Thank you for support! I found the mistake: It was a bad solderid pin from the preassebled Si5351 chip! 73 Carl

#progrock #problem #si5351a #test

Prog-Rock with a strange error ! I bought two prog rock sets. With one SI5351 module I only get a frequency when I switch on for the first time. When I switch off and on again, the LED is permanently

#progrock #problem #si5351a #test

Since the undesirable effects of the power supply on the functioning of the SI5351 circuit have been discussed many times, I have analyzed a number of solutions. In fact I'm working on a never ending

#si5351a

Hi, problem solved ! I was confused by the presence of 1 pps of the yellow led, which in turn is the TX data being sent. The green led of the real 1 pps signal is off, I checked and the RF module does

#u3s #qlg1 #si5351a

Chris Yes, the part you quote "In particular : " this means that the actual reference oscillator value is 150Hz too high. So enter 27,000,150 in the “Ref. Frq.” setting." "the actual reference oscilla

#u3s #qlg1 #si5351a

Hello Alan, Tuesday, September 17, 2019 Thank you Alan, I believe I see it now, and I am sure you are correct, but I would respectfully suggest some additional or changed wording in the manual might m

#u3s #qlg1 #si5351a

Chris actually measure 13.500075. Your output frequency is 75 Hz too high. So the U3 is thinking the crystal is lower than it actually is. It is informed by what the stored Reference Frequency tells i

#u3s #qlg1 #si5351a

David, Yes, provided that the GPS is locked. If the QLG1 flashes then the heartbeat should be seen. 73 Alan G4ZFQ

#u3s #qlg1 #si5351a

Hello Alan, thanks for the quick reply. Indeed the GPS must be enabled, and it is so. Current time is display and I can get all the GPS data on the stand-by screen display. I believe also that the GPS

#u3s #qlg1 #si5351a

Hello Alan, Tuesday, September 17, 2019 OK, call me dumb, I have broad shoulders and a sense of humour :) I have never really understood this section of the manual: "Once you have measured the actual

#u3s #qlg1 #si5351a

David, Page 15 tells you about calibration. If you have PPS then GPS must be enabled. Then set calibration as suggested on page 15, make step (default 1) larger to calibrate quickly, then smaller for

#u3s #qlg1 #si5351a

Dear all, currently testing the U3S + si5351a and its GPS on 40 m band. The actual TX frequency is abt 200 Hz too high. The assembling manual page 19 says that no calibration is required when having t

#u3s #qlg1 #si5351a

My thoughts are its scope hookup has issues and is adding in extraneous noise that the DSO is trying to sync on. Since the signal is both amplitude and phase I'd suspect outside sources getting into t

#si5351a #problem #ocxo

This is hyterodyne, and this jumping I got from CLK1 Thank you Steve!

#si5351a #problem #ocxo

So, what are we looking at there? The output of the Si5351 or the output of your heterodyne mixer? Either way, unless the signal goes through a band pass filter, there will be significant harmonic con

#si5351a #problem #ocxo

Hi Dear Team, I have homemade heterodyne (OCXO/Si5351A + Arduino with a control program) and I have a strange situation, frequency of output signal is cycling changes, you can see it on the video in a

#ocxo #si5351a #problem

Mikael : I suspected that those resistors were acting as pullups and that explained why there were no instructions to remove them. Thanks for confirming that. Cheers Michael VE3WMB P.S. I am enjoying

#si5351a #synth

The answer is yes, you need to connect those 1kohm pullup on the SCL and SDA lines to vcc or it wont work. 73 /Mikael

#si5351a #synth

I am just building up my REV 4 Si5351a Synth board and I plan to use it with 3.3v Logic (an Arduino Pro Mini 3.3v @ 8Mhz). I understand that Q1, Q2, IC2, R1, R2, R5 and R6 are not needed and that I ne

#si5351a #synth

Hi Frank, Well done for getting it working. With the bias set high the bs170 would run hot building up heat inside the case, because the pa is below the crystal rising heat would cause the crystal to

#si5351a #u3s