Date   

Directly Connected FSL's

Gary DeBock
 

Hello All,

Despite warnings to the contrary, I decided to experiment with a
Ferrite Sleeve Loop antenna directly connected to the PL-380 model,
replacing the internal stock loopstick. The idea of having the FSL's
great gain boost without the need for double tuning (of the ULR radio
and external tuning capacitor) was a powerful temptation, providing
enough incentive to risk destruction of the PL-380's Si4734 DSP chip to
find out if this direct-connection idea was viable. As it turns out,
the dire warnings about the risk to the DSP chip from a
directly-connected FSL are probably overblown, although the cost of the
ferrite bars (to make this kind of FSL) can easily "fry" the
pocketbook.

A directly-connected FSL of 14 type 33 Amidon ferrite rods (each one
4" x 1/2") was constructed with a single 1700 uh coil (of 100/44 Litz
wire from eBay seller "Mkmak222"), for a final coil diameter of 3.25".
This classic-design FSL (photo at
http://www.mediafire.com/i/?mrbd1trj7b574dj ) was directly connected in
place of the stock loopstick in a PL-380, and then matched in
performance against the "G" model 7.5" LW loopstick PL-380 (the same
model used by Rob, Patrick and I to receive over 100 NDB stations).

The daytime NDB-DX "shootout" around local noon proved that the new,
directly-connected FSL was a very sensitive antenna, although the "G"
model PL-380 could match it station-for-station. The FSL typically had
higher RSSI and S/N readings on each fringe NDB station, but the "G"
model PL-380 received the same number of fringe NDB's. Probably the
biggest difference between the two competitors (photo at
http://www.mediafire.com/i/?rgqcz3v8oio5v6w ) was the cost of
construction-- $75 for the "G" model, and about $175 for the FSL model
(mainly because of the pricey Amidon ferrite rods, running $8 apiece).
As such, even though this type of directly-connected FSL may be a very
sensitive antenna (and has survived multiple testing without any harm
to the host PL-380), unless cheaper sources of ferrite are used for the
cylindrical rod assembly, this type of antenna option may be
impractical for most DXers. The single-loopstick "G" model may have
lost the signal shootout, but was the clear winner in practical value.

73 and Good DX,
Gary DeBock (in Puyallup,, WA, USA)


LW band is open to Europe and Africa

Tony Germanotta
 

I won't get into a long list, but just about every frequency in the broadcast LW band has somebody on it this evening here in Chesapeake, VA. I am using a Tecsun PL-310 with a LW crate loop I just whipped up yesterday after Chuck Rippel inspired me. It is directly tuned by the SiLab using the stereo ring and ground mod to the unused stereo imputs of the antenna in jack.
 
There are broadcasters at various signal strengths on 153, 162, 171, 189, 198, 207, 216, 225, 234, 252, 261 and 270 kHz. I am about 25 miles from the oceanfront and doing this in my living room, so those in a lower noise, or true coastal location should do very well indeed. If it weren't so nasty out tonight, I might have tried a backyard DX session, but as I reminded Chuck just recently, this stuff is supposed to be fun, and I don't have fun freezing. It's why I never took to ice fishing. 




.



Re: Kchibo KK- D202 for 2010-Shootout

antonsamon <antonsamon@...>
 

--- In ultralightdx@..., "gregcoonan" <gregcoonan@...> wrote:

Thanks for reply Gary
A bit more research shows that the KK-D202 only has 9khz AM stepping which is OK for us in Australia but no good for the States.
Regards
GREG

--- In ultralightdx@..., D1028Gary@ wrote:

Hello Greg,

Thank you very much for the information on the Kchibo KK-D202, and the link
to the review-- which are both appreciated

Apparently in the Kchibo model designation system the KK-D models all use
the same DSP chip, which has capabilities somewhat less than an Si4734 DSP
chip (as in the PL-300WT/ G8, PL-310, PL-380, PL-360 and D96L models) but
still reasonably competitive. One of the models that will be featured in the
2010 Shootout, the Kchibo KK-D6110, has this same DSP chip (with
specifications apparently very close to those of the KK-D202 model).

