|
rick robinson <w4dst@...>
My Thanks to Gary for the CCrane SWP Slider that is now a fine addition to my shack. Now that it is DXing season, I hope to be able to give it a good workout with some new DX and hopefully some TA loggings. I have been comparing it to some of the other receivers in the shack and I thought I'd pass along my observations. These are not scientific, just objective but I've tried to be impartial. Some of the results are surprising.
One of my receivers is a Sangean ATS-803A that I picked up at a hamfest over the Labor Day weekend and have given it a good alignment. The ATS-803A/Radio Shack DX-440 and the Sony 2010 were considered 2 of the best MW radios of their day and are still excellent performers. I am fortunate to own both and thought I'd see how the slider stood up to these 2 classics. My 2010 has 2 Kiwa filters in it, the CCrane has a 2.5kHz MuRata 6 element ceramic filter replacing the stock filter and the Sangean has both stock filters. Selectivity wise, the CCrane's MuRata filter is even better than the narrow Kiwa filter in the Sony, which was surprising, and as good as, or better than the Sangean narrow filter. The filters in the Sangean surprised me at how good they are and the audio in the Sangean easily beats the others hands down.
When testing the sensitivity during the day, the slider came out the winner over both receivers due the nice job Gary did on the slider antenna. Being able to tune the antenna to the receiver is a very valuable asset for DXing as others have noted. The Sangean, Sony and the slider ferrite bars are all very close in length, 7.5" and all are wound in much the same method with the windings closely wound on the left end as you face the bar. The slider is slightly better than the Sangean in nulling and equal to the Sony.
The only radio I have that takes on the slider and comes out ahead in any way is my classic Radio Shack 12-655. This is a TRF design from the early 1980s with a similar size ferrite bar. It is a analog radio, very simple in operation and is legendary in MW DXing circles for its outstanding sensitivity and nulling ability. During the day, I can twist and turn my 12-655 and completely null out local WHKP 1450 6 miles away, and hear WATA in Boone, NC, 140 miles to my north with full audio. No other radio or my Quanum loop antenna is capable of this, only my antenna phasing system can duplicate this feat. I have no idea what contributes to it's amazing nulling quality since the antenna looks to be wound just like the other 3 bars. As we say in the QRP community, the 12-655 just has mojo. The slider and the 12-655 are very close in sensitivity and it would be difficult without test equipment measurements to determine which is the more sensitive. My 12-655 has always been my benchmark for sensitivity and nulling capabilities and will continue to be.
I have also experimented with a 280uH fixed coil ferrite bar antenna that I wound on a 20cm, 7 7/8", bar from a junked Grundig S350L. It has a 1/8" stereo plug on the end to interface with my PL-310 with its "Laurie" mod. It and the slider seem to be equal in sensitivity. However, the digital filter in the Si4734 has the edge on the MuRata filter in the CCRane. Once again, I am impressed with Scott and the rest of the folks at Silicon Labs and the design of this fantastic chip. It's amazing so much can be packed into this tiny chip.
Good DXing in the upcoming season to everyone.
Rick W4DST
Hendersonville, NC
|
|
|
Gary DeBock
Hi Rick,
Thanks for your generous comments on the SWP Slider models. Only about
5 of these models were ever made (in cooperation with Steve Ratzlaff, who
installed the Murata CFJ455K5 filters), including the one that I am
currently using for TP-DXing each morning. Far more Eton E100 Slider models were
made and sent out, including several by John Bryant (with his plywood frame
mounting style).
When the first Si4734 chip 1 kHz DSP model (the Kchibo D96L) was released
in August of last year, there was intense interest in whether or not the model's
stock 1 kHz DSP selectivity would be competitive with the premium Murata
CFJ455K5 IF filters transplanted into our modified SWP and E100 models.
That month I took a new Kchibo D96L to a famous Pacific beach DXpedition site
here in Washington state (Grayland), and made comparison MP3's
during the reception of two South Pacific stations. A 3' portable PVC loop was
used to boost signals, and the SWP was tuned 1 kHz off the DX station's
frequency (away from domestic splatter) to provide crisper audio (this could not
be done with the D96L, because of the "soft mute" issue). In the first 15
seconds, the D96L (with its 1 kHz Si4734 DSP filtering) receives the South
Pacific split-frequency station, and in the last 15 seconds the SWP Slider (with
a Murata CFJ455K5 filter) receives the same signal:
Of course the receivers' audio sections also influenced the quality of the
received signals, but at the time I reported to the group that the D96L's 1 kHz
DSP selectivity (from its Si4734 chip) was fairly competitive
with that provided by the transplanted Murata K filter in the SWP. The
consensus among the group, however, was that the Murata filter SWP had
somewhat more "mellow" audio than that provided by the Si4734 chip's 1 kHz
DSP setting. The Si4734 chip's 1 kHz DSP filtering is a
tremendous breakthrough for inexpensive stock Ultralights, though, and I've used
both the 7.5" loopstick PL-380 and the 7.5" loopstick SWP Slider for South
Pacific DXpeditions this past summer.
73, Gary DeBock (in Puyallup, WA)
In a message dated 10/18/2010 8:13:45 A.M. Pacific Daylight Time,
w4dst@... writes:
toggle quoted message
Show quoted text
My Thanks to Gary for the CCrane SWP Slider that is now a fine
addition
to my shack. Now that it is DXing season, I hope to be able to
give it a
good workout with some new DX and hopefully some TA loggings.
I have been
comparing it to some of the other receivers in the shack and
I thought I'd
pass along my observations. These are not scientific,
just objective but
I've tried to be impartial. Some of the results are
surprising.
One
of my receivers is a Sangean ATS-803A that I picked up at a hamfest
over
the Labor Day weekend and have given it a good alignment. The
ATS-803A/Radio Shack DX-440 and the Sony 2010 were considered 2 of the
best MW radios of their day and are still excellent performers. I am
fortunate to own both and thought I'd see how the slider stood up to
these 2 classics. My 2010 has 2 Kiwa filters in it, the CCrane has a
2.5kHz MuRata 6 element ceramic filter replacing the stock filter and
the Sangean has both stock filters. Selectivity wise, the CCrane's
MuRata filter is even better than the narrow Kiwa filter in the Sony,
which was surprising, and as good as, or better than the Sangean narrow
filter. The filters in the Sangean surprised me at how good they are
and the audio in the Sangean easily beats the others hands
down.
When testing the sensitivity during the day, the slider came out
the
winner over both receivers due the nice job Gary did on the slider
antenna. Being able to tune the antenna to the receiver is a very
valuable asset for DXing as others have noted. The Sangean, Sony and
the slider ferrite bars are all very close in length, 7.5" and all are
wound in much the same method with the windings closely wound on the
left end as you face the bar. The slider is slightly better than the
Sangean in nulling and equal to the Sony.
The only radio I have
that takes on the slider and comes out ahead in
any way is my classic
Radio Shack 12-655. This is a TRF design from the
early 1980s with a
similar size ferrite bar. It is a analog radio, very
simple in operation
and is legendary in MW DXing circles for its
outstanding sensitivity and
nulling ability. During the day, I can
twist and turn my 12-655 and
completely null out local WHKP 1450 6 miles
away, and hear WATA in Boone,
NC, 140 miles to my north with full
audio. No other radio or my Quanum
loop antenna is capable of this,
only my antenna phasing system can
duplicate this feat. I have no
idea what contributes to it's amazing
nulling quality since the antenna
looks to be wound just like the other 3
bars. As we say in the QRP
community, the 12-655 just has mojo. The slider
and the 12-655 are very
close in sensitivity and it would be difficult
without test equipment
measurements to determine which is the more
sensitive. My 12-655 has
always been my benchmark for sensitivity and
nulling capabilities and
will continue to be.
