Re: [IRCA] â"Science Fiction PL-380"-- Pest Control Version

[d1028gary@xxxxxxxxxxx]

<<<ÂÂ Wishful thinking, I guess, Gary. ÂNow, is there a simple way of converting 
the failed FSL/FLG 100 combo to the traditional setup? ÂIs it simply a 
matter of switching out the FLG and replacing it with a variable capacitor? 
ÂÂ73,...WaltÂÂ >>> 
 
Yes, conversion back to a tunable FSL model would be easy-- by replacement of the FLG100 with a tuning capacitor. But if you really want to transform the antenna into aÂhot little performer I would recommend replacementÂof the 660/46 Litz wire with the ultra-sensitive new 1162/46 wire. This is the Litz wire used on all the recent Oregon Cliff DXpedition FSL antennas. 
73, Gary 
 

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

From: "Walter Salmaniw" <canswl@xxxxxxxxx> 
To: "Mailing list for the International Radio Club of America" <irca@xxxxxxxxxxxxxxxx> 
Sent: Saturday, January 23, 2016 10:19:11 PM 
Subject: Re: [IRCA]ÂÂÂÂÂÂÂÂâ"Science Fiction PL-380"-- Pest Control Version 

Wishful thinking, I guess, Gary. ÂNow, is there a simple way of converting 
the failed FSL/FLG 100 combo to the traditional setup? ÂIs it simply a 
matter of switching out the FLG and replacing it with a variable capacitor? 
ÂÂ73,...Walt 

On Sun, Jan 24, 2016 at 3:48 AM, <d1028gary@xxxxxxxxxxx> wrote: 

