[Elecraft] K3 PK-232 FSK RTTY Setup

[David Wilburn]

I'm in the process of picking up a PK-232, primarily for EmComm / 
Pactor 1.  I'm not intending to start a passionate discussion between 
FSK / AFSK, but had a question.

I have been running AFSK since I received my K3 last March.  It has 
worked well, but it is the only RTTY I have known.  I have seen the 
reason given for running FSK vs. AFSK as the ability to use the 
radio's filters.  That is a moot point in the K3.

I also understand that when using FSK, it is a different distribution 
of resources.  I have MMTTY running with N1MM (when I am contesting), 
and MMTTY triggers the radio via VOX.  This has the annoyance that 
when I click on a SSB spot, then a noise in the shack triggers the VOX 
kicks in and causes feedback.

Now to my question.  If I am happy with how the RTTY is performing now 
using AFSK, what is the incentive to setup for FSK?

Dave Wilburn
NM4M

Ed Gray W0SD wrote:
> For those now or in the future wanting to setup the PK-232 with the K3
> using FSK here is the information.  I would think you could do this very
> similarly for the Hal and  other TNC'S.  Of course the specific wiring 
> would be different but the same general hook up should work.  This set 
> up does not use the computer sound card at all.
> 
> First you need a software program to control the PK-232 or the TNC you
> are going to use.  I used Writelog but there are other software programs
> that will work.
> 
> The PK-232 has a cable from it to a serial COM port port on your 
> computer which you need to set up in your software, in my case Writelog. 
> That is all you need between the PK-232 and the computer.  There is 
> absolutely nothing hooked to the computer sound card.
> 
> The K3 should be set to FSK D, see page 31 of the K3 manual revision D1.
> Next you should be sure your software program is set up for the same
> tone and shift that you have the K3 set to.  On the K3 activate pitch
> and set it accordingly.  Most common would be 2125-170 which is what I
> have Writelog set at.
> 
>  From the K3 run an audio line from the line out to the Radio 1 or Radio
> 2 RX input on the PK-232.  This jack is hooked respectively to the same 
> place as J4 or J6  which is the 5 pin flat connector.  I would suggest 
> using Radio 1 and running an audio cable from the K3 line out to J3 
> which is the Radio 1 RX input.  The K3 end is a sterio plug and the 
> PK-232 is a mono plug. On the K3  go ahead and use a stereo cable and 
> plug it into the K3 line out.  On the PK-232 end of this cable cut off 
> the stereo plug and solder on a mono plug.  The tip from the stereo plug 
> should be hooked to the tip of the mono plug which will be the left 
> channel.  This will be the K3 audio.  The ring(one next to the tip) 
> would be the SUB so just leave it unhooked and hook the barrel from the 
> stereo plug to  the ground of the mono plug.  Go to the K3 config:Line 
> out.  I set it for about about 25.  Remember the K3 manual is talking 
> about sound card input when they mention 10 and here we are talking 
> about input into the PK-232. The PK-232 manual says to have at least 200 
> mv RMS of receive audio. Using my scope and then calculating RMS I came 
> up with the setting of 25 to get 200 mv RMS.  It is better to be a 
> little low than too high so you don't have distortion.
> 
> For FSK transmit you need to hook the PK-232 FSK keying which is pin 1
> of the DIN plug J7 to Pin 1 FSK Input of the K3 accessory plug.  You
> hook the ground, Pin 2 of J7 to Pin 5 of the K3 accessory plug. J7 on
> the back of the PK-232 is labeled so that is easy.  The K3 accessory 
> jack information is on page 18 of the K3 manual revision D1.
> 
> Be sure and note that the picture you are looking at in the K3 manual of
> the accessory jack is the radio pin out and not the plug on the cable
> you are making so be careful to use the correct pins. I just took a
> Video cable and cut the female connector off and used the appropriate
> wires to hook to the PK-232. The extra wires can be folded back and cut
> to different lengths and heat shrink tubing put over them so no wires
> can short to each other.
> 
>  From J4 on the PK-232 which is the 5 pin flat connector hook up the PTT
> line Pin 5 to the K3 accessory plug pin 4.  This should complete the FSK 
> setup for the K3 with the PK-232.
> 
> Ed W0SD
> 
> 
> 
> 
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