> > Obviously a possibility here for Elecraft to offer the KIO3 in either > version (RS-232 or USB connector) as an ordering option, if they've a mind > to...
There are a few issues here: 1) Does the internal RS232 charge pump have harmonics in any Amateur bands? Are they audible? In the KIO3 we took great pains to not use a charge pump based RS232 level shifter since this circuitry is extremely close to the KXV3(A) which may carry the Rx Antenna path. Instead, we created a clean oscillator at audio and derived the necessary negative bias voltages from it. The RS232 interface is also right next to the KRX3 SubReceiver antenna input. One must be very careful about noise management here -- or go to use of castings and lots of internal shields like some radios use. 2) For an internal USB interface, we'd like to see Rx Audio (stereo) and Tx audio, along with FSK, in a way that requires no special drivers for most computers running most current or recent OSes. This reduces cabling requirements. Conceptually, think of a microHAM device (or Navigator, RigExpert Plus, ...) internal to the radio. 3) For the present configuration, you need a cable between the K3's RS232 port and the computer. Changing to an internal USB<->RS232 adapter does not reduce or simplify cabling requirements, and in fact reduces the flexibility of the radio's interface! 4) Some products, like the P3, interpose themselves into the RS232 control path in a daisy-chain fashion. If the RS232 is changed to USB on the K3, the interposing device either needs to become a USB host (perhaps USB-OTG is sufficient) or an intelligent "bridge" device. This is far more complex and potentially much more costly than the present solution. Again, the RS232 interface appears to be the better choice at present. Enjoy! 73, Lyle KK7P ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