I have also
experimented with a 280uH fixed coil ferrite bar antenna
that I wound on a
20cm, 7 7/8", bar from a junked Grundig S350L. It
has a 1/8" stereo plug
on the end to interface with my PL-310 with its
"Laurie" mod. It and the
slider seem to be equal in sensitivity.
However, the digital filter in the
Si4734 has the edge on the MuRata
filter in the CCRane. Once again, I am
impressed with Scott and the
rest of the folks at Silicon Labs and the
design of this fantastic
chip. It's amazing so much can be packed into
this tiny chip.
Good DXing in the upcoming season to
everyone.
Rick W4DST
Hendersonville, NC
|
|
|
Gary DeBock
Hi Stephen,
To be honest, despite your apparent impressions, the PL-380 (and the other
Si4734 chip based ULR's) actually have above average AM-band overload resistance
among the Ultralight radio class. The reason for my conclusion is detailed
testing with various ULR's inductively coupled to the 9' PVC loop, which will
seriously overload any pocket radio which is not "crunch resistant." The 9'
loop overloads the analog design Ultralights (SRF-39FP, R9012, R911,
etc.) so badly that whenever the radio is brought within inductive coupling
range of the loop, the loop's tuning capacitor can actually tune the radio from
530-1700 kHz (regardless of where the radio's tuning capacitor is set).
The SWP Slider model has outstanding resistance to overload,
which makes it ideal for use with the 9' loop. In this respect, it's probably a
shade more impressive than the Si4734 models. The fact that the SWP Slider
has its own tunable loopstick contributes to this stability, and when the
tunable Slider loopstick is combined with the 9' loop's tuning capacitor, the
ultimate selectivity of the system is probably close to optimum in the
Ultralight class.
Anyway, Stephen, even though there are no more SWP Sliders being
made, it's always possible to boost up your TP-chasing ability by going
with a larger tuned passive loop (than your SAT), or with a 7.5" loopstick
PL-380 (which can partially null out some of your pests, if their bearing is
about 90 degrees off of the NW direction). The only way you will know which TP's
are possible in your "RF Zoo" is to get up early, and try chasing
them before sunrise. Nobody has a perfect location, or a perfect radio. The
most successful TP-DXers (or TA DXers) are the ones who push their luck
constantly, no matter what handicaps they may face. Optimism, persistence
and determination are the main ingredients for success-- even if your radio,
antenna or location has some limitations. Keep trying, and I'm sure that
you will receive many more TP's this season.
73, Gary
In a message dated 10/18/2010 10:42:54 P.M. Pacific Daylight Time,
pianoplayer88key@... writes:
toggle quoted message
Show quoted text
CQ CQ Calling N7EKX...
I'd be interested in finding out how they
compare with separating a very strong signal from a very weak one (even if it
is 10kHz away) when nulling the strong signal isn't an option. With my PL-380,
even in the 1kHz mode, I can hear some of my strong locals 12kHz away. Across
town I was trying to listen to KDIS-1110 yesterday on my way to a Bible study
service. Unfortunately, their faint 41/00 signal was being stepped on by
residual chirps/chatter from XEPRS-1090, which was booming in at a solid
63/25. (I didn't have the G8 with me, but I would guess XEPRS probably would
have been around 72-76/25 or thereabouts.) However, I was almost right on
KDIS's 2mV/m "local" contour according to Radio-Locator, or possibly just
slightly outside it at the time, in Ocean Beach (a few miles northwest of San
Diego airport). When I have been in rural areas, though, I've been able to get
listenable audio on weaker signals, including some for which I was well
outside Radio-Locat or's estimated 0.15mV/m "fringe" contour - in a few cases
even twice as far, maybe more.
I was wondering how well the
Slider+Murata'ed SWP would do in a test which my PL-380, even in 1kHz BW mode,
fails miserably. In a place where (I'm guessing, as I don't own one to know
its actual sensitivity) the PL-360 would be indicating somewhere around 93/25
to 96/25 WITHOUT an antenna plugged in... how well would the SWP (and if you
want to check it with your 7.5-inched PL-380 (mine's stock) that's fine too)
hear a signal 10kHz away coming from the same direction as the strong pest,
for which you are about 1.5 to 2x past Radio-Locator's predicted 0.15mV/m
"fringe" contour? My PL-380 utterly fails that test. If it passed it, I'd be
able to hear one of the stations I originally wanted to be able to hear in the
daytime, KERN-1180 Wasco-Greenacres, CA, for which I'm about 2x past the
0.15mV/m contour. Unfortunately, KCBQ-1170's 77/25 signal still has
significant splatter audible on 1180 (which does die out by around 1182 or
1183 or so), and even KXMX Anaheim 's 43/00 signal is only barely
audible.
73... Stephen (No, I haven't gone past the no-turning-back
point and gotten a Ham license.)
--- In ultralightdx@...,
D1028Gary@... wrote:
>
> Hi Rick,
>
> Thanks for your
generous comments on the SWP Slider models. Only about 5
> of these
models were ever made (in cooperation with Steve Ratzlaff, who
>
installed the Murata CFJ455K5 filters), including the one that I am currently
> using for TP-DXing each morning. Far more Eton E100 Slider models
were made
> and sent out, including several by John Bryant (with his
plywood frame
> mounting style).
>
> When the first Si4734
chip 1 kHz DSP model (the Kchibo D96L) was released
> in August of last
year, there was intense interest in whether or not the
> model's stock
1 kHz DSP selectivity would be competitive with the premium
> Murata
CFJ455K5 IF filters transplanted into our modified SWP and E100 models.
> That month I took a new Kchibo D96L to a famous Pacific beach
DXpedition
> site here in Washington state (Grayland), and made
comparison MP3's during
> the reception of two South Pacific stations.
A 3' portable PVC loop was
> used to boost signals, and the SWP was
tuned 1 kHz off the DX station's
> frequency (away from domestic
splatter) to provide crisper audio (this could not
> be done with the
D96L, because of the "soft mute" issue). In the first 15
> seconds, the
D96L (with its 1 kHz Si4734 DSP filtering) receives the South
> Pacific
split-frequency station, and in the last 15 seconds the SWP Slider
>
(with a Murata CFJ455K5 filter) receives the same signal:
>
>
567-2YA Wellington, New Zealand 1250 UTC 8-9-09
> _http://www.mediafire.com/?8n4ce5j2y1hfw6c_
(http://www.mediafire.com/?8n4ce5j2y1hfw6c)
>
> 738-Tahiti Mahina, Tahiti 1215 UTC 8-9-09
> _http://www.mediafire.com/?l02marixc0xvhuh_
(http://www.mediafire.com/?l02marixc0xvhuh)
>
> Of course the receivers' audio sections also influenced the
quality of the
> received signals, but at the time I reported to the
group that the D96L's 1
> kHz DSP selectivity (from its Si4734 chip)
was fairly competitive with
> that provided by the transplanted Murata
K filter in the SWP. The consensus
> among the group, however, was that
the Murata filter SWP had somewhat more
> "mellow" audio than that
provided by the Si4734 chip's 1 kHz DSP setting.
