Ferrite Sleeve Antenna Permeability (Amidon -61 rods)


Steve Ratzlaff <steveratz@...>
 


Hi Raph,
I'd be happy to experiment with Amidon -61 rods if you'd be willing to purchase them. :)))  Just have them sent to me, I'd send them back to you to keep after the tests.  :)   (Are we talking about the 7.5" rods, 40 of them?)
73,
Steve

----- Original Message -----
Sent: Tuesday, March 15, 2011 9:21 AM
Subject: RE: [ultralightdx] Re: Ferrite Sleeve Antenna Permeability

Agreed—this is all consistent—now awaiting some “optimization” of the ferrite sleeve approach—waiting for someone to buy 40 of the Amidon 61 bars…

 

Optimal aperture size?

Optimal wire for coil winding?

Optimal positioning of coil on bars?

Optimal # of turns in coil?

Tight versus loose coil winding?

Position/# of turns, etc. for pick-up coil?

Distance between primary coil and ferrite bars?

Optimal length of ferrite bars?

 

It will be interesting to see how this evolves. Still hoping for some “hands on” evaluation of the sleeve versus monster ferrite bar approach for MW reception. There must be some comparabilities; e.g., the old teaching that length of ferrite bar is proportionate to diagonal measure of air core box loop regarding Q, depth, of null, etc. A bit concerned that the ferrite sleeve comparisons with Terk loop are only a bit (1.7-fold?) better…How much gain can one really make use of? Is the selectivity of the sleeve so much better than that of the single monster ferrite rod or air core loop. The selectivity issue is key, and includes “nullability” as well as low(est) achievable noise floor. And of course all of these concerns are trumped by being in the right location; i.e., not in RFI heaven like downtown Houston, Texas…!

 

Awaiting the verdict of the mavens!


Pollock,Raphael E <rpollock@...>
 

Oh my gosh, sorry Steve, I was being a little “tongue-in-cheek”, and my sincere apologies to you at that. The cost of 40 Amidon 61 ferrite rods would be several hundred dollars, almost as much as a Pixel RP Pro antenna w/o the certainty of definitive results. I so very much appreciate the experimentation that you and several other knowledgeable and intrepid explorers are carrying out on behalf of the rest of us. I am hopeful that an optimized ferrite sleeve system will result from the various experiments now being conducted, such that the purchase of sufficient Amidon 61 rods might then be justified as part of a debugged and optimized finished product. I anticipate that a ferrite sleeve antenna with top of the line ferrite bar and litz wire components, with really good protective coverings given the fragility of the ferrite arrays, will easily run at least $100-150, which is a lot more than some throw down PVC from Lowe’s, some Dave Schmarder litz wire, and a piece of ferrite from Stormwise.

 

 My deep apologies if my one liner email below was misinterpreted as either an offer or a teaser!

 

Raph

 

From: ultralightdx@... [mailto:ultralightdx@...] On Behalf Of Steve Ratzlaff
Sent: Tuesday, March 15, 2011 1:40 PM
To: ultralightdx@...
Subject: Re: [ultralightdx] Re: Ferrite Sleeve Antenna Permeability (Amidon -61 rods)

 

 



Hi Raph,

I'd be happy to experiment with Amidon -61 rods if you'd be willing to purchase them. :)))  Just have them sent to me, I'd send them back to you to keep after the tests.  :)   (Are we talking about the 7.5" rods, 40 of them?)

73,

Steve

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

Sent: Tuesday, March 15, 2011 9:21 AM

Subject: RE: [ultralightdx] Re: Ferrite Sleeve Antenna Permeability

 

Agreed—this is all consistent—now awaiting some “optimization” of the ferrite sleeve approach—waiting for someone to buy 40 of the Amidon 61 bars…

 

Optimal aperture size?

Optimal wire for coil winding?

Optimal positioning of coil on bars?

Optimal # of turns in coil?

Tight versus loose coil winding?

Position/# of turns, etc. for pick-up coil?

Distance between primary coil and ferrite bars?

Optimal length of ferrite bars?

 

It will be interesting to see how this evolves. Still hoping for some “hands on” evaluation of the sleeve versus monster ferrite bar approach for MW reception. There must be some comparabilities; e.g., the old teaching that length of ferrite bar is proportionate to diagonal measure of air core box loop regarding Q, depth, of null, etc. A bit concerned that the ferrite sleeve comparisons with Terk loop are only a bit (1.7-fold?) better…How much gain can one really make use of? Is the selectivity of the sleeve so much better than that of the single monster ferrite rod or air core loop. The selectivity issue is key, and includes “nullability” as well as low(est) achievable noise floor. And of course all of these concerns are trumped by being in the right location; i.e., not in RFI heaven like downtown Houston, Texas…!

 

Awaiting the verdict of the mavens!


