[aprssig] FYI: D700 Operation Without Control Head

Steve Noskowicz noskosteve at yahoo.com
Fri May 15 03:28:20 EDT 2009

  I don't know if this has been hashed out here before, but a recent question and response on the D700 Yahoo group prompted a bit of an investigation.

The following applies WITH or WITHOUT the Control Head connected.

  You can turn on the radio from the serial port. The command is simple ASCII "PS 1" no quotes, end with a Carrage Return (CR) character. In Hex this is &h50 &h53 &h20 &h31 &h0D.


  It appears to be an issue of having serial port activity for some time period because of the following observations.

  Typing manually with Hyperterm, it takes 2 or 3 PS 1 commands.

  Testing at 9600 baud, it takes about 35 characters to wake up the processor to then accept the command.

  I found that sending 35 or more CRs followed by the PS 1 CR works well. In HEX this is 35 &h0D's then &h50 &h53 &h20 &h31 &h0D.

  Other characters work, but if you have more than 35 before the PS 1 command, the radio will balk at the command and respond with "?". The number 35 seems to be slightly different for different characters. Sending complete PS 1 commands takes 8 of them which is 36 characters before the final command. Sending from 32 to 34 CRs in the "prefix" will turn on the radio, but it responds with "?". This is not recommended, use = or > 35.

  I did find some variations from the 35 character "prefix" that would both power up the radio and respond with a "?". Then, subsequently sending any other command resulted in receiving a PS 1 from the radio. It has to get that out of it's system, so to speak.

  When the radio powers up, it responds with the same thing as the command, namely "PS 1".

  I also found some variations (usially 2 or 3 less characters) that did NOT power up the radio, but responded with the "?".

  Less than about 30 or 31 characters of prefix has no effect (no response from radio).

  I did not do any exhaustive testing of other commands once powered up sans head, but a few worked normally, so It's a safe bet that everything that can normally be done from the serial port works and pretty much normal radio control is possible. I know that there are some things that can only be done with the Control Head, however, I do not have a complete list compiled.

  I also have a free for the download Excel spreadsheet that does control and memories including ALL PMs. I'll have to add the power up sequence and basic volume and squelch capability in the future.

Other key words for a search.
Head stolen missing

73, Steve, K9DCI


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