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!

----- 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 :

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?


Joachim Rabe

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