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  Extending the Band Limits of
the Vertex CE49 Software

By Robert W. Meister WA1MIK
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The Vertex VX4000, VX5500, and VX6000 radios use the CE49 programming package. By default, that program limits the frequency coverage to what's listed in the various manuals and spec sheets. For the low-band models, this means 29.7-37 MHz and 37-50 MHz, depending on the band split (A or B). The most common high-band limits are 148-174 MHz and the UHF limits are 450-480 MHz. The CE49 program has band split limits shown below:

Low-Band: 29.7-37 MHz; 37-50 MHz.
High-Band: 134-160 MHz; 148-174 MHz.
UHF: 400-430 MHz; 450-480 MHz; 480-512 MHz.

These radios have many nice features and are appealing to amateur radio operators except that the ham bands are specifically excluded from the operating ranges. For 6-meters we need to get the software to allow frequencies in the 50-54 MHz range. There are also hardware modifications necessary (VCO adjustments) to get the radios to perform on the ham bands. This article deals only with the software issue.


I was handed a copy of the CE49 software so I could analyze the operation and figure out what locations needed to be changed. I had neither a radio nor a programming cable, however someone else supplied me with the file he read and saved from one of his radios. Someone else had already figured out that the band limits are stored in a file with a ".C49" extension, and that person supplied a hex value to look for: 2FAF080. I could NOT find that value no matter how hard I looked. I knew I had to find the value 50,000,000 somewhere, and that it was a 32-bit integer.

I eventually determined that my hex editor and my own search programs were analyzing the file looking for data in Intel format, which is also called "Little Endian". In this format, the four bytes of data for the decimal value 50,000,000 are stored in the computer and in a file as 80 F0 FA 02, where the least significant byte is stored at the lowest or leftmost address. If you look carefully, you'll notice that the bytes are in the reverse order from what I expected to find at the end of the previous paragraph. This storage order, where the most significant byte comes first, is also known as "Big Endian" and is often called the Motorola format. (Read more about this on the Wikipedia page for "Endianness".) As I was viewing files created by a Windows program and running on an Intel processor, I naturally assumed that the data would be in Intel format. Wrong! As soon as I flipped the bytes around and looked for 02 FA F0 80 and viewed it in Motorola format, the value 50,000,000 stood out like a sore thumb. The Windows Calculator will also display the hex value as 2FA F080 (16-bit groups with no leading zeroes), so be careful when using your hex editor. Had I searched for the full hex value, rather than the decimal value, I'd have found it right away.

Further analysis indicates that the microprocessor used on these radios is loosely based on the old 8-bit Intel 8051 chip, which oddly enough is Big Endian for multi-byte values and addresses.

Modifying the File:

My hex editor is able to search and replace data in many formats, including 32-bit integers. When I told it to find 50000000 as a decimal value in Intel format, it failed, but as soon as I switched to Motorola format, it found it right away. I was able to change 50000000 to 54000000 in two places in the saved ".C49" file and that opened up the frequency limits quite nicely. I was then able to enter frequencies through the CE49 software up to 54.000000 MHz with no problems. Anything higher was reset to 54.000000 MHz.

In the ".C49" file, the lower and upper band limits are adjacent to each other. You can change either or both values for your particular radio. Verify that the expected data is present BEFORE you change it. The ".C49" file has two halves; you need to make the change to both locations and they're 4000 (hex) bytes apart. The first half covers the "master" radio while the second half covers the "slave" radio in a dual radio configuration. For example, I set up a dual radio with the master LOW-B and slave LOW-A. 3118/311C shows 37-50 MHz (the master) while 7108/710C shows 29.7-37 MHz (the slave).

The table below lists the hex addresses, hex and decimal values, and purpose/use from a stock 37-50 MHz (LOW-B) radio. The value pairs are stored every 16 bytes and in the same order as the "Common...Hardware...Freq-Band" drop-down menu: LOW-A, LOW-B, VHF-A, VHF-C, UHF-A, UHF-D, UHF-F. Note that the addresses are different and unique for each band split. A ".C49" file can have multiple value pairs filled in for a given radio, although I have no idea how the radio figures out which one to use. Perhaps the firmware makes that decision.

Addr.Value ValuePurpose or Use
311802 34 93 40 37000000Lower Limit LOW-B (master)
311C02 FA F0 80 50000000Upper Limit LOW-B (master)
711802 34 93 40 37000000Lower Limit LOW-B (slave)
711C02 FA F0 80 50000000Upper Limit LOW-B (slave)

For completeness, here's the full band limit data. The starting addresses are hex values. "M" = Master; "S" = Slave. Frequencies are in MHz. Each value is four bytes long.

NameLowerM Addr.S Addr. UpperM Addr.S Addr.
LOW-A29.731087108 37.0310C710C
LOW-B37.031187118 50.0311C711C
VHF-A134.031287128 160.0312C712C
VHF-C148.031387138 174.0313C713C
UHF-A400.031487148 430.0314C714C
UHF-D450.031587158 480.0315C715C
UHF-F480.031687168 512.0316C716C

To modify the ".C49" file, you need to change the lower or upper limits appropriately. For the 6-meter band, you only need to change one or two locations: the two upper limits. Here are some values that may be of use to expand the amateur bands.

DecimalHex Value
5400000003 37 F9 80
14400000008 95 44 00
4400000001A 39 DE 00

Step-by-Step Procedure:

The steps to modify the ".C49" file are listed below.

  1. Start the CE49 software.
  2. Put the radio into programming mode (see note below).
  3. Connect and read the data from the radio.
  4. Save the data from the radio into a ".C49" file.
  5. Exit the CE49 software.
  6. Hex edit that saved ".C49" file to give it the new band limits.
  7. Start the CE49 software.
  8. Open the previously modified ".C49" file.
  9. Modify the channel frequencies as needed.
  10. Put the radio into programming mode (see note below).
  11. Connect and write the data to the radio.
  12. Save the data as a new ".C49" file.
  13. Exit the CE49 software.

NOTE: To enter PC-CLONE (programming) mode, press and hold the PF Button (just below the POWER Button) while turning the transceiver on.

The band limit changes will stick with the radio and you won't have to hex-edit that radio's ".C49" file ever again. I don't know if radio-to-radio cloning will also propagate the new band limits.

Note that the various band limits are also found within the main CE49 ".EXE" file. These probably could be altered to permanently affect all radios programmed with this particular program. If you create a new ".C49" file without reading a radio first, that file will be populated with the default values obtained from the main CE49 ".EXE" file.

Acknowledgements and Credits:

This was a team effort. John W1GPO purchased two VX5500 radios, the CE49 programming software, and a programming cable. Dennis N1MAT obtained everything from John and sent me copies of the files. I made and tested the modifications to the ".C49" file and sent that info back to Dennis who then verified it with the actual radios. John and Dennis did the hardware modifications and tuned up the radios.

Contact Information:

The author can be contacted at: his-callsign [ at ] comcast [ dot ] net.

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This page originally created on Monday 18-Dec-2017.

Article text, layout, and HTML © Copyright 2017 by Robert W. Meister WA1MIK.

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.