[Elecraft] USB to Serial adapter for KIO2

[Fred Jensen]

OK Harry, as you wish, but just DO NOT plug a USB-Serial adapter cable 
into the DE-9 connector on the back of the K2 ... unless you strive to 
have Don repair it for you afterward. The connector on the back of your 
K2 is *NOT* an RS-232 serial port.  It does have 2 standard RS-232 wires 
in it [3 if you count signal ground], but all the other pins are 
internal signals at TTL levels and will not tolerate RS-232 signal 
levels which can range up to +/-12V.

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 3/30/2017 2:20 PM, Harry Yingst via Elecraft wrote:
> For my use it fits my needs better as I do not plan to use Elecrafts Transverters nor their 100 watt amp remotely.
> So it becomes a simpler solution.
>
>
>
>        From: Don Wilhelm <donwilh at embarqmail.com>
>   To: Harry Yingst <hlyingst at yahoo.com>; Elecraft Email List <elecraft at mailman.qth.net>
>   Sent: Thursday, March 30, 2017 4:30 PM
>   Subject: Re: [Elecraft] USB to Serial adapter for KIO2
>     
> Harry,
>
> OK in broad concept - EXCEPT, things get bogged down in the details:
> You will have some problems to solve if using that device.
>
> First of all, the K2 MCU RX and TX signals need to be TTL (0 to 5V)
> instead of RS-232 and the polarity must be inverted - so you will need
> some more logic circuits to make it work.
>
> 2nd, the KIO2 provides internal K2 signals needed for Elecraft
> accessories like the KAT100, KRC2, XVseries Transverters.  If you ever
> want to add any of those accessories, you will be back "where you started".
>
> 3rd, if you ever add the KPA100, you will have to give up all your work.
> Although that device will mount on the KPA100 board, the levels and
> polarity are not right AND it contains ALL the RS-232 signal lines, not
> just TXD and RXD and Signal Ground.  You would have to make extensive
> modifications to the KPA100 board to make it work - and you still do not
> have the internal K2 signal lines to support the external Elecraft
> accessory boxes.
>
> Simple "solutions" are often complex.  It is easier to use an external
> USB to serial adapter IMHO.
>
> 73,
> Don W3FPR
>
>