Re: K2 question (KUSB and KIO2)

[Geert Jan de Groot]

> Is the KUSB cable compatible with the K2?  Should have asked this before I
> bought the cable.  My K2 has worked with a serial port adapter from Keyspan
> for several years and with a variety of logging programs.
> So I went with the KUSB.  When I connect it, the K2 does strange things.
> Power control turned all the way down results in a nice 10 watt output  and
> normal operation.  When Power control is turned up I get a HiCurr and LoPWR
> error and the display only shows power, not frequency.

Please read the KIO2 documentation: any serial device may only be
connected *if only pin 2, 3, 5* are connected. If you connect a serial
device with the other pins connected, which the KUSB as well as most
other devices have, *you can cause serious damage to your K2*.

It is essential that the other pins are left unconnected, they are used
for other signals and the RS232 signals give voltages that cause damage.

So, if you use the KUSB, make sure to insert a short cable that ONLY
connects these 3 wires, NOTHING ELSE.

How much damage is done partially depends on the hardware mod version of
your K2. The "B" mods includes some modifications that should limit some
of the most serious damage, like blowing up the main processor of your
K2. There is a document somewhere that describes what damage a K2
suffers because of this; it's a long list

Despite the fact that the KIO2 sports a DE9 connector, it really isn't a
standard serial port. In hindsight, Elecraft should have chosen a DE15
connector instead (making sure that a "VGA cable" would not cause
damage. Ah well, too late now..

73, Geert Jan
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[Dave Sublette-2]

Thanks for the info. I will have to make up that short cable! Fortunately
my K2 is the B level.

73,

Dave

On Sat, Feb 27, 2021 at 5:10 PM Geert Jan de Groot <[hidden email]> wrote:

>
> > Is the KUSB cable compatible with the K2?  Should have asked this before
> I
> > bought the cable.  My K2 has worked with a serial port adapter from
> Keyspan
> > for several years and with a variety of logging programs.
> > So I went with the KUSB.  When I connect it, the K2 does strange things.
> > Power control turned all the way down results in a nice 10 watt output
> and
> > normal operation.  When Power control is turned up I get a HiCurr and
> LoPWR
> > error and the display only shows power, not frequency.
>
> Please read the KIO2 documentation: any serial device may only be
> connected *if only pin 2, 3, 5* are connected. If you connect a serial
> device with the other pins connected, which the KUSB as well as most
> other devices have, *you can cause serious damage to your K2*.
>
> It is essential that the other pins are left unconnected, they are used
> for other signals and the RS232 signals give voltages that cause damage.
>
> So, if you use the KUSB, make sure to insert a short cable that ONLY
> connects these 3 wires, NOTHING ELSE.
>
> How much damage is done partially depends on the hardware mod version of
> your K2. The "B" mods includes some modifications that should limit some
> of the most serious damage, like blowing up the main processor of your
> K2. There is a document somewhere that describes what damage a K2
> suffers because of this; it's a long list
>
> Despite the fact that the KIO2 sports a DE9 connector, it really isn't a
> standard serial port. In hindsight, Elecraft should have chosen a DE15
> connector instead (making sure that a "VGA cable" would not cause
> damage. Ah well, too late now..
>
> 73, Geert Jan
>

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[Geert Jan de Groot]

> How much damage is done partially depends on the hardware mod version of
> your K2. The "B" mods includes some modifications that should limit some
> of the most serious damage, like blowing up the main processor of your
> K2. There is a document somewhere that describes what damage a K2
> suffers because of this; it's a long list

Apologies for replying to my own post - didn't want Dave to sustain any
more damage! - but for those who have done the unthinkable and connected
a regular RS232 device to KIO2,
https://folk.universitetetioslo.no/sverre/LA3ZA/blog/K2/N0SS/k2_wrong_ser_cbl_damage.pdf 
should be helpful information.

Step 10 of the K2 "Upgrading the elecraft K2 to revision B" document on
the Elecraft website has a valuable step that I missed when I did other
upgrades.

BTW, if your K2 is the 10W version, you don't use the RS232 port and you
don't have the "K2 amplifier keying circuit" that can be found on the
Elecraft website, it is possible to put that circuit inside a DE9
connector hood: have a DE9-M connector that plugs in the KIO2, and a
cable to key your amplifier. I added another transistor to switch a
small LED so that the connector now lights up when the K2 is
transmitting. I use this to key a chain of transverters for the QO100
satellite. And it avoids drilling a hole for the PTT key plug.

73,

Geert Jan

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