If the KK-D202 model is ordered by one of our Ultralightdx members and is
found have performance superior to the KK-D6110 model, I will be very happy
to include it in either the current or next Shootout. The current 2010
Shootout has been somewhat delayed by the author's sudden decision to chase
South Pacific DX one last time in Oregon recently (especially from Australia
:-) , but should still be completed within this month of September.

73 and Good DX,
Gary DeBock (in Puyallup, WA, USA)

In a message dated 9/3/2010 4:43:44 P.M. Pacific Daylight Time,
gregcoonan@ writes:




Hi Gary
With its great size advantages and albeit lower quality DSP and A$25 Ebay
price,could this radio be a candidate for the shootout.I found one
favourable review on it here:

_http://goldismoney2.com/showthread.php?3168-Shortwave-radio-catching-up-wit
h-cell-phone-technology._
(http://goldismoney2.com/showthread.php?3168-Shortwave-radio-catching-up-with-cell-phone-technology.)

Thanks
GREG
Kchibo kk-d202 has 10 and 9 Khz step in MW.


Re: First FSL

Gary DeBock
 

-----Original Message-----
From: rabej_de <rabej_de@...>
To: ultralightdx <ultralightdx@...>
Sent: Mon, Mar 28, 2011 1:56 am
Subject: [ultralightdx] First FSL

Hello Joachim,

Congratulations on your successful FSL project, and your video is quite
impressive.

Like Steve says, the Longwave FSL's work better oudoors, away from
house wiring and computer noise. When the weather (and LW propagation)
is good, I'm sure that you will have a lot of fun chasing NDB's
outdoors with your new FSL antenna.

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



-----Original Message-----
From: rabej_de <rabej_de@...>
To: ultralightdx <ultralightdx@...>
Sent: Mon, Mar 28, 2011 1:56 am
Subject: [ultralightdx] First FSL

 
Hi, list!

For anybody who might be interested I've added a short movie of my
first indoor-test to my Flickr-account :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

73s

Joachim Rabe

--- In ultralightdx@..., "rabej_de" <rabej_de@...>
wrote:

Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam
former, 23 ferrite bars, 100x20x3, permeability 400, 3 layers of bubble
wrap and 55 turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2
sections in parallel.
Pictures of it can be found here :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun
PL-380 and I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I
was not able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs
running etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?
&gt;
73s

Joachim Rabe


First FSL

rabej_de <rabej_de@...>
 

Hi, list!

For anybody who might be interested I've added a short movie of my first indoor-test to my Flickr-account : http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

73s

Joachim Rabe

--- In ultralightdx@..., "rabej_de" <rabej_de@...> wrote:

Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam former, 23 ferrite bars, 100x20x3, permeability 400, 3 layers of bubble wrap and 55 turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2 sections in parallel.
Pictures of it can be found here : http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun PL-380 and I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I was not able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs running etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?

73s

Joachim Rabe


Re: Inexpensive source of ferrite for LF FSL (first FSL built)

rabej_de <rabej_de@...>
 

Thanks, Steve!

I'll build some sort of stand for it over the week and give it a try in our backyard some 10 m from our house.

73s

Joachim Rabe

--- In ultralightdx@..., "Steve Ratzlaff" <steveratz@...> wrote:

Hi Joachim,
Congratulation on constructing your new FSL. That's a good size, probably
about 165 mm coil diameter. And if you're hearing the noise level increase
when you tune it, it must be resonating where you want it to, in the LF
band.
I can't really say why it's not giving a large sensitivity boost to your
PL-380 other than like you note perhaps your noise level indoors is just too
high. The easiest would be just to go outside and try it there, or somewhere
where the noise level is much lower, if only to test it.
Good luck!
Steve

----- Original Message -----
From: "rabej_de" <rabej_de@...>
To: <ultralightdx@...>
Sent: Sunday, March 27, 2011 11:58 AM
Subject: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL


Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam former, 23
ferrite bars, 100x20x3, permeability 400, 3 layers of bubble wrap and 55
turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2 sections in
parallel.
Pictures of it can be found here :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun PL-380 and
I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I was not
able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs running
etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?

73s

Joachim Rabe


Re: Inexpensive source of ferrite for LF FSL

rabej_de <rabej_de@...>
 

Thanks for your comments, Gary!

And yes, during my tests, the FSL was parallel to the table.
I will tro to reduce coil inductance then and see what happens.

