3 inch (76mm) Baby FSL Vs. 2.8 inch (71mm) Micro FSL

The battle of the lightweight Ferrite Sleeve Loop antennas-- a 3 inch (76mm) diameter model using Russian surplus ferrite rods and a 2.8 inch (71mm) model using American-made Amidon ferrite rods. The two fight it out in the reception of two tough daytime DX fringe stations-- 610-KONA in Pasco, WA (5 kW at 173 miles/ 278 km) and 790-KGMI in Bellingham, WA (5 kW at 104 miles/ 167 km). Watch the real world performance of the latest in compact FSL design!

[@pe1etr]

Thanks Gary. To my ears they are both similar.

[@DXerGary]

Thanks Peter, I would tend to agree with you!

[@alekz1958]

Excelent video to my ear I think the smaller unit is more sensitive and selective but that is purely objective. Both units are excelent units

[@DXerGary]

Thank you Alek, during initial testing the smaller unit also seemed slightly more sensitive to me, but most DXers say they are about the same in performance. Best 73!

[@michaelbrown-ns4dl]

That is so cool! I used to use a 4 foot loop made of pvc but it is so unwieldy I switched to a much smaller loop wound on a 3 inch long
section of 15" schedule 40 PVC. I measured it's Q at 720. Not great, not terrible. I just rewound it and now am at a Q of 1320. It works much better!!!
I have some 61 mix short ferrite rods coming from Ukraine enough to build a 8 inch ferrite sleeve loop. The rods are only 2.66 inches long and I
will wind the coil with 18ga silver plated multistrand Teflon insulated wire. I know Litz is better but the silver Teflon wire is much more rugged!!!
I will let you know how it measures and performs. Good DXing my friend and I really enjoy your videos!
I like AM BCB dxing as well as LF NDB DXing. Best wishes!

[@DXerGary]

Thanks for your comment, Michael. Good luck in your new FSL construction, and best of DX to you!

[@twistian40]

Another great video Gary. Thanks

[@DXerGary]

Thanks Christian!

[@carldewhitt7337]

I think on the first station,the micro FSL has a very slight edge. On the second station, I can't tell.

[@DXerGary]

Thanks Carl, the 2.8" Micro FSL does seem to have a very slight edge on the extreme low AM band (530-650 kHz), but this edge disappears on the other frequencies. This is probably because of the differences in ferrite material (Amidon rods in the 2.8" Micro FSL, and Russian surplus rods in the 3" Baby FSL).

[@AlexeyDXman]

Make ferrite rods great again! )))
Another great project Gary! You do big work for MW/LW/NDB community with FSL designs! They are about the same in performance.
I think that price/result ratio better on Baby FSL.

[@DXerGary]

Thanks Alexey, your comment is appreciated! And yes, the two FSL's are about the same in performance, but the 2.8" Micro FSL (the lightweight model) costs more to build, with 28 Amidon ferrite rods costing $4.50 apiece ($126.00, before shipping). Best of DX to you! Gary (N7EKX)

[@RSears]

@DXerGary Do you have any list of build tweaks to make the Micro? I'd like to try. There will be a lot of similarities with the Baby, obviously. And from what I can gather some differences in rod, rod size, number; drum prep; and numbers of windings.

[@DXerGary]

@RSears, a design photo of the 2.8 inch Micro FSL is posted at
dreamcrafts.box.com/s/whfqm8av3j6335uddei4b0c0sjuht8nz
Although the performance of the Micro FSL is superb, each of the 28 Amidon 4" x 1/4" ferrite rods costs $US8, so it's kind of a special project (with a total cost of around US$300). Despite this, the performance is so special that the high cost is worth it if a DXer desires a lightweight FSL for air travel, or other portable situations. I've used it for air travel to Hawaii, where it really ran wild.

[@RSears]

@@DXerGary Thanks. I'll cost it out. I really like the package and want to try one of your FSL designs. I got 560 KMON Great Falls, Montana 5kW at 1 pm MDT today. And from Lacombe AB that's 560 km / 348 mi. I was using a SR-286 and a 25' long wire (up a 7m vertically mounted goture and 8' counterpoise). That seemed big to me; how does it compare with your experience?

[@vu3mes]

Is this available commercially?

[@DXerGary]

Sorry, it is not available commercially, but a full construction article is being drafted for the 3 inch Baby FSL with the Russian surplus ferrite rods. A design photo for this model is posted at dreamcrafts.box.com/s/b5cw8peawni2runigskuj8fof8f2pe69