> Hi Walt, 
> 
> <<< Â Fellas, I'm interested again with the removal of the variable tuning 
> capacitor and use for broad spectrum Perseus SDR captures. ÂAs you recall, 
> a number of these early large units were kindly built by Gary. ÂOne was 
> sent my way (and I may have the same in Masset). ÂResults have been 
> variable. ÂWould anything different be done with these units compared to 
> what we know today? Â >>> 
> 
> Thanks for your comments. 
> 
> Although these hard-wired FSL antennas perform exceptionally well in the 
> PL-380 model, they can do this only because the radio has a Silicon Labs' 
> Si4734 DSP chip with an antenna-tuning function. Whenever the DXer changes 
> frequency the DSP chip automatically responds by peaking sensitivity for 
> the new frequency, eliminating the need for the DXer to peak a variable 
> capacitor (as with traditional FSL antennas). 
> 
> Since the Perseus-SDR and other spectrum capture receivers don't have 
> this critical component, hard-wiring those 7" FSL antennas into their 
> circuitry wouldn't really accomplish anything (except maybe melting down 
> the Perseus' front end with an RF overload). The hard-wired FSL's do behave 
> somewhat like broadband antennas in the PL-380, but that's only because of 
> the DSP chip's antenna tuning function. The combination essentially becomes 
> single-optimized frequency reception from 531-1701 kHz, selectable by the 
> DXer. 
> 
> 73, Gary 
> 
> 
> 
> ----- Original Message ----- 
> 
> From: "Walter Salmaniw" <canswl@xxxxxxxxx> 
> To: "Mailing list for the International Radio Club of America" < 
> irca@xxxxxxxxxxxxxxxx> 
> Sent: Saturday, January 23, 2016 5:52:37 PM 
> Subject: Re: [IRCA] Â Â Â Ââ"Science Fiction PL-380"-- Pest Control Version 
> 
> Fellas, I'm interested again with the removal of the variable tuning 
> capacitor and use for broad spectrum Perseus SDR captures. ÂAs you recall, 
> a number of these early large units were kindly built by Gary. ÂOne was 
> sent my way (and I may have the same in Masset). ÂResults have been 
> variable. ÂWould anything different be done with these units compared to 
> what we know today? Â 73,...Walt 
> 
> On Sun, Jan 24, 2016 at 12:37 AM, <d1028gary@xxxxxxxxxxx> wrote: 
> 
> > Hi Guy, 
> > 
> > Thanks for your comments. 
> > 
> > <<< Â I'm still puzzled as to the best way to go for nulling of pests, 
> > regarding 
> > diameter vs length proportions. Initially the "long and skinny" antennas 
> > such as in the SRF-T615 were praised for their nulling, but now the 
> > "stubby" FSLs appear to have the upper hand. Â Â>>> 
> > 
> > Guy, there's no doubt that the stubby, hard-wired FSL's have really 
> > created a new level of nulling capability-- in an entirely different 
> league 
> > than the loopsticks or long ferrite rods that preceded them. There are 
> two 
> > primary reasons for this. The new hard-wired FSL's are completely 
> isolated 
> > away from the radio circuitry, and they have no variable tuning capacitor 
> > to upset their RF symmetry. They present a completely symmetrical RF coil 
> > for reception purposes, which can null out pest stations under 
> > laboratory-perfect conditions every time. All of the preceding antenna 
> > designs were limited either by surrounding radio circuitry, a variable 
> > tuning capacitor to upset the RF symmetry, or both. 
> > 
> > <<< Â I guess this is an unfair apples to oranges comparison (hollow FSL 
> vs 
> > traditional solid rod antenna). To compare FSL to FSL then, are you 
> finding 
> > better nulling the "stubbier" you make the antennas? Â >>> 
> > 
> > Yes, there is now no doubt that the shorter and stubbier a hard-wired FSL 
> > coil becomes, the greater its nulling capability will be-- so long as the 
> > RF design is completely isolated , and completely symmetrical. 
> > 
> > <<< Â Do you recall the large diameter, short rod FSLs that Kevin 
> > Schanilec built 
> > inside of Christmas wreath containers? I wonder if those models were 
> > excellent at nulling. I do remember that he did a lot of his testing 
> > indoors, which can screw up nulls and reception completely. High 
> > performance ferrite antennas CANNOT be reliably evaluated indoors! Â Â>>> 
> > 
> > All traditional FSL's (including Kevin's designs) have a variable tuning 
> > capacitor-- which is a distraction from a perfectly symmetrical RF 
> > reception pattern. The larger and clunkier the variable capacitor, the 
> > worse and worse the nulling capability gets. Long hookup wires to a 
> > variable cap also upset the symmetrical RF reception pattern, further 
> > reducing nulling capability. The new hard-wired FSL's avoid both issues 
> > completely-- with perfect symmetry and no variable tuning capacitor. 
> > 
> > By the way, all of the local pests except for 1450-KSUH have been nulled 
> > down into the noise. My guess is that the over-modulated KSUH is 
> > broadcasting on more frequencies than its fundamental, making it tough to 
> > null each one :-) 
> > 
> > 73, Gary 
> > 
> > 
> > 
> > 
> > 
> > ----- Original Message ----- 
> > 
> > From: "Guy Atkins" <dx@xxxxxxxxxxxxx> 
> > To: "Mailing list for the International Radio Club of America" < 
> > irca@xxxxxxxxxxxxxxxx> 
> > Sent: Saturday, January 23, 2016 3:02:59 PM 
> > Subject: Re: [IRCA] Â Â Â Ââ"Science Fiction PL-380"-- Pest Control 
> Version 
> > 
> > > 
> > > âGary, 
> > > 
> > 
> > âI'm still puzzled as to the best way to go for nulling of pests, 
> regarding 
> > diameter vs length proportions. Initially the "long and skinny" antennas 
> > such as in the SRF-T615 were praised for their nulling, but now the 
> > "stubby" âFSLs appear to have the upper hand. 
> > 
> > Do you think the cylindrical (hollow) design of the FSLs changes the 
> > response to a groundwave pest station so that a high diameter-to-length 
> > ratio *FSL* nulls better than a *solid* rod with a high 
> LENGTH-to-diameter 
> > ratio? 
> > 
> > I guess this is an unfair apples to oranges comparison (hollow FSL vs 
> > traditional solid rod antenna). To compare FSL to FSL then, are you 
> finding 
> > better nulling the "stubbier" you make the antennas? 
> > 
> > Do you recall the large diameter, short rod FSLs that Kevin Schanilec 
> built 
> > inside of Christmas wreath containers? I wonder if those models were 
> > excellent at nulling. I do remember that he did a lot of his testing 
> > indoors, which can screw up nulls and reception completely. High 
> > performance ferrite antennas CANNOT be reliably evaluated indoors! 
> > 
> > 73, 
> > 
> > Guy Atkins 
> > Puyallup, WA 
> > 
> > > â 
> > > 
> > > 
> > > ---------- Forwarded message --------- 
> > > From: d1028gary@xxxxxxxxxxx 
> > > To: Mailing list for the International Radio Club of America < 
> > > irca@xxxxxxxxxxxxxxxx> 
> > > Cc: 
> > > Date: Sat, 23 Jan 2016 13:40:28 +0000 (UTC) 
> > > Subject: [IRCA] 
> > > ââ 
> > > "Science Fiction PL-380"-- Pest Control Version 
> > > Hello All, 
> > > 
> > > The first of the new hard-wired FSL models specifically designed to 
> have 
> > > an unusually sharp nulling capability is now a reality. With a "short 
> and 
> > > stubby" FSL design that emphasizes symmetry, isolation and a tidy RF 
> > > reception pattern, this model can put all of my semi-locals (Seattle 
> and 
> > > Tacoma) down in the noise-- and even receive a few competing stations 
> on 
> > > their fundamental frequencies. Using 22 of the commonly available 
> Russian 
> > > surplus 62mm x 12mm x 4mm bars, this model is one of the "spinoff" 
> > versions 
> > > of the 3" Bar FSL PL-380 model (for which the 15-page "Heathkit-like" 
> > > construction article was posted at 
> > > http://www.mediafire.com/view/w0gcek56f6aq7kr/3_Inch_FSL_Tecsun_PL.doc 
> > > Â), and has an FSL "sensitivity score" (coil diameter x ferrite length) 
> > of 
> > > 264-- pretty close to the 300 point score of the article version (with 
> > > 100mm ferrite bars). The advantage of this model is that there is a 
> huge 
> > > supply of the Russian surplus 62mm ferrite bars, currently sold on eBay 
> > by 
> > > two different sellers. You can get 20 of them for $13-- including 
> > shipping 
> > > from Lithuania. 
> > > 
> > > Construction of this model is identical to the article version, except 
> > for 
> > > the FSL construction (which may be added as an addendum). All of the 
> > > construction parts are readily available, also. Unless you live 
> > practically 
> > > next door to a local pest, this "pest control" model should cut 
> > > your offenders way down to size. A photo of the new model is posted at 
> > > https://app.box.com/s/5r95oxc9v24vm9hbpe2w1g800lbt4d3b 
> > > 
> > > 73 and Good DX, 
> > > Gary DeBock (in Puyallup, WA, USA) 
> > > 
> > > 
> > > 
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