[Elecraft] K3 manual question

[Don Wilhelm]

Steve,

The manual differs from the schematic, and I would strongly suggest that 
the schematic is correct.  RTS is on pin 7 and DTR is on pin 4 according 
to the schematic.

Second question:  If your computer application puts the FSK data on TxD, 
then yes, you add an RS-232 to TTL conversion stage and feed that output 
to ACC pin 1.  If your application uses DTR for the data line, then you 
would use the DTR signal rather than TxD - I do not know your 
application, you will have to become familiar with how your application 
provides data output.  I do not know of any applications that use 
anything other than TxD for the data.

Third question - I know of no instance where one would want to activate 
either PTT or Keying with the TxD - all application that I have heard 
about use either DTR or RTS.

The K3 does not have a *full* RS-232 interface.  It implements only TxD, 
RxD, RTS, DTR and signal ground.  The computer communications for the K3 
does not use handshaking, only the TxD and RxD lines are used (note that 
one should configure the computer port for handshaking = none) - leaving 
RTS and/or DTR for PTT and Keying purposes.  That is compatible with 
most or even all the ham radio applications that generate PTT and/or 
Keying.  The instructions for the application will tell you whether it 
uses DTR or RTS for keying and/or PTT.  Yes, FSK normally uses TxD, but 
that is not 'keying' in the normal sense - it is 'data'.

73,
Don W3FPR

K4FJ at aol.com wrote:
> Hi,
>  
> Page 18 of my K3 manual shows the breakout for the RS232 connector.   It says 
> pin 6 is RTS.  I thought RTS was on pin 7 in the standard DB9  configuration.
>  
> Second question:  The manual is clear that pin 1 of the Aux I/O  connector is 
> for FSK IN.  Does that mean that I run my computer's RS232 pin  3 (txd) or 4 
> (dtr) through a NPN level adjuster, or either?
>  
> Third question:  I am confused because I read (in the manual) that  Config: 
> PTT-KEY settings address only OFF or DTR/RTS or RTS/DTR.  No  mention of TXD.  
> Does KEY relate only to CW and not FSK/RTTY?
>  
> Just another non-computer jock trying to keep up.
>  
> This reflector, Elecraft, and the K3 are just great.
>  
> 73, Steve, K4FJ
>      K3/#290
>   
>