Message-ID: <00a801cd5b8d$c6978eb0$1502a8c0@Clemens04>
From: "Clemens  Paul" <cpaul@gmx.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>
Date: Fri, 6 Jul 2012 17:41:08 +0200
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Subject: Re: LF: RE: Analog oscillators
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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
>>
>
>