Re: [IRCA] Bizarre FSL Antenna Shootout (Part 2)

[d1028gary@xxxxxxxxxxx]

Chuck - 
 
<<<ÂÂ Being a PL-380 owner, I'm hoping there's an ounce of cure. Is there any idea why the het appears on 603? And at least to me it's unknown whether there are hets on other frequencies.ÂÂ >>> 
 
The PL-380 and all Tecsun radios withÂthe SiLabs' Si4734 DSP chip have a congenital issue of internally generated heterodynes on some frequencies,Âbut not on all frequencies.ÂIt is one of the "rough edges" of the first-generation DSP chip, which has been corrected in later pocket radio models like the CC Skywave and Eton Traveler III. There is no practical way to getÂrid of these heterodynes without replacing the DSP chip-- an impractical option.ÂMostÂPL-380 users learn to tolerate these, in view of the $40 model'sÂmany advantages (sharp DSP selectivity, multiple digital search functions, etc.). 
 
<<<ÂÂÂÂI don't see any spec for the notch bandwidth in the Timewave. The CW filter bandwidth is specified and happens to be 5 Hz. >>> 
 
With the Timewave DSP 599zx you can set up a manual notch filter with any center frequency and notch width that you desire-- a very convenient feature. It's the perfect solution for any internally-generated PL-380 heterodynes thatÂfindÂtheir way into your MP3 recordings. Because the new hard-wired FSL's provide unusually good audio reproduction quality in PL-380 DX recordings (for the Ultralight radio genre, that is) it's a good idea toÂremove theseÂstray heterodynes and enjoy the best TP-DX audio that the pocket radio class has to offer. 
 
Gary 
 
 
 
ÂÂÂÂÂÂÂÂÂ 

----- Original Message -----

From: "Chuck Hutton" <charlesh3@xxxxxxx> 
To: "Mailing list for the International Radio Club of America" <irca@xxxxxxxxxxxxxxxx> 
Sent: Friday, March 18, 2016 5:11:37 PM 
Subject: Re: [IRCA] Bizarre FSL Antenna Shootout (Part 2) 

Gary - 

Being a PL-380 owner, I'm hoping there's an ounce of cure. Is there any idea why the het appears on 603? And at least to me it's unknown whether there are hets on other frequencies. 

I don't see any spec for the notch bandwidth in the Timewave. The CW filter bandwidth is specified and happens to be 5 Hz. 

Chuck 

________________________________________ 
From: IRCA <irca-bounces@xxxxxxxxxxxxxxxx> on behalf of d1028gary@xxxxxxxxxxx <d1028gary@xxxxxxxxxxx> 
Sent: Friday, March 18, 2016 10:47 PM 
To: America, Mailing 
Subject: [IRCA] Bizarre FSL Antenna Shootout (Part 2) 

Hello All, 

Posted previously was a direct MP3 comparison of the relative reception capability during the exact same minute in receiving a weak-signal TP (603-HLSA) by a 15" FSL antenna inductively coupled to a CC Skywave model 
(a $1000+ combination, posted at https://app.box.com/s/xq7bs7nvptf0d5ts1vxzli0izqza2ncf Â) 

and a new stand-alone 3" FSL Tecsun PL-380 model (a $95 modified pocket radio, with a hard-wired 3" FSL antenna) posted at 
https://app.box.com/s/4r27auio85caqadccsyb8pwcatw5rku0 

There is a little more to the story, however. Although the modified PL-380 does generate somewhat of a heterodyne on 603, this type of issue is easily corrected by a DSP signal processor (such as the Timewave DSP 599zx), which is routinely used to remove TP heterodynes from DXpedition MP3's recorded on pocket radios. When this is done (filtering the 740 Hz heterodyne with a 5 Hz notch filter), the 3" FSL Tecsun PL-380's signal ends up sounding like this: 
https://app.box.com/s/bcj3ap8g0tefie0ku903z28g5njtrfgc 

When comparing this "Science Fiction PL-380"Âsignal with that of the inductively coupled 15" FSL (which already has a stellar DXpedition record on the lower frequencies at Rockwork 4), the implications are pretty obvious. Five of these little monsters covering different high priority frequencies at an ocean cliff site could dramatically increase the effectiveness of Ultralight transoceanic DXing. 

73, Gary DeBock (in Puyallup, WA, USA) 








_______________________________________________ 
IRCA mailing list 
IRCA@xxxxxxxxxxxxxxxx 
http://montreal.kotalampi.com/mailman/listinfo/irca 

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers 

For more information: http://www.ircaonline.org 

To Post a message: irca@xxxxxxxxxxxxxxxx 

_______________________________________________ 
IRCA mailing list 
IRCA@xxxxxxxxxxxxxxxx 
http://montreal.kotalampi.com/mailman/listinfo/irca 

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers 

For more information: http://www.ircaonline.org 

To Post a message: irca@xxxxxxxxxxxxxxxx 


_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx