| Author |
Message |
    
Audiophile73
Intermediate Member
Username: Audiophile73
Post Number: 140
Registered: 5-2004
| | Posted on Friday, September 21, 2007 - 2:04 am: | 
|
OK here it goes, RCI 2950 driving texas star mod, driving xforce 400hd. Odd ball set up I know so spare me, class AB driving two class C amps, I don't understand it myself. Anyway I am trying to check my SWR. I am well aware of the 2nd harmonic playing a factor so I am not checking it with the amp on wondering why it is so high. SWR is good between antenna and xforce. SWR is high between texas star and xforce. SWR=2.0;1 on ch40, SWR=1.3;1 on ch1. I am connecting it with 3 foot jumper cables, but technically ther is six feet of jumper wire there. So technically wouldn't that change the SWR if your using more coax. How do you check SWR with multiple amps? I need help please |
Alsworld
Senior Member
Username: Alsworld
Post Number: 1023
Registered: 1-2002
| | Posted on Friday, September 21, 2007 - 5:40 pm: |
|
Your meter should be the last thing inline before the antenna, check SWR there. Don't try in between amps. With the meter last inline, you can see antenna SWR and reflect fine with dual amps.
In a perfect world, length of jumpers should not matter. But, it isn't perfect and types, lengths, velocities, differing manufactures, etc. of coax charactersistics can and sometimes do change the SWR. If you have good SWR's with 3ft jumpers and no amp relay chattering, leave things alone.
From your SWR readings, seems like you may want to shorten the antenna (or tune it as applicable). But, I would start first by reading the SWR in the right location (meter last inline before antenna).
Let us know how that works.
Alsworld
CEF 101 |
Dale
Senior Member
Username: Dale
Post Number: 1156
Registered: 12-2002
| | Posted on Friday, September 21, 2007 - 6:23 pm: |
|
texas stars seem to be that way.well at least from my experience anyway.might wanna try grounding,if ya havent already.what type of
jumpers ya using.at least rg8x or mini 8.
as far as checking swrs with mulitle amps
i belive ya did it right but for kicks check
it at the antenna with everything inline but turned off.then turn everthing on and see if
theres any difference.im thinking ya probaly will
see a difference
dale/a.k.a.hotrod
cef426
cvc#64
|
|
