electronic goldmine ferrite rods on sale


Steve Ratzlaff
 

I bought some of these about 8 months ago and tested them on the Q meter. They have good Q and I believe would make a good FSL, given their short length. They go on sale like they are now every few months.

73,

Steve

On 9/3/2020 6:03 AM, Joe wrote:
Hi Gary.
Sorry. OT but thought this might get your attention.
Would these be any good for a MW FSL?
https://www.goldmine-elec-products.com/prodinfo.asp?number=G19561&utm_source=Goldmine&utm_campaign=a6dc633095-MAY23-2014_COPY_01&utm_medium=email&utm_term=0_15cb8e0368-a6dc633095-60297685
73, Joe-WA9LAE.


Joe
 

Thanks Steve for your reply!
Certainly seem quite reasonable. I've purchased a number of items
from the Goldmine. I've never been disappointed!
73, Joe.


Gary DeBock
 

Hi Joe (and Steve),

Thanks for posting the link about the 3.125" x .39" ferrite rods for sale from Electronic Goldmine.

They sound interesting, but in comparison to the Russian surplus ferrite rods (sold on eBay) commonly used for FSL antenna construction, their relatively short length would make their performance similar to that of the 62mm x 8mm Russian surplus ferrite rods, which were extensively tested in many FSL antenna designs during all-out experimentation for a 2012 article (posted at https://dreamcrafts.box.com/s/mr7aec2o4fid5u4dc48xz0t6u9uto8xh

Back in 2012 (a year after Graham Maynard of the U.K. introduced modern FSL antennas) there were multiple controversies about whether ferrite rods or bars were superior, whether long ferrite rods or thick, solid ferrite was superior, whether huge diameter FSL coils with short ferrite rods could outperform smaller models with longer ferrite, etc. The article linked above was an all-out effort to honestly evaluate all possible FSL antenna configurations by recording their weak signal performance on fringe daytime DX signals, comparing the recorded signals against each other in switched A/B tests, and posting the MP3 recordings to back up my conclusions. This article was the experimental basis for the "FSL Antenna Sensitivity Score" conclusion-- that the relative sensitivity of any FSL antenna can be determined by multiplying the coil diameter by the length of the ferrite sleeve, as long as all other factors are identical (ferrite permeability, ferrite manufacturer, type of Litz wire, etc.).

So for the short ferrite rods for sale from Electronic Goldmine, since their size is similar to the 62mm x 8mm Russian surplus ferrite rods used in the "short rod" designs in the article, you can be pretty sure that their FSL performance would be similar (i.e. the least sensitive of all the different FSL designs).

Gary DeBock (in Puyallup, WA, USA)

   


Paul S. in CT
 

Interesting... the 3 1/8" (80cm) length is suitable for a cake-frosting can (16oz!). Place them as inside perimeter: wind the coil outside. Might need 2 dozen.

Regards
Paul S. in CT FN31nl


vbifyz
 

Hi Gary,
Very interesting experiments, great work.
A couple more ideas for experiments. Maybe you or somebody else tried these already?
1. Place the rods "in series", creating an arbitrary long stick. Say, 4x140mm=560mm.
2. Leave spaces between the rods on the sleeve. The diameter stays the same with fewer rods, or the diameter can be increased with the same number of rods.
Combining the 2 ideas, one can make a long and wide ferrite antenna with fewer rods.

73, Mike AF7KR


Gary DeBock
 

Hi Mike,

<<<   A couple more ideas for experiments. Maybe you or somebody else tried these already?
1. Place the rods "in series", creating an arbitrary long stick. Say, 4x140mm=560mm.
2. Leave spaces between the rods on the sleeve. The diameter stays the same with fewer rods, or the diameter can be increased with the same number of rods.
Combining the 2 ideas, one can make a long and wide ferrite antenna with fewer rods.   >>>

Thanks for the experimental suggestions, Mike. Unfortunately all of these have been tried previously by myself or others, and never did result in any gain boost (or even equivalent performance) with the "standard" tightly packed ferrite rod cylindrical sleeve.

When the early FSL antenna experimentation was going on (2011-2012) all the major experimenters were trying every possible way to save money, since the cost of multiple ferrite rods was already extremely steep, even when purchased on eBay from eastern Europe. We tried every possible way to get equivalent gain by spending less money, including some wacky ideas which were never publicized. Unfortunately there were only two guaranteed ways to improve FSL antenna sensitivity-- use longer ferrite rods (or bars) in the sleeve, or increase the diameter of the ferrite sleeve by adding more rods (or bars) in the cylindrical assembly. The most sensitive FSL antennas turned out to be models which were tweaked in both ways-- although that started the infamous search for the Ultimate Gain Monster FSL (38 pound models costing over $1K to build).

Gary DeBock (in Puyallup, WA, USA)



 

   


vbifyz
 

38lbs! That's not quite UltraLight :)
You mention 2012 as the  year when FSL was introduced.
Here is a design from 2006 by UA6CA, the link still works:
http://www.cqham.ru/ant6.htm
It is in Russian, but the pictures are informative enough. They also used it for TX on 160 and 80m, up to 10W.

73, Mike AF7KR


vbifyz
 

One more link, dated 2005. The design itself is probably much earlier.
http://www.rxcontrol.org/Receivers/AN510/index.html


Phillip Fimiani
 

The russian site translated very well in Google Translate

Mortimer says "Stay Safe"
Best Regards
Phil
KD2HTN / WA2069SWL
Long: 34.210293 Lat:-78.057048
FM04xf 30dl
______________________________




On Monday, September 7, 2020, 11:37:06 PM EDT, vbifyz <3ym3ym@...> wrote:


38lbs! That's not quite UltraLight :)
You mention 2012 as the  year when FSL was introduced.
Here is a design from 2006 by UA6CA, the link still works:
http://www.cqham.ru/ant6.htm
It is in Russian, but the pictures are informative enough. They also used it for TX on 160 and 80m, up to 10W.

73, Mike AF7KR

--
73
Phil
KD2HTN / WA2069SWL
Long: 34.210293 Lat:-78.057048
FM04xf 30dl


lamontcranston17
 

"One more link, dated 2005. The design itself is probably much earlier.
http://www.rxcontrol.org/Receivers/AN510/index.html"

Could someone explain the purpose of the stepper relay?

Doesn't look like it has anything to do with controling AL or AZ.

                             Mikek


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