Re: ProgRock not working #progrock

Alan de G1FXB

Hi Sid,

Created from a blank sheet of paper so all (?) will be my own, and no errant strings of ???????

Is this the same progrock build, you had the problem with in end of April where you report a consistent 1-3 Hz inaccuracy
What is different to now, where the current results reported are in the order of 2-3 KHz?

for the purposes of diagnosis.
Trial the progrock with it's minimum requirements

a/. In your additional details in section 2, you describe that the 5v supply is clean,
presumably this is reference to your "bench" top supply.
This suggests you are not using the 4.3.1. build choice, but it's built according to option given at step 4.3.2

b/. Therefore on the progrock PCB.
IC2 not fitted but in / out pads are jumpered across, and R1 & R2 are not fitted.

c/. On the Si5351 PCB.
IC2, R5, R6, C1 are not fitted.

d/. (the LM317 is not fitted on either progrock or the Si5351 PCB's. as you have taken over the task of providing the 5v supply)
(See all sections of 4.3.x of the build manual for verification)
As a final check, perhaps redo step 8 of page 10, and verify 5 and 3.3v (likely on the high side) voltages are present off board to the Si5351 module.

The progrock just requires just power in,
There are no other dependencies in order to output an signal to a "normal" Xtal controlled accuracy, the default is 10MHz.
Get that verified first before moving to PPS discipline

having removed the PPS signal make sure that pad of the progrock is grounded to the adjacent pad, to guarantee not inadvertently placing FW in PPS correction mode.

perform a factory reset, to give known straight out of the box settings

g/. Power cycle, to make sure latest configuration changes are applied

h/. what are the measurements results when made on the CLK0?
There "should" be a calibration error, and a smaller element of drift, likely caused by temperature variation

i/. if the CLK output is still "walkabout" in the order of KHz.? Taking care not to load it's oscillator, how stable is the 27MHz reference from which CLK0 is derived?


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