> The Si4734 chip's 1
kHz DSP filtering is a tremendous breakthrough for
> inexpensive stock
Ultralights, though, and I've used both the 7.5" loopstick
> PL-380 and
the 7.5" loopstick SWP Slider for South Pacific DXpeditions this
> past
summer.
>
> 73, Gary DeBock (in Puyallup, WA)
>
>
>
>
> In a message dated 10/18/2010 8:13:45 A.M. Pacific
Daylight Time,
> w4dst@... writes:
>
>
>
>
> My Thanks to Gary for the CCrane SWP Slider that is now a fine
> addition to my shack. Now that it is DXing season, I hope to be able
to
> give it a good workout with some new DX and hopefully some TA
loggings.
> I have been comparing it to some of the other receivers in
the shack and
> I thought I'd pass along my observations. These are not
scientific,
> just objective but I've tried to be impartial. Some of
the results are
> surprising.
>
> One of my receivers is a
Sangean ATS-803A that I picked up at a hamfest
> over the Labor Day
weekend and have given it a good alignment. The
> ATS-803A/Radio Shack
DX-440 and the Sony 2010 were considered 2 of the
> best MW radios of
their day and are still excellent performers. I am
> fortunate to own
both and thought I'd see how the slider stood up to
> these 2 classics.
My 2010 has 2 Kiwa filters in it, the CCrane has a
> 2.5kHz MuRata 6
element ceramic filter replacing the stock filter and
> the Sangean has
both stock filters. Selectivity wise, the CCrane's
> MuRata filter is
even better than the narrow Kiwa filter in the Sony,
> which was
surprising, and as good as, or better than the Sangean narrow
> filter.
The filters in the Sangean surprised me at how good they are
> and the
audio in the Sangean easily beats the others hands down.
>
> When
testing the sensitivity during the day, the slider came out the
>
winner over both receivers due the nice job Gary did on the slider
>
antenna. Being able to tune the antenna to the receiver is a very
>
valuable asset for DXing as others have noted. The Sangean, Sony and
>
the slider ferrite bars are all very close in length, 7.5" and all are
> wound in much the same method with the windings closely wound on the
> left end as you face the bar. The slider is slightly better than the
> Sangean in nulling and equal to the Sony.
>
> The only
radio I have that takes on the slider and comes out ahead in
> any way
is my classic Radio Shack 12-655. This is a TRF design from the
> early
1980s with a similar size ferrite bar. It is a analog radio, very
>
simple in operation and is legendary in MW DXing circles for its
>
outstanding sensitivity and nulling ability. During the day, I can
>
twist and turn my 12-655 and completely null out local WHKP 1450 6 miles
> away, and hear WATA in Boone, NC, 140 miles to my north with full
> audio. No other radio or my Quanum loop antenna is capable of this,
> only my antenna phasing system can duplicate this feat. I have no
> idea what contributes to it's amazing nulling quality since the
antenna
> looks to be wound just like the other 3 bars. As we say in
the QRP
> community, the 12-655 just has mojo. The slider and the
12-655 are very
> close in sensitivity and it would be difficult
without test equipment
> measurements to determine which is the more
sensitive. My 12-655 has
> always been my benchmark for sensitivity and
nulling capabilities and
> will continue to be.
>
> I have
also experimented with a 280uH fixed coil ferrite bar antenna
> that I
wound on a 20cm, 7 7/8", bar from a junked Grundig S350L. It
> has a
1/8" stereo plug on the end to interface with my PL-310 with its
>
"Laurie" mod. It and the slider seem to be equal in sensitivity.
>
However, the digital filter in the Si4734 has the edge on the MuRata
>
filter in the CCRane. Once again, I am impressed with Scott and the
>
rest of the folks at Silicon Labs and the design of this fantastic
>
chip. It's amazing so much can be packed into this tiny chip.
>
>
Good DXing in the upcoming season to everyone.
>
> Rick
W4DST
> Hendersonville, NC
>
|
|
|
CQ CQ Calling N7EKX...
I'd be interested in finding out how they compare with separating a very strong signal from a very weak one (even if it is 10kHz away) when nulling the strong signal isn't an option. With my PL-380, even in the 1kHz mode, I can hear some of my strong locals 12kHz away. Across town I was trying to listen to KDIS-1110 yesterday on my way to a Bible study service. Unfortunately, their faint 41/00 signal was being stepped on by residual chirps/chatter from XEPRS-1090, which was booming in at a solid 63/25. (I didn't have the G8 with me, but I would guess XEPRS probably would have been around 72-76/25 or thereabouts.) However, I was almost right on KDIS's 2mV/m "local" contour according to Radio-Locator, or possibly just slightly outside it at the time, in Ocean Beach (a few miles northwest of San Diego airport). When I have been in rural areas, though, I've been able to get listenable audio on weaker signals, including some for which I was well outside Radio-Locator's estimated 0.15mV/m "fringe" contour - in a few cases even twice as far, maybe more.
I was wondering how well the Slider+Murata'ed SWP would do in a test which my PL-380, even in 1kHz BW mode, fails miserably. In a place where (I'm guessing, as I don't own one to know its actual sensitivity) the PL-360 would be indicating somewhere around 93/25 to 96/25 WITHOUT an antenna plugged in... how well would the SWP (and if you want to check it with your 7.5-inched PL-380 (mine's stock) that's fine too) hear a signal 10kHz away coming from the same direction as the strong pest, for which you are about 1.5 to 2x past Radio-Locator's predicted 0.15mV/m "fringe" contour? My PL-380 utterly fails that test. If it passed it, I'd be able to hear one of the stations I originally wanted to be able to hear in the daytime, KERN-1180 Wasco-Greenacres, CA, for which I'm about 2x past the 0.15mV/m contour. Unfortunately, KCBQ-1170's 77/25 signal still has significant splatter audible on 1180 (which does die out by around 1182 or 1183 or so), and even KXMX Anaheim's 43/00 signal is only barely audible.
73... Stephen (No, I haven't gone past the no-turning-back point and gotten a Ham license.)
toggle quoted message
Show quoted text
--- In ultralightdx@..., D1028Gary@... wrote:
Hi Rick,
Thanks for your generous comments on the SWP Slider models. Only about 5
of these models were ever made (in cooperation with Steve Ratzlaff, who
installed the Murata CFJ455K5 filters), including the one that I am currently
using for TP-DXing each morning. Far more Eton E100 Slider models were made
and sent out, including several by John Bryant (with his plywood frame
mounting style).
When the first Si4734 chip 1 kHz DSP model (the Kchibo D96L) was released
in August of last year, there was intense interest in whether or not the
model's stock 1 kHz DSP selectivity would be competitive with the premium
Murata CFJ455K5 IF filters transplanted into our modified SWP and E100 models.
