Date   

Re: Thai Score

Everett N4CY
 

All PE, polyethylene foam, is basically the same. Some is open cell and some 
is closed cell. The cell size determines the density, the listed density is in pounds 
per cubic. In some cases PE foam is cross linked with other materials that are added to improve the strength. 

Everett N4CY


On Mar 8, 2016, at 12:36 PM, dx@... [ultralightdx] <ultralightdx@...> wrote:

 

I believe I've read it in a crystal radio enthusiasts forum, but it's my understanding that the "Dissipation Factor" of various plastics, foam, (or other materials) is what makes the difference. A very low dissipation factor is desirable.


Check out this list of "Electrical Properties of Plastics": Electrical Properties of Plastics

 

73, 
Guy Atkins
Puyallup, WA



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

Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop

Michael

On 04.03.16 23:50, D1028Gary@... [ultralightdx] wrote:

> <<< I am in the process of gathering materials to build the 3 " FSL
> antenna, I am just wondering where you can buy the Oatey 4x4 foam closet
> spacers? >>>
> The Oatey 4" foam spacer material is sold at Home Depot stores within
> the USA, and is located in the plumbing section of such stores. It is
> extremely cheap, with a full roll of the material (good enough for 2 or
> 3 antenna jobs) costing just over $1.
> Because this material is so cheap and because it is actually quite
> important for proper FSL coil sensitivity, substitutions are not
> recommended. Already one DXer did a very good job in constructing his 3"
> FSL PL-380 model but used a different type of foam, and ended up with
> seriously reduced MW sensitivity as a result.
 


Re: Thai Score

Guy Atkins
 

I believe I've read it in a crystal radio enthusiasts forum, but it's my understanding that the "Dissipation Factor" of various plastics, foam, (or other materials) is what makes the difference. A very low dissipation factor is desirable.

Check out this list of "Electrical Properties of Plastics": Electrical Properties of Plastics

 

73, 
Guy Atkins
Puyallup, WA



---In ultralightdx@..., <michael.setaazul@...> wrote :

Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop

Michael

On 04.03.16 23:50, D1028Gary@... [ultralightdx] wrote:

> <<< I am in the process of gathering materials to build the 3 " FSL
> antenna, I am just wondering where you can buy the Oatey 4x4 foam closet
> spacers? >>>
> The Oatey 4" foam spacer material is sold at Home Depot stores within
> the USA, and is located in the plumbing section of such stores. It is
> extremely cheap, with a full roll of the material (good enough for 2 or
> 3 antenna jobs) costing just over $1.
> Because this material is so cheap and because it is actually quite
> important for proper FSL coil sensitivity, substitutions are not
> recommended. Already one DXer did a very good job in constructing his 3"
> FSL PL-380 model but used a different type of foam, and ended up with
> seriously reduced MW sensitivity as a result.
 


Re: Is there a "lightweight class?" Sony SRF-T615

Guy Atkins
 

Hi Keith,

I share your enthusiasm for the PR-D5 and the newer model PR-D15.

A couple months ago I purchased both the D5 and D15 to try out for close comparisons of DXing performance, features, and ergonomics. 

For me, the D15 won out easily. It surpassed the D5 in half of the DXing tests of selectivity, and was always equal and often better in terms of sensitivity. The handle of the D15 makes a big difference for ease of use in my opinion.

The D5 was returned to Amazon but the D15 is a keeper and I use it every day. On a recent visit to the Oregon coast I had fun pulling in some TPs with the barefoot D15, as well as with my SDRs and other radios along for the trip. I'm finding the D15 to be very versatile and useful. Rarely do I find a radio to be just as adept at everyday, common use around the house as it is a DXing receiver!

73,

Guy Atkins
Puyallup, WA


Re: Thai Score

Michael <michael.setaazul@...>
 

Thanks for the clarification, Gary. It is curious that there can
be such a difference with different foam. Material composition
may be significant, but is thickness and spacing more critical
than quality or composition of the foam?

Has anyone in the Old World experimented with locally
available materials - including hoarded packaging stuff?

