New Roof Antenna Installed with question

[CentralFloridaGMRS]

Installed a UHF 440-470 MHz Slim Jim Antenna. It's on the roof. Now I can pick up more GMRS Traffic compared to the  N9TAX Slim Jim. But now I can't get the Orlando 700 Repeater. I did a signal Simplex Test and the UHF 440-470 picks up more signal by far including a new repeater but anyone know why the Orlando 700 is not being picked up? Also note I did have the N9TAX facing east but was at least 6 feet lower. It picked up the 700 repeater no problem. Could this be weather related? 

[tweiss3]

Rotate the antenna 90 degrees and see if it reaches. J-Poles are a bit directional.

[SteveShannon]

1 minute ago, tweiss3 said:

Rotate the antenna 90 degrees and see if it reaches. J-Poles are a bit directional.

And if that doesn’t help drop it down to the same height you had the previous antenna. 
I agree that probably doesn’t make sense; I’m just looking at the things you changed. 

[CentralFloridaGMRS]

42 minutes ago, tweiss3 said:

Rotate the antenna 90 degrees and see if it reaches. J-Poles are a bit directional.

Thank You. I will try that 

[CentralFloridaGMRS]

39 minutes ago, Sshannon said:

And if that doesn’t help drop it down to the same height you had the previous antenna. 
I agree that probably doesn’t make sense; I’m just looking at the things you changed. 

I will be trying the turning first and also relocation if that doesn't do the trick. Big thanks to you all 

[Lscott]

19 hours ago, WRPG818 said:

Installed a UHF 440-470 MHz Slim Jim Antenna. It's on the roof. Now I can pick up more GMRS Traffic compared to the  N9TAX Slim Jim. But now I can't get the Orlando 700 Repeater. I did a signal Simplex Test and the UHF 440-470 picks up more signal by far including a new repeater but anyone know why the Orlando 700 is not being picked up? Also note I did have the N9TAX was facing east but was at least 6 feet lower. It picked up the 700 repeater no problem. Could this be weather related? 

Looking at the photo I don't see any kind of "balum", usually a ferrite slipped over the coax at the feed point, or several oops of coax in a coil also at the feed point. Without the balum the coax ends up coupling into the antenna that results is a distorted radiation pattern.

https://www.w8ji.com/Slim Jim antenna.html

https://w6nbc.com/articles/2020-TBDcoaxchokebalun.pdf

 

[SteveShannon]

49 minutes ago, Lscott said:

Looking at the photo I don't see any kind of "balum", usually a ferrite slipped over the coax at the feed point, or several oops of coax in a coil also at the feed point. Without the balum the coax ends up coupling into the antenna that results is a distorted radiation pattern.

https://www.w8ji.com/Slim Jim antenna.html

https://w6nbc.com/articles/2020-TBDcoaxchokebalun.pdf

 

The word is actually balun, which stands for balanced to unbalanced. It would probably be better just to refer to that as a feedline choke rather than speculating whether it’s a balun or an unun.  Coax is unbalanced feedline and a j-pole has elements of both unbalanced and balanced antennas. The short section of the j-pole is a stub match so a balun or unun isn’t truly needed, but having a choke can help with common mode interference.

https://palomar-engineers.com/wp-content/uploads/Choosing-a-Feedline-Choke-RFI-Tip-Sheet-RC-1-by-AK6R.pdf

[Lscott]

19 minutes ago, Sshannon said:

The word is actually balun, which stands for balanced to unbalanced.

I'm and engineer, spelling wasn't my strong point.

[SteveShannon]

1 hour ago, Lscott said:

I'm and engineer, spelling wasn't my strong point.

I’m an engineer too, but for some reason I got both the spelling gene and the pedantry gene. 

[BoxCar]

That's what we need here, more enginears, injuneers, engineerz, - well, you get what I mean.

[SteveShannon]

1 hour ago, BoxCar said:

That's what we need here, more enginears, injuneers, engineerz, - well, you get what I mean.

Train drivers?

