Re: Gary's PL-360 antenna arrives! - FARMERIK


pianoplayer88key
 

Yeah, you're probably right that the PL-360 is not the radio for me. ;)  And no, I'm definitely not satisfied with the PL-380 here, although I really wanted to like it :( especially based on your glowing review which almost convinced me that I would be able to get clear audio on a TA even when leaning right up against the fence surrounding the tower of a local 50kW IBOC pest 1kHz away. ;)  (Ok, you didn't actually say it was THAT good. ;) )

For example... I'm near 32°45'40"N 116°56'50"W.  The pests will be listed in bold, the targets (most of which I'd like to be able to hear in walkaround mode (radio (including any external antenna used) in my pocket, not paying attention to which direction it's facing)) will be in normal font.  (For the ZipSignal, I used http://v-soft.com/zipsignal for reference).  Zip 91941 is about 1 + 7/8 miles west of me, and only lists AM signals with predicted field strength greater than about 0.32mV/m.

            PL-380  Zip 91941
Freq  Call  Signal  Signal mV/m  Comments
 600  KOGO  63,25     72.44mV/m  IBOC
 610  KAVL  20,00                barely detectable IF nulling KOGO's IBOC.  It helps that they're at right angles from each other.  Radio-Locator's map shows me as being about 20% outside their fringe signal.
 680  KNBR  32,00                carrier detectable if using Select-A-Tenna (SAT).  Radio-Locator shows their fringe just barely making it to Santa Barbara, about 200 miles northwest of here.
 690  XEWW  63,25
 700  KALL  27,00                used SAT, unsure if I heard an undecipherable hint of mumbling audio between XEWW's splatter and 710 KSPN (27,22 on frequency)'s IBOC.  Radio-Locator shows their fringe stopping a bit short of Las Vegas, about 250-270 miles northeast of here.
1110  KDIS  35,00                probably would have a fair signal if KSDO and KCBQ weren't so strong here.  Radio-Locator says I'm a little inside their "distant" contour.
1130  KSDO  63,00                this is one of the strongest locals, topped only by KCBQ.
1140  KNWQ  41,00                required SAT and tuning to 1141 to partially unsuccessfully dodge splatter from KSDO, even though I was using the 1kHz bandwidth.  Radio-Locator shows me as being a little inside their fringe signal.
1150  KTLK  39,00                I did use the SAT, although I almost can tell there's a hint of a signal there without it.  Radio-Locator shows me as probably being right on the fringe line.
1170  KCBQ  63,00                This is my strongest daytime local.
1180  KERN  37,00                The SAT, and tuning to 1181 to partially dodge KCBQ splatter, is required to hear even a hint of a signal.  Radio-Locator shows me as being about 50-75% outside their fringe signal.
1350  KTDD  32,06                barely detectable barefoot.  Radio-Locator says I'm about 25% outside the fringe.
1360  KLSD  63,25

As you can see, there are some elevated RSSI readings with 0dB SNR.  On the other hand, when I'm in an area where the RF environment isn't quite so saturated, I've been able to get 16-18dB SNR on stations that are indicating an RSSI of 16 dBu.  Also, as for my listing stations for which I'm OUTSIDE radio-locator's coverage maps as targets... on other frequencies that aren't too close to the pests, I have been able to get barefoot reception of a few, even though I'm outside their coverage area...
 960  KIXW  25,00  I'm about 50% outside their area, but can hear enough of a barefoot signal to ID it.
1430  KMRB  25,00  see below
1430  KWST  25,00  I'm probably almost twice as far as their fringe signal on both stations, but I can faintly hear them both.
1440  KDIF  34,00  I'm about 40% outside their fringe signal but can tell it's there, barefoot.
1560  KNZR  24,00  I can tell it's there barefoot, even though I'm probably at least twice as far as their fringe signal line on Radio-Locator.

