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 remover).
73, Rik ON7YD - OR7T
________________________________________
Van: [email protected] [[email protected]]
namens Clemens Paul [[email protected]]
Verzonden: vrijdag 6 juli 2012 17:41
Aan: [email protected]
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: <[email protected]>
To: <[email protected]>
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" <[email protected]>
> To: <[email protected]>
> 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
>>
>
>
|
