I have acquired the necessary parts and tools which are also listed in the above referenced tutorial. 
Since I have never used the analyzer, I am currently watching YouTube videos and learning how to use it.



1) Coax cable; 50 ohm LMR 200
2) Copper tubing for sleeve
3) SMA Male crimp connectors
4) U.FL pigtail adapter
5) RF Vector Antenna Analyzer Meter; PS100  137.5 mHz - 2.7 Ghz.

I already have a crimp tool from prior coax work.


I will take some pictures and add as I go.

Hi Krohsis,

What are the tolerances for the 75.5mm active element  and the 58mm copper sleeve?

In cutting the copper tubing, I realize that it is somewhat challenging to get an exact cut.

Also, what about the thickness of the copper tubing? I have a couple of different thicknesses. 

What about the tolerance on the 1/4 inch of ground "mesh" exposure on the coax? 

As I understand, the overall length is 10.5 inches with a 1/2 inch tolerance (+/-).

Thanks.

Any deviation on the active and passive element lengths will have an effect on the where the antenna resonates. Very small deviations should not make the antenna unusable, but performance will take a hit.  As to the 1/4 inch attachment point to the sleeve it may not be as critical.

I used a tubing cutter on my first build.  The tubing cutter closed down the inside diameter.  I chose to remove that ridge with an X-acto knife.  Bad decision.  Removing copper from the sleeve caused the attenuation of that antenna to be way off, even though the length was spot on..  So, the sleeve dimensions are critical, and even loss of copper at the correct length is bad news.

Like I mentioned in the tutorial, attention to detail is at a high level with this antenna.

Hi Krohsis,

I have cut two pieces of tubing for copper sleeves. The moto tool does not provide an even edge, so I dressed it a little with a bench grinder. Neither of the pieces are perfect. When measured around the edges, the length varies from about 57.80 to 58.06. The second piece is closer ranging from 57.80 to 58.13. So, I guess I will try it again, yeah this time I will use a tubing cutter and see how that goes.

So are both of these first cuts just useless

I have now cut a third piece of copper for the sleeve. This one measures from 57.96 to 58.05. Since there is one spot where the measurement is 57.99, I am hesitant to dress any more from the sleeve. For this one, I dressed down the length with a file and emery paper. 

As expected, getting a precise 58.00 mm square cut is a little challenging. 

Thing is, I don't know if it is better a little under or a little over 

So, I now have three (3) pieces of copper. 
 
1)  57.80 to 58.06
2)  57.80 to 58.13
3)  57.95 to 58.05     << This one is pretty close

Do I use one of these or keep cutting copper  

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NOTE:  I tinned the inside of one end of the copper tubing before cutting it to length.   
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I think the tolerances you are dealing with Harry likely will be fine.

(19-Nov-2020, 11:41 PM)Krohsis Wrote: I think the tolerances you are dealing with Harry likely will be fine.

Hi Krohsis,

I will start with number 3) 57.95 to 58.05 since it is the closest and has the least deviation.

This one was cut with a tubing cutter, deburred, and filed down as best that I could with a diamond file and emery paper.

Also, each piece was pre-tinned inside before cutting to length. 

In my opinion, getting this copper sleeve properly prepared might actually be the hardest part.

Thanks for your advice.  

Hi Krohsis,

This is my first attempt at connecting the sleeve to the coax.

I know it looks a little rough, but right now I want to focus on functionality {yeah, pretty will come later, maybe}.

First, the solder extends beyond the copper sleeve by about 1.6mm. Is this OK 
Or, do I need to try to remove the extra solder       { IF I can }

Next, does the solder count as part of the sleeve in the overall sleeve length  
If so, I will need to trim the copper sleeve at the other end. { OR remove the excess solder to shorten the overall length }.
I think so, but not sure.

Finally, does the foil covered plastic insulation need to be cut back flush with the solder connection 
If so, I will need to trim it back.
Again, I think so, but not sure.

Thoughts and suggestions 

Thanks 

(20-Nov-2020, 06:53 PM)iFly4rotors Wrote: Hi Krohsis,

This is my first attempt at connecting the sleeve to the coax.

I know it looks a little rough, but right now I want to focus on functionality {yeah, pretty will come later, maybe}.

First, the solder extends beyond the copper sleeve by about 1.6mm. Is this OK 
Or, do I need to try to remove the extra solder       { IF I can }

Next, does the solder count as part of the sleeve in the overall sleeve length  
If so, I will need to trim the copper sleeve at the other end. { OR remove the excess solder to shorten the overall length }.
I think so, but not sure.

Finally, does the foil covered plastic insulation need to be cut back flush with the solder connection 
If so, I will need to trim it back.
Again, I think so, but not sure.

Thoughts and suggestions 

Thanks 

Hey Harry,

Take a look at my solder job on the tutorial.  You want the sleeve at the same level as the exposed shielding.  You expose 1/4 inch of the shielding, tin that with solder.  Then have the upper edge of the copper sleeve a the same height as the shielding. Then have your solder kind of go down between the copper sleeve and the shielding.  Have a wet cloth there and do very small sections at a time.  Too large of an area will heat up the job and you will compromise the nylon sheath and degrade the whole build at a minimum and perhaps cause a short between the shielding and the center conductor.  Also, even though you are paying attention to not melt the nylon, you have to make sure you don't end up with a cold solder joint between the shielding and the sleeve.  It takes time, little bites at a time with cooling using the wet cloth.  

