SWR Reading

[bobtompp]

I am new to the GMRS radio. I just set up a base station. I have  a Midland 40w radio, tram-browning BR-6140 450MHz- 470MHz pretuned land mobile fiberglass antenna. Used LMR 400 cabling with lightning arrester installed in line. My SWR reading on channel 1-7 is 1.76, channel 15-22 is 2.67. Should I be good with these readings

thanks

 

[PACNWComms]

I have never used that model of Tram antenna, but that SWR seems a little high as well. Which model of lightening arrester did you use? May have high insertion loss. LMR-400 and that antenna spec out to lower SWR from other users on sites I am also a member of. I would also make sure the lighting protector is installed the correct direction, there usually is an arrow to show the direction toward antenna and to the radio on them. 

[bobtompp]

I used the OPEX model LP350. I didn’t think about the direction indicator. I’ll check. 

[bobtompp]

OPEK 

[axorlov]

Channels 1-7 are in between channels 15-22. The difference is power: 5W on 1-7 and full 40W on 15-22. They should show same SWR, if everything is correct. I hazard to guess, your problem is related to measurement setup: connectors, meter calibration, interpretation of the readings.

[dhardin53]

Try pulling out the lighting arrester and see what you get .

 

[ShadetreeMechanic]

What meter are you using to check SWR? If it is the type where you have to set it before you take the reading, then changes in power levels will throw it out of calibration. You would need to re calibrate your meter each time you change power output. Set it for channels 1-7 and check it, then set it for 15-22 and check it. I would bet that your SWR is ok. 

[PACNWComms]

You may have a worn lightning arrester cartridge......higher than normal SWR for your OPEK LP350, as this is an indicator. https://www.americanradiosupply.com/lp-350a-arc-gas-lightning-transient-voltage-surge-protector/

I only use Polyphaser at this point, but you could have an OPEK unit that needs a new cartridge. Trying with it (entire OPEK LP350 device) removed as mentioned above would let you know what the next step should be.