So yes, the radio is plenty sensitive enough barefoot to hear stations even though I'm supposed to be outside their fringe area. :)  Where it doesn't excel as well as I'd like, though, is getting usable signals on signals for which I am in their coverage area, when there are strong local pests nearby on the dial. :(


At my grandparents house in San Gabriel, CA, not far from 34°6'58"N 118°4'50"W, the urban splatter is MUCH worse!  A few stations are listed below (pests in bold, as above).  As above, I won't be listing all targets or all pests, only the targets that I actually heard there, or in some cases ones that Radio-Locator says I would be within their fringe signal, adjacent to the pests.  (I will also list some stations that, other than having a 0dB signal due to the elevated noise floor / desensitization, would have a fairly good signal.)  As for the pests, I'll list the ones hampering reception of a station I otherwise should be able to hear, and will list some of the strongest pests, including IBOC ones, even if they don't happen to be close on the dial to targets.  Some of them may be strong enough to contribute to the noise floor even on stations several steps away.

            PL-380  Zip 91775
Freq  Call  Signal  Signal mV/m  Comments 
 640  KFI   63,25     66.90mV/m  IBOC
 790  KABC  58,25     16.29mV/m  
 800  XESPN 43,00                radio-locator shows I'm between the distant and fringe signal
 860  XEMO             0.61mV/m  radio-locator shows I'm probably right on their distant signal line
 870  KRLA  63,25     81.17mV/m  
 960  KIXW  45,00      0.43mV/m  radio-locator shows I'm just outside their distant signal, but still well within the fringe.
 980  KFWB  63,25     48.82mV/m  IBOC
1000  KCEO                       radio-locator shows I'm probably right on the fringe line.
1020  KTNQ  63,25    111.68mV/m
1030  XESDD 47,00                radio-locator shows me probably being outside their coverage, although my qth there is a bit off the map.
1090  XEPRS 49,18      1.97mV/m  probably wiped out if my antenna faces KDIS
1110  KDIS  63,25    271.16mV/m  50kW transmitter 4.8 miles east
1150  KTLK  60,25     29.75mV/m
1170  KCBQ  50,00                radio-locator shows I'm just barely within the fringe signal area.
1180  KERN  50,00                radio-locator shows I'm just barely within the fringe signal area.
1220  KWKU             0.96mV/m  radio-locator shows I'm within the distant signal, but a little outside the local.
1230  KYPA  50,00      5.18mV/m  radio-locator shows I'm probably within their local signal.
1240  KEZY                       radio-locator shows I'm somewhat outside their distant signal, but still well within the fringe.
1260  KGIL  50,00      6.09mV/m  radio-locator shows I'm within their local signal.
1280  KFRN  50,00      2.83mV/m  radio-locator shows I'm probably right on the local signal line.
1290  KKDD                       radio-locator shows I'm just within the fringe signal.
1300  KAZN  63,25    578.34mV/m  23kW transmitter 1/4-1/3 mile north-northwest
1330  KWKW  50,00     10.27mV/m  radio-locator shows I'm well within their local signal
1350  KTDD  ?????                hint? of carrier too weak to ID, radio-locator shows I'm between the distant and fringe signal
1370  KWRM  ?????      1.21mV/m  hint? of carrier too weak to ID, radio-locator shows I'm between the local and distant signal
1420  XEXX                       radio-locator shows I'm probably right on the fringe signal line
1430  KMRB  63,25   3149.90mV/m  50kW transmitter 1/4-1/3 mile north-northwest
1440  KDIF                       radio-locator shows I'm between the distant and fringe signal
1460  KTYM  50,00      6.86mV/m  radio-locator shows I'm within the local signal

In fact, 1300 KAZN and 1430 KMRB are so strong that many of their harmonics can be easily heard there...

  harmonics of KAZN:
2600 = 56,25
3900 = 43,13
5200 = 35,00

  harmonics of KMRB:
 2860 = 59,25
 4290 = 48,16
 5720 = 37,01
 7150 = 28,01
 8580 = 27,00
10010 = 25,00

According to Zip Signal, KMRB's field strength is a whopping 3,149.9 millivolts/meter - that's over THREE VOLTS!!!!  Wikipedia says a station's blanketing interference contour is one volt/meter.  Am I expecting too much to be able to hear 0.15mV/m stations 10 kHz away?  (I was also unsuccessful trying to log any TP or TA stations on 1431 kHz.)

