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Re: [IRCA] Tecsun PL-300WT-- A Sizzler on AM & FM, A Fizzler on LW and SW
These new series of DSP radios are interesting from another point of view, at least from those of us lamenting the move away from US production of high-end receivers (e.g. Drake): the Silicon Labs chips - the heart of these radios - are designed and prototyped in Austin, TX. The production wafers are purhcased in Taiwan, and most likely the chips are fabricated there too. These then end up in China and are integrated into a product there, and marketed domestically, via ebay, and probably in the not too distant future in US and Europe too.
Paul
--- On Tue, 6/2/09, D1028Gary@xxxxxxx <D1028Gary@xxxxxxx> wrote:
> From: D1028Gary@xxxxxxx <D1028Gary@xxxxxxx>
> Subject: Re: [IRCA] Tecsun PL-300WT-- A Sizzler on AM & FM, A Fizzler on LW and SW
> To: irca@xxxxxxxxxxxxxxxx
> Date: Tuesday, June 2, 2009, 11:02 AM
> Hi Paul,
>
> Thanks for the information on the PL-300WT's AM-FM DSP
> chip, and of course
> the radio's uneven performance on LW and SW certainly makes
> me agree with
> your statements.
>
> It's obvious now that Tecsun designed the breakthrough DSP
> performance to
> apply only on AM and FM, and the LW and SW bands are
> mediocre additions
> which border on the defective. I myself have been
> puzzling why Tecsun would
> even wish to include them in this innovative
> receiver, but I suppose that if
> they were lacking, purchasers might think that this
> was only another typical
> AM-FM portable receiver for local reception (which of
> course would be a
> great mistake), and pass over this receiver in favor of its
> 4-band
> competitors.
>
> 73, Gary
>
>
> In a message dated 6/1/2009 10:16:22 P.M. Pacific Daylight
> Time,
> texnote@xxxxxxxxx
> writes:
>
>
> Gary,
>
> According to the ebay description of the Tecsun
> PL-300WT (by the seller
> "liypn"), this radio uses the Silicon Labs Si4737 DSP
> chip which can only
> demodulate MW, FM, and the Weather Band. See slide 12
> of
> https://www.silabs.com/Marcom%20Documents/Resources/Si473x_Presentation.pdf
> and
> https://www.silabs.com/products/audiovideo/amfmreceivers/Pages/Si473637.aspx
>
> If liypn's information is correct (verified by
> opening the radio up and
> locating the Silicon Labs chip), Tecsun must use this
> chip for MW/FM, and a
> separate non-DSP single or dual conversion
> demodulator/tuner with much
> poorer selectivity and sensitivity for shortwave.
>
> For shortwave enthusiasts, it will be interesting to
> see which one of the
> forthcoming DSP radios from Tecsun use the Si4734 or
> Si4735 chips, which
> demodulate MW, FM, and SW.
>
> In terms of price, the Si4737 chip starts at $3.06 in
> quantities of 10K;
> the Si4734/35 starts at $3.27 in quantities of 10K.
>
> Paul
>
> --- On Mon, 6/1/09, D1028Gary@xxxxxxx
> <D1028Gary@xxxxxxx>
> wrote:
>
> > From: D1028Gary@xxxxxxx
> <D1028Gary@xxxxxxx>
> > Subject: [IRCA] Tecsun PL-300WT-- A Sizzler on
> AM & FM, A Fizzler on LW
> and SW
> > To: irca@xxxxxxxxxxxxxxxx,
> am@xxxxxxxxxxx, ultralightdx@xxxxxxxxxxxxxxx,
>
> odxa@xxxxxxxxxxxxxxx
> > Date: Monday, June 1, 2009, 9:45 PM
> > Hello All,
> >
> > Although evidence indicates that a huge ordering
> boom has
> > started for the
> > DSP-enhanced Tecsun PL-300WT Ultralight radio, for
> those of
> > you still on the
> > fence about this innovative pocket radio,
> some further
> > information may be
> > of interest.
> >
> > Tecsun's primary focus in developing this
> breakthrough
> > model appears to
> > have been in transforming the AM and FM
> circuitry to set
> > new standards of
> > weak-signal performance, and with superlative
> sensitivity
> > and selectivity in
> > both bands, they appear to have accomplished
> their purpose.
> > However, the
> > model does have other bands included in the
> package, which
> > frankly appear to
> > have been neglected, and border on the
> substandard.
> >
> > The Longwave band (153-513 kHz) of the
> PL-300WT was
> > thoroughly searched
> > for any possible signals at local sunset,
> without any
> > results. This is not
> > unusual for small portables with LW capability,
> but
> > in most cases, one or two
> > of the strongest beacons will at least make an
> > appearance at sunset.
> >
> > The Shortwave bands of the PL-300WT are filled
> with local
> > MW station spurs,
> > and mixing products. The signal of local
> KSUH-1450 has a
> > "coverage" of
> > about 6 Mhz on the Tecsun's shortwave
> bands, from 9.5
> > Mhz to 15.5 Mhz. WWV on
> > 10 Mhz is really just a mixing product with
> KSUH.
> > Legitimate SW stations
> > have anemic signal levels, to the point of
> being
> > crowded out by the MW spurs.
> > The Tropical Band is especially bad, with
> a sorry
> > collection of MW
> > station spurs and mixing products overpowering
> any
> > legitimate stations.
> >
> > Of course the argument could be made that for a
> $50
> > receiver, Tecsun has
> > already provided an outstanding value with the
> superlative,
> > DSP-enhanced
> > reception on the AM and FM bands. The puzzling
> aspect is
> > why Tecsun would
> > include such dreadful LW and SW sections in a
> model which
> > is otherwise so
> > superb. In summary, if LW or SW reception is
> your top
> > priority in a portable, my
> > strong recommendation would be to avoid the
> PL-300WT,
> > despite its
> > breakthrough DSP capabilities.
> >
> > 73, Gary DeBock
> >
> >
> >
> > **************An Excellent Credit Score is 750.
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