5.2  YAESU5 configuration option


 FT847, FT817, FT818  

These radios have a quite limited CAT control command set. They include the following features:


  • All outgoing commands are 4 bytes optional BCD data followed by a single byte hexadecimal opcode.


  • There are three 'read' commands:

- Frequency + mode returning five bytes.  Bytes 1 to 4 (BCD) = freq / 10. Byte  5 = mode


       - Receive status returning a single binary byte.   Bits 0 to 4 = S meter (0-31)

                    Bit 5 - discriminator / mode ??   Bit 6 CTCSS status. Bit 7 squelch status.


       - Transmit status returning a single binary byte. Bits 0 - 4 = Tx power. Bit 5 = split on/off.
               Bit 6 = high SWR.  Bit 7 = PTT (0 = Tx,  1 = Rx)


  • The command set is quite limited compared to the FT920, FT1000 and more modern radios.
    This leaves piWebCAT's screen looking relatively unpopulated.
    The available commands differ between radios.
    eg: the FT847  CAT does not have control of split, VFO A/B toggle or clarifier.


FT847:  Early FT847s had no status read capability. A firmware update for this is not now available.
       Fortunately, my FT847 does have read capability. I could therefore test S meter, power meter etc.
       Its serial number suggests that it would have needed the firmware update.
       I have no recollection of the upgrade    . But I have had the radio for ? 17 years !!!


The initial development was done on my FT847 with support from an FT818 user.
I used the FT818 manual (with comparisons to the FT847 manual).


The CAT manuals do not actually state that Rx and Tx status requests return only one byte.
This caused me confusion until I found the following very useful internet reference:


     http://www.ka7oei.com/ft817_meow.html


Hardware - connection:

  • The FT847 has a 9 pin D  RS232 connector which requires a crossover (null modem) cable.
  • The FT817 and FT818 needs a Yaesu CT-62 cable  ... or home made equivalent.