As you can tell, southern California is a major urban RF jungle for me, especially when I visit my grandparents in San Gabriel!  It doesn't help that they happen to live 1/3 mile away from two stations (23kW and 50kW), and that several other stations (including a 50kW 5 miles away) use IBOC.
One of my especially desired stations is 1290 KKDD San Bernardino, Radio Disney (yes, I like some of their music).  KKDD, for now, is apparently running full 10kHz analog bandwidth, although they're not running analog stereo like KDIS used to do.  (KDIS, and KMIK 1580, a signal that sometimes comes in upwards of 55-56dBu barefoot at night here, both run IBOC and limit their analog bandwidth to 5kHz or maybe 6kHz.)  Here at home with the Select-A-Tenna, I can detect a faint trace of KKDD, but it's dominated by co-channel KZSB Santa Barbara, a station that can be faintly heard barefoot here.  At my grandparents place, even though radio-locator says I'm within their signal area, I can't even so much as detect a hint of a trace of 1290 KKDD, no-thanks to 1300 KAZN's 23kW transmitter 1/3 mile away.


One other thing...  I'm curious to know what are the typical barefoot readings on your DSP radios at your location at Pullyaup, WA, in the daytime. :)  Also, as 1450 KSUH is a very strong signal there, is there any trace of a signal on the 2nd harmonic of 2900 kHz in the shortwave band?  What about for 1300 KKOL's 2nd harmonic, 2600 kHz?


So.... is my situation utterly hopeless for being able to use an ultralight-priced-and-sized (including the antenna if not contained within the cabinet) radio for daytime barefoot listening of fringe (on radio-locator) stations 10kHz away from powerful or IBOC locals, especially when visiting my grandparents? :(



