Sirio Vector 4000 tuning

[radioman24]

I have a sirio vector 4000 I installed and the swr on channel 1 to 40 is a little to high to me it is like 2 to 2.5, now do I need to lower or raise the top part or lower or raise the gamma rod?


Thanks

 

[GnG8d]

It depends on what the frequency sweep suggests.

 

[curlyjo]

Did you look at the post (Vector 4000 won't even calibrate to set swr.) It is on about the fourth page in the CB antenna thread index.

 

[HomerBB]

I have a sirio vector 4000 I installed and the swr on channel 1 to 40 is a little to high to me it is like 2 to 2.5, now do I need to lower or raise the top part or lower or raise the gamma rod?


Thanks

Can you check SWR beyond channels 40 and 1? If so, where does the SWR go the lowest? If you can not, which end of the band, ch1 or 40 is the 2.0:1 SWR, which is 2.5:1 SWR?

Try setting the dog bone at about 31" - 33" from the bottom of the gamma match tube up on the center vertical, and pull the top end of the gamma rod out to about 35" - 37" from the bottom of the gamma tube. See what happens.

As a note, when the gamma rod is pushed into the tube you are electrically lengthening the antenna, when you are pulling the rod out of the tube you are electrically shortening the antenna.

Hope this helps. If not, let me know and I will go out tomorrow afternoon and measure where my gamma is set as a starting point of reference for you. The above is based on my memory such as it is . . .

Add all the exposed lengths together plus the bottom 55" and the ball length on top to set your overall length for the total vertical length.

 

[MusicODC]

Can you check SWR beyond channels 40 and 1? If so, where does the SWR go the lowest? If you can not, which end of the band, ch1 or 40 is the 2.0:1 SWR, which is 2.5:1 SWR?

Try setting the dog bone at about 31" - 33" from the bottom of the gamma match tube up on the center vertical, and pull the top end of the gamma rod out to about 35" - 37" from the bottom of the gamma tube. See what happens.

As a note, when the gamma rod is pushed into the tube you are electrically lengthening the antenna, when you are pulling the rod out of the tube you are electrically shortening the antenna.

Hope this helps. If not, let me know and I will go out tomorrow afternoon and measure where my gamma is set as a starting point of reference for you. The above is based on my memory such as it is . . .

Add all the exposed lengths together plus the bottom 55" and the ball length on top to set your overall length for the total vertical length.

you can adjust the top to about 25 & ¾ inches, the gamma rod to around 22 & some odd fraction... may want to put support @ the top of the ring identical to the center support(s)piece