Xiegu XPA125B firmware V2.0.0 build 014
======================================

WHAT THIS IS
------------
Xiegu XPA125B firmware V2.0.0 build 014, the version Radioddity's download
page lists as "Xiegu XPA125B original firmware V2.0.0". The firmware file
inside Radioddity's zip is named XPA125_FW_V2.0.0_build014.xgf (note:
"XPA125", without "B", in the file name).

History, as far as it could be established:
- Build 014 first appears in public in 2023 on the Xiegu-XPA125B group
  (groups.io message #132, topic "New Firmware for amplifier etc"): an
  owner whose amplifier had failed contacted Xiegu technical support,
  who "sent me the latest firmware update with instructions", and posted
  XPA125_FW_V2.0.0_build014.xgf with Xiegu's tutorial. Another owner
  (#134) reported that it cured a false high input-SWR reading at PTT
  that build 013 (from cqxiegu.com) had not fixed.
- Radioddity published it as the "original firmware V2.0.0" (the zip on
  its server is dated 2025-10-21).
- Xiegu published no release note for it. Radioddity's V2.0.1 notes list
  the previous version as "V2.0.0 Build 013 as of September 20th, 2022"
  with "No release details provided by Xiegu"; they do not mention
  build 014.
- Superseded by V2.0.1 (2025-01-14), also in this archive. It remains
  useful as the version one owner returned to when V2.0.1's band-voltage
  handling did not suit a home-made band controller (groups.io #399).

Whether build 014 differs from build 013 only in the SWR behaviour
reported by owners could not be confirmed.

APPLIES TO
----------
Xiegu XPA125B. Although the file name says "XPA125", it was supplied by
Xiegu support for an XPA125B, reported working on XPA125B amplifiers,
and is offered by Radioddity for the XPA125B. Xiegu's tutorial warns that
XPA125B firmware must not be loaded into the older XPA125; no firmware for
the XPA125 is in this archive.

BEFORE STARTING
---------------
As for every XPA125B firmware (Xiegu tutorial 2020-01-09; Radioddity):
- External DC supply set to 13.8 V.
- The amplifier's data cable (the supplied USB cable; Xiegu also allows
  the G90 / X5105 data cables) and its driver on the PC.
- A terminal program with XMODEM-1k: TeraTerm. Group members report
  TeraTerm 4.96 works where newer versions stalled (a separate entry in
  this archive).
- The upgrade clears the tuner's stored data (Xiegu).

CONTENTS OF THIS ZIP
--------------------
The zip published on fubsypoly.com wraps the vendor file(s)
byte-for-byte, unmodified.

XIegu_XPA125B_Original_FW_V2.0.0.zip
    81,006 bytes
    SHA-256 03cb05832df7965983b0df257cc512cbb62cacf044101f11d08ea47037deeb29
    Radioddity's zip (its own spelling "XIegu"). Contains:
      XPA125_FW_V2.0.0_build014.xgf (84,688 bytes)
          SHA-256 a4b1b1cb1304471f1a41e10107fa3431edee4bbd018c120da9bb49ce3350c0e3
README.txt
    This file.
SHA256SUMS
    SHA-256 checksums of the files above.

INSTALLATION
------------
From Xiegu's tutorial and Radioddity's V2.0.1 instructions (same
procedure for every XPA125B firmware):
 1. Power the XPA125B from 13.8 V; switch it off.
 2. Connect the data cable; open TeraTerm on the cable's COM port
    (115200 baud per M0PQA's write-up).
 3. Hold [PA] + [BAND] and press [POWER]; release all keys at the
    bootloader screen.
 4. Press [PA] (UPDATE). The firmware is erased; after about 3 seconds
    TeraTerm shows "Waiting Connect.C".
 5. TeraTerm: File > Transfer > XMODEM > Send, select
    XPA125_FW_V2.0.0_build014.xgf, TICK "1k", send.
 6. The amplifier restarts by itself when the transfer completes. Unplug
    the data cable and switch the amplifier off and on.

VERIFYING
---------
Firmware before V2.0.1 does not display its version (groups.io #419), and
the bootloader screen shows only the bootloader version (#102). No way to
read the installed version of V2.0.0 builds was found. Successful restart
into normal operation is the only confirmation.

IF SOMETHING GOES WRONG
-----------------------
- "Update finish! Entering user code.... Cannot not find an application"
  and the amplifier starts only in bootloader mode: repeat steps 3-6 with
  the 1k box ticked; group members found an un-ticked 1k box or a TeraTerm
  version other than 4.96 to be the cause (#244-#246; M0PQA).
- Transfer stalls near the end: use TeraTerm 4.96 (#134).
- Tuner memories cleared: expected after any firmware load.

DOWNGRADING
-----------
Loading build 014 over V2.0.1 is itself a downgrade and was done
successfully by an owner (groups.io #399). Build 013 (also in this
archive) is loaded the same way.

PROVENANCE
----------
- File: XIegu_XPA125B_Original_FW_V2.0.0.zip
- Retrieved from:
  https://radioddity.s3.amazonaws.com/XIegu_XPA125B_Original_FW_V2.0.0.zip
- Date retrieved: 2026-09-18
- Official page: https://www.radioddity.com/pages/xiegu-download
  ("Xiegu XPA125B original firmware V2.0.0")
- Status: verified (from the official distributor's own host)
- Discrepancy recorded: Radioddity calls this "original firmware V2.0.0";
  the file inside is build 014, while Radioddity's own release notes name
  build 013 (2022-09-20) as the version before V2.0.1.

MORE INFORMATION
----------------
- https://radios.fubsypoly.com/xiegu-xpa125b/vol-3/
- Radioddity guide:
  https://www.radioddity.com/blogs/all/how-to-update-xiegu-xpa125b-firmware
- M0PQA, "Xiegu XPA-125B: Firmware update and unbricking":
  https://www.m0pqa.com/2023/12/xiegu-xpa-125b-firmware-update-and.html
- No Reference Library copy of the XPA125B manual has been catalogued yet.