73s

Joachim Rabe

--- In ultralightdx@..., D1028Gary@... wrote:

Hello Joachim,

Thanks for sharing the results of your first FSL project with us.

Steve and Kevin may have their own comments, but I'll suggest a couple
of tips. For covering the NDB band with an inductively-coupled FSL,
1615 uh may be a little high for coil inductance. 1615 uh is close to
the inductance normally used for a directly-connected LW loopstick
coil, and your FSL's variable capacitor would extend the FSL's longwave
frequency coverage even lower. With your current components, you
probably should be able to cover the entire NDB band with about 1000 uh
of coil inductance.

The only operating suggestion that I could make (after viewing your
photos) is to ensure that the FSL is parallel to the table when you are
using it (and not standing on one end, like in your last photo with
ther variable cap connected). Any FSL standing on one end will not
receive much of anything, although the tuning noise will be there (as
you describe).

73 and Good Luck,
Gary DeBock (in Puyallup, WA, USA)

-----Original Message-----
From: rabej_de <rabej_de@...>
To: ultralightdx <ultralightdx@...>
Sent: Sun, Mar 27, 2011 11:58 am
Subject: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL

 
Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam former, 23
ferrite bars, 100x20x3, permeability 400, 3 layers of bubble wrap and
55 turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2 sections in
parallel.
Pictures of it can be found here :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun PL-380
and I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I was
not able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs
running etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?

73s

Joachim Rabe

--- In ultralightdx@..., "rabej_de" rabej_de@
wrote:

Hi, list!

Found these ferrite rods on eBay :
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&;item=400137000838&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

They measure 8 x 125 and are said to be 400 permeability.

Ony comments on using them for a LF-FLS?

Thanks very much in advance.

73s
&gt; Joachim Rabe


Re: LED Tuning light

Gary DeBock
 

Hi Brian and Kevin,

An LED that it not lighting (when it should) usually has two possible
causes-- either the LED itself is burned out, or the active device
(diode or transistor) driving the LED circuit has failed. Usually a
technican would use a voltmeter to determine whether or not the LED
input circuit has a positive voltage (to ground) when the LED should be
lighting. If there is the normal positive voltage, the LED itself is
probably bad. If the voltage on the input circuit is missing at all
times, most likely the diode or transistor (or sometimes IC) driving
the circuit has probably failed. You will need to locate these
components on your schematic diagram, Brian, then check for that LED
input voltage (either on the circuit board, or LED input pin).

73, Gary

-----Original Message-----
From: dhsatyadhana <dhsatyadhana@...>
To: ultralightdx <ultralightdx@...>
Sent: Sun, Mar 27, 2011 5:48 pm
Subject: [ultralightdx] Re: LED Tuning light

 
Hi Brian:

Alas, all I can give is qualitative suggestions - I am probably about
as handy with true tech work as you are, so wouldn't feel comfortable
going any further. Anyone else???

Kevin

--- In ultralightdx@..., "Jerry"
<brianalexmiller@...> wrote:

Hi Kevin -

Thanks for the reply.

I am so green on radio surgery that I'm not even quite sure what
the "trace" is. The wires coming from the pcb to the led?

What do I test with?

I have the service manual for the radio. I had to get it to figure
out how exactly to route the tuning dial string. I was amazed I was
able to actually do it after a few tries.

I've looked at the manual for awhile and can't figure the
indicator light out from looking at the schematic, but again, I am far
from a technician.

I guess what might help me most is if you or someone could tell me
the general concept behind what causes the indicator to light, where it
usually would connect to.....

anyway -
&gt; Thanks again


--- In ultralightdx@..., "dhsatyadhana"
<dhsatyadhana@> wrote:

Hi Brian:

Have you tried testing the LED itself? Not sure if these
burn out.

Disconnecting the trace to the LED (to test the LED) would
allow you to test if there is voltage coming to the LED as well?
&gt; >
Kevin S

--- In ultralightdx@..., "Jerry"
<brianalexmiller@> wrote:
&gt; I know this is the ultralight DX board, but it is the
most active DX message board I know of so maybe someone can answer me
even though this is not about ULR's.