--- In ultralightdx@..., D1028Gary@... wrote:
>
> Hi Stephen,
>  
> Thanks for your comments and suggestions.
>  
> As much fun as it is to plug in a 7.5" loopstick into the new Tecsun  
> PL-360 model and receive a huge AM sensitivity boost, the radio would probably  
> not be the first choice for urban DXers troubled by many strong local pests. 
> The  DSP selectivity in this Si4734 model is fixed at 3 kHz, which provides 
> fairly  good adjacent-channel rejection in comparison to non-DSP portables, 
> but not  in relation to the Tecsun DSP models offering the 1 kHz filtering 
> option, like  the PL-380 and PL-310. If you are not satisfied with the 
> PL-380's selectivity in  your urban RF jungle, the PL-360 is not likely to thrill 
> you-- no matter which  antenna you use.
>  
> In playing around with the 7.5" plug-in loopstick in the PL-360, however, I 
>  did discover that the loopstick's extreme isolation from the radio cabinet 
>  allows the user to null out many strong locals, especially when the 
> antenna is  tilted slightly off of the horizontal. This ability seems to be 
> unusual (in  comparison to other modified Ultralights), and is apparently related 
> to the  isolated loopstick's cleaner electromagnetic reception pattern. 
> Using this  plug-in antenna, my most troublesome local pest (1450-KSUH) can 
> always be nulled  at night, to bring in one or two competing stations on 1450 
> kHz. Other similar  pests here (1300-KKOL and 1360-KKMO) can also be nulled at 
> night, allowing easy  reception of the stations on adjacent frequencies. 
> The nulls are hair-trigger  and very sharp, but they are available for those 
> DXers willing to find them. The  clean nulling pattern of this loopstick is 
> probably similar to that of the  "Quantum Loops," with their 
> isolated-loopstick design system. It's probably  a question of how much hassle the DXer 
> wants to go through to find the best  null, in order to win a "victory" over a 
> local pest :-)
>  
> 73, Gary         
>  
>  
> In a message dated 5/7/2010 10:41:35 P.M. Pacific Daylight Time,  
> pianoplayer88key@... writes:
>  
>  
>  
> So, is this "super portable DXing machine" able to hear a distant station  
> (for which you are just outside Radio-Locator'So, is this "super portable 
> DXing machine" able to hear a distant station  (for which you are just outside 
> Radio-Locator's predicted fringe coverage  area) strong enough to 
> casually listen t
> If you haven't already, when you go to do the test on the  PL-360 (with the 
> stock and other loopsticks), I'd like to suggest that you  review it from 
> maybe a few particular locations...If y
> 2622 29th  Ave E, Tacoma, WA (off Route 167 - River Rd E)
> Try for reception of:
> 860  KPAM Troutdale, OR - Radio-Locator says that location is halfway 
> between  distant and fringe.
> Local pest would be 850 KHHO, 10kW IBOC, you'd be just  outside the gate to 
> their transmitter site. (50kW 1300 KKOL is about 1.44mi  145.82° distant.)
> Bonus points for successful barefoot/stock reception of  840 KMAX Colfax, 
> WA and/or KSWB Seaside, OR - you'd be about twice as far as  R-L's predicted 
> fringe signal.
> The next couple sites are on Vashon  Island. In my opinion, for it to be a 
> good stress test (especially when  testing selectivity & resistance to 
> overload), the test needs to be  conducted as close as possible to a local pest's 
> transmitter site, bonus  points for one that runs 50kW and/or IBOC.
> north end of 105th Ave SW,  north of Cemetery Rd (transmitter site for 820 
> KGNW & 950 KJR, both  50kW)
> Target: 810 KTBI Ephrata, WA - R-L map shows fairly close to fringe  line
> on Dockton Rd SW, between SW Point Robinson Rd & 75th Ave  SW
> Targets:
> 560 KPQ Wenatchee, WA - Radio-Locator shows that location  being about a 
> quarter of the way or so from distant to fringe
> 700 KXLX  Spokane, WA - Radio-Locator shows it being about 50-65% past 
> fringe
> 780  CKOK Penticton, BC - R-L indicates about 50-60% past fringe
> 1100 KFXX  Portland, OR - R-L indicates about 20-30% past fringe
> Pests:
> 710 KIRO,  50kW - approx 1/4 mi NNW
> 770 KTTH & 1090 KPTK, 50kW - approx 1/4 mi  SE
> 570 KVI, 5kW - about 1.6 mi N, mostly over water
> (820 KGNW & 950  KJR are 2.87 miles away, but considering Washington 
> State's abysmal ground  conductivity, you're probably outside their 1V/m 
> "blanketing contour", which  in my opinion would cause it to be less of a stress 
> test, hence my listing  that location and its targets separately.)
> Too bad you couldn't make a  trip down to Southern California (for example, 
> L.A.), and review some radios  here. ;) There's plenty of splatter, IBOC, 
> etc, to go around. In some places,  you're probably almost always within 10 
> miles and 50 kHz of an IBOC or 50kW  blowtorch. :) I happen to be near San 
> Diego, but the dial here isn't quite as  crowded as it is in Los Angeles. Also 
> my lone IBOC station is about 10 miles  away, and about 90° offset from the 
> adjacent targets, making it a little  easier to null the pest, and my 
> closest 50kW daytimer is 9 miles  away.
> While I'm not currently in the market for a PL-360, as it doesn't  have 
> selectable bandwidths and probably would still choke when faced with a  50kW 
> IBOC blowtorch 500 feet away (like the PL-380, which uses the same chip,  
> does), I'll still be interested in seeing the review, and seeing if there's  any 
> way it's improved over the PL-380 in that area. :)
> I personally would  like to see the radio reviews conducted from fairly 
> close to the pests'  transmitter sites, like within 1/4 mile or so.
> --- In _ultralightdx@ultralightdxult_ (mailto:ultralightdx@...) 
> ,  D1028Gary@,  D1
> >
> > Hello Farmerik and Kevin,
> >  
> > Thanks to you both for the initial reports, and I'm glad you are both  
> > having fun with the plug-in 7.5" loopsticks!
> > 
> > This  has been one of the most enjoyable loopstick modification projects 
> >  I've ever done, and even I find it a total blast to chase domestic 
> stations  
> > with one of these "super portable DXing machines" (Kevin's  appreciated 
> > description) description). For a hard-core TP-DXer, that's saying  a 
> lot :-
> > 
> > 73, Gary 
> > 
> >  
> > 
> > 
> > In a message dated 5/7/2010 12:14:57 P.M. Pacific  Daylight Time, 
> > farmerik@ writes:
> > 
> > 
> >  
> > 
> > Just a quick comparison, after Gary's ferrite antenna for  the PL-360 
> > arrived today. Mid afternoon test- AM 560 again.
> >  
> > Stock antenna- 37 19
> > Gary's ferrite- 47 25
> > 
> >  It makes a big difference in how clear and noise free the signal too. 
> The  
> > PM 'meter' readings are very steady, no need to 'average' the  readings. 
> > 
> > If anyone wants me to, I could check near the top  of the band, and I am 
> > certain I will be listening to this tonight!  
> > 
> > Thanks again to Gary for making these available! -  FARMERIK
> >
>

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