That month I took a new Kchibo D96L to a famous Pacific beach DXpedition
site here in Washington state (Grayland), and made comparison MP3's during
the reception of two South Pacific stations. A 3' portable PVC loop was
used to boost signals, and the SWP was tuned 1 kHz off the DX station's
frequency (away from domestic splatter) to provide crisper audio (this could not
be done with the D96L, because of the "soft mute" issue). In the first 15
seconds, the D96L (with its 1 kHz Si4734 DSP filtering) receives the South
Pacific split-frequency station, and in the last 15 seconds the SWP Slider
(with a Murata CFJ455K5 filter) receives the same signal:
567-2YA Wellington, New Zealand 1250 UTC 8-9-09
_http://www.mediafire.com/?8n4ce5j2y1hfw6c_ (http://www.mediafire.com/?8n4ce5j2y1hfw6c)
738-Tahiti Mahina, Tahiti 1215 UTC 8-9-09
_http://www.mediafire.com/?l02marixc0xvhuh_ (http://www.mediafire.com/?l02marixc0xvhuh)
Of course the receivers' audio sections also influenced the quality of the
received signals, but at the time I reported to the group that the D96L's 1
kHz DSP selectivity (from its Si4734 chip) was fairly competitive with
that provided by the transplanted Murata K filter in the SWP. The consensus
among the group, however, was that the Murata filter SWP had somewhat more
"mellow" audio than that provided by the Si4734 chip's 1 kHz DSP setting.
The Si4734 chip's 1 kHz DSP filtering is a tremendous breakthrough for
inexpensive stock Ultralights, though, and I've used both the 7.5" loopstick
PL-380 and the 7.5" loopstick SWP Slider for South Pacific DXpeditions this
past summer.
73, Gary DeBock (in Puyallup, WA)
In a message dated 10/18/2010 8:13:45 A.M. Pacific Daylight Time,
w4dst@... writes:
My Thanks to Gary for the CCrane SWP Slider that is now a fine
addition to my shack. Now that it is DXing season, I hope to be able to
give it a good workout with some new DX and hopefully some TA loggings.
I have been comparing it to some of the other receivers in the shack and
I thought I'd pass along my observations. These are not scientific,
just objective but I've tried to be impartial. Some of the results are
surprising.
One of my receivers is a Sangean ATS-803A that I picked up at a hamfest
over the Labor Day weekend and have given it a good alignment. The
ATS-803A/Radio Shack DX-440 and the Sony 2010 were considered 2 of the
best MW radios of their day and are still excellent performers. I am
fortunate to own both and thought I'd see how the slider stood up to
these 2 classics. My 2010 has 2 Kiwa filters in it, the CCrane has a
2.5kHz MuRata 6 element ceramic filter replacing the stock filter and
the Sangean has both stock filters. Selectivity wise, the CCrane's
MuRata filter is even better than the narrow Kiwa filter in the Sony,
which was surprising, and as good as, or better than the Sangean narrow
filter. The filters in the Sangean surprised me at how good they are
and the audio in the Sangean easily beats the others hands down.
When testing the sensitivity during the day, the slider came out the
winner over both receivers due the nice job Gary did on the slider
antenna. Being able to tune the antenna to the receiver is a very
valuable asset for DXing as others have noted. The Sangean, Sony and
the slider ferrite bars are all very close in length, 7.5" and all are
wound in much the same method with the windings closely wound on the
left end as you face the bar. The slider is slightly better than the
Sangean in nulling and equal to the Sony.
The only radio I have that takes on the slider and comes out ahead in
any way is my classic Radio Shack 12-655. This is a TRF design from the
early 1980s with a similar size ferrite bar. It is a analog radio, very
simple in operation and is legendary in MW DXing circles for its
outstanding sensitivity and nulling ability. During the day, I can
twist and turn my 12-655 and completely null out local WHKP 1450 6 miles
away, and hear WATA in Boone, NC, 140 miles to my north with full
audio. No other radio or my Quanum loop antenna is capable of this,
only my antenna phasing system can duplicate this feat. I have no
idea what contributes to it's amazing nulling quality since the antenna
looks to be wound just like the other 3 bars. As we say in the QRP
community, the 12-655 just has mojo. The slider and the 12-655 are very
close in sensitivity and it would be difficult without test equipment
measurements to determine which is the more sensitive. My 12-655 has
always been my benchmark for sensitivity and nulling capabilities and
will continue to be.
I have also experimented with a 280uH fixed coil ferrite bar antenna
that I wound on a 20cm, 7 7/8", bar from a junked Grundig S350L. It
has a 1/8" stereo plug on the end to interface with my PL-310 with its
"Laurie" mod. It and the slider seem to be equal in sensitivity.
However, the digital filter in the Si4734 has the edge on the MuRata
filter in the CCRane. Once again, I am impressed with Scott and the
rest of the folks at Silicon Labs and the design of this fantastic
chip. It's amazing so much can be packed into this tiny chip.
Good DXing in the upcoming season to everyone.
Rick W4DST
Hendersonville, NC
|
|
|
Hi Gary... Well, actually, I originally bought the PL-380 - not to chase TPs, but so that in the daytime (via groundwave of course) I could listen to some domestic out-of-town stations (and a few out-of-state - the Colorado River is about 129.5 miles east of me at its closest point) which my previous radio could not hear at all, not only because I was at or past Radio-Locator's 0.15mV/m contour, but also because in many cases there was a station 10kHz away that bled just as loudly 50-80kHz away, and could still be heard faintly almost halfway across the band (usually worse on the high side than on the low side). Also, I find it very interesting that my Panasonic RQ-SW20, the radio I was referring to above as my previous radio (which I think has selectivity comparable to the Sony SRF-M37) pulled in some stations quite well near a couple transmitter sites that the PL-380 struggled with or didn't hear at all, in spite of the 380's superior sensitivity and selectivity. For example, here's some comparison recordings - http://cid-6bdd1917662288cb.office.live.com/browse.aspx/AM%20radio%20files/PL-380%20vs%20RQ-SW20%20comparisons/near%20KFSD%201450%20transmitter - made about 70-75 feet or so from 1kW KFSD-1450's tower, and there are some comparisons included in this link - http://cid-6bdd1917662288cb.office.live.com/browse.aspx/AM%20radio%20files/2010-09-18%20-%20near%20KCBQ%20%5E0%20KECR - at a location 700 feet from one of the 7 towers of diplexers 5kW KECR-910 and 50kW KCBQ-1170. Although, like I said, I originally wasn't planning to chase TPs... I did get a little adventurous a few weeks ago, and did manage to record a few in the vicinity of local sunrise toward the end of last month. You've heard and helped confirm a couple of the recordings already. I will say that using the SAT DEFINITELY helps with the local pests, especially if you can position it right. For example.... I'd like to know your opinion of this recording of JOUB-774 - http://cid-6bdd1917662288cb.office.live.com/self.aspx/AM%20radio%20files/0774%20JOUB%20-%2020100929%200642%20PDT%20-%20PL-380%20facing%20SAT%5EJ%2028%5EJ17%20-%20KFMB-760%20at%205kW%5EJ%2066%5EJ25%20after%200630%20PDT%5EJ%20night%2050kW%5EJ%2077%5EJ25%20760%5EJ%2043%5EJ00%20774%20barefoot.mp3 - that I recorded last month. I cut it so that mostly the stronger signals are in there. That was recorded somewhere around 6:40 to 6:55pm or so, after local radio sunrise. (Translation: in September, local stations were switching to their daytime facilities at 6:30am in San Diego, CA.) As it may