[CentralFloridaGMRS]

4 hours ago, Lscott said:

Looking at the photo I don't see any kind of "balum", usually a ferrite slipped over the coax at the feed point, or several oops of coax in a coil also at the feed point. Without the balum the coax ends up coupling into the antenna that results is a distorted radiation pattern.

https://www.w8ji.com/Slim Jim antenna.html

https://w6nbc.com/articles/2020-TBDcoaxchokebalun.pdf

 

Yes. I will be adding them. I used  the good stuff for cable . Photo was taken before Cable was added. I moved the Antenna just 90 degrees and now get the Orlando 700. Today my meter arrives so I will be checking the SWR on it. I used LMR-400. Do I need to add 

 

3 hours ago, Sshannon said:

The word is actually balun, which stands for balanced to unbalanced. It would probably be better just to refer to that as a feedline choke rather than speculating whether it’s a balun or an unun.  Coax is unbalanced feedline and a j-pole has elements of both unbalanced and balanced antennas. The short section of the j-pole is a stub match so a balun or unun isn’t truly needed, but having a choke can help with common mode interference.

https://palomar-engineers.com/wp-content/uploads/Choosing-a-Feedline-Choke-RFI-Tip-Sheet-RC-1-by-AK6R.pdf

Tomorrow I will be checking the SWR. Used LMR-400 CABLE. As for the Choke how do I do this?

[SteveShannon]

10 minutes ago, WRPG818 said:

Yes. I will be adding them. I used  the good stuff for cable . Photo was taken before Cable was added. I moved the Antenna just 90 degrees and now get the Orlando 700. Today my meter arrives so I will be checking the SWR on it. I used LMR-400. Do I need to add 

 

Tomorrow I will be checking the SWR. Used LMR-400 CABLE. As for the Choke how do I do this?

How do you do what? Make a choke?

Just loop the antenna end of your coax through a ferrite several times right where it connects to the antenna. 

[CentralFloridaGMRS]

29 minutes ago, Sshannon said:

How do you do what? Make a choke?

Just loop the antenna end of your coax through a ferrite several times right where it connects to the antenna. 

Some  said to loop it several times while others have said use a ferrite. The LMR-400 is not easy to loop. I have one loop  at the bottom going into the house making it a drip line So using Snap-on Ferrite Beads 11mm would be the solution?

[SteveShannon]

8 minutes ago, WRPG818 said:

Some of said to loop it several times while others have said use a ferrite. The LMR-400 is not easy to loop. I have one loop  at the bottom going into the house making it a drip line So using Snap-on Ferrite Beads 11mm would be the solution?

You can run a straight piece of coax through several ferrite beads or you can make several loops of the coax through a ferrite toroid.  I don't know that one is better than the other.  If you're having difficulties looping the LMR=400 maybe you're trying to make the diameter of the loops too small.  Every coax has a minimum bend radius which you should never go under.  If you bend coax sharper than that the inner conductor and shield can migrate towards each other and even eventually short against each other.  If you don't like the large loops you get with LMR-400, then the ferrite beads would seem to be preferable. 

The best thing I can tell you to do is to read and possibly re-read the document at Palomar Engineering that I linked above. I'll link it here again.  Notice that unun type 2 is what we're talking about and the pictures that accompany this example show both ferrite beads and coax looped through a ferrite toroid:

https://palomar-engineers.com/wp-content/uploads/Choosing-a-Feedline-Choke-RFI-Tip-Sheet-RC-1-by-AK6R.pdf

[Blaise]

2 hours ago, BoxCar said:

That's what we need here, more enginears, injuneers, engineerz, - well, you get what I mean.

Ingener, Enjuneer, I math good...

[CentralFloridaGMRS]

Finally tested the Antenna with the SWR Meter. Outstanding readings. All below 1.25

[SteveShannon]

17 minutes ago, WRPG818 said:

Finally tested the Antenna with the SWR Meter. Outstanding readings. All below 1.25

Excellent!  Enjoy!