With the rods recovered from old hotel radios, I might give
it a try. However without comparison with an optimised design,
I would never know how well my knock-up was performing :-)

Michael

On 07.03.16 02:35, D1028Gary@aol.com [ultralightdx] wrote:
. . .
The choice and thickness of the foam between an FSL's coil and its
ferrite material is a major factor in determining an FSL's ultimate
sensitivity. The 1/4" (6mm) thick Oatey foam is strong and resilient,
and has provided excellent results in FSL antennas since 2011. Along
with substitutions in the type of Litz wire and ferrite material,
substitutions in the type of foam are not recommended if someone wishes
to obtain the designed MW sensitivity in a hard-wired FSL Tecsun PL-380
project.

After the U.K.'s Graham Maynard published his original Ferrite Sleeve
article in 2011 there was a torrent of experimentation here in the U.S.
to determine the best possible components for maximum FSL sensitivity.
Ferrite bars, ferrite rods, Litz wire, foam material, frame material and
variable caps were all thoroughly investigated. Various brands of foam
material were tested in various thicknesses, and the original FSL
experimenters (Steve, Kevin and I) determined that a thickness of about
1/4" (6mm) was close to ideal for maximum sensitivity.
. . .


Re: Thai Score

jerry popiel
 

Jerry, there is another option re the foam tape to try. I used “Aerotape Self-Adhesive  Insulation Foam Tape for 3 of my FSL projects including the latest 3” FSL.  The tape comes in rolls of 1/8” X 2” X 30ft. So you need to double it up to get the required 1/4” spacing. It works well and holds the 100mm Ferrite Bars in as a bonus.
You can find it on Amazon.com

Amazon.com: Itp Aerotape Self Adhering Foam Tape 1/8 " X  2 “  X  30FT

See picture below. 
Jerry 

  


Re: Is there a "lightweight class?" Sony SRF-T615

keith beesley
 

I love my PR-D5s! I have a white one I bought new several years ago, and a black one I found recently in a thrift store for $5! (for some reason, radios often seem to come to me in twos). Both work perfectly and they're among my favorite "general purpose" radios--great reception, good sound (better on FM than AM), easy to carry around from room to room or outside on a nice day. 

A similar radio I like a lot is the Sangean H201 "shower radio," far more than just an average bathroom radio. Sturdy build, reception as good or almost as good as the PR-D5 despite having only a small wire antenna for FM, and it also gets the NOAA weather forecasts. 

Keith Beesley
Seattle WA 


Re: Thai Score

Gary DeBock
 

Hi Jerry,
 
<<<   I am going to use Sill Seal, 5 1/2" width found at
Menard's, by Plymouth Foam Co.    >>>
 
You are of course welcome to use any type of foam that you wish, but already one DXer tried using window sill foam instead of the Oatey foam, and ended up with seriously reduced MW sensitivity as a result. The model's MW sensitivity was fully restored when the window sill foam was replaced with the Oatey foam.
 
73, Gary DeBock (in Puyallup, WA, USA)

  
 
 

-----Original Message-----
From: Jerry Rappel ww0e@q.com [ultralightdx]
To: ultralightdx
Sent: Mon, Mar 7, 2016 6:16 pm
Subject: Re: [ultralightdx] Re: Thai Score

 
I am going to use Sill Seal, 5 1/2" width found at


Jerry  WWØE


From: "jga747@... [ultralightdx]" <ultralightdx@...>
To: ultralightdx@...
Sent: Monday, March 7, 2016 5:47:26 PM
Subject: Re: [ultralightdx] Re: Thai Score

 
Gary,

         I've looked at several local Home Depots and Lowe's for the foam closet spacers and have had no luck, I've even checked the website and they only list the 4x82 foot sections. So I may have to take you up on your offer. Please let me know your email address and we can coordinate.