The shielding is essentially the beginning of the passive element.  If you are below the beginning you are electrically adding length to the sleeve/passive element. That will have a negative affect on the whole build.

Are you having fun yet??

Hi Krohsis,

Yeah, that's what I thought.  More like your joint (Here).

So, now I have "dressed it down" and cleaned it up. 

1) Trim the excess solder with an Xacto knife while inner plastic insulation was still intact. {slow and easy}.
2) Slowly file the solder with a diamond hand file until level with the copper tube. {Check the measurement often}.
3) Trim the inner insulation (with the foil on it) flush with the top of the copper tube.
4) Add a very THIN "coat" {almost like paint}  of Bondic across the top of the solder.

Now, the passive element varies from 57.97 mm to 58.03 mm when measuring around the tube.

Take look. 

Also, the analyzer does not appear to be calibrated so I have ordered a 50 ohm SMA calibration set.
{I only have the antenna on the R9 module to test with and the numbers appear to be way off}.

I will refine the build process on the next antenna.
{yeah, I will go ahead and build a couple more while I am at it}

Are we having fun yet     H*ll YES    ABSOLUTELY   

Thanks  

Yes, that looks much better.  

As to  your concern on the analyzer being uncalibrated, I caution you on your basis for that belief.  First out of probably a dozen guys who have those, me included, no one has experienced that.  But, you could be especially lucky,   and yours is the one that is out of spec.  But using anything R9 as a calibration standard is risky at best.  (not a fan of anything R9)  

I have posted my findings here on the forum with my analyzer and several  antennas from different manufacturers are WAY out of spec.  Even my favorite antenna, the Diamond was out of spec....even though it was marketed as a 915mhz antenna it splits the 868mhz and 915mhz points, and even a bit heavy to the 868mhz side of that spread.  Some the Immortal T antennas I had were pretty close, and some were seriously out of spec.  

I know my analyzer is well calibrated (as well as it can be for a analyzer for less than 200.00 can be) as it was compared to much more sophisticated analyzers by a friend of mine who is a long time Ham and builds antennas for fun. (clearly he needs a life   ).  He gave me my analyzer as a gift. 

Glad you're having fun.  As for me, I have a bunch of materials for building more Gen3s, but I will be putting Gen 2s on my "Wyvern" when I get back to building it.  Helping to build a shop for a friend. Visiting family in California...building rockets for my granddaughter before her visit for Thanksgiving....so many other things come before my 10 inch build.

Maybe you will be the forum's ace antenna builder and we all can buy them from you!!  

I'm enjoying your build vicariously.....

(21-Nov-2020, 02:20 PM)Krohsis Wrote: Yes, that looks much better.  
...

Glad you're having fun.  As for me, I have a bunch of materials for building more Gen3s, but I will be putting Gen 2s on my "Wyvern" when I get back to building it.  Helping to build a shop for a friend. Visiting family in California...building rockets for my granddaughter before her visit for Thanksgiving....so many other things come before my 10 inch build.

Maybe you will be the forum's ace antenna builder and we all can buy them from you!!  

I'm enjoying your build vicariously.....  

Hi Krohsis,

First, thanks for all your help. 

As for being an "antenna builder / supplier"       Thanks for the pat on the back 

Sounds like you will be busy with "life" for a while. Enjoy and have fun     

Happy Thanksgiving 

(21-Nov-2020, 08:57 PM)iFly4rotors Wrote:  

Happy Thanksgiving 

Happy Thanksgiving to you and your wife as well!

Well, I almost had the first build together when I broke off the active element, BUMMER.
Try again, this time being careful; or so I thought. When removing the shielding from the active element, I broke it right off, GRRR.

Now I am being SUPER CAREFUL with the active element. First I left the inner shielding on the active element until the very end. Now, being EXTREMELY CAREFUL, I removed the final inner shielding a little bit at a time, in sections, so as not to put too much stress on it. OK. I now have the first complete (less shrink wrap tubing).

I have received the calibration kit for the antenna analyzer. So, let's get that done.

This is pretty easy.
1) Press CTRL and M twice to enter the calibration menu.
2) Press right arrow.
3) Press OK.
4) Follow the directions:
4a) attach open calibrator, press left arrow key, wait.
4b) attach short calibrator, press left arrow key, wait.
4c) attach 50 ohm calibrator, press left arrow key wait.
Done.

As a guide, I followed this YouTube video

 

Now I  check my antenna.

Well, the VSWR is about 6.000 (more or less) which is not very good; only about 50 percent efficient.

Thing is, I have no idea what to change or how to fix it     

My suspicion is the passive element   , but I really have NO idea    , NO clue at all.        

So, I am on hold until I figure something out. I don't mind experimenting if I know which way to go. 

@Krohsis, if you check in, point me in some direction.  Thanks.