[RTTY] DXP-38- keep it or sell it?

[Ed Muns]

Rudy Bakalov, N2WQ, asked:
> I have a pair of DXP-38 modems that I got a couple of years 
> ago, but never bothered integrating into my station. I no 
> longer have a computer with serial ports and was wondering if 
> the DXP-38 was worth the USB to serial cables. I know it's 
> juts a few bucks, but sometimes less is more, i.e. keep it simple.
> So, compared to MMTTY, how well does the HAL play?

In my experience, 99% of the time they decode identically.  Sometimes one is
better than the other.  The DXP38 prints off-frequency signals better.  This
is helpful in S&P and perhaps in running if the pile-up is small enough that
you don't need to pare it down with narrow filtering.

> My 
> thinking was to use it in diversity reception,

How do you plan to do this on RTTY?

> fronted by a 
> Timewave DSP-599zx in RTTY tone pair regeneration mode or 
> just the data mode filter. This is where the complexity comes 
> into play.
> So, keep them pair or sell them?

Keep the pair, depending on how you use them.  Their resell value continues
to hold up, so selling them is a good alternative too.

RTTY modems are like antennas ... Some are better in specific situations,
everyone has their favorite and you can never have enough (variety) to cover
all situations.  As just one example, I habitually use the DXP38 in parallel
with multiple MMTTY profiles, all decoding the same audio stream, for
contesting.  There are times, albeit rarely, where one decoder will print
clearly when others don't.  Sometimes it is one of the MMTTY profiles, and
sometimes only the DXP38 decodes clearly.  A specific example is in the
early morning hours local time in Aruba, JA stations are often unprintable
with any of the MMTTY profiles when the DXP38 prints clearly.  This only
occurs for a short time and sometimes never, but when it is the case, I am
very grateful to have the DXP38s on-line.

> If keep them, shall I 
> bother with the DSP front-end or just feed them with the 
> regular audio from my Icom 756P3s?

I used the JSP NIR-12 between the 756Pro3 and my RTTY decoders mostly out of
habit with older radios.  I don't think the NIR-12 improved the audio on DSP
rigs like the 756, but it did provide an independent audio level control,
and buffering, for the headphone audio and the decoder audio.

73,
Ed
--------------
Ed Muns - W0YK
www.w0yk.com