Thanks,

Joe




Re: Thai Score

Jerry Rappel <ww0e@...>
 

I am going to use Sill Seal, 5 1/2" width found at
Menard's, by Plymouth Foam Co. 

 http://www.menards.com/main/building-materials/insulation/insulation-accessories/plymouth-foam-5-1-2-x-50-standard-foam-sill-sealer/p-1444451015061.htm


Jerry  WWØE


From: "jga747@... [ultralightdx]"
To: ultralightdx@...
Sent: Monday, March 7, 2016 5:47:26 PM
Subject: Re: [ultralightdx] Re: Thai Score

 

Gary,


         I've looked at several local Home Depots and Lowe's for the foam closet spacers and have had no luck, I've even checked the website and they only list the 4x82 foot sections. So I may have to take you up on your offer. Please let me know your email address and we can coordinate.

Thanks,

Joe





Re: Thai Score

Gary DeBock
 

Hi Joe,
 
<<<      I've looked at several local Home Depots and Lowe's for the foam closet spacers and have had no luck, I've even checked the website and they only list the 4x82 foot sections. So I may have to take you up on your offer. Please let me know your email address and we can coordinate.  >>>
 
No problem. My email address is d1028gary@... , and I can send you a pack of the Oatey foam ASAP if you give me your shipping address privately, along with a $5 PayPal payment (I assume that you are in the U.S.). For those outside of the U.S. who really want to build the 3" FSL Tecsun PL-380 but who can't find the Oatey foam, please send me an email, and I'll try to help out.
 
73, Gary DeBock (in Puyallup, WA, USA)
 
 
 
 

-----Original Message-----
From: jga747@... [ultralightdx]
To: ultralightdx
Sent: Mon, Mar 7, 2016 3:47 pm
Subject: Re: [ultralightdx] Re: Thai Score

 
Gary,

         I've looked at several local Home Depots and Lowe's for the foam closet spacers and have had no luck, I've even checked the website and they only list the 4x82 foot sections. So I may have to take you up on your offer. Please let me know your email address and we can coordinate.

Thanks,

Joe


Re: Thai Score

Joe
 

Gary,

         I've looked at several local Home Depots and Lowe's for the foam closet spacers and have had no luck, I've even checked the website and they only list the 4x82 foot sections. So I may have to take you up on your offer. Please let me know your email address and we can coordinate.

Thanks,

Joe


Re: Thai Score

Gary DeBock
 

Everett,
 
You are certainly entitled to your opinions regarding the foam, and any other parts of the FSL antenna. Having been through all of the FSL design controversies since Graham Maynard's introductory article in February of 2011, I have learned that the best possible approach is to respect the opinions of others, and concentrate on A/B testing of my own designs to maximize their effectiveness in actual weak-signal DXing. Most DXers pay far more attention to actual DXing results (MP3's and/ or videos) than grandiose claims about antenna performance, and as long as an antenna is successful by that standard it is a meaningful contribution to our hobby community, regardless of the designer.
 
73, Gary DeBock (in Puyallup, WA)
 
 
 
 

-----Original Message-----
From: Everett Sharp everettsharp@... [ultralightdx]
To: ultralightdx
Sent: Mon, Mar 7, 2016 3:53 am
Subject: Re: [ultralightdx] Re: Thai Score

 
Gary,

I again see that you fail to recognize any of my work and, or experiments with the FSL and other ferrite experiments. Rightly so Steve and Kevin should be given credit too, as they too did a lot of experiments with the FSL. All three of us made/did  a lot of experiments with different FSL configurations, communicating with each other, off list, each contributing to the final product. I don't proclaim to be an expert, however, I put in many hours of experimentation operating under the "What If" and came up with many results that I believe were of value to the group, or some of the group. I is not just all about "Gary". 

 My conclusion, based on my experiments, is that 1/2" thick polyethylene foam is a better choice for a FSL and also in my Stacked Toroid Loop Stick experiments too. Using 1/2" foam gave a few more kHz of band coverage vs thinner foam, with no loss in performance. I also saw no loss in inductance using the same length of wire, however, there were a few less turns using 1/2" vs 1/4" foam. 

In some of my early experiments I used EVA foam and later found that it gave a little higher inductance vs the PE foam, for the same number of turns/length of wire, but could never see any difference in performance between the two foams. 

