FT-817ND No 6m band

[Palmitoxico]

Well, I bought a used FT-817ND radio that seems to work ok on all bands except 6m (50-54 MHz). It simply jumps from 10m to commercial FM radio (88 MHz) when changing bands.

Awkwardly, if I program a memory channel setting the frequency to 50 MHz using CHIRP I can later access this memory and listen / transmit on the 6m band!

Searching on the web, I came across this post: https://groups.io/g/ft817/topic/44820635?p=,,,20,0,0,0::,,,0,0,0,44820635, I read the EEPROM bytes 4 and 5 and these are set to 0x00 0x3F, respectively.

I opened the radio and it seems that it was modified (widebanded maybe?) as all jumpers were shorted:


I tried to restore it to the original configuration mentioned here: https://www.pa1ca.nl/my-first-mod/, but after doing a full reset (power button + home) nothing changes (the EEPROM 4 and 5 bytes still set to 0x00 0x3F).

If you have an unmodified FT817ND rig I would be eternally grateful if you can provide the correct EEPROM bytes 4 and 5 values.

Here is the 'Technical Supplement' manual that I found on the net: https://elektrotanya.com/yaesu_vertex_ft-817nd_sm.pdf/download.html#dl if someone is interested in digging further (I couldn't find any info concerning the original jumper / EEPROM configuration).

Thanks,
Augusto.

[Palmitoxico]

Tried to change the jumper configuration to apply the wideband mod from these instructions: https://m5poo.co.uk/wp-content/uploads/2023/01/FT-817_wideband.pdf, but after resetting the configuration by pressing "PWR + V/M" it still doesn't let me select the 6m band.

The EEPROM bytes 4 and 5 didn't change, so proceeded to try overwriting these bytes to 0xD8 0xBF. Sending the 0x00 0x04 0xD8 0xBF 0xBC command via the CAT interface I get a 0xF0 as response. Reading these bytes again, they still set to 0x00 0x3F !?

I've made a backup of the EEPROM contents before writing to avoid risking losing factory calibration data (attached bellow).

[TheSteve]

Interesting problem. I know I've read my 817 eeprom but it was so long ago I no longer have a copy of it. I still have the 817 but no longer have a serial interface for it.
There has got to be some copies posted somewhere.

[Palmitoxico]

I've hooked up my logic analyser to the I2C bus of the external AT24C64 EEPROM to observe what the microcontroller is doing when I issue the commands to read / write the EEPROM.

I'm using this page as a reference for the CAT commands: https://www.ka7oei.com/ft817_meow.html.

When reading (0x00 0x04 0x00 0x00 0xBB), everything occurs as expected:


But issuing a write command (0x00 0x04 0xD8 0xBF 0xBC), I see no activity in the I2C bus... Maybe the FT817ND has a different command interface than the FT817 (non ND)?

[Palmitoxico]

Ok, I did more tests and discovered more things...

I got the EEPROM memory map from here: https://www.ka7oei.com/ft817_memmap.html

When reading the EEPROM address 0x59 (VFO band select) and changing bands via the band up / down buttons, it really skips the 6m band. It goes from 0x28 (VFOa = 10m) to 0x2A (VFOa = commercial FM, 88 MHz).

If then I send a EEPROM write command to set VFOa to 6m (0x00 0x59 0x29 0x52 0xBC) then it changes to the 6m band!

So, maybe this is a firmware corruption problem? Also, it seems that the EEPROM write command works only on some regions, bytes 4 and 5 seems to be 'read-only'.

[ddosegov]

As far as I remember, JP4006, JP4007, JP4008 should be shorted and JP4004, JP4005, JP4009 should be open. F + M/V + power on to reset...
Try to find out other jumper settings from pictures on net, as there are were some countries that didn´t allow 6m operation, so I think there may be "disable 6m" jumper inside.

[Palmitoxico]

As far as I remember, JP4006, JP4007, JP4008 should be shorted and JP4004, JP4005, JP4009 should be open. F + M/V + power on to reset...
Try to find out other jumper settings from pictures on net, as there are were some countries that didn´t allow 6m operation, so I think there may be "disable 6m" jumper inside.

Well, pressing F + V/M + PWR did restore the 6m band (I was using V/M + PWR or HOME + PWR before with no effect)! BUT it seems that my radio lost all calibration data (S meter gets stuck in S+, no audio output)!.

I was thinking, okay, I've made a backup before, so I should be fine, but inspecting the binary I've noticed that all odd addresses where set to 00, the software I was using to backup the EEPROM contents lost half of the data it was supposed to save!

I didn't know it was possible to issue an 'erase all calibration' command from the front panel buttons. Well, lets see what I can do...

[ddosegov]

BUT it seems that my radio lost all calibration data (S meter gets stuck in S+, no audio output)!.

RF gain set to max? If not, that could be the cause.

I was thinking, okay, I've made a backup before, so I should be fine, but inspecting the binary I've noticed that all odd addresses where set to 00, the software I was using to backup the EEPROM contents lost half of the data it was supposed to save!

I didn't know it was possible to issue an 'erase all calibration' command from the front panel buttons. Well, lets see what I can do...

I´d replace EE with new one and go thru adjustmrents section of service manual. Takes one day and requires pile of equipment, but after some 20 years it deserved complete adjustment.

[Palmitoxico]

BUT it seems that my radio lost all calibration data (S meter gets stuck in S+, no audio output)!.

RF gain set to max? If not, that could be the cause.

I was thinking, okay, I've made a backup before, so I should be fine, but inspecting the binary I've noticed that all odd addresses where set to 00, the software I was using to backup the EEPROM contents lost half of the data it was supposed to save!

I didn't know it was possible to issue an 'erase all calibration' command from the front panel buttons. Well, lets see what I can do...

I´d replace EE with new one and go thru adjustments section of service manual. Takes one day and requires pile of equipment, but after some 20 years it deserved complete adjustment.

Ok ok, it was the RF Gain that was to low, almost had an heart attack. I've set the jumpers to the original US configuration and looking at the manual, in this case, the SQL/RF knob is used as the RF Gain by default. Seems to be working ok now!

In the end it was entirely my fault for not reading the instructions correctly (I was pressing PWR + V/M instead of PWR + V/M + F).

Thank you ddosegov!

[Palmitoxico]

For future reference, I've attached the correct EEPROM contents of my radio, now the correct data (wrote my own python script to do it instead of relying on a random GitHub project).

Here is the jumper configuration I'm using:

[ddosegov]

Thank you ddosegov!

Have good time surfing radio waves.
Hope to hear you on HF.

9A4BP