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Test Equipment / Re: EEVBlog 121GW Multimeter Owners Club
« Last post by bitseeker on Today at 05:13:04 AM »
will check tonight (Edit; checked)  :-+, thanks Cliff re up loading the YT video.

Rob, thanks for the auto-ranging shootout (a great way to leverage your TEA ;D). That was very interesting. The Metrahit is really fast.
RF, Microwave, HAM Radio / Re: Minivna Tiny Reflection Measurement Issue
« Last post by hagster on Today at 05:12:19 AM »
I tried one a few years ago and though it was very painful use. Today I had a go with an ELAD SNA. Again I thought that was totally useless too.

The KC901 looks like about the best cheap VNA that I have seen. There is a review on The Signal Path.
I do not quite understand your disappointment with the monetization threshold change. How much $ do you think you will lose?  I have a quite bigger channel (in terms of both subscribers and views) and let me tell ya, it does not make any money that would really be worth the trouble.

For your size of channel, I am guessing a couple of $ a month at best. So I do not think that this change is any kind of big hit for anyone. But I do not judge if  that change does make sense or if it is reasonable (which I think it is not). I might have lost few hundreds of $ because I started my monetization not that long ago. I have the channel almost for 10 years.
Microcontrollers & FPGAs / Re: STLink doesn't connect to STM32F101
« Last post by andyturk on Today at 05:09:03 AM »
Any guesses on what I'm doing wrong?
Well, one mistake is beginning your STM32 journey with a bare chip and a clone programmer. :-//

You'd be much better off buying something like a USD $12.50 STM32L152 Discovery board.

That provides you with working hardware and an official ST-Link programmer that's built-in.
Microcontrollers & FPGAs / Re: How to run USB in PIC32MZ
« Last post by Ustek on Today at 05:08:59 AM »
Hmmm maybe this is it but my project works fine all the time. I mean then I'm using (in harmony) primary oscillator as HS then MCU is working (PWM's and something like that). Tomorrow I will go buy 24MHz generator. I understand Revision A1 but Im confused because of Figure 1 and Table 3 in this errata. What they mean?
Machine Debugging and Self-test
1. Preparation:
Keep the work table clean, tools neatly placed; AC outlet, power tools, anti-static buckle should be grounded; the operator should be with a good anti-static buckle before the operation.
2. Tool?
Electric screwdriver
3. Step:
3.1 Preheat the machine for 20 minutes. Preheat requirements: machine powered, dual-channel switch output is turned on (can be without load);
3.2 198 transformer parameter calibration: Access the regulated source to the target power supply (note:”ZH009” 198V power output setting: Select “M1”as output mode and the voltage at 198V; press “A•SET” to set the output current at “0.9A” then press “A•SET” again to confirm setting, press “ON/OFF” to turn on), switch the target power supply to individual mode, and input “30325” from panel to enter the calibration. Set the output (30V, 3A) and press “<?” on the panel to confirm the revised parameter after the parameters turn stable. Press “?” and input “78945” to exit the debug mode and check if the current is “0” as figure 1 shows. If not, calibrate it again. If so, input “78945” to exit the debug mode.

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3.3 .Adjust the grid? Input “50809” through the panel to enter the debugging interface, turn the knob to adjust the parameters, enter 78945 to exit the current debug mode?
3.4. Time Setting: set the machine time as current time.
3.5. Get 5V? Connect the FLUKE8845A digital multimeter (Figure 2), the target machine output 5V. Observe the digital multimeter and manually calibrate. Adjust the rectifier filter board "RW1" (Figure 3) range between "4.99V-5.01V", with a load of 1.7?. Reduce the resistance until the current display on electronic load at 3A. Observe the multimeter, the display voltage should be 4.95 or higher;

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3.6. Individual channel voltage auto calibrate: Switch to AC voltage supply. Connect FLUKE8845A digital multimeter (as shown in Figure 4), connect FLUKE and target ODP3032 with serial port line; connect CH1 output terminal to the voltage input end of digital multimeter. Input "30320" through panel, then start automatically calibrate the voltage. After the calibration is completed, there will be a beep; Implement the same operation on CH2, enter the debug mode by inputting "40320";

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3.7. Test the voltage? Set the value at 0.5,1,2,3,4,5,6,7,8,9,10,15,20,25,30, test the output voltage through the digital multimeter to see whether the measured value is consistent with the set value. And check if the read back value displayed on the machine interface matches the set value. (1. Measurement error of output voltage: ± 3mV when below 10V, ± 5mV when above 10V; 2. Error between display value and setting value: ± 2mV) If there is discrepancies, implement manual calibration. Manually calibrate the voltage output via panel input "31320", manually calibrate the voltage read back via panel input "31321" and exit manual calibration via input "78945". For example: When viewing the set point of 1V, assume the output is inaccurate, input 31320 on panel to enter the manual calibration, through the left and right keys to find the corresponding calibration point, and then change the output by up and down key and X10 scale, through the knob X1 scale to change the value. Adjust the channel at ON status. Adjust the display value accordingly after then.
3.8. Individual channel current auto calibrate? As shown in Figure 5, the output of the channel is connected in series with the load and connected to the current measurement terminal of the digital multimeter. Set the electronic load as 3721A, press the "SET" key and press the up and down keys to select "CRM" and set the load resistance to "8?". Press "Input" to turn on. Input "30321" through the panel, then automatically calibrate the output current. After the calibration, there will be a beep; Implement the same operation on CH2, enter the debug mode by inputting "40321"