be apparent in the filename, I actually saw a reading of 28,17 at least once on that station, and it could have even gone higher, I don't remember. The Select-A-Tenna did a very good job of taming the nearby local pest, KFMB-760, who is 7.3 miles north/northwest from me at a heading of 320°. Also, it helped that KFMB was on their 5kW omnidirectional daytime power at the time. During the day, KFMB comes in at around 66,25 or so on the G8 (pegs the meter at 63,25 on my PL-380), and when it's not TP reception time, shows about 32,00 or 34,00 on 747 and 774 kHz. At night, KFMB's directional 50kW signal has a lobe in my direction, and regularly hits 77,25 on the G8, and 43,00 on 747 and 774 kHz. In a couple places, for example on top of my upright piano, I actually get readings of 81,25 on 760, and 49,00 on 747 and 774. If I combine the Select-A-Tenna with the power pole at the street out front (I've found the powerline seems to inductively couple as if it was a very high gain, but broadband, longwire antenna), I get a 98,25 reading with a sound like http://cid-6bdd1917662288cb.office.live.com/self.aspx/AM%20radio%20files/760%20KFMB%205kW%20to%2050kW%20sunset%20change%20-%2020100930%201900%20-%20PL-380%5EJ%20SAT%5EJ%20powerpole.mp3 and 50,00 from about 153kHz to around 3MHz or so. However, even with KFMB's killer signal at my location at night, I think reception of TPs on 747 and 774 kHz may be possible. Do you hear anything identifiable in these two recordings? http://cid-6bdd1917662288cb.office.live.com/self.aspx/AM%20radio%20files/2010-09-23%2006am%20-%209khz%20splits/0747%20khz%20%5E50615am%5E6%20-%20pl380%5EMsat%20offset%20face%20west%5EJ%2027%5EJ01%20to%2034%5EJ03%20approx%5EJ%20qrm%20kbrt-740%20iboc%5EJ%20unid%20750%20maybe.mp3http://cid-6bdd1917662288cb.office.live.com/self.aspx/AM%20radio%20files/2010-09-23%2006am%20-%209khz%20splits/0774%20khz%20%5E50608am%5E6%20-%20pl380%5EMsat%5EJ%20offset%20face%5EJ%20slight%20cw%20of%20west%5EJ%20rssi%5E0snr%20range%2022%5EJ12%20to%2050%5EJ00.mp3In checking the recordings myself, I think I hear what I now know to be JOUB in the 774 recording about 3 and a half minutes into it. I'm having a little more difficulty with the 747kHz recording, though. I do hear the soft mute cutting in and out quite a bit, which to me seems to indicate that something's there, but I think it would help if more expert ears (than mine) could discern whether I'm actually hearing a TP on 747, or splatter from 760, 750 or IBOC 740. I should mention those last two recordings were made before 6:30am on Sept 23, when KFMB-760 was still using its nighttime 50kW facility.
--- In ultralightdx@..., D1028Gary@... wrote:
Hi Stephen,
To be honest, despite your apparent impressions, the PL-380 (and the other
Si4734 chip based ULR's) actually have above average AM-band overload
resistance among the Ultralight radio class. The reason for my conclusion is
detailed testing with various ULR's inductively coupled to the 9' PVC loop,
which will seriously overload any pocket radio which is not "crunch
resistant." The 9' loop overloads the analog design Ultralights (SRF-39FP, R9012,
R911, etc.) so badly that whenever the radio is brought within inductive
coupling range of the loop, the loop's tuning capacitor can actually tune the
radio from 530-1700 kHz (regardless of where the radio's tuning capacitor is
set).
The SWP Slider model has outstanding resistance to overload, which makes
it ideal for use with the 9' loop. In this respect, it's probably a shade
more impressive than the Si4734 models. The fact that the SWP Slider has its
own tunable loopstick contributes to this stability, and when the tunable
Slider loopstick is combined with the 9' loop's tuning capacitor, the
ultimate selectivity of the system is probably close to optimum in the Ultralight
class.
Anyway, Stephen, even though there are no more SWP Sliders being made,
it's always possible to boost up your TP-chasing ability by going with a
larger tuned passive loop (than your SAT), or with a 7.5" loopstick PL-380
(which can partially null out some of your pests, if their bearing is about 90
degrees off of the NW direction). The only way you will know which TP's are
possible in your "RF Zoo" is to get up early, and try chasing them before
sunrise. Nobody has a perfect location, or a perfect radio. The most
successful TP-DXers (or TA DXers) are the ones who push their luck constantly, no
matter what handicaps they may face. Optimism, persistence and
determination are the main ingredients for success-- even if your radio, antenna or
location has some limitations. Keep trying, and I'm sure that you will
receive many more TP's this season.
73, Gary
In a message dated 10/18/2010 10:42:54 P.M. Pacific Daylight Time,
pianoplayer88key@... writes:
CQ CQ Calling N7EKX...
I'd be interested in finding out how they compare with separating a very
strong signal from a very weak one (even if it is 10kHz away) when nulling
the strong signal isn't an option. With my PL-380, even in the 1kHz mode, I
can hear some of my strong locals 12kHz away. Across town I was trying to
listen to KDIS-1110 yesterday on my way to a Bible study service.
Unfortunately, their faint 41/00 signal was being stepped on by residual
chirps/chatter from XEPRS-1090, which was booming in at a solid 63/25. (I didn't have
the G8 with me, but I would guess XEPRS probably would have been around
72-76/25 or thereabouts.) However, I was almost right on KDIS's 2mV/m "local"
contour according to Radio-Locator, or possibly just slightly outside it at
the time, in Ocean Beach (a few miles northwest of San Diego airport). When
I have been in rural areas, though, I've been able to get listenable audio
on weaker signals, including some for which I was well outside Radio-Locat
or's estimated 0.15mV/m "fringe" contour - in a few cases even twice as
far, maybe more.
I was wondering how well the Slider+Murata'ed SWP would do in a test which
my PL-380, even in 1kHz BW mode, fails miserably. In a place where (I'm
guessing, as I don't own one to know its actual sensitivity) the PL-360 would
be indicating somewhere around 93/25 to 96/25 WITHOUT an antenna plugged
in... how well would the SWP (and if you want to check it with your
7.5-inched PL-380 (mine's stock) that's fine too) hear a signal 10kHz away coming
from the same direction as the strong pest, for which you are about 1.5 to
2x past Radio-Locator's predicted 0.15mV/m "fringe" contour? My PL-380
utterly fails that test. If it passed it, I'd be able to hear one of the
stations I originally wanted to be able to hear in the daytime, KERN-1180
Wasco-Greenacres, CA, for which I'm about 2x past the 0.15mV/m contour.
Unfortunately, KCBQ-1170's 77/25 signal still has significant splatter audible on 1180
(which does die out by around 1182 or 1183 or so), and even KXMX Anaheim
's 43/00 signal is only barely audible.
73... Stephen (No, I haven't gone past the no-turning-back point and
gotten a Ham license.)
--- In _ultralightdx@... (mailto:ultralightdx@...)
, D1028Gary@ wrote:
Hi Rick,
Thanks for your generous comments on the SWP Slider models. Only about 5
of these models were ever made (in cooperation with Steve Ratzlaff, who
installed the Murata CFJ455K5 filters), including the one that I am
currently
using for TP-DXing each morning. Far more Eton E100 Slider models were made
and sent out, including several by John Bryant (with his plywood frame
mounting style).
When the first Si4734 chip 1 kHz DSP model (the Kchibo D96L) was released
in August of last year, there was intense interest in whether or not the
model's stock 1 kHz DSP selectivity would be competitive with the premium
Murata CFJ455K5 IF filters transplanted into our modified SWP and E100 models.
