[time-nuts] Double ovened 10811-60158 on ebay

[Ed Palmer]

> Date: Sat, 19 Jul 2008 20:40:24 -0700 (PDT)
> From: "Rick Karlquist" <richard at karlquist.com>
> Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay
> To: "Discussion of precise time and frequency measurement"
> 	<time-nuts at febo.com>
> Message-ID:
> 	<11409.69.12.192.152.1216525224.squirrel at webmail.sonic.net>
> Content-Type: text/plain;charset=iso-8859-1
>
> Ed Palmer wrote:
>   
>> Bill,
>>
>> I picked up a couple of these 'naked' oscillators.  I was surprised to
>> hear that you stripped yours down.  I'm planning to build it back up to
>> its former glory with a controller for the outer oven and a new cover of
>> some sort.  Is there any reason not to do that?
>>     
>
> The possible reason is that the oven thermal gain isn't all that
> great (AFAIK), so you go to fair amount of trouble for marginal
> benefits.  You will probably have to use a very long time constant
> which will sort of rule out a simple analog integrator, forcing
> a PID digital controller.  If you're good with a PIC, it might not
> be too hard.  I'm an analog guy; I don't speak PIC. :-)
>
> Rick Karlquist N6RK
>   
I wasn't planning on doing anything fancy - just copy the original 
controller since the schematic is available.  And it's all analog. :-)

But now that I look around, I can't find anything to tell me that the 
double-oven version performs any better than the regular version.  The 
10811 specification document says that the thermal performance of the 
-60158 version is the same as the regular D/E version.  I'm guessing 
that's when it's _not_ in a double oven configuration.  The only 
differences in specs are things that the double oven wouldn't affect 
(e.g. aging).

It started out as such a nice little project..........

Ed