I buy my foam from The Foam Factory http://www.thefoamfactory.com/closedcellfoam/polyethylene.htmland use the 1/2" thick 2.1 # density.

Everett N4CY










On Mar 6, 2016, at 8:35 PM, D1028Gary@... [ultralightdx] <ultralightdx@...> wrote:

 
Hi Michael,
 
<<<   Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop   >>>
 
The choice and thickness of the foam between an FSL's coil and its ferrite material is a major factor in determining an FSL's ultimate sensitivity. The 1/4" (6mm) thick Oatey foam is strong and resilient, and has provided excellent results in FSL antennas since 2011. Along with substitutions in the type of Litz wire and ferrite material, substitutions in the type of foam are not recommended if someone wishes to obtain the designed MW sensitivity in a hard-wired FSL Tecsun PL-380 project.
 
After the U.K.'s Graham Maynard published his original Ferrite Sleeve article in 2011 there was a torrent of experimentation here in the U.S. to determine the best possible components for maximum FSL sensitivity. Ferrite bars, ferrite rods, Litz wire, foam material, frame material and variable caps were all thoroughly investigated. Various brands of foam material were tested in various thicknesses, and the original FSL experimenters (Steve, Kevin and I) determined that a thickness of about 1/4" (6mm) was close to ideal for maximum sensitivity. In my own FSL's I settled on the Oatey foam as the ideal type because of its low cost, thickness and durability. I'm aware that this type of foam may be tough to track down in foreign countries, but is a DXer is very serious about building the FSL-PL-380 model and needs the Oatey foam to complete his parts list, I'm very willing to send a pack of the foam for the cost of postage.
 
73, Gary DeBock (in Puyallup, WA, USA)
 
     
 
 
 
 
-----Original Message-----
From: Michael michael.setaazul@... [ultralightdx] <ultralightdx@...>
To: ultralightdx <ultralightdx@...>
Sent: Sun, Mar 6, 2016 6:24 am
Subject: Re: [ultralightdx] Re: Thai Score

 
Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop

Michael

On 04.03.16 23:50, D1028Gary@... [ultralightdx] wrote:

> <<< I am in the process of gathering materials to build the 3 " FSL
> antenna, I am just wondering where you can buy the Oatey 4x4 foam closet
> spacers? >>>
> The Oatey 4" foam spacer material is sold at Home Depot stores within
> the USA, and is located in the plumbing section of such stores. It is
> extremely cheap, with a full roll of the material (good enough for 2 or
> 3 antenna jobs) costing just over $1.
> Because this material is so cheap and because it is actually quite
> important for proper FSL coil sensitivity, substitutions are not
> recommended. Already one DXer did a very good job in constructing his 3"
> FSL PL-380 model but used a different type of foam, and ended up with
> seriously reduced MW sensitivity as a result.


Re: Is there a "lightweight class?" Sony SRF-T615

Clyde Smith <hkryclyde@...>
 

thank you very much. should have recognized the abbreviations. clyde


Re: Is there a "lightweight class?" Sony SRF-T615

Camille LeBlanc
 

Hello Clyde,

TA means Trans Atlantic
TP means Trans Pacific

Listening for stations beyond or outside of the western hemisphere

In most cases these stations are on 9 KHz channel spacing vs the 10 KHz spacing we have in the Americas (North, Central and South)

Hope this answers your question.

Regards
Cam
--------------------------------------------

On Mon, 3/7/16, Clyde Smith hkryclyde@yahoo.com [ultralightdx] <ultralightdx@yahoogroups.com> wrote:

Subject: [ultralightdx] Re: Is there a "lightweight class?" Sony SRF-T615
To: "ultralightdx@yahoogroups.com" <ultralightdx@yahoogroups.com>
Received: Monday, March 7, 2016, 10:12 AM


 









forgive a stupid question but what are ta and tp
stations????

thanks clyde











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Re: Is there a "lightweight class?" Sony SRF-T615

Clyde Smith <hkryclyde@...>
 

forgive a stupid question but what are ta and tp stations????
thanks clyde


Re: Thai Score

Everett N4CY
 

Gary,

I again see that you fail to recognize any of my work and, or experiments with the FSL and other ferrite experiments. Rightly so Steve and Kevin should be given credit too, as they too did a lot of experiments with the FSL. All three of us made/did  a lot of experiments with different FSL configurations, communicating with each other, off list, each contributing to the final product. I don't proclaim to be an expert, however, I put in many hours of experimentation operating under the "What If" and came up with many results that I believe were of value to the group, or some of the group. I is not just all about "Gary". 