That month I took a new Kchibo D96L to a famous Pacific beach DXpedition
site here in Washington state (Grayland), and made comparison MP3's during
the reception of two South Pacific stations. A 3' portable PVC loop was
used to boost signals, and the SWP was tuned 1 kHz off the DX station's
frequency (away from domestic splatter) to provide crisper audio (this could not
be done with the D96L, because of the "soft mute" issue). In the first 15
seconds, the D96L (with its 1 kHz Si4734 DSP filtering) receives the South
Pacific split-frequency station, and in the last 15 seconds the SWP Slider
(with a Murata CFJ455K5 filter) receives the same signal:
567-2YA Wellington, New Zealand 1250 UTC 8-9-09
__http://www.mediafire.com/?8n4ce5j2y1hfw6c__ (http://www.mediafire.com/?8n4ce5j2y1hfw6c_) (_http://www.mediafire.com/?8n4ce5j2y1hfw6c_
(http://www.mediafire.com/?8n4ce5j2y1hfw6c) )
738-Tahiti Mahina, Tahiti 1215 UTC 8-9-09
__http://www.mediafire.com/?l02marixc0xvhuh__
(http://www.mediafire.com/?l02marixc0xvhuh_) (_http://www.mediafire.com/?l02marixc0xvhuh_
(http://www.mediafire.com/?l02marixc0xvhuh) )
Of course the receivers' audio sections also influenced the quality of
the
received signals, but at the time I reported to the group that the D96L's 1
kHz DSP selectivity (from its Si4734 chip) was fairly competitive with
that provided by the transplanted Murata K filter in the SWP. The consensus
among the group, however, was that the Murata filter SWP had somewhat more
"mellow" audio than that provided by the Si4734 chip's 1 kHz DSP setting.
The Si4734 chip's 1 kHz DSP filtering is a tremendous breakthrough for
inexpensive stock Ultralights, though, and I've used both the 7.5" loopstick
PL-380 and the 7.5" loopstick SWP Slider for South Pacific DXpeditions this
past summer.
73, Gary DeBock (in Puyallup, WA)
In a message dated 10/18/2010 8:13:45 A.M. Pacific Daylight Time,
w4dst@ writes:
My Thanks to Gary for the CCrane SWP Slider that is now a fine
addition to my shack. Now that it is DXing season, I hope to be able to
give it a good workout with some new DX and hopefully some TA loggings.
I have been comparing it to some of the other receivers in the shack and
I thought I'd pass along my observations. These are not scientific,
just objective but I've tried to be impartial. Some of the results are
surprising.
One of my receivers is a Sangean ATS-803A that I picked up at a hamfest
over the Labor Day weekend and have given it a good alignment. The
ATS-803A/Radio Shack DX-440 and the Sony 2010 were considered 2 of the
best MW radios of their day and are still excellent performers. I am
fortunate to own both and thought I'd see how the slider stood up to
these 2 classics. My 2010 has 2 Kiwa filters in it, the CCrane has a
2.5kHz MuRata 6 element ceramic filter replacing the stock filter and
the Sangean has both stock filters. Selectivity wise, the CCrane's
MuRata filter is even better than the narrow Kiwa filter in the Sony,
which was surprising, and as good as, or better than the Sangean narrow
filter. The filters in the Sangean surprised me at how good they are
and the audio in the Sangean easily beats the others hands down.
When testing the sensitivity during the day, the slider came out the
winner over both receivers due the nice job Gary did on the slider
antenna. Being able to tune the antenna to the receiver is a very
valuable asset for DXing as others have noted. The Sangean, Sony and
the slider ferrite bars are all very close in length, 7.5" and all are
wound in much the same method with the windings closely wound on the
left end as you face the bar. The slider is slightly better than the
Sangean in nulling and equal to the Sony.
The only radio I have that takes on the slider and comes out ahead in
any way is my classic Radio Shack 12-655. This is a TRF design from the
early 1980s with a similar size ferrite bar. It is a analog radio, very
simple in operation and is legendary in MW DXing circles for its
outstanding sensitivity and nulling ability. During the day, I can
twist and turn my 12-655 and completely null out local WHKP 1450 6 miles away, and hear WATA in Boone, NC, 140 miles to my north with full
audio. No other radio or my Quanum loop antenna is capable of this,
only my antenna phasing system can duplicate this feat. I have no
idea what contributes to it's amazing nulling quality since the antenna
looks to be wound just like the other 3 bars. As we say in the QRP
community, the 12-655 just has mojo. The slider and the 12-655 are very
close in sensitivity and it would be difficult without test equipment
measurements to determine which is the more sensitive. My 12-655 has
always been my benchmark for sensitivity and nulling capabilities and
will continue to be.
I have also experimented with a 280uH fixed coil ferrite bar antenna
that I wound on a 20cm, 7 7/8", bar from a junked Grundig S350L. It
has a 1/8" stereo plug on the end to interface with my PL-310 with its
"Laurie" mod. It and the slider seem to be equal in sensitivity.
However, the digital filter in the Si4734 has the edge on the MuRata
filter in the CCRane. Once again, I am impressed with Scott and the
rest of the folks at Silicon Labs and the design of this fantastic
chip. It's amazing so much can be packed into this tiny chip.
Good DXing in the upcoming season to everyone.
Rick W4DST
Hendersonville, NC
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rick robinson <w4dst@...>
On 10/19/2010 3:02 AM, D1028Gary@... wrote:
>The SWP Slider model has outstanding resistance to
overload, which makes it ideal for use with the 9' loop. In this
respect, it's probably a shade more impressive than the Si4734
models. The >fact that the SWP Slider has its own tunable
loopstick contributes to this stability, and when the tunable
Slider loopstick is combined with the 9' loop's tuning
capacitor, the ultimate selectivity of >the system is
probably close to optimum in the Ultralight class.
Hi Gary,
I recently tested the SWP Slider against a stock PL-310 at
a site about a 1/4 mile from my local WHKP
1450 antenna. I may have failed to post my findings and if so
here they are again although the signal strength readings from
the PL-310 are lost. The PL-310 overloaded and no stations were
heard from 1390 up through 1560 kHz except for an image of 1450
which appeared at 1540. I had noted this image in a previous
trip to the transmitter site. The Slider could log 1440kHz in
Greenville, SC,50 miles away and 1400kHz in Waynesville, NC 35
miles away both with good audio, neither of which the PL-310
could hear at all. There was even a trace of audio on the
Slider from 1460 WHBK in Marshall, NC, about 45 miles to the
north so there was very little desensitizing of the front end on
the SWP even with the Slider. There was also no image at 1540 on
the SWP , I wasn't expecting one, although
one did show up on 540, which is 1450 minus 2X the SWP IF of
455kHz. This is quite common for single conversion 455kHz IF
frequency receivers although on the SWP it was at a much lower
level than many other receivers. At my mother-in-law's house 3
miles away, there was no trace of images on either radio at
their respective image frequencies. My old Sangean ATS-909 had
a very strong image of 1450 WHKP on 550 at her house. The
Sangean IF was/is 450kHz rather than the more common 455kHz. I
would have expected the SWP with that big ferrite bar to have
had some serious problems with overload and imaging but that
just wasn't the case even as close as I was to the antenna
tower.
Even with a large ferrite bar antenna, the SWP exhibits much
better front end resistance to high RF levels than the PL-310, at
least in my tests it does. But it should be noted this is an apples
to oranges comparison since the SWP is a more "traditional" radio
with a 455kHz IF and analog style front end, as opposed to the
digital circuitry of the Si4734 based radios. The digital filters
in the Si4734 radios are outstanding for my east coast DXing, but
the ability to tune the Slider, along with the SWP features which
the Tecsun radios lack, makes the SWP Slider my MW radio of
choice. There are features in the Tecsuns that I wish were in the
SWP, like the ability to keep the back light on and of course the
signal strength readout. The Tecsuns need a 10/9kHz UP/DOWN feature
like the SWP. The G8 has it and I wish my '310 and '380 had that
feature.
