field strenght meter advice

[1iwilly]

hello to all
besides a digital field strenght meter what othe meter can i use close to accuracy to adjust my back door right now all i hace is the radio shack one.
also is it 30 feet in the front and 30 feet in the rear for testing.???? also what the correct wattage for testing 4 watts or 1 watt
which is more importan to have a slight increase in reflect but lower reading in the back door or low reflect with a slight leak out the back
thanks

[North Texas Mudduck]

hello to all
besides a digital field strenght meter what othe meter can i use close to accuracy to adjust my back door right now all i hace is the radio shack one.
also is it 30 feet in the front and 30 feet in the rear for testing.???? also what the correct wattage for testing 4 watts or 1 watt
which is more importan to have a slight increase in reflect but lower reading in the back door or low reflect with a slight leak out the back
thanks

FaTBoY

RE-307 Relative Digital Field Strength Meter


- Excellent in aiding antenna. development or adjustment.

- Includes SO239 on back for external antenna for extra sensitivity.

- Large Digital Readout (3.5 inch).

- Runs on internal 9V battery

['Doc]

1iwilly,
I'm afraid that just doesn't tell me much about what you are trying to do. I think I understand you to be trying to adjust a directional antenna of some sort. If so, then the 'ideal' would be no reflected power, and a very low level of radiation from the 'back' side of that antenna when compared to the front of that antenna.
There are conditional aspects to that, meaning, you can have a fairly high gain with very little attenuation to the 'back side' as one extreme, and medium to low forward gain and a very large amount of attenuation of signal to the back. And then there's all the 'stages' in between those two extremes. From one extreme to the other, having the lowest reflected power reading (SWR) is a very good idea, and merely requires proper tuning.
Field strength meters and accuracy are not exactly the best two words to use in the same sentence. The accuracy of a field strength meter is 'relative', it's only as accurate as how the readings are taken and the amount of calculation you are willing to put into it. To end up with numbers that really mean anything, there's a lot of calculating to be done. You would have to know the actual radiated power of the transmitter, the distance from the antenna of each reading, the actual sensitivity of the meter used, and then plot all those thingys on a graph to show a representation of the resulting radiation pattern.
The amount of power radiated determines the distance used to take those measurements. Lower power means a shorter distance from the antenna, higher power means a longer distance from the antenna. That deals with the sensitivity of the meter used. That distance is typically NOT measured in feet, or yards, but in a big chunks of feet or yards! Then again, it just depends on that meter.
The average person with a field strength meter will be able to get some very crude readings, nothing like what is typically seen on an antenna testing range. Those crude readings can tell you more than you might think, if interpreted correctly. There's more to it than you might think.

Now, if you aren't adjusting a directional antenna as I assumed, then all the above is a total waste of time. Another way of doing this sort of thing is to read how others have done it, and have reliably documented it. I really doubt if someone hasn 't already done it before. The 'trick' is finding that documentation, and figuring out just how accurate/reliable the findings are. You typically will NOT find that sort of information on 'CB' forums. Not that CB'ers aren't smart enough to do it! It's just a lot of work for very little useful information, sort of.
- 'Doc

[1iwilly]

thanks for the replies yes it is for my bounce back system on my astro van