Steve Ratzlaff <steveratz@...>
 


Hi Raph,
I attempted to respond in the same "tongue in cheek" vein--I never thought you were serious! I used some internet "extreme smiley" characters, to attempt to convey that thought--I guess it didn't convey very well.  :))))))
 
I don't expect the FSL is going to change the world but it's been fun playing with it, and I'm still doing experiments and having fun.
73,
Steve
 

----- Original Message -----
Sent: Tuesday, March 15, 2011 12:04 PM
Subject: RE: [ultralightdx] Re: Ferrite Sleeve Antenna Permeability (Amidon -61 rods)

Oh my gosh, sorry Steve, I was being a little “tongue-in-cheek”, and my sincere apologies to you at that. The cost of 40 Amidon 61 ferrite rods would be several hundred dollars, almost as much as a Pixel RP Pro antenna w/o the certainty of definitive results. I so very much appreciate the experimentation that you and several other knowledgeable and intrepid explorers are carrying out on behalf of the rest of us. I am hopeful that an optimized ferrite sleeve system will result from the various experiments now being conducted, such that the purchase of sufficient Amidon 61 rods might then be justified as part of a debugged and optimized finished product. I anticipate that a ferrite sleeve antenna with top of the line ferrite bar and litz wire components, with really good protective coverings given the fragility of the ferrite arrays, will easily run at least $100-150, which is a lot more than some throw down PVC from Lowe’s, some Dave Schmarder litz wire, and a piece of ferrite from Stormwise.

 

 My deep apologies if my one liner email below was misinterpreted as either an offer or a teaser!

 

Raph


Steve Ratzlaff <steveratz@...>
 


Hi Raph,
I attempted to respond in the same "tongue in cheek" vein--I never thought you were serious! I used some internet "extreme smiley" characters, to attempt to convey that thought--I guess it didn't convey very well.  :))))))
 
I don't expect the FSL is going to change the world but it's been fun playing with it, and I'm still doing experiments and having fun.
73,
Steve
 

----- Original Message -----
Sent: Tuesday, March 15, 2011 12:04 PM
Subject: RE: [ultralightdx] Re: Ferrite Sleeve Antenna Permeability (Amidon -61 rods)

Oh my gosh, sorry Steve, I was being a little “tongue-in-cheek”, and my sincere apologies to you at that. The cost of 40 Amidon 61 ferrite rods would be several hundred dollars, almost as much as a Pixel RP Pro antenna w/o the certainty of definitive results. I so very much appreciate the experimentation that you and several other knowledgeable and intrepid explorers are carrying out on behalf of the rest of us. I am hopeful that an optimized ferrite sleeve system will result from the various experiments now being conducted, such that the purchase of sufficient Amidon 61 rods might then be justified as part of a debugged and optimized finished product. I anticipate that a ferrite sleeve antenna with top of the line ferrite bar and litz wire components, with really good protective coverings given the fragility of the ferrite arrays, will easily run at least $100-150, which is a lot more than some throw down PVC from Lowe’s, some Dave Schmarder litz wire, and a piece of ferrite from Stormwise.

 

 My deep apologies if my one liner email below was misinterpreted as either an offer or a teaser!

 

Raph


Pollock,Raphael E <rpollock@...>
 

Whew, good…had me worried for a minute. In my day job I supervise 121 other surgeons here in Houston, and learned the hard way a while back about the strengths and weaknesses of the email as a means of communicating. Again, I deeply appreciate what you are doing as well as your willingness to share with the rest of us less knowledgeable mortals…

 

Raph Pollock

 

From: ultralightdx@... [mailto:ultralightdx@...] On Behalf Of Steve Ratzlaff
Sent: Tuesday, March 15, 2011 2:16 PM
To: ultralightdx@...
Subject: Re: [ultralightdx] Re: Ferrite Sleeve Antenna Permeability (Amidon -61 rods)

 

 



Hi Raph,

I attempted to respond in the same "tongue in cheek" vein--I never thought you were serious! I used some internet "extreme smiley" characters, to attempt to convey that thought--I guess it didn't convey very well.  :))))))

 

I don't expect the FSL is going to change the world but it's been fun playing with it, and I'm still doing experiments and having fun.

73,

Steve

 

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

Sent: Tuesday, March 15, 2011 12:04 PM

Subject: RE: [ultralightdx] Re: Ferrite Sleeve Antenna Permeability (Amidon -61 rods)

 

Oh my gosh, sorry Steve, I was being a little “tongue-in-cheek”, and my sincere apologies to you at that. The cost of 40 Amidon 61 ferrite rods would be several hundred dollars, almost as much as a Pixel RP Pro antenna w/o the certainty of definitive results. I so very much appreciate the experimentation that you and several other knowledgeable and intrepid explorers are carrying out on behalf of the rest of us. I am hopeful that an optimized ferrite sleeve system will result from the various experiments now being conducted, such that the purchase of sufficient Amidon 61 rods might then be justified as part of a debugged and optimized finished product. I anticipate that a ferrite sleeve antenna with top of the line ferrite bar and litz wire components, with really good protective coverings given the fragility of the ferrite arrays, will easily run at least $100-150, which is a lot more than some throw down PVC from Lowe’s, some Dave Schmarder litz wire, and a piece of ferrite from Stormwise.

 

 My deep apologies if my one liner email below was misinterpreted as either an offer or a teaser!

 

Raph