hi swr

[pat]

hi, how is everybody. i have a question in regards to swr. when i hook up meter to check swr i get reading of 1.2 to 1.5. this is good right. i know 1.0 is perfect. but here is the catch. if i hook up the same meter between the amp and antenna to check the output wattage of the amp and the swr i get an large increased swr reading of 3.0 or better. is this normal. please help. thanks

 

[Beetle]

What kind of meter?

 

[Lazybones1222]

thats because none of those meters are calibrated for more than 4 watts for swr purposes.

I have often thought that as well, but never really knew for sure. I always just check SWR with a barefoot radio. It is what it is. Power does not change a ratio.

 

[Switch Kit]

inside radio meters can be ballparked to give a ballpark reading (not perfect but something to go on) Most SWR bridges and or run of the mill type meters (Radio Shack) will basically give a slighty better SWR reading ,again not perfect but at least something to go on . Most of those type meters will need at least a 3 to 4 watt DK into them for them to work correctly , (quoting Linearone) to low a DK (like 1 or 2 watts which many amps are tuned for) will not work these meters correctly enough for the ballpark readings. IM far from a perfectionist in this Hobby and Radio Shack type meters have worked very well for me over the years , again I say ,it's not perfect , but more so good enough then not. if you want to spend some money there are plenty of other "better" meters out there on the market..and when I mean spend ............300.00 or so for a Antenna analizer ain't cheap , but there are lessers models for lesser dollars. I suppose I'd have to be really into antenna's and or installs (or hit the lotto) for me to ever invest that kind of money for one of those antenna analizers. Those things surely have a way of making guys who use other matching devises look bad.........but no matter how technical we can get ........Ballpark works.

 

[667 chicago mobile]

inside radio meters can be ballparked to give a ballpark reading (not perfect but something to go on) Most SWR bridges and or run of the mill type meters (Radio Shack) will basically give a slighty better SWR reading ,again not perfect but at least something to go on . Most of those type meters will need at least a 3 to 4 watt DK into them for them to work correctly , (quoting Linearone) to low a DK (like 1 or 2 watts which many amps are tuned for) will not work these meters correctly enough for the ballpark readings. IM far from a perfectionist in this Hobby and Radio Shack type meters have worked very well for me over the years , again I say ,it's not perfect , but more so good enough then not. if you want to spend some money there are plenty of other "better" meters out there on the market..and when I mean spend ............300.00 or so for a Antenna analizer ain't cheap , but there are lessers models for lesser dollars. I suppose I'd have to be really into antenna's and or installs (or hit the lotto) for me to ever invest that kind of money for one of those antenna analizers. Those things surely have a way of making guys who use other matching devises look bad.........but no matter how technical we can get ........Ballpark works.

Yeap,
An Antenna Analizer is the way to go. All my antenna's are tune with an analizer. But like you said Ballpark work's also.

 

[Hamin' X]

Apparently your first reading was taken between the radio and the amp. This will only tell you the match between the radio and the amp's input. 1.2-1.5 is fine. When you moved the meter to the output side of the amp, did you recalibrate the meter to the higher output of the amp? If not, do so. Actually, you should check the SWR to the antenna without the amp in line. Just place the meter where the amp is. If your SWR is OK without the amp in line, don't worry about it.

Rich

 

[pat]

thank you forv the input.

 

[freecell]

always use ONLY the minimum amount of power necessary to obtain a set (calibration point) meter reading prior to making measurements. failure to do so will result in higher than normal swr readings.

 

[Hamin' X]

always use ONLY the minimum amount of power necessary to obtain a set (calibration point) meter reading prior to making measurements. failure to do so will result in higher than normal swr readings.

This depends on the meter that you are using, but for most of the cheaper ones, this is all too true.

Rich

 

[Beetle]

This has to be a defect in the meter. Power level does not affect the RATIO between forward and reflected power.

 

[Hamin' X]

This has to be a defect in the meter. Power level does not affect the RATIO between forward and reflected power.

Not in a good meter, designed for the power level that you are using. However, if you take a $10 meter, designed for the typical 4 watt CB, it will work on much higher power levels, but you will have to crank the calibrate knob way down. I suspect that the erroneous reading at higher power levels come from leakage of the the forward power to the reverse reading. Is it a defect? No more so than than operating anything else, outside of it's designed parameters is liable to give unpredictable results.

Rich