My question is about a red LED tuning light on a
portable Sony analog AM/FM radio - TFM-7250W.
&gt;
I got the thing at a garage sale last year for five
bucks and I took it apart to clean it and to retro-fit it with an 18"
outboard ferrite antenna.

Everything is working great except for I cannot get the
little red tuning led to light anymore.
&gt; >
All of the connections look good to me but obviously I'm
missing something.

I guess my question is if anyone knows where that kind
of a connection would be made generally.

Thanks

Brian Miller

Berkley, MI
&gt; USA


Re: ferrite quality?

Steve Ratzlaff <steveratz@...>
 

Hi Michael,
No, we don't know anything about the "quality" of any of the ferrite we've been using, that I know of. I don't know how one would determine "quality", anyway. I know that the ferrite I've been using, which is a combination of the NOS Russian eBay ferrite as well as Amdion rods.
73,
Steve

----- Original Message -----
From: "Michael" <michael.setaazul@...>
To: <ultralightdx@...>
Sent: Sunday, March 27, 2011 3:56 PM
Subject: Re: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL (first FSL built)


Do we know the quality of the "vintage" Soviet ferrite?
The date stamp suggests older production. I once had
a transistor radio from the Soviet era. Sensitivity was
poor - it worked better, with an aviary of birdies,
with a longish wire attached :-)

Michael UK


Re: LED Tuning light

Kevin Schanilec
 

Hi Brian:

Alas, all I can give is qualitative suggestions - I am probably about as handy with true tech work as you are, so wouldn't feel comfortable going any further. Anyone else???

Kevin

--- In ultralightdx@..., "Jerry" <brianalexmiller@...> wrote:

Hi Kevin -

Thanks for the reply.

I am so green on radio surgery that I'm not even quite sure what the "trace" is. The wires coming from the pcb to the led?

What do I test with?

I have the service manual for the radio. I had to get it to figure out how exactly to route the tuning dial string. I was amazed I was able to actually do it after a few tries.

I've looked at the manual for awhile and can't figure the indicator light out from looking at the schematic, but again, I am far from a technician.

I guess what might help me most is if you or someone could tell me the general concept behind what causes the indicator to light, where it usually would connect to.....

anyway -

Thanks again


--- In ultralightdx@..., "dhsatyadhana" <dhsatyadhana@> wrote:

Hi Brian:

Have you tried testing the LED itself? Not sure if these burn out.

Disconnecting the trace to the LED (to test the LED) would allow you to test if there is voltage coming to the LED as well?

Kevin S

--- In ultralightdx@..., "Jerry" <brianalexmiller@> wrote:

I know this is the ultralight DX board, but it is the most active DX message board I know of so maybe someone can answer me even though this is not about ULR's.

My question is about a red LED tuning light on a portable Sony analog AM/FM radio - TFM-7250W.

I got the thing at a garage sale last year for five bucks and I took it apart to clean it and to retro-fit it with an 18" outboard ferrite antenna.

Everything is working great except for I cannot get the little red tuning led to light anymore.

All of the connections look good to me but obviously I'm missing something.

I guess my question is if anyone knows where that kind of a connection would be made generally.

Thanks

Brian Miller

Berkley, MI

USA


Re: Inexpensive source of ferrite for LF FSL (first FSL built)

Michael <michael.setaazul@...>
 

Do we know the quality of the "vintage" Soviet ferrite?
The date stamp suggests older production. I once had
a transistor radio from the Soviet era. Sensitivity was
poor - it worked better, with an aviary of birdies,
with a longish wire attached :-)

Michael UK

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

From: "Steve Ratzlaff" <steveratz@...>
To: <ultralightdx@...>
Sent: 27 March 2011 23:41
Subject: Re: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL (first FSL built)


Hi Joachim,
Congratulation on constructing your new FSL. That's a good size, probably
about 165 mm coil diameter. And if you're hearing the noise level increase
when you tune it, it must be resonating where you want it to, in the LF
band.
I can't really say why it's not giving a large sensitivity boost to your
PL-380 other than like you note perhaps your noise level indoors is just too
high. The easiest would be just to go outside and try it there, or somewhere
where the noise level is much lower, if only to test it.
Good luck!
Steve

----- Original Message -----
From: "rabej_de" <rabej_de@...>
To: <ultralightdx@...>
Sent: Sunday, March 27, 2011 11:58 AM
Subject: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL


Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam former, 23
ferrite bars, 100x20x3, permeability 400, 3 layers of bubble wrap and 55
turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2 sections in
parallel.
Pictures of it can be found here :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun PL-380 and
I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I was not
able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs running
etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?

