware stores there are sometimes small brass tubes.  If you buy a piece that just slides onto the wire you’re using you can slide it longer or shorter to tune your antenna. 

I'll go shopping at some point.  Have to get a long drill bit anyway to get the LMR-400 through the outer wall.  It would be great to have a rig I could tune that way.  Something I would wait till spring to do as interference from things in the house can probably have as much influence as minute tuning.  I sense that tuning below 1:1.2 is going to be very fine tuning.  

I put another pigtail on the original and it reads 1.2 on the low side and 1.4 on the high side of the band.  For the first time I got a real good solid solder on the PL connectors.  That 300W did the trick.  

[SteveShannon]

16 minutes ago, WSKY567 said:

I'll go shopping at some point.  Have to get a long drill bit anyway to get the LMR-400 through the outer wall.  It would be great to have a rig I could tune that way.  Something I would wait till spring to do as interference from things in the house can probably have as much influence as minute tuning.  I sense that tuning below 1:1.2 is going to be very fine tuning.  

I put another pigtail on the original and it reads 1.2 on the low side and 1.4 on the high side of the band.  For the first time I got a real good solid solder on the PL connectors.  That 300W did the trick.  

I don’t know if I would even try to tune it below 1.2:1 or 1.4:1. You’ll never hear a difference. It’s just not worth chasing.  I thought you said the ratio was 1:2, not 1.2:1.

[WSKY567]

A couple more pics of original build:

Stand-Off or spacer

 

 

Spacing at bottom of antenna and connection point

[WSKY567]

3 hours ago, SteveShannon said:

 I thought you said the ratio was 1:2, not 1.2:1.

The first build, the one with bare wire was 1:1.2 but the second build with insulated wire was 1:2, so you read right.  

[WRYZ926]

3 hours ago, SteveShannon said:

I don’t know if I would even try to tune it below 1.2:1 or 1.4:1. You’ll never hear a difference. It’s just not worth chasing.  I thought you said the ratio was 1:2, not 1.2:1.

I have to agree. I would leave well enough alone as those SWR numbers are good.

[SteveShannon]

50 minutes ago, WSKY567 said:

The first build, the one with bare wire was 1:1.2 but the second build with insulated wire was 1:2, so you read right.  

Insulated wire has a different velocity factor than bare wire. An analyzer would tell you for sure but I suspect you could shorten the insulated wire a little more. 

[WSKY567]

4 minutes ago, SteveShannon said:

Insulated wire has a different velocity factor than bare wire.

Wondered if the insulation would have an impact. An analyzer would be nice.  How would you rig that up?  Use another antenna to feed the analyzer as a receiver?  I have an oscilloscope so maybe I'll tap the antenna at the feed points and see if I can get a decent resonant frequency read.  It won't work well as a spectrum analyzer.  If I do use another antenna as a receiver, that antenna may also cause variation in frequency, is that correct?  I guess I could get a frequency generator and use that as a comparison but every option is $$$$$$$$.  Not sure I'll make too many more antennas.  It's fun to do but I don't see putting them to good use.  

[SteveShannon]

7 minutes ago, WSKY567 said:

Wondered if the insulation would have an impact. An analyzer would be nice.  How would you rig that up?  Use another antenna to feed the analyzer as a receiver?  I have an oscilloscope so maybe I'll tap the antenna at the feed points and see if I can get a decent resonant frequency read.  It won't work well as a spectrum analyzer.  If I do use another antenna as a receiver, that antenna may also cause variation in frequency, is that correct?  I guess I could get a frequency generator and use that as a comparison but every option is $$$$$$$$.  Not sure I'll make too many more antennas.  It's fun to do but I don't see putting them to good use.  

Sorry, I meant an antenna analyzer or a NanoVNA. You connect it directly to the antenna and it graphs various properties of the antenna over whatever range of frequencies you specify. They’re really handy to have around. 
I’ll try to build the same antenna as you sometime this weekend and run the analyzer on it. 
 

[WSKY567]

7 minutes ago, SteveShannon said:

Sorry, I meant an antenna analyzer or a NanoVNA. You connect it directly to the antenna and it graphs various properties of the antenna over whatever range of frequencies you specify. They’re really handy to have around. 
I’ll try to build the same antenna as you sometime this weekend and run the analyzer on it. 
 

That would be great!!!  I'll grab some measurements tomorrow.  I can't get the to elements exact (limits of micrometers) but I can get the connection point and spacing exact.  

[SteveShannon]

8 minutes ago, WSKY567 said:

That would be great!!!  I'll grab some measurements tomorrow.  I can't get the to elements exact (limits of micrometers) but I can get the connection point and spacing exact.  

1/16” is close enough. 
I might also build a similar antenna using copper tubing. I’ve got some half inch stuff around here. The larger diameter should result in wider bandwidth. 

[WSKY567]

10 hours ago, SteveShannon said:

1/16” is close enough. 
I might also build a similar antenna using copper tubing. I’ve got some half inch stuff around here. The larger diameter should result in wider bandwidth. 

Ok,

Short element is 6.5"

Long element is 18.75"

Spacing = 12.76mm

Connection point = 14.54mm

 

I put the antenna on the oscilloscope but due to the limited horizontal resolution (1ns), I can't get an exact frequency measurement but it is very close.  I'm getting about 2.2 units and 462mhz is 2.16ns.  I was testing for 462.500 MHZ.  

[SteveShannon]

50 minutes ago, WSKY567 said:

Ok,

Short element is 6.5"

Long element is 18.75"

Spacing = 12.76mm

Connection point = 14.54mm

 

I put the antenna on the oscilloscope but due to the limited horizontal resolution (1ns), I can't get an exact frequency measurement but it is very close.  I'm getting about 2.2 units and 462mhz is 2.16ns.  I was testing for 462.500 MHZ.  

Are those the measurements for the insulated 12 ga. version or the uninsulated, or both?

Is the width measurement an inside measurement or center to center?  I know your earlier post said metal to metal, which I think probably means an inside measurement.

Same question about the connection point.