[time-nuts] End of Range Oscilloquartz 8600-3

[Bob kb8tq]

Hi

One of the basic issues with a quartz resonator is that it is sensitive to barometric pressure. 
Some are more sensitive than others, but there always is some effect. Various techniques 
get used to isolate the resonator. Solder sealing (or welding) the package closed is one of 
them. The inner oven in the 8600 may well be sealed up pretty tight …. I would expect the
parts you need to get to are all in there with the resonator. 

Bob

> On Dec 12, 2017, at 2:59 AM, Ulf Kylenfall via time-nuts <time-nuts at febo.com> wrote:
> 
> 
> 
> Emailed Oscilloquartz that now has another name: Advaoptical... This in my capacity as aresearch engineer at Onsala Space Observatory.And the oscillator is at my work bench. Nothingprivate/hobby about this.
> The answer was that since we do not have a service agreement,they would not disclose any information.
> (Compare this with Keysight who has a free downlad area for oldmanuals. IMO the Keysight approach benifits their businessin the long term).
> So...
> I went along and started to dissassemble the 8600-3.
> The outer case was easy. Inside is a PCB with RF buffersand temperature regulation circuitry.
> Then there is a thermo bottle with the ovenized oscillator.This unit is connected to the PCB using two flex cables.
> The oscillator unit can simply be extracted from thebottle using an Metric 3 mm screw lightly screwed inone of the holes in the oscillator assembly.
> The assembly can be accessed by carfully unscrewingthe flex-cable end from the other mechanics. No needto touch the three small screws at the lid.
> Now it is starting to get intersting. I have not foundthe RF wiring into the crystal. The PCB in this unitseems to deal only with temperature regulation.Possibly, the RF is routed together with some heaterwinding.
> Or the crystal and the oscillator parts is sealedin such a way that there will be no wayto dissassemble it. There are several thermistorsglued inside to various parts of the oscillator/ovenassembly. That will make any further attemptsdifficult as the connecting wires are thin and delicateif they needs to be unsoldered.
> The construction is a nice piece of engineering.I'll give them that.
> Right now, I cannot see any typical oscillatorcircuitry (pF, nH, RF transistors) etc.
> I think I'll contemplate on the next movefor a day or so...
> 
> Ulf Kylenfall 
> 
> 
> 
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