73s

Joachim Rabe


------------------------------------

Yahoo! Groups Links


Re: Inexpensive source of ferrite for LF FSL (first FSL built)

Steve Ratzlaff <steveratz@...>
 

Hi Joachim,
Congratulation on constructing your new FSL. That's a good size, probably about 165 mm coil diameter. And if you're hearing the noise level increase when you tune it, it must be resonating where you want it to, in the LF band.
I can't really say why it's not giving a large sensitivity boost to your PL-380 other than like you note perhaps your noise level indoors is just too high. The easiest would be just to go outside and try it there, or somewhere where the noise level is much lower, if only to test it.
Good luck!
Steve

----- Original Message -----
From: "rabej_de" <rabej_de@...>
To: <ultralightdx@...>
Sent: Sunday, March 27, 2011 11:58 AM
Subject: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL


Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam former, 23 ferrite bars, 100x20x3, permeability 400, 3 layers of bubble wrap and 55 turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2 sections in parallel.
Pictures of it can be found here : http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun PL-380 and I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I was not able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs running etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?

73s

Joachim Rabe


Re: Inexpensive source of ferrite for LF FSL

Gary DeBock
 

Hello Joachim,

Thanks for sharing the results of your first FSL project with us.

Steve and Kevin may have their own comments, but I'll suggest a couple
of tips. For covering the NDB band with an inductively-coupled FSL,
1615 uh may be a little high for coil inductance. 1615 uh is close to
the inductance normally used for a directly-connected LW loopstick
coil, and your FSL's variable capacitor would extend the FSL's longwave
frequency coverage even lower. With your current components, you
probably should be able to cover the entire NDB band with about 1000 uh
of coil inductance.

The only operating suggestion that I could make (after viewing your
photos) is to ensure that the FSL is parallel to the table when you are
using it (and not standing on one end, like in your last photo with
ther variable cap connected). Any FSL standing on one end will not
receive much of anything, although the tuning noise will be there (as
you describe).

73 and Good Luck,
Gary DeBock (in Puyallup, WA, USA)

-----Original Message-----
From: rabej_de <rabej_de@...>
To: ultralightdx <ultralightdx@...>
Sent: Sun, Mar 27, 2011 11:58 am
Subject: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL

 
Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam former, 23
ferrite bars, 100x20x3, permeability 400, 3 layers of bubble wrap and
55 turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2 sections in
parallel.
Pictures of it can be found here :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun PL-380
and I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I was
not able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs
running etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?

73s

Joachim Rabe

--- In ultralightdx@..., "rabej_de" <rabej_de@...>
wrote:

Hi, list!

Found these ferrite rods on eBay :
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&;item=400137000838&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

They measure 8 x 125 and are said to be 400 permeability.

Ony comments on using them for a LF-FLS?

Thanks very much in advance.
&gt; 73s

Joachim Rabe


Re: Sony ICF-SW7600GR 7.5" Loopstick Mod Completed

Gary DeBock
 

Hello Frank,

Thanks for your intererst in the Sony ICF-SW7600GR 7.5" loopstick
modification. This project was designed (in July of 2008) to provide a
very compact, sensitive SSB spotting receiver for Ultralight radio
TP-chasing on ocean beaches, and was quite successful in this
objective.

A photo of the modified ICF-SW7600GR is posted at
http://www.mediafire.com/i/?kyneobkgsk21n3c . On an Amidon 7.5" Type 61
ferrite bar (available from http://www.amidoncorp.com. for $20 plus
shipping), on a base of J & J 2" waterproof tape (adhesive side out),
wind a center large coil of 120 turns of 40/44 Litz wire (983 uh), and
a separate, single turn of the wire 1/2 inch to the left of the large
center coil. After recording the Litz wire color-coded connections to
the stock loopstick, desolder the connections and carefully remove the
loopstick (which usually needs some "persuasion" because of a serious
amount of glue on the bottom). Install the replacement loopstick on the
frame of your choice, and duplicate the original Litz wire connections
to the new loopstick. You should enjoy a huge boost in sensitivity,
making your tiny ICF-SW7600GR more than competitive with a stock
ICF-2010 on both MW and LW.

