Modifications, hints, tips and technical information
What is the difference between the AnyTone AT-D878UV and AT-D868UV?
From a features viewpoint, the AT-D878UV has some extra features over and above the D868, such as APRS for FM, roaming (automatic switching to a repeater with the strongest signal, intended for large linked networks) and at extra cost can have either Bluetooth or extra audio recording capacity added as an add-in module. The D878 also has a new screen colour scheme, and talker alias has been implemented. Some other literature mentions the 878 has a faster processor and more memory than the 868, but my investigations show this is not factual.
Internal examination of a new AT-D878UV shows that the hardware is identical to D868 v2 hardware: same processor, same flash memory, the D878 PCB is even stamped with D868UV2!
FCC documents relating to the AT-D878UV Part 90 approval confirm this: the same processor & flash are used, and the PCB is stamped with D868UV2.
So it seems the only difference between the v2 hardware 868 and the 878 is the firmware loaded and some other data in the external flash memory. This means it should be possible to upgrade a D868 to a D878 via software alone, but more investigation is needed.
Either way, you could likely apply many of these hints, tips & modifications to the 878 equally as you could the 868.
Similarities between AnyTone AT-D878UV and Alinco DJ-MD5 ?
A quick glance at Alinco’s new dual band DMR handheld DJ-MD5 shows many similarities to the AnyTone 878 radio: similar size, similar general layout, near identical display icons, display layout and menus, and the Alinco CPS programming software looks & feels the same as the AnyTone CPS. There are some differences, too: change in case and branding labels of course, more narrow and taller LCD display, no P1 or P2 function buttons, no top mounted PF3 button, and more.
Closer examination of the internals of the Alinco DJ-MD5 from the FCC approval at http://radioaficion.com/cms/alinco-dj-md5-fcc-certification/ reveals that the DJ-MD5 and 868/878 are different internally, but that both use the very same major components eg: MCU, AT1846, RF PAs, DMR DSP, bulk flash memory chip and so on. It appears as if the DJ-MD5 is a redesigned AnyTone 878. To take it one step further, I even downloaded the CPS programming software for the Alinco, and it was able to talk to the AnyTone – it recognised that the model didn’t match, but that in itself proves that the Alinco & AnyTone share the same USB driver, same MCU and same USB communication protocols.
AT-D878UV programming cable pinout
Unlike many other Baofeng programming cables, the 878 cable has no electronics inside, but does need a driver to be installed. You can even make your own spare programming cable if you wanted, using this pinout as a guide.
Selecting operational bands
At the time of writing, there are fourteen for the 878 combinations of bands that you can select to use.
Begin by turning the radio off, then press and hold the PTT and 1 buttons while turning on the radio, hold those two buttons until you see ’TEST MODE’ appear on screen. After releasing the buttons the radio will start up with the text ’MODE:00000’ to the bottom of the screen. Rotate the top dial to change the mode number, which will select the following bands.
Then turn off the radio, which will save your selected mode setting, and from that point on, your radio will use the frequency limits that correspond with the mode setting you selected. You can repeat the process to change bands at any time.
Note: that whenever you do change mode / bands, the radio will reset and you will lose your programmed data. Make sure you have a saved copy of your codeplug. Each saved codeplug will have the mode / band it was created under encoded within it. If you try to reload the same codeplug after changing mode / band, the CPS software will reject it, saying that it is the wrong band. To fix this, you will need to ’hex edit’ the codeplug rdt file: change byte 0x0011 to match the mode / band selected. For example, if you set mode=00002 then edit your codeplug file 0x0011 to be hex value 02. Or if you set mode=00010 then set 0x0011 to hex value 0A.
Expanding RX frequencies
As delivered by the factory, covers up to 520 MHz. There are countries around the world that make use of the radio spectrum above 480 MHz for two way radio, and this modification will allow you to hear those transmissions. The modification intentionally inhibits transmit in these expanded areas.