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3.9. Test the current? The setting value is 0.6; 1.2; 1.8; 2.4; 3.0 (A as unit), output voltage setting (30V), serial connection load (load setting 8?) and digital multimeter. Test the output current through a digital multimeter to see if the measured value matches the set value and check that the read back value displayed on the machine interface matches the setpoint. (1. Measurement output current error: less than 1A ± 3mA, 3A ± 5mA; 2.Display and setting error: ± 4mA), If there is discrepancies, implement manual calibration Manually calibrate the displayed value (readback) via inputting "31324" and exit manual calibration via output "78945". (Specific steps and seizure voltage description similar);
3.10. Change the switch point: connect as shown, set CH1 output at 5V/0.5A, electronic load M9710 at 10?, adjusting the electrical load M9710 resistance as shown in Figure 6. When the constant voltage switch to the constant current voltage, write down the voltage and current. The voltage range should be 4.93V ~ 5.07V, the current value range should be 0.4925A ~ 0.5075A;Switch point manual calibration? Need to adjust the adjustable resistance on acquisition board, if the data is inaccurate while switch from constant voltage to constant current, adjust RW4; if the data is inaccurate while switch from constant current to constant voltage, adjust RW3 as shown in Figure 7; implement the same setting on CH2, If the data is inaccurate while manual calibrate to adjust the switching from constant voltage to constant current, adjust RW2; If the data is inaccurate while constant current switch to constant current, adjust RW1;constant current cut constant voltage is not allowed, the transfer RW1; After the debug, test 10V/1A,20V/2A,30V/3A scale, the error is allowed to range between ±1.5%;

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3.11. Parallel current calibration? Keep the connection of step 8 unchanged (Figure 8), set the electronic load 3721A to "4?", and connect the measurement system to the CH1 output. Press the "MODE" button to switch to the parallel operation mode as shown in Figure 9, and input "30323" through the panel to start automatic calibration of parallel current output. After the calibration there will be beep;

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3.12. Examine the current under parallel mode: Set the value at 0.6,1.2,1.8,2.4,3.0,3.6,4.2,4.8,5.4,6.0 (unit A), set the output voltage to 30V, observe the reading of digital multimeter. Examine the output current through digital multimeter to see if the measured value matches the set point and see if the read back value displayed matches the set point. If there are discrepancies calibrate it manually. (1. Measured output current error: less than 1A (set value * 0.05% ± 3mA), 1A or more (set value * 0.08% ± 3mA); 2.Display value and set value error: set value * 0.05% ); Manually calibrate the output current value via panel input "31323", manually calibrate the current read back via panel input "31325" and exit manual calibration via output "78945". (The specific operation steps are the same as the first step);

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3.13 Series Voltage Calibration?Ensure that the power output is empty, that is, the output terminal is not connected to anything. Press "MODE" key again to switch to series mode as shown in the figure, input "30324" through the panel, then automatically calibrate the series output voltage. After calibration, there will be "beep"

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3.14. Examine the voltage under series mode:Set the value at 2,4,6,8,10,12,14,16,18,20,30,40,50,60 ( V),set the output current at 3A and connect the digital multimeter voltage output terminal with both end as Figure 12 shown. Test the output voltage through a digital multimeter to see if the measured value matches the set value and see if the readback value displayed matches the set value. (1. Measured output voltage error: 10V or less (set value * 0.05% ± 3mV), 10V or more (set value * 0.08% ± 5 mV); 2.Display value and set value error: Set value * 0.05 %).Any discrepancies can be manually calibrated. Manually calibrate the voltage output via panel input "31326" and exit manual calibration via "78945" output;

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3.15. Export TXT and import: After debugging the machine, connect with computer through the USB and export TXT document. Turn off the TXT debug mode command and re-writes to the machine, then flows to the next process. (Note: While exporting TXT, the machine must be in independent mode as shown in Figure 13, and the brightness should be at 5);

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3.1. Edit Excel?Clear the data in the programmable table, open the software "ODP" ? choose "programmable" platform as shown in Figure 14 ? Click the "Send" button then select the "CLEAN.xls" document (in the software directory Excel document).When finish downloading, there will be "command sent successfully" message

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4. If there is a temporary change, operate with the notice of change.
I don't know how many hours of viewing you have now but I see your subs are now up a little. I've just subscribed and I will leave the videos running to get you some more view hours :-)

I don't know until 48 hours has passed, there is only real time statistics on the number of views, which is double of my normal view rate, so thank you all for the support, I hope it will not be in vain.  :phew:
Contests & Events / Re: Wave 2018 (formerly Scope Month)
« Last post by radar_macgyver on Today at 05:06:19 AM »
2.   RF Bundle – N9918A 26.5 GHz FieldFox with both VNA and Spec An options + N7555A ECal kit

Hummana hummana hummana....  :popcorn:
RF, Microwave, HAM Radio / Re: Inductors as antennas
« Last post by hagster on Today at 05:05:47 AM »
All wires have inductance. For example a monopole antenna is bassically an inductor. It has a resonance where the capacitance between it and the ground plane cancels out the inductance. At that point you are basically left with the radiation resistance which which hopefully matches your source if you want maximum power transfer.

You can use spiral wound antenna elements to increase the inductance and shorten the length required to hit this resonance. However when you make antennas shorter you have less aperture to capture(or deliver) em fields so they are less efficient.

At the extreme end you can have loop antennas or ferrite rod antennas that are made to resonate using a discrete capacitors. Again the efficiency is reduced by the small relative size(compared to the wavelength).
Beginners / Re: Back to back microwave oven transformers for isolation?
« Last post by Hero999 on Today at 05:05:09 AM »
Yes, that's a possibility. There are plenty of tutor microwave oven transformer rewinding tutorials on the Internet.

After skimming through a few, here's one of the better ones:

Personally, I wouldn't bother. I'd buy an isolation transformer. If I bought one today, I'd consider one with two 120V secondary windings, so it can be configured for either 120V or 240V.
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