My original post on this project (from July 2008) is pasted below
(minus the numerous ??? marks, which may make me seem more confused
than I normally am :-)

73, Gary

-----Original Message-----
From: maxyhopy <fsphotos@...>
To: ultralightdx <ultralightdx@...>
Sent: Sun, Mar 27, 2011 10:58 am
Subject: [ultralightdx] Re: Sony ICF-SW7600GR 7.5" Loopstick Mod
Completed

 
Hello Gary,

I am very interested in modifying my SW7600GR. Could you tell me what
size litz wire you used and also approximately how many turns you used
in modifyoing your Sw7600GR ? Appreciate any help. Frank

Hello Guys,

Although it's a little too large to qualify as an Ultralight
radio, the ICF-SW7600GR provides fairly competent MW performance in a
compact, SSB-capable design. For those MW DXers unable to accommodate
an ICF-2010 for space or financial reasons, this Sony portable would be
perfect as an SSB "spotting receiver" for Ultralight radio transoceanic
targets on an ocean beach... if only it had more sensitivity. Having
had an unused unit sitting around since the Ultralight "Boom" started
late last year (and faced with a situation where a multi-family
vacation would make packing space extremely limited), there was a
sudden compulsion to replace the stock 4.75" x .37" loopstick with a
much more effective Amidon 7.5" x .5" loopstick wound with 40/44 Litz
wire. This MW frequency-optimized combination has provided an
incredible sensitivity increase in the SRF-39FP and Eton E100
Ultralight models (enabling both to receive Australia signals at
Grayland), and I was curious how far it would boost the performance of
this compact SSB portable.

The ICF-SW7600GR has a stock loopstick very similar to that of
the
ICF-2010, in which a fixed larger center coil is mated with a much
smaller tickler coil, used for adjustment of the unit's spurious signal
rejection. As such, the instructions for "supercharging" the ICF-2010
(currently posted in dxer.ca's Ultralight File section) are
electrically applicable to the ICF-SW7600GR, although the lsmaller unit
has a large coil inductance of 983 uh, and the stock loopstick does not
have a snap-out design like the 2010, requiring the hobbyist to use a
moderate amount of effort in separating the glue at the base of the
ferrite bar.

The performance improvement for this $30 modification has
certainly exceeded expectations! When the stock unit was checked
against a stock ICF-2010 prior to modification, it was clearly inferior
in sensitivity on all frequencies. The stock 2010 was far more
effective in digging out weak daytime fringe stations, with or without
the Synch function. After the ICF-SW7600GR received the Amidon 7.5"
loopstick, the situation was completely reversed. The still-compact
SW7600GR now clearly outperforms the stock 2010 on all MW frequencies--
low, middle and high band. High-band performance is particularly
striking, with Synch lock performance on a 1610 TIS station completely
inaudible on the stock 2010. This has been achieved despite a very
modest expenditure for parts (about $20 for the Amidon ferrite bar, and
under $10 for the Litz wire and other items). The modified SW7600GR is
also much smaller and lighter than a stock 2010, providing a very
practical, compact SSB "spotting receiver" for Ultralight TP/TA chasers.

Two pictures of this modified ICF-SW7600GR have been uploaded to
the "ultralightdx" Yahoo Group site, in the "Roll Your Own DXing
Monster" album. It is hoped that various MW DXers will feel motivated
to modify their own ICF-SW7600GR units, and obtain the outstanding MW
performance possible with this model.

73, Gary DeBock


Re: Inexpensive source of ferrite for LF FSL

rabej_de <rabej_de@...>
 

Hi, list!

Yesterday I built my first FSL using a 150 mm dia. Styrofoam former, 23 ferrite bars, 100x20x3, permeability 400, 3 layers of bubble wrap and 55 turns of 100/44 litz wire = 1615 uH.
I connected it to a 3-section 12 - 460 pF var. cap. with 2 sections in parallel.
Pictures of it can be found here : http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

I only had time to do some qick in-shack tests using my Tecsun PL-380 and I must admit that I am a bit disappointed.
Yes, the noise level increases when the FSL is tuned exactly but I was not able to hear more NDBs than without the FSL.
Maybe this is due to the high noise level indoors with PCs and TVs running etc. - I have to check that.

