PSR500/600 Spurious Calculator

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Mike_G_D

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Many moons ago I posted this in the General section; maybe not the best place but anyway, I made a few changes/improvements and have decided to re-post here this time.

What is it?

Excel workbook that allows one to calculate some of the major known spurious results based on the internal frequency plan of the PSR500/600 and similar model scanners (works for the Radio Shack equivalents as well as older Pro-95's, 96, 97, etc.).

Why?

1) Want to know why you hear 900MHz paging signals in the VHF-HI federal range? This will show you.

2) Want to know why you hear some 800MHz signals (like a strong CC) in the 700MHz range? This will show you.

3) Want to know why you hear some signals in the 460MHz range in the 417MHz range? This will show you.

4) Want to know why GRE closed off part of the 700MHz range in later firmware releases? This will show you.

5) Just want to see how the internal synthesizers and mixing scheme works in the scanner? Assuming you have some prior understanding of this then this calculator will allow you to "play" with the numbers. NOTE: It's not limited, yet, to just the bands the scanner covers so it will allow you to go beyond the designed band edges. Just be aware.

It's just a tool that can help some with understanding why some oddball signals pop up in unexpected places. It is not comprehensive - pretty hard to cover ALL possible spurious mixing products in a simplified manner. This just covers some of the more common major culprits.

Latest change: added a "tune" feature so that you can enter a frequency and desired step size and then slide up or down in frequency and read out the possible interferer frequencies and internal synthesizer settings.

How to use:

NOTE: Make sure you enable Macros to allow this workbook to work correctly!

1) Enter your desired frequency where indicated (the one you want to listen to).

2) Click the "RESET" button.

3) Read out the potential interferer frequencies where indicated.

4) If desired, click on the up or down arrow keys to slide or "tune" the frequency above and below your initial setting. Enter the desired step size in KHz where indicated.

-Mike
 

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  • freqplancalc_A3.zip
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