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  2. Tecsun PL-380 "Soft Mute" (or lack thereof)

Re: Tecsun PL-380 "Soft Mute" (or lack thereof)

Gary DeBock
 

Hi Roy,
 
It really seems that Tecsun didn't change anything with these three PL-380's, since the filter selections, filtering performance, and the ability to tune 1 kHz up or down from a weak station (without a severe soft-mute drop-off) is exactly the same as my earlier PL-380 models. I don't know if these are the official "new model" PL-380's (mentioned by Joyce of Anon-co), or not. Nothing seems different to me.
 
I plan to perform some loopstick modifications and other experiments on these models, but since two of them are destined for other DXers after thorough testing, I'll save any strip-down work for the model I plan to keep. It may be the weekend before I can do much with them, however, since my Amidon shipment (with the LW-optimized ferrite bars and shorter type 61 bars for the PL-310 internal loopstick tinkering) apparently hasn't even shipped yet. Amidon certainly must be wondering how so many orders came suddenly, despite the poor economy :-)
 
73, Gary  
 
In a message dated 1/5/2010 1:25:35 A.M. Pacific Standard Time, roy.dyball@... writes:

 

Hi Gary

Perhaps the new 380s have the new Ver40 firmware. You would have to strip it down and remove the RF shield from the Si4734 to read the top of the chip to find out. Are the filter selections the same?

Roy.

--- In ultralightdx@yahoogroups.com, D1028Gary@... wrote:
>
> Hello All,
>
> For those interested in whether the newer PL-380 models have the irritating
> "soft mute" function disabled or not, a recent shipment from Joyce at
> "Anon-co" may be of interest.
>
> For experimentation (and for forwarding to other DXers), three PL-380's
> were ordered from Joyce on December 29th. She kindly upgraded the shipping to
> EMS (express mail) at no additional charge, so that the radios were
> received today.
>
> All three of the PL-380's were manufactured in December, and all have two
> screws in the battery compartment. The serial numbers are also similar:
>
> 36920091200993
> 36920091200998
> 36920091201009
>
> All three were tested against a soft mute-enabled PL-310, to see if there
> was any difference in the soft mute perf ormance. Similar to the other two
> PL-380 models here, tuning the new PL-380 models 1 kHz up or down from a
> weak station's frequency did result in a reduction of signal strength, but it
> was a moderate reduction, not the very steep drop off in audio like on the
> PL-310. This was with the DSP filtering set at 1 kHz (typical in TP-DXing).
> The PL-380's were also checked for intermittent signal drop out during
> weak station reception, but did not have this soft mute-related issue, either.
>
> Whereas one of the first two PL-380's received here had instability on the
> SW bands (with intermittent oscillations, as reported in the PL-380
> review), all of the three new PL-380's have stable SW reception. One of the new
> models does have a tuning control which seems slightly stiff, however, and
> one new model seems to have slightly lower AM sensitivity than the other two
> (I suspect a loopstick issue, which would make this model a nice candidate
> for a transplant :-)
>
> In general, there doesn't seem to be any real evidence yet that Tecsun is
> changing the PL-380's to the full soft mute mode, but any DXer receiving
> one of the official "new models" is requested to notify the group ASAP if
> soft mute changes are suspected.
>
> 73, Gary DeBock (in Puyallup, WA)
>
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