Any other advise or hint as to what may have gone wrong?

73s

Joachim Rabe

--- In ultralightdx@..., "rabej_de" <rabej_de@...> wrote:

Hi, list!

Found these ferrite rods on eBay : http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=400137000838&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

They measure 8 x 125 and are said to be 400 permeability.

Ony comments on using them for a LF-FLS?

Thanks very much in advance.

73s

Joachim Rabe


Re: Sony ICF-SW7600GR 7.5" Loopstick Mod Completed

maxyhopy
 

Hello Gary,

I am very interested in modifying my SW7600GR. Could you tell me what size litz wire you used and also approximately how many turns you used in modifyoing your Sw7600GR ? Appreciate any help. Frank

--- In ultralightdx@..., D1028Gary@... wrote:

Hello Guys,

???? Although it's a little too large to qualify as an Ultralight radio, the ICF-SW7600GR provides fairly competent MW performance in a compact, SSB-capable design. ?For those MW DXers?unable to accommodate an ICF-2010 for space or financial reasons, this Sony portable would be perfect as an SSB "spotting receiver" for Ultralight radio transoceanic targets on an ocean beach...? if only it had more sensitivity.? Having had an unused unit sitting around since the Ultralight "Boom" started late last year (and faced with a situation where a multi-family vacation would make packing space extremely limited), there was a sudden compulsion to replace the stock 4.75" x .37" loopstick with a much more effective Amidon 7.5" x .5" loopstick wound with 40/44 Litz wire.? This MW frequency-optimized combination has provided an?incredible sensitivity increase in the SRF-39FP and Eton E100 Ultralight models (enabling both to receive Australia signals at Grayland), and I was curious how far it would boost the performance of this compact SSB portable.

???? The ICF-SW7600GR has a stock loopstick very similar to that of the ICF-2010, in which a fixed larger center coil is mated with a much smaller tickler coil, used for adjustment of the unit's spurious signal rejection.? As such, the instructions for "supercharging" the ICF-2010 (currently posted in dxer.ca's Ultralight File section) are electrically applicable to the ICF-SW7600GR, although the lsmaller unit has a large coil inductance of 983 mh, and the stock loopstick does not have a snap-out design like the 2010, requiring the hobbyist to use a moderate amount of effort in separating the glue at the base of the ferrite bar.

???? The performance improvement for this $30 modification has certainly exceeded expectations!? When the stock unit was checked against a stock ICF-2010 prior to modification, it was clearly inferior in sensitivity on all frequencies.? The stock 2010 was far more effective in digging out?weak daytime fringe stations, with or without the Synch function.? After the ICF-SW7600GR received the Amidon 7.5" loopstick, the situation was completely reversed.? The?still-compact SW7600GR now?clearly outperforms the stock 2010 on all MW frequencies--? low, middle and high band.? High-band performance is particularly striking, with Synch lock performance on a 1610 TIS station completely inaudible on the stock 2010.? This has been achieved despite a very modest expenditure for parts (about $20 for the Amidon ferrite bar, and under $10 for the Litz wire and other items).? The modified SW7600GR is also much smaller and lighter than a stock 2010, providing a very practical, compact SSB "spotting receiver" for Ultralight TP/TA chasers.

???? Two pictures of this modified ICF-SW7600GR have been uploaded to the "ultralightdx" Yahoo Group site, in the "Roll Your Own DXing Monster" album.? It is hoped that?various MW DXers will feel motivated to modify their own ICF-SW7600GR units, and obtain the outstanding MW performance?possible with this model.

???????????????????????? 73,? Gary DeBock?


Re: LED Tuning light

Brian Miller
 

Hi Kevin -

Thanks for the reply.

I am so green on radio surgery that I'm not even quite sure what the "trace" is. The wires coming from the pcb to the led?

What do I test with?

I have the service manual for the radio. I had to get it to figure out how exactly to route the tuning dial string. I was amazed I was able to actually do it after a few tries.

I've looked at the manual for awhile and can't figure the indicator light out from looking at the schematic, but again, I am far from a technician.

