[time-nuts] Practical considerations making a lab standard with an LTE lite
saidjack at aol.com
Mon Nov 24 11:32:05 EST 2014
Correct, and thats why its all a bad trade off if you have to use 50 Ohms termination. Either more heat or more PN, and more circuitry.
So driving 50 Ohms inputs is not optimal here, 1M inputs are much better for this purpose.
I had discussed the advantages of CMOS open-ended termination some months ago here in detail..
Sent From iPhone
> On Nov 24, 2014, at 5:32, "Dr. David Kirkby (Kirkby Microwave Ltd)" <drkirkby at kirkbymicrowave.co.uk> wrote:
> On 24 November 2014 at 03:44, Said Jackson via time-nuts
> <time-nuts at febo.com> wrote:
>> On the 20MHz units there is already a strong buffer that can drive 50 Ohms terminations so adding a buffer in front of the coax connector on that version would have just added unnecessary phase and AM noise, parts count and cost, and power consumption, and would have resulted in a product with worse performance than we have now.
> IIRC you said that using this will generate more heat on the board
> near the crystal.
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