the diode on the bottom of the nano. near the usb conn. i put in a 1n400xs, fixes most of them. stinky

“However, the new PCB has pads for the RD16HHF1” Thank you !!!!!! Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch –

Yes, you’ve got it. The Nyquist sampling theory sets the limit of resolving the Power (and hence SWR), and the A/D rate needs to be faster than that or it won’t work properly. For a 3 KHz signal

Also have some MPSA13 coming in, those are the darlington, not the MPSA18, sorry about the confusion. Part number is pretty well the same except one number. The 13 is what I meant to ask about using

The hfe on these is typically 1150. Max is 1500, min is 500. I was curious as to if the higher gain might help with the drive on 30 meters and

my favorite to92 npn gain guy. bes ide the xx390x twins the best transistor you can buy. tayda sells .12 each hfe ~400-500

Thank you, Jerry - that helps guide me through the code and chip documentation (I was getting puzzled at doing all of these computations in unsigned 32-bit integer space with overflows and stuff to

Yes, the plan was to use an RD device for the new version. We ran into availability issues. The lead time from Mitsuibishi was 10 weeks. So, I took a call to continue with the IRF510s. However, the

Ashar, Is this mod going to be implemented on new production? Thanks! 73 Steve G1KQH

HI John & Jerry, Now see other thread... Geoff

Hi John, Jerry etc, After stumbling about in the dark, I realised I had not entered Newline or 57600 baud as required. I ran it again and Lo! 1 gives "Equal inputs read by Arduino" 2 gives nothing 3

Hi Tim, I'm interested to know how your connecting your SA to the circuit, from my recollection the majority of SA equipment has a 50 ohm input impedance, an input impedance that low is not conducive

Has anyone else encountered a failure to compile the Arduino Sketch for the ubitx? I am getting an error code for some type of return in the menu portion of the code. -Justin N2TOH

Arv… Hmmm… we should probably take this off-line at this point. This has to do with A/D resolution time vs. filter time. I’m rethinking…that diodes would be a better choice just

Thanks. This confirms what we tried two months ago. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton,

Jerry, The outputs are as follows (from the log book): 3.5 MHz - 12W 7 MHz - 14W 10 MHz - 11W 14 MHz - 10W 21 MHz - 7.8W 28 MHz - 4.4W (The preset was kept at maximum) - f

Bill K9HZ Not sure I follow your analysis. The added capacitance lowers upper frequency limit by a significant amount. You can even go as high as 0.1 MFD so that the detector output is filtered to

Very cool, thanks for digging into this. I tried various schemes in LT-Spice, but improving the final is more difficult than it seems going in. I could seldom correctly predict the results I

I forgot the picture of the experiment. - f

So, here are the final mods, Replace C81 from 0.1uf to 470pf Replace R83 from 10 ohms to 2.2 ohm (you can short R83 as well) Replace 97, R98 from 47 ohms to 220 ohms Remove C261, C262. So, what