 My conclusion, based on my experiments, is that 1/2" thick polyethylene foam is a better choice for a FSL and also in my Stacked Toroid Loop Stick experiments too. Using 1/2" foam gave a few more kHz of band coverage vs thinner foam, with no loss in performance. I also saw no loss in inductance using the same length of wire, however, there were a few less turns using 1/2" vs 1/4" foam. 

In some of my early experiments I used EVA foam and later found that it gave a little higher inductance vs the PE foam, for the same number of turns/length of wire, but could never see any difference in performance between the two foams. 

I buy my foam from The Foam Factory http://www.thefoamfactory.com/closedcellfoam/polyethylene.htmland use the 1/2" thick 2.1 # density.

Everett N4CY










On Mar 6, 2016, at 8:35 PM, D1028Gary@... [ultralightdx] <ultralightdx@...> wrote:

 

Hi Michael,
 
<<<   Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop   >>>
 
The choice and thickness of the foam between an FSL's coil and its ferrite material is a major factor in determining an FSL's ultimate sensitivity. The 1/4" (6mm) thick Oatey foam is strong and resilient, and has provided excellent results in FSL antennas since 2011. Along with substitutions in the type of Litz wire and ferrite material, substitutions in the type of foam are not recommended if someone wishes to obtain the designed MW sensitivity in a hard-wired FSL Tecsun PL-380 project.
 
After the U.K.'s Graham Maynard published his original Ferrite Sleeve article in 2011 there was a torrent of experimentation here in the U.S. to determine the best possible components for maximum FSL sensitivity. Ferrite bars, ferrite rods, Litz wire, foam material, frame material and variable caps were all thoroughly investigated. Various brands of foam material were tested in various thicknesses, and the original FSL experimenters (Steve, Kevin and I) determined that a thickness of about 1/4" (6mm) was close to ideal for maximum sensitivity. In my own FSL's I settled on the Oatey foam as the ideal type because of its low cost, thickness and durability. I'm aware that this type of foam may be tough to track down in foreign countries, but is a DXer is very serious about building the FSL-PL-380 model and needs the Oatey foam to complete his parts list, I'm very willing to send a pack of the foam for the cost of postage.
 
73, Gary DeBock (in Puyallup, WA, USA)
 
     
 
 
 
 
-----Original Message-----
From: Michael michael.setaazul@... [ultralightdx] <ultralightdx@...>
To: ultralightdx <ultralightdx@...>
Sent: Sun, Mar 6, 2016 6:24 am
Subject: Re: [ultralightdx] Re: Thai Score

 
Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop

Michael

On 04.03.16 23:50, D1028Gary@... [ultralightdx] wrote:

> <<< I am in the process of gathering materials to build the 3 " FSL
> antenna, I am just wondering where you can buy the Oatey 4x4 foam closet
> spacers? >>>
> The Oatey 4" foam spacer material is sold at Home Depot stores within
> the USA, and is located in the plumbing section of such stores. It is
> extremely cheap, with a full roll of the material (good enough for 2 or
> 3 antenna jobs) costing just over $1.
> Because this material is so cheap and because it is actually quite
> important for proper FSL coil sensitivity, substitutions are not
> recommended. Already one DXer did a very good job in constructing his 3"
> FSL PL-380 model but used a different type of foam, and ended up with
> seriously reduced MW sensitivity as a result.