I guess what might help me most is if you or someone could tell me the general concept behind what causes the indicator to light, where it usually would connect to.....

anyway -

Thanks again

--- In ultralightdx@..., "dhsatyadhana" <dhsatyadhana@...> wrote:

Hi Brian:

Have you tried testing the LED itself? Not sure if these burn out.

Disconnecting the trace to the LED (to test the LED) would allow you to test if there is voltage coming to the LED as well?

Kevin S

--- In ultralightdx@..., "Jerry" <brianalexmiller@> wrote:

I know this is the ultralight DX board, but it is the most active DX message board I know of so maybe someone can answer me even though this is not about ULR's.

My question is about a red LED tuning light on a portable Sony analog AM/FM radio - TFM-7250W.

I got the thing at a garage sale last year for five bucks and I took it apart to clean it and to retro-fit it with an 18" outboard ferrite antenna.

Everything is working great except for I cannot get the little red tuning led to light anymore.

All of the connections look good to me but obviously I'm missing something.

I guess my question is if anyone knows where that kind of a connection would be made generally.

Thanks

Brian Miller

Berkley, MI

USA


New file uploaded to ultralightdx

ultralightdx@...
 

Hello,

This email message is a notification to let you know that
a file has been uploaded to the Files area of the ultralightdx
group.

File : /5 Antennas and Equipment/C. Crain Twin_Coil_Antenna Patent.pdf
Uploaded by : tomrb@... <tomrb@...>
Description : C. Crane Twin coil Antenna Patent

You can access this file at the URL:
http://groups.yahoo.com/group/ultralightdx/files/5%20Antennas%20and%20Equipment/C.%20Crain%20Twin_Coil_Antenna%20Patent.pdf

To learn more about file sharing for your group, please visit:
http://help.yahoo.com/l/us/yahoo/groups/original/members/web/index.html
Regards,

tomrb@... <tomrb@...>


Re: LED Tuning light

Kevin Schanilec
 

Hi Brian:

Have you tried testing the LED itself? Not sure if these burn out.

Disconnecting the trace to the LED (to test the LED) would allow you to test if there is voltage coming to the LED as well?

Kevin S

--- In ultralightdx@..., "Jerry" <brianalexmiller@...> wrote:

I know this is the ultralight DX board, but it is the most active DX message board I know of so maybe someone can answer me even though this is not about ULR's.

My question is about a red LED tuning light on a portable Sony analog AM/FM radio - TFM-7250W.

I got the thing at a garage sale last year for five bucks and I took it apart to clean it and to retro-fit it with an 18" outboard ferrite antenna.

Everything is working great except for I cannot get the little red tuning led to light anymore.

All of the connections look good to me but obviously I'm missing something.

I guess my question is if anyone knows where that kind of a connection would be made generally.

Thanks

Brian Miller

Berkley, MI

USA


Re: optimistic seller

keith beesley
 

Sorry you have had a problem. In my experience, the ultra-cheap pocket radios from China (under c. USD $20.) are extremely variable in quality (as one might expect). The Sony S10MK2 and SRF-59 and Panasonic RF-P50 are cheap and very good for the price (and also available from local retailers). On the other hand, my Coby CX-5 is tiny and gets about 5 FM and 3 AM stations; I sometimes carry it around and listen to news or ballgames on it; it does get quite loud.

For serious listening and DXing I use my 1103, Redsun 2100 (aka C. Crane CCSW), Eton E10 or E100; I've never had any problems with any of those. I also only order from sellers with plenty of positive feedback; "liypn," "anon.co," "tqchina," and "hygt369" are a few who spring to mind. I've never bothered to return anything to China. 

The only ebay sellers I've had trouble with have been based in the USA, LOL.

Regards,
Keith B.   


--- On Sat, 3/26/11, kg4lac wrote:

From: kg4lac
Subject: [ultralightdx] Re: optimistic seller
To: ultralightdx@...
Date: Saturday, March 26, 2011, 4:48 AM

 

Try returning a defective item to an Asian seller and then you will get burned. Sure the sellers claim you can return it. Just try to do so. Shipping rates are the same or higher than the cost of the item. I found out the hard way. Live and learn. Do not purchase from sellers outside your own continent.