We are planning a trip to the SC coast in the next couple of weeks
and I will post my loggings to the list. That is a good place for
TA, Cuban, Caribbean, and sometimes South American DX. The problem
I have is finding time to DX since this is mine and my wife's
get-away vacation and playing with the radio is not one of her top
priorities.
Rick W4DST
|
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Gary DeBock
Hi Rick,
Thanks for your detailed testing of the SWP Slider's resistance to
overload, which is much appreciated.
It's true that the stock C.Crane SWP model has somewhat of a
problem with image frequencies, but the 7.5" Slider loopstick acts as a
tuned circuit to filter out these nuisance signals (when the coil is peaked on
the frequency that has the image). In my local environment the 1450-KSUH pest
typically puts in a strong image on 540 kHz with 455 kHz IF radios (SWP,
E100, etc.) but the Slider loopstick can reduce the strength of the image
down to a very low level. The additional tuned circuit provided by an
external tuned passive loop can finish the job by making all images
disappear completely. In agreement with your findings, I've been very happy with
the SWP Slider's resistance to overload, which is of extreme
importance when using a high-gain antenna like the 9' PVC box loop.
73, Gary
In a message dated 10/19/2010 4:12:14 P.M. Pacific Daylight Time,
w4dst@... writes:
toggle quoted message
Show quoted text
On 10/19/2010 3:02 AM, D1028Gary@... wrote:
>The SWP Slider model has outstanding resistance to
overload, which makes it ideal for use with the 9' loop. In this respect, it's
probably a shade more impressive than the Si4734 models. The >fact
that the SWP Slider has its own tunable loopstick contributes to this
stability, and when the tunable Slider loopstick is combined with the 9'
loop's tuning capacitor, the ultimate selectivity of >the system is
probably close to optimum in the Ultralight class.
Hi Gary,
I
recently tested the SWP Slider against a stock PL-310 at a site about a 1/4 mile from
my local WHKP 1450 antenna. I may have failed to post my findings and if
so here they are again although the signal strength readings from the PL-310
are lost. The PL-310 overloaded and no stations were heard from 1390 up
through 1560 kHz except for an image of 1450 which appeared at 1540. I
had noted this image in a previous trip to the transmitter site. The
Slider could log 1440kHz in Greenville, SC,50 miles away and 1400kHz in
Waynesville, NC 35 miles away both with good audio, neither of which the
PL-310 could hear at all. There was even a trace of audio on the Slider
from 1460 WHBK in Marshall, NC, about 45 miles to the north so there was very
little desensitizing of the front end on the SWP even with the Slider.
There was also no image at 1540 on the SWP , I wasn't expecting one, although one did
show up on 540, which is 1450 minus 2X the SWP IF of 455kHz. This is
quite common for single conversion 455kHz IF frequency receivers although on
the SWP it was at a much lower level than many other receivers. At my
mother-in-law's house 3 miles away, there was no trace of images on either
radio at their respective image frequencies. My old Sangean ATS-909 had
a very strong image of 1450 WHKP on 550 at her house. The Sangean IF
was/is 450kHz rather than the more common 455kHz. I would have expected
the SWP with that big ferrite bar to have had some serious problems with
overload and imaging but that just wasn't the case even as close as I was to
the antenna tower.
Even with a large ferrite bar antenna, the SWP exhibits much
better front end resistance to high RF levels than the PL-310, at least in my
tests it does. But it should be noted this is an apples to oranges
comparison since the SWP is a more "traditional" radio with a 455kHz IF and
analog style front end, as opposed to the digital circuitry of the Si4734
based radios. The digital filters in the Si4734 radios are outstanding
for my east coast DXing, but the ability to tune the Slider, along with the
SWP features which the Tecsun radios lack, makes the SWP Slider my MW radio of
choice. There are features in the Tecsuns that I wish were in the
SWP, like the ability to keep the back light on and of course the signal
strength readout. The Tecsuns need a 10/9kHz UP/DOWN feature like the
SWP. The G8 has it and I wish my '310 and '380 had that feature.
We are planning a trip to the SC coast in the next couple of weeks and
I will post my loggings to the list. That is a good place for TA, Cuban,
Caribbean, and sometimes South American DX. The problem I have is
finding time to DX since this is mine and my wife's get-away vacation and
playing with the radio is not one of her top priorities. Rick
W4DST
|
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Gary DeBock
Hi Carl,
Yes, both the Eton E100 and the C.Crane SWP models have image issues
on frequencies 910 kHz below strong local stations (for example, WBCR-1470 minus
910 kHz equals a "WBCR-560" image). The strength of these images can be reduced
either by using a tuned passive loop (which filters out any signal which is not
actually on 560 kHz), a Slider loopstick (which does the same thing), or
both.
The SRF-59 has an IF much lower than 455 kHz, so it does
not suffer from these typical image frequency issues. The 450 kHz
ULR's like the SRF-T615, SRF-M37V, DT-400W and DT-200VX usually do suffer from
images, but on frequencies 900 kHz lower than local pests. These images can also
be reduced or eliminated with the filtering provided by an
external tuned passive loop, or Slider loopstick.
73, Gary
In a message dated 10/21/2010 3:20:35 P.M. Pacific Daylight Time,
carl_elissa@... writes:
toggle quoted message
Show quoted text
Gary:
I get an image from semi local WBCR 1470,Alcoa,Tn.on 560 on my
stock E-100.It seems to be very nullable with a passive loop such as my
Grundig AN-200 or my Select-A-Tenna.I can pretty much make it go away.I have
not checked all the other ULRs but the analog ones (the SRF 59 and Kaito
WRX-911 ) do not seem to have this problem.
Carl
DeWhitt
Maryville,Tn.
--- In ultralightdx@...,
D1028Gary@... wrote:
>
> Hi Rick,
>
> Thanks for your
detailed testing of the SWP Slider's resistance to
> overload, which is
much appreciated.
>
> It's true that the stock C.Crane SWP model
has somewhat of a problem with
> image frequencies, but the 7.5" Slider
loopstick acts as a tuned circuit to
> filter out these nuisance
signals (when the coil is peaked on the
> frequency that has the
image). In my local environment the 1450-KSUH pest typically
> puts in
a strong image on 540 kHz with 455 kHz IF radios (SWP, E100, etc.)
>
but the Slider loopstick can reduce the strength of the image down to a
> very low level. The additional tuned circuit provided by an external
tuned
> passive loop can finish the job by making all images disappear
completely. In
> agreement with your findings, I've been very happy
with the SWP Slider's
> resistance to overload, which is of extreme
importance when using a
> high-gain antenna like the 9' PVC box
loop.
>
> 73, Gary
>
>
> In a message dated
10/19/2010 4:12:14 P.M. Pacific Daylight Time,
> w4dst@...
writes:
>
>
>
>
> On 10/19/2010 3:02 AM,
_D1028Gary@..._ (mailto:D1028Gary@...)
> wrote:
>
>
>The SWP Slider model has outstanding resistance to overload, which makes
> it ideal for use with the 9' loop. In this respect, it's probably a
shade
> more impressive than the Si4734 models. The >fact that the
SWP Slider has
> its own tunable loopstick contributes to this
stability, and when the tunable
> Slider loopstick is combined with the
9' loop's tuning capacitor, the
> ultimate selectivity of >the
system is probably close to optimum in the
> Ultralight class.