Re: Puyallup, WA Ultralight TP's for 3-2

Gary DeBock
 

 Hello Again Mark,
 
 <<<   I've heard past FSL airchecks.  Have you made any with the new DC FSL?   >>>
 
Yes, the following TP-DX recordings were direct comparisons between reception on an inductively coupled 15" FSL (on a C.Crane Skywave model) and a directly-connected 3" FSL on the Tecsun PL-380 model. You can hear the difference in audio quality between the two setups (although the PL-380 typically has somewhat of a background tone thrown in, as an Si47434 DSP chip side effect):
 
594-JOAK  (7.5" loopstick C.Crane Skywave, inductively coupled to a 15" FSL antenna)  Japanese male speech at 1410
594-JOAK  (3" FSL Tecsun PL-380 model, barefoot)  Same Japanese male speech at 1410
 
603  China  (Hulun Buir?)  Fair Chinese female speech at 1410 (CC Skywave and 15" FSL)
603  China  (Hulun Buir?)  Same signal on the "barefoot" 3" FSL Tecsun PL-380 handheld model
 
603  HLSA  Namyang, S. Korea  Korean vocal music dominating over China at 1427 (CC Skywave and 15" FSL)
603  HLSA  Namyang, S. Korea  Same signal on the "barefoot" 3" FSL Tecsun PL-380
 
73, Gary DeBock (in Puyallup, WA, USA)
 
 
 
  
 
 

-----Original Message-----
From: mdh@... [ultralightdx]
To: ultralightdx
Sent: Sun, Mar 6, 2016 10:10 am
Subject: Re: [ultralightdx] Puyallup, WA Ultralight TP's for 3-2

 
I've heard past FSL airchecks.  Have you made any with the new DC FSL?


Re: Thai Score

Gary DeBock
 

Hi Michael,
 
<<<   Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop   >>>
 
The choice and thickness of the foam between an FSL's coil and its ferrite material is a major factor in determining an FSL's ultimate sensitivity. The 1/4" (6mm) thick Oatey foam is strong and resilient, and has provided excellent results in FSL antennas since 2011. Along with substitutions in the type of Litz wire and ferrite material, substitutions in the type of foam are not recommended if someone wishes to obtain the designed MW sensitivity in a hard-wired FSL Tecsun PL-380 project.
 
After the U.K.'s Graham Maynard published his original Ferrite Sleeve article in 2011 there was a torrent of experimentation here in the U.S. to determine the best possible components for maximum FSL sensitivity. Ferrite bars, ferrite rods, Litz wire, foam material, frame material and variable caps were all thoroughly investigated. Various brands of foam material were tested in various thicknesses, and the original FSL experimenters (Steve, Kevin and I) determined that a thickness of about 1/4" (6mm) was close to ideal for maximum sensitivity. In my own FSL's I settled on the Oatey foam as the ideal type because of its low cost, thickness and durability. I'm aware that this type of foam may be tough to track down in foreign countries, but is a DXer is very serious about building the FSL-PL-380 model and needs the Oatey foam to complete his parts list, I'm very willing to send a pack of the foam for the cost of postage.
 
73, Gary DeBock (in Puyallup, WA, USA)
 
     
 
 
 
 

-----Original Message-----
From: Michael michael.setaazul@... [ultralightdx]
To: ultralightdx
Sent: Sun, Mar 6, 2016 6:24 am
Subject: Re: [ultralightdx] Re: Thai Score

 
Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop

Michael

On 04.03.16 23:50, D1028Gary@... [ultralightdx] wrote:

> <<< I am in the process of gathering materials to build the 3 " FSL
> antenna, I am just wondering where you can buy the Oatey 4x4 foam closet
> spacers? >>>
> The Oatey 4" foam spacer material is sold at Home Depot stores within
> the USA, and is located in the plumbing section of such stores. It is
> extremely cheap, with a full roll of the material (good enough for 2 or
> 3 antenna jobs) costing just over $1.
> Because this material is so cheap and because it is actually quite
> important for proper FSL coil sensitivity, substitutions are not
> recommended. Already one DXer did a very good job in constructing his 3"
> FSL PL-380 model but used a different type of foam, and ended up with
> seriously reduced MW sensitivity as a result.


