Message-ID: <001801cd5ba0$840a3990$8d01a8c0@JAYDELL>
From: <jrusgrove@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
References: <KOEAKFKINDBIGKCFCJEDGEBJCAAA.victor13@online.nl> <7E7DFBB4D102A04DB5ADC88D66628A4A0FAB99CC@ICTS-S-MBX5.luna.kuleuven.be> <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>
Date: Fri, 6 Jul 2012 13:55:20 -0400
MIME-Version: 1.0
Subject: Re: LF: RE: Analog oscillators
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Clemens

As Rick noted it's methyl-ethyl-ketone ... which is still readily available here in the states. 
Maybe it has a different name in DL.

Here's some more info on making your own 
http://www.cliftonlaboratories.com/coil_coating_compounds.htm .

Jay


----- Original Message ----- 
From: "Clemens Paul" <cpaul@gmx.net>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, July 06, 2012 11:41 AM
Subject: 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 circuits. 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 world' ... but you can make your own. See 
>> http://www.radiobanter.com/showthread.php?t=149757 . Also a recipe there for Napalm should you 
>> need any of that ;~)
>>
>> Jay W1VD  WD2XNS  WE2XGR/2
>>
>>
>> ----- Original Message ----- 
>> From: "Stefan Schäfer" <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 hand, 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 boiling water for 10 minutes.
>>>> This removes the mechanical stress and the winding settles down.
>>>>
>>>> 73,
>>>> Roelof, pa0rdt
>>>
>>
>>
>
>