Inexpensive source of ferrite for LF FSL (first FSL built)


rabej_de <rabej_de@...>
 

Thanks, Steve!

I'll build some sort of stand for it over the week and give it a try in our backyard some 10 m from our house.

73s

Joachim Rabe

--- In ultralightdx@..., "Steve Ratzlaff" <steveratz@...> wrote:

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!
Steve

----- 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 :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

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?

73s

Joachim Rabe


Michael <michael.setaazul@...>
 

Do we know the quality of the "vintage" Soviet ferrite?
The date stamp suggests older production. I once had
a transistor radio from the Soviet era. Sensitivity was
poor - it worked better, with an aviary of birdies,
with a longish wire attached :-)

Michael UK

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

From: "Steve Ratzlaff" <steveratz@...>
To: <ultralightdx@...>
Sent: 27 March 2011 23:41
Subject: Re: [ultralightdx] Re: Inexpensive source of ferrite for LF FSL (first FSL built)


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!
Steve

----- 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 :
http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

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?

73s

Joachim Rabe


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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!
Steve

----- 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 : http://www.flickr.com/photos/61090953@N06/sets/72157626359000212/

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?

73s

Joachim Rabe