At the heart of the D878 is an AT1846S ’radio-on-a-chip’ that is designed to work from 134-174 MHz, 400-520 MHz and 200-260 MHz. In practice, the chip will cover even more than that.
To carry out this modification do the following:
- Make sure you have saved your codeplug / rdt configuration file first.
- For AnyTone AT-D878UV, download the expanded frequency coverage firmware (based on version 1.06) here:
AT-D878UV firmware expanded frequency v1.06
- Unzip this firmware into a folder
- Using the regular firmware updating software & process, send this frequency expanded firmware to the radio.
- Power off your 878, press and hold the PTT and number 1 button while turning it on. Hold these keys until D878UV TEST MODE is displayed on the screen. Then release the buttons, the 868 will power up into a test mode.
- At the bottom of the screen will be a MODE:0000x display. Use the top selector rotary knob to select whichever mode you want according to your desired TX frequency range from the table below; RX permitted tuning range for all bands (modes) will be set to 120-200 MHz and 210 to 520 MHz. The text displayed on the LCD sometimes will not match the actual bands selected, refer to the table below which will be correct. Power off the 868.
- Update your codeplug / rdt configuration file to be compatible with version 2.33 (AT-D868UV) or V1.02 (DMR-6×2) firmware. If you want to reuse your saved copeplug rdt configuraiton file, you may need to modify one byte with a hex editor as detailed below in red.
- Enjoy extra receive frequency coverage of around 127-178 MHz, 190-280 MHz (with a gap between 200-210 MHz) and 380-520 MHz.
Note that whenever you do change mode / bands, the radio will reset and you will lose your programmed data. Make sure you have a saved copy of your codeplug. Each saved codeplug will have the mode / band it was created under encoded within it. If you try to reload the same codeplug after changing mode / band, the CPS software will reject it, saying that it is the wrong band. To fix this, you will need to ’hex edit’ the codeplug rdt file: change byte 0x0011 to match the mode / band selected. For example, if you set mode=00002 then edit your codeplug file 0x0011 to be hex value 02. Or if you set mode=00010 then set 0x0011 to hex value 0A.
FCC Part 90 approval information:
The FCC has documented quite a bit of interesting technical information regarding AT-D878IV regarding their Part 90 approvals. You can find internal photographs, test reports, SAR radiation exposure limit testing reports and more. Visit the page at:
Notice that the at-d878uv approval documents also include details of the Bluetooth module. This Bluetooth module not only uses the Beken BK3260 Bluetooth IC, but also has a Beken BK2452 2.4GHz WiFi IC installed as well, though it doesn’t have an antenna connected
General technical information
AT-D878UV contains the following devices:
- GD32F303VTG6 ARM Cortex-M4 32 bit MCU with 1024kbyte flash and 96kbyte SRAM & 12.0 MHz oscillator
- Toshiba TC58CVG0S3HRAIG 1Gbit / 128Mbyte NAND flash memory
- Sicomm CT3258TD baseband processor for DMR & dPMR with built in AMBE2+ vocoder & 12.2 MHz oscillator
- Texas Instruments TLV320AIC3204 DSP / codec
- AT1846S radio-on-a-chip & 26.0 MHz reference oscillator
- RDA 5802N FM broadcast band receiver
- H&M Semiconductor HM8872 8 watt audio power amp
- NXP AFT05MS006NT1 LDMOS 6 watt RF power amp, 18dB narrowband gain, for independent VHF & UHF power amp stages
- 2SC3356 based low noise preamps for VHF & UHF receiver stages
- VHF and UHF receive front ends each have four stages of varactor track tuned filtering
- Infineon BGM781N11 GPS front end and ATGM336H GPS / GNSS positioning module (GPS models only)
- Battery backup for real time clock
- Solder pads for expansion memory SOIC size IC and a small push fit expansion connector for add on Bluetooth or extra memory module.
Related post: Theory behind the frequency expansion mod.
© Copyright Jason Reilly, 2018