From: Rik Strobbe <Rik.Strobbe@fys.kuleuven.be>
To: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
Thread-Topic: LF: RE: Analog oscillators
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Date: Fri, 6 Jul 2012 17:16:09 +0000
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 <1SmrFA-199XcW0@fwd21.t-online.de> <4FF5EB68.9040507@iup.uni-heidelberg.de>
 <op.wgzqhb2nyzqh0k@pc-roelof> <4FF61402.6000703@iup.uni-heidelberg.de>
 <op.wg0kwirbyzqh0k@pc-roelof> <4FF6F362.3050305@iup.uni-heidelberg.de>
 <002101cd5b85$3c1eec90$6d01a8c0@DELL4>,<00a801cd5b8d$c6978eb0$1502a8c0@Clemens04>
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Clemens,

MEK stands for "methyl-ethyl-ketone" and is also known as butanone.
It is a rather strong organic solvent mainly used in industry.
An alternative might be acetone. It is commonly available (nail polish remo=
ver).

73, Rik  ON7YD - OR7T

________________________________________
Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org=
] namens Clemens  Paul [cpaul@gmx.net]
Verzonden: vrijdag 6 juli 2012 17:41
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: RE: Analog oscillators

Jay,

what is "MEK" which is referred to in the link you've given?

'...What I did was to dissolve polyfoam shipping material
in a mixture of MEK and xylol. '

73
Clemens
DL4RAJ

----- Original Message -----
From: <jrusgrove@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, July 06, 2012 4:40 PM
Subject: Re: LF: RE: Analog oscillators


> Stefan
>
> As others have pointed out "6" material is about the best for VFO circuit=
s.
> Ferrite, especially very high perm material is quite inferior.
>
> For securing turns I've found 'old fashioned' polystyrene coil Q dope to =
be a
> good choice. Doubt that it is sold anymore in the current 'scaredy cat wo=
rld'
> ... but you can make your own. See
> http://www.radiobanter.com/showthread.php?t=3D149757 . Also a recipe ther=
e for
> Napalm should you need any of that ;~)
>
> Jay W1VD  WD2XNS  WE2XGR/2
>
>
> ----- Original Message -----
> From: "Stefan Sch=E4fer" <Stefan.Schaefer@iup.uni-heidelberg.de>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Friday, July 06, 2012 10:17 AM
> Subject: Re: LF: RE: Analog oscillators
>
>
>> Hi Roelof,
>>
>> Another interesting information which is new for me. Thank you. I think =
many
>> of us have learned a bit from the topic.
>>
>> I thought about using super glue to fix the winding on the core.
>>
>> Or is this not to be recommended for some reason?.
>>
>> I will use a T50-6 then. This will take a few days until i have it on ha=
nd,
>> unfortunately.
>>
>> 73, Stefan
>>
>> Am 06.07.2012 09:39, schrieb Roelof Bakker:
>>> Hello Stefan,
>>>
>>> A FT-37-43 ferrite toroid is not suitable for a VFO as you found.
>>> Powdered iron cores from Amidon are much better in this regard.
>>> From the common available parts -6 material has the lowest temperature
>>> coefficient,
>>> -7 is slightly better:
>>>
>>> T-50-2: 95 ppm/C
>>> T-50-6: 35 ppm/C
>>> T-50-7: 30 ppm/C
>>>
>>> The temperature coefficient does not vary with the size of the toroid.
>>>
>>> There are tricks to achieve mechanical stable windings on a Toroid.
>>> One is to wind it as tight as you can and than place the coil in boilin=
g
>>> water for 10 minutes.
>>> This removes the mechanical stress and the winding settles down.
>>>
>>> 73,
>>> Roelof, pa0rdt
>>
>
>=