Hooray!? ?I figured out what was causing those "communications errors' that were causing the disconnects.

Using interactive version rotctl (not daemon rotctld) I tested changing to Yaesu 232B instead of Yaesu "generic" and bingo! all the communications errors disappeared and it provided perfect angles.

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I'm looking at small relay pcbs on Amazon that would save me printed circuit board design work and make it easier to replace the output relays.? ?I read a bit about how AC rotators change direction.? ?Soon I think I can start laying out a board.? ?I'll buy at least one of the relay boards first to get sizes etc.? ??

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Then I have to start putting together rotators in earnest.? ??

Mechanically adept people with a METAL WORKING SHOP would be far better off than me; I only really have wood working abilities.

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But it can be done!? I'll start simple with azimuth first and then add my 2nd rotator and the cool 90 degree gearbox I got from Amazon.

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Gordon KX4Z

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It looks as if I have pulled up the pcb trace to one of the Q101 pads. I'll try to repair that and put in a new 2n2219. Surface mount components have always presented a challenge for me

Scratch that , the drain of Q101 isn't grounded. I'm sure I'm in the neighborhood?

The gate of Q101 doesn't seem to be grounded. This might explain it...

So, I don't believe that Q9 is switching, I have .6v on the gate and 12v on drain and source. PTT doesn't change anything.?

I can't say anything about the zBitx, but HF Signals did just inform me that sbitx v4 would available the end of March?

I appreciate it.? I don't have problems with the smaller isolated circuits. I haven't really jumped into anything beyond basic diagnostics for a few years and just recently reaquirrred proper test equipment. I will try the checks that you have suggested, and let you know what I discovered.?

The radio above (prior post and profile pic) is a Version 5 but has a Nextion 2.5" screen.? I just tested it as it happens to be opened up. The supply is at 15.8V going into this resistor and and the voltage out to the 7805 is about 13.6.? Now, that's where Pieter's trouble BEGINS, but if he were to employ this trick, he may be OK.? I agree that 5ohms would be a safer bet since he's not runnning his radio on steroids. ?

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But - the diode string works, nobody will see it, and there's nothing destructive about this.? Thus, I'd agree that 5 diodes of at least 1A ought to do the job.

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Also, for what it's worth, I'm using to drop the radio back to 12.2 volts, for true QRP levels below 15 meters. No noise at all witnessed when this is switched it and I'm considering adding a second one to replace the whole 7805 deal.? If this happens, I'll report back on the noise again.

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72,

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Ted

K3RTA

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Is there a timeline for resuming the zBitx sales and when the v4 will be available?

Michael,

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I've added more instructions to the spreadsheet.?

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To test D6, the PTT must be pressed, and the tab of Q9 at the line in voltage (12 volts in the spreadsheet case).

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If the banded side of D6 is still less than 5.5 volts, then D6 is bad, or R77 is faulty.

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Start with verifying that Q9 is switching on the 12 volts to the driver stages.

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This is a good test for the clarity of the document.? Thank you for the feedback.

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73

Evan

AC9TU

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D6 is only 600mv.

If you adjust the PABIAS1 pot, you must return it to the full counterclockwise position until the TR switching is working.? This will protect the IRF510 finals from burning out.? I only adjust the pot when setting the bias for the finals.

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Did you verify that the D6 banded side is at 5.6 volts?

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73

Evan

AC9TU

Hi Michael,

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Start by checking if the tab (drain) of Q9 switches between 0 and almost the input voltage (12).? Q9 provides the power to the driver and bias stages.

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If the Q9 drain is not changing, verify that the TX signal (gate of Q10) changes between 0.6 volts and 3.3 volts.? That is the transmit signal from the Raspberry Pi.

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Once you get the TR switching working, then verify the voltages on the transistor sides of R10 and R49.? R10 will indicate that the predriver Q11 is at its operating point.? R49 voltage indicates that the four drivers are at their operating point.

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Once all the driver stages are verified to be at the operating point, switch to the RF probe sheet, CW mode, and the power settings to trace with the probe.

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Good Luck, and happy hunting for the problems.

73

Evan

AC9TU

Also, I don't have voltage to any of the lpf switching diodes.?

So I have made some mistake somewhere because I have .9v on the gate of Q9 and that voltage is on the base of the 2n2219s and the gate of Q11 and gate and drain of Q101, the bias adjust can vary this up to about 2v.?

Hi!

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More work following the path that Ashhar suggested.? ?I have also bought an older Icom 810H that has full duplex VHF/UHF.

I'm doing initial experiments on Windows PC, but I have already demonstrated full Doppler shift control of sBitx acting as the 10m transceiver to a transverter, so this can all move to the sBitx....

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GPREDICT re-installed due to better location, tracking any satellite I like.? Does all the trig and doppler MATH

RIGCTLD - previously studied and working; receives tcp/ip commands from GPREDIT? to do doppler shift adjustments of sBitx or Icom radio

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Today:

ROTCTLD -- figured out how to run this on a windows machine.? ?Receives trig output of GPREDICT.? ?Converts (in this case) to Yaesu type rotator commands for Az/ elevation and sends out serial port (in my case, COM4, 9600 baud)

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K3NG Rotator Controller -- I havent made a board for this yet.? ?So I took one of my homebrew WINKEYER ARDUINO simulators, and reprogrammed it using K3NG code to "act like" the controller, handling Az, El controls, reading the CW speed control as if it were an azimuth potentiometer; running the display and activating the "key" and "PTT" to rotate clockwise or counterclockwise.

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The reprogramming of my Winkeyer Arduino appeard to be a huge success.? ?I properly set the pins to run the display, which worked FINE.

It was reading the speed pot as an azimuth reading, and if I pushed "buttons" it would read different elevations.

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ROTCLD happily connected to it at 9600 baud, and the "rotator controller" accepted commands and displayed them.? ?I was not able on the first test to monitor whether it activated simulated motor controls (key output, etc) -- but that will come.? ??

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So huge success here and soon (days, weeks?)? I should be able to lay out a board (many others have done so before me, but some just did crazy wiring between variuous "shields")? ?to put all this in a neat little package with relay outputs, possibly with PWM output (dunno)., to control available rotators for real.??

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73

Gordon KX4Z

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Yes, thank you, the dc point voltages will at least give me an idea of where to look. If I can find out what is happening there, I will move to the rf measurements. Much appreciated!

Michael,

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I put together this spreadsheet with voltage measurements of the PA section.? It requires a DMM and an RF probe.

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Let me know if this helps.

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73

Evan

AC9TU

So, after replacing the power components of the PA section, and putting in a fresh pair of 510s, I put it all together, all is OK, except, ZERO output... At this point I'm running out of places to look. I have power to the finals, no heating up, of anything. Wondering where the disconnect is now. Suggestions?