Amp swr

[BLACKMAGIC]

Hey guys need some help with swr issue. I have a Stryker 655 with a 3 pill driving and 8 pill with a predator 10k antenna. SWR is 1.1 with just the radio, radio driving the 3 pill, and the radio, 3 pill, and 8 pill. But when I try to run just the 8 pill the SWR jumps big time. Any ideas??

[295 antenna]

When you try to run just the 8 pill is the 2 pill still inline or no ?

[BLACKMAGIC]

Yes both are inline

[295 antenna]

It's a process of elimination. I you tried taking the 3 pill out of kine and going from the Stryker into the eight and then check the swr. I guess what I'm looking for is a good pass thru tune

[MN785]

You didn't mention where you are making the SWR measurement. If you are going by the radio's SWR meter, the only load it sees is the input of whats next in line, which is the amplifier input or antenna. A high SWR at the antenna would have no effect on the SWR going into the amplifier, likewise, a high SWR due to a bad input tune on the second amp will not appear at the input of the first amp (unless it is powered off). If they are both in line and the 3 pill is powered off (passing the signal through), the radio sees the input tune of the 8 pill (with a bit of impedance change due to the relay and wiring) almost as if the 3 pill wasn't there (but not quite). If the SWR going into the 8 pill is high with the 3-pill physically removed, you have a bad input tune on the 8 pill the 3-pill hides. If the SWR into the 8-pill is good with the 3-pill physically removed, you can suspect the T/R relay of the 3-pill is failing and having an affect on the tune when powered off and passing the signal through.

[BLACKMAGIC]

Thanks everyone for the input. So I took the 3 pill out of line and swr were normal.so does that mean the relay in 3 pill is bad??

[295 antenna]

Could be or a popped register in the output section