>
> Hi Gary,
>
> I recently tested the SWP Slider against a
stock PL-310 at a site about a
> 1/4 mile from my local WHKP 1450
antenna. I may have failed to post my
> findings and if so here they
are again although the signal strength readings
> from the PL-310 are
lost. The PL-310 overloaded and no stations were heard
> from 1390 up
through 1560 kHz except for an image of 1450 which appeared at
> 1540.
I had noted this image in a previous trip to the transmitter site.
>
The Slider could log 1440kHz in Greenville, SC,50 miles away and 1400kHz
> in Waynesville, NC 35 miles away both with good audio, neither of
which the
> PL-310 could hear at all. There was even a trace of audio
on the Slider
> from 1460 WHBK in Marshall, NC, about 45 miles to the
north so there was very
> little desensitizing of the front end on the
SWP even with the Slider.
> There was also no image at 1540 on the SWP
, I wasn't expecting one, although
> one did show up on 540, which is
1450 minus 2X the SWP IF of 455kHz. This
> is quite common for single
conversion 455kHz IF frequency receivers
> although on the SWP it was
at a much lower level than many other receivers. At
> my
mother-in-law's house 3 miles away, there was no trace of images on
>
either radio at their respective image frequencies. My old Sangean ATS-909 had
> a very strong image of 1450 WHKP on 550 at her house. The Sangean IF
> was/is 450kHz rather than the more common 455kHz. I would have
expected the
> SWP with that big ferrite bar to have had some serious
problems with overload
> and imaging but that just wasn't the case even
as close as I was to the
> antenna tower.
>
>
>
Even with a large ferrite bar antenna, the SWP exhibits much better front
> end resistance to high RF levels than the PL-310, at least in my
tests it
> does. But it should be noted this is an apples to oranges
comparison since
> the SWP is a more "traditional" radio with a 455kHz
IF and analog style
> front end, as opposed to the digital circuitry of
the Si4734 based radios.
> The digital filters in the Si4734 radios are
outstanding for my east coast
> DXing, but the ability to tune the
Slider, along with the SWP features which
> the Tecsun radios lack,
makes the SWP Slider my MW radio of choice. There
> are features in the
Tecsuns that I wish were in the SWP, like the ability
> to keep the
back light on and of course the signal strength readout. The
> Tecsuns
need a 10/9kHz UP/DOWN feature like the SWP. The G8 has it and I
> wish
my '310 and '380 had that feature.
>
> We are planning a trip to
the SC coast in the next couple of weeks and I
> will post my loggings
to the list. That is a good place for TA, Cuban,
> Caribbean, and
sometimes South American DX. The problem I have is finding time
> to DX
since this is mine and my wife's get-away vacation and playing with
>
the radio is not one of her top priorities.
>
> Rick
W4DST
>
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Gary:
I get an image from semi local WBCR 1470,Alcoa,Tn.on 560 on my stock E-100.It seems to be very nullable with a passive loop such as my Grundig AN-200 or my Select-A-Tenna.I can pretty much make it go away.I have not checked all the other ULRs but the analog ones (the SRF 59 and Kaito WRX-911 ) do not seem to have this problem.
Carl DeWhitt
Maryville,Tn.
toggle quoted message
Show quoted text
--- In ultralightdx@..., D1028Gary@... wrote:
Hi Rick,
Thanks for your detailed testing of the SWP Slider's resistance to
overload, which is much appreciated.
It's true that the stock C.Crane SWP model has somewhat of a problem with
image frequencies, but the 7.5" Slider loopstick acts as a tuned circuit to
filter out these nuisance signals (when the coil is peaked on the
frequency that has the image). In my local environment the 1450-KSUH pest typically
puts in a strong image on 540 kHz with 455 kHz IF radios (SWP, E100, etc.)
but the Slider loopstick can reduce the strength of the image down to a
very low level. The additional tuned circuit provided by an external tuned
passive loop can finish the job by making all images disappear completely. In
agreement with your findings, I've been very happy with the SWP Slider's
resistance to overload, which is of extreme importance when using a
high-gain antenna like the 9' PVC box loop.
73, Gary
In a message dated 10/19/2010 4:12:14 P.M. Pacific Daylight Time,
w4dst@... writes:
On 10/19/2010 3:02 AM, _D1028Gary@..._ (mailto:D1028Gary@...)
wrote:
The SWP Slider model has outstanding resistance to overload, which makes it ideal for use with the 9' loop. In this respect, it's probably a shade
more impressive than the Si4734 models. The >fact that the SWP Slider has
its own tunable loopstick contributes to this stability, and when the tunable
Slider loopstick is combined with the 9' loop's tuning capacitor, the
ultimate selectivity of >the system is probably close to optimum in the
Ultralight class.
Hi Gary,
I recently tested the SWP Slider against a stock PL-310 at a site about a
1/4 mile from my local WHKP 1450 antenna. I may have failed to post my
findings and if so here they are again although the signal strength readings
from the PL-310 are lost. The PL-310 overloaded and no stations were heard
from 1390 up through 1560 kHz except for an image of 1450 which appeared at
1540. I had noted this image in a previous trip to the transmitter site.
The Slider could log 1440kHz in Greenville, SC,50 miles away and 1400kHz
in Waynesville, NC 35 miles away both with good audio, neither of which the
PL-310 could hear at all. There was even a trace of audio on the Slider
from 1460 WHBK in Marshall, NC, about 45 miles to the north so there was very
little desensitizing of the front end on the SWP even with the Slider.
There was also no image at 1540 on the SWP , I wasn't expecting one, although
one did show up on 540, which is 1450 minus 2X the SWP IF of 455kHz. This
is quite common for single conversion 455kHz IF frequency receivers
although on the SWP it was at a much lower level than many other receivers. At
my mother-in-law's house 3 miles away, there was no trace of images on
either radio at their respective image frequencies. My old Sangean ATS-909 had
a very strong image of 1450 WHKP on 550 at her house. The Sangean IF
was/is 450kHz rather than the more common 455kHz. I would have expected the
SWP with that big ferrite bar to have had some serious problems with overload
and imaging but that just wasn't the case even as close as I was to the
antenna tower.
Even with a large ferrite bar antenna, the SWP exhibits much better front
end resistance to high RF levels than the PL-310, at least in my tests it
does. But it should be noted this is an apples to oranges comparison since
the SWP is a more "traditional" radio with a 455kHz IF and analog style
front end, as opposed to the digital circuitry of the Si4734 based radios.
The digital filters in the Si4734 radios are outstanding for my east coast
DXing, but the ability to tune the Slider, along with the SWP features which
the Tecsun radios lack, makes the SWP Slider my MW radio of choice. There
are features in the Tecsuns that I wish were in the SWP, like the ability
to keep the back light on and of course the signal strength readout. The
Tecsuns need a 10/9kHz UP/DOWN feature like the SWP. The G8 has it and I
wish my '310 and '380 had that feature.
We are planning a trip to the SC coast in the next couple of weeks and I
will post my loggings to the list. That is a good place for TA, Cuban,
Caribbean, and sometimes South American DX. The problem I have is finding time
to DX since this is mine and my wife's get-away vacation and playing with
the radio is not one of her top priorities.
Rick W4DST
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