[time-nuts] MV89A / MTI-260 / HP10811 carrier board

[Magnus Danielson]

Hi Gerhard,

Interesting. I would consider the PICDIV such as that of TADD-2, which 
has the benefit of producing a range of frequencies, so that a suitable 
can be selected as matching the needs. I've found it very useful 
property of the TADD-2, where I have my TADD-2s wired up to output one 
of each. I also wired them to output the buffered variant of the clock, 
which gives better measures compared to running the sine straight into 
the counters.

The power-supply input didn't look all that clear. It would be handy if 
a single input could be used.

I could probably have use for several of these boards.

Cheers,
Magnus

On 02/25/2016 04:25 PM, Gerhard Hoffmann wrote:
> HI,
>
> I have made some progress on my crystal oven carrier board.
>
> It will offer a home for one of these:
>
> - MTI-260
>
> - Morion MV89A
>
> - HP 10811-611
>
>
> It provides regulated voltages for either of them, and the needed
> electronics.
>
> It will be possible to lock the resident oscillator to an external
> reference frequency,
>
> tune it a few Hz using a 10-turn-pot or an external tuning voltage from
> 0 to 5 volts.
>
> The 10811 oscillator does not have a stable tuning reference voltage
> output, it will be
>
> provided.
>
> There is a Xilinx Coolrunner 2C64 CPLD that generates a 1pps output from
> the
>
> resident oscillator with the usual 20 us pulsewidth.
>
> The squarer that feeds the CPLD is either a LT6759-4 or my
> implementation of
>
> C.Steinmetz's interpretation of C.Wenzel's version of the standard
> differential limiter.
>
> The 1PPS can drive 3V3 CMOS, terminated with 50 Ohms. The output of the
> CPLD
>
> is re-clocked in a 74LVC74 Flipflop directly from the limiting amplifier.
>
> There is a 1 stage common base isolation amplifier between the output of
> the oscillator
>
> and the output of the board. It can be configured to work as a push-pull
> active frequency
> doubler without attenuation instead. There are 2 or 3 crystal notches to
> remove the
> closest (sub-)harmonics without affecting carrier phase stability.
>
>
> Board size is abt. 100 * 110 square mm.
>
> The design is modular from predefined macros. You can cut it into pieces
> and get:
>
>
> 3 positive voltage regulators, LM317 style
>
> 1 negative voltage regulator, LM337 style
>
> 2 current feedback amplifiers using LMH6702 / AD8009 etc
>
> 1 ring mixer using a low 1/f noise Avago diode ring
>
> 1 PLL-regulator
>
> 1 isolation or frequency doubler amplifier
>
> 1 LT6759-4 limiter
>
> 1 Wenzel limiter
>
> 1 Xilinx 2C64 Coolrunner with pins on 100 mil grid
>
> 1 3V3-CMOS reclocked driver for 50 Ohm load.
>
> 1 input power meter
>
>
> Connections to the modules are on a 100 mil grid, so one can
>
> rearrange/recycle everything on Vector board or such.
>
> This is open source hardware under BSD rules.
> I do not intend to sell boards on a commercial base,
>
> maybe there will be some samples to get things started.
> All parts are available from Digikey/Mouser.
>
> I'm currently doing the layout and will be trough with it in a week or so.
> proposals, spotted errors, what to do with the empty space etc. are
> welcome.
> (but not on parts values, that will be taken care of later)
>
> circuits can be found under
>
> <
> http://www.hoffmann-hochfrequenz.de/downloads/CrystalOvenCarrierBoard.pdf >
>
> This is no product documentation but a quick snapshot as of this afternoon.
> One thing that is missing is sync'ing on a 1PPs instead of the external
> frequency reference.
>
> regards, Gerhard, DK4XP
>
>
>
>
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