[RTTY] interface

[Kok Chen]

WD5DBV asked:
> I will be replacing my pk 232 with a newer unit I am looking at the Hal 
> DXP-38 and Kam 98and comments pro or con or any other units I should 
> consider. Any help would be appreciated I will use it mostly for rtty 
> dxing and a little contesting

Hi Roy,

The modems that I currently have are a modified KAM Plus, a KAM 98,
a HAL DSP-4100 and a Timewave DSP-599zx.

In terms of ability to decode signals, for my use, I would rate them as

Modified KAM Plus about the same as KAM 98
HAL better than KAM (very noticeable)
Timewave a little better than HAL (enough to be noticeable)

Except for a couple of features (balanced audio inputs, perhaps Clover, 
and
the lack of a tuning meter on the 4100), my understanding is that 
DSP-4100
is pretty much the same as the DXP-38.

If you have a stand-alone means of providing a tuning indicator, I would 
recommend
keeping your current modem, and wire a Timewave DSP-599zx into the audio 
chain
and always turn on the "remodulator" function (where the DSP-599 not 
only filters
the FSK but also demodulates it, and then send a clean FSK signal to 
your modem).

The only problem when you use the remodulation mode is that your current 
TNC's
tuning meter is inoperable (since it will be receiving either nothing, 
or a perfectly
formed FSK waveform), and the meter on the DSP-599zx isn't what I would 
consider
anywhere close to a contest grade tuning indicator.

Just MHO.

73
Chen, AA6TY