[time-nuts] EFC divider resistors

[Bob Stewart]

Hi Volker,

Thanks for the ideas.  The resistors are all within a short radius of each other.  I hadn't thought about bundling them all together.  I suppose I could epoxy them together as a last resort.  I've got some EPF foam, so I could try putting that on the board right against them.  In fact, I could try that while waiting for the new parts.  I've already used foam to fill most of the space in the box, except for around and above the OCXO.





>________________________________
> From: Volker Esper <ailer2 at t-online.de>
>To: Robert LaJeunesse <lajeunesse at mail.com>; Discussion of precise time and frequency measurement <time-nuts at febo.com> 
>Sent: Friday, January 31, 2014 1:51 PM
>Subject: Re: [time-nuts] EFC divider resistors
> 
>
>Sorry, missing picture...
>
>Am 31.01.2014 20:47, schrieb Volker Esper:
>> Here's how to place the divider resistors. The picture is from 1992, I
>> didn't use SMDs then. But the results are promising at a very low price.
>>
>>
>> Isolierband = insulation tape
>> wärmeleit. Kern = thermoconducting core
>>
>> The picture shows two examples, the left one if you need three
>> resistors, the right one if you need six. Use metal film types with low
>> tempco. Keep in mind: it's the fluctuating _difference_ between the
>> resistor values, that'll kill your stability. So avoid everything, that
>> leads to different temperatures at the resistors. In particular avoid
>> placing them into an airstream.
>>
>> Volker
>>
>