[RTTY] SPOT:SV2ASP/A 18.107.6 RTTY

[Joe Subich, W4TV]

AMTOR or not, the PK-232 was designed primarily for HF Packet and
uses 200 Hz shift for both transmit and receive on HF.  The modem is
a typical 1980's filter/slicer for receive (multiple stages of op-
amp based filters) and a PLL for transmit.  "Nominal" HF tones are
2110/2310 Hz.

There is a modification for the PK-232 that will convert it to
170 Hz (http://www.qsl.net/k0bx/align.htm).  The modification
involves replacing four resistors (in the receive filter) and
aligning the AFSK generator for 170 Hz (to 2125/2295).

73,

    ... Joe, W4TV


On 4/28/2011 11:29 PM, Kok Chen wrote:
>
> On Apr 28, 2011, at 4:05 PM, Kok Chen wrote:
>
>>   (the dreaded Amtor shift).
>
> Whoops, sorry to disparage Amtor. I just remember that Amtor shift
> isalso 170 Hz. It is HF Packet that uses 200 Hz shift.
>
> 73
> Chen, W7AY
>
>
>
>
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