Is there a "lightweight class?" Sony SRF-T615

Les Rayburn
 

This morning, I was attempting to troubleshoot some problems with another portable. I ended up doing a backyard performance test of several portables just to establish baseline. 

The targets for testing were: 

WSM, Nashville 650 AM. About 200 miles distant. Their 50KW signal means they are a fairly easy daytime DX target. 
WJOX, Birmingham 690 AM. Local pest station. Their 50KW signal means wall to wall signal. 

Test were conducted outside the house, in the quietest spot in my suburban RF hell. 

Radios tested were: 

Sangean PR-D5
Tecsun PL-380
CC Crane Skywave
Sony SRF-T615

The results were interesting. The clear winner was the heavyweight Sangean PR-D5. WSM was easy copy. Not armchair strength but certainly strong enough to listen to a game or your favorite song. With the local, it could null their signal deep enough to allow traces of another station underneath. 

Second would have been the CC Skywave (on 1KHz bandwidth setting). Able to copy WSM well enough to pick out a song or ID. Deep null on WJOX but not deep enough to completely bury the signal. 

The Tecsun PL-380 received WSM about as well as the slightly smaller Skywave, but could not achieve quite as deep a null. Again, using the 1KHz bandwidth. 

Then the lightweight of the division, a true ultralight. The Sony SRF-T615 could not detect any audio from WSM 650 but did achieve the 2nd best null on local WJOX. It put their signal into the mud, almost completely gone. At night, this ability comes in very handy. 

When it comes to performance, I wonder if we’re not also “weighting” results based on those seeking TA and TP targets. Searching for those stations, the 1KHz DSP bandwidth is critical for success, but for those chasing domestic targets, it’s not as much of a factor. 

The Sangean PR-D5 has a fixed bandwidth and beautiful sound. It’s big and heavy compared to the others but it’s a great radio for AM DXing. 

The Sony SRF-T615 is a true ultralight, fitting easily into a shirt pocket. Used with headphones, it’s a wonderful machine to take when walking the dogs. Searching for domestics, both are quite capable. The Tecsun and Skywave are probably better choices for DXing TA and TP targets. 

Fun test. Should have thought of it sooner. All of these have been in the house for months or years. Maybe we need weight classes or two scales—one for TA/TP Performance and another for Domestics. 




73,

Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 
EM63nf

Member WTFDA, IRCA, NRC. Former CPC Chairman for NRC & IRCA. 

Elad FDM-S2 SDR, AirSpy SDR, Quantum Phaser, Wellbrook ALA1530 Loop, Wellbrook Flag, Clifton Labs Active Whip. 



Re: Puyallup, WA Ultralight TP's for 3-2

Mark/airchecklover
 

I've heard past FSL airchecks.  Have you made any with the new DC FSL?


Re: Thai Score

Michael <michael.setaazul@...>
 

Any idea why some foam results in poorer performance?
Last year I tried a "knock-up" with old hotel-radio
ferrites, good litz (with and without a silver-plated
air-spaced variable C) and whatever was to hand. So maybe
the UK-sourced foam was part of the reason for disappointment.
Could it be that some foam has metallic content?
To try again, I would have to try foam from different
sources on a hit-and-miss basis. As LW and MW is dying
in Europe, I am reticent to risk too much outlay and will
probably return to a longer single ferrite rod and/or
1meter dia frame loop

Michael

On 04.03.16 23:50, D1028Gary@aol.com [ultralightdx] wrote:

<<< I am in the process of gathering materials to build the 3 " FSL
antenna, I am just wondering where you can buy the Oatey 4x4 foam closet
spacers? >>>
The Oatey 4" foam spacer material is sold at Home Depot stores within
the USA, and is located in the plumbing section of such stores. It is
extremely cheap, with a full roll of the material (good enough for 2 or
3 antenna jobs) costing just over $1.
Because this material is so cheap and because it is actually quite
important for proper FSL coil sensitivity, substitutions are not
recommended. Already one DXer did a very good job in constructing his 3"
FSL PL-380 model but used a different type of foam, and ended up with
seriously reduced MW sensitivity as a result.

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