[Elecraft] Kpod not Working on K3

[Geert Jan de Groot]

On 19/11/2023 23:20, elecraft-request at mailman.qth.net wrote:
> Hi All, I have taken my Kpod from my K4 
> and put it on my K3. (I assume it works for both rigs). The K3 has had 
> the Mod completed as per the Kpod manual with a 6.8 Ohm, 1/8 W Leaded 
> Resistor as per pages 16-18 of the Kpod manual. Problems. 1. Kpod does 
> not power up with the Data cable between K3 & Kpod connected (No leds 
> lit up at all. 2. When I power Kpod with a 12v source the On led shows 
> as does D1 - D3 when switched with the rocker switch. 3. The large 
> tuning knob on the Kpod does not function in any way. I have tested the 
> Data cable with a network tester it is wired correctly 2-6 pins only and 
> they show satisfactory on the tester. 

The RJ45 connector on the bottom seems to be a "manufacturing connector" 
that later got re-used to support the K-POD. Originally, it would be 
able to program the main processor of the K3.

Exactly how this works is on sheet 4 (of 7) of the K3 Front Panel - MCU 
schematics, where this connector is labelled "J3 - ICD-2".
The name ICD-2, as well as the names of the signals on this connector - 
MCLR, PGD, PGC - are familiar if you do microchip programming and they 
go directly to U1 PIC18LF8722 which is the main controller for the front 
panel.

My recommendation would be to open up the KPOD (for which schematics can 
also be downloaded, as well as for the K3 itself) and check if you 
actually get 5V, and GND correctly from the K3. I suspect that the cable 
is reversed or the "wrong" pin1 is clipped.

I would resist the temptation to make a cable that is rolled. The 
signals go directly to the processor and measuring, instead of changing 
the cable.
These flat cables have a "flat" side and a "seam side. On my 
Elecraft-supplied cable, one end has the seam up and the other end has 
the flat up.

Also, if the R82 mod (6.8ohm resistor) is not fully connected then pin6 
will not carry 5volts as soon as the KPOD is connected since the KPOD 
draws more current. Having said that - the fact that the KPOD powers up 
with an external 12V supply but then still doesn't communicate suggests 
an issue with the cable even though your description is pretty good.

What software version is your K3 running? Manual says 5.54 minimal for 
KPOD support.

Geert Jan