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You posted this on the 8th. I didn't get it until this morning - something's going on with groups.io as their emails are delayed anywhere from 1 to 5 days lately. Tim Gorman was complaining about the

Im not sure I am understanding.? I cannot load anything onto the bitx40 arduino as it does not even show up in the device manager.? The arduino program gives me an error to select a port but there

If device manage is recognizing ch340, you can try to load firmware if you had the procedure practiced once atleast. It might call for a calibration. why not try calibration with some known time

Yed, both working devices show ch340 in the device manager. Tim KF7VUT

This might be an opportunity for somebody to create yet another new Raduino Add buffer amps to all three clocks from the si5351 to help solve the spur problem. Choose a processor clock that won't beat

Tim, check whether both are using CH340g.

Thanks Vic for the reply.? Yes that is correct it power on with just a USB plugged in but the computer acts like it doesn't see anything (windows 10 and windows 7).? I have another Arduino board and

Unless we add an amp to each of the three clocks between the si5351 and the mixers, we are trading off si5351 crosstalk, local oscillator injection level, and reflections due to? driving the mixer

You need to put your radio in calibration mode and change the frequency calibration and after retune the bfo.

Just to understand the problem correctly: Your BitX40 is receiving and displaying correctly using the OEM sketch and you want to upload a new sketch, is that right? And, you do not see any additional

Generally ch340 G works off12MHz resonator. On the photo of r arduino pcb i clearly read 25MHz, thanks for the nice focusing

You can use this tool?http://paulkaplan.me/HexUploader/ However you have to install Arduino IDE that this tool needs that when uploading.

To drastically increase the Q and thus the notch depending on whether the circuit is in series or in parallel one can lower or increase the impedance of the filters with impedance transformers at the

Right Brian, I don't really understand that as well. Maybe it might make sense but I should see how the schematics would be. The 91mhz might make sense to notch out the harmonics of 45mhz if this is

Received the circuit board from a group member! Thank you! Darryl

you are right jerry. i remember encountering this ... back to the bench to try this out... - f [email protected] wrote:

How did you arrive at 47pF and 5uH for 12mhz? freq = 1/(2*pi*sqrt(L*C)) = 1/(2*pi*sqrt(47e-12 * 5e-6)) =?10382123 Hz Though that 30mhz LPF is a fairly complicated network to hang an LC trap on, there

allison and others, the traps are capable of adding a notch of -20 db. so even if you don't hit the bottom precisely, a 10 db reduction is all that is necessary to clean it up to the required level.

My guess is that the two intended filter frequencies are:? 90Mhz (second harmonic of 45MHz 1st LO) and 12MHz (2nd LO).? The parts represent the right values for a filter at 90MHz, but it seems that

Allison, I'm not 100% sure what his LC traps are doing, but they may not have to move around. My best guess is that the one at TP13 (tuned to around 90mhz) just removes the 2'd harmonic of the 45mhz