Mostly videos on hobby electronics, test & measurement, ham radio, and other stuff. The site is mainly geared towards the hobbyist. Be sure to let me know if there's a similar topic that you'd like to see a video on! With big thanks to long-time subscriber Dino (KL0S), I've now got an index to all of the videos (arranged numerically and by topic) - see the link at the lower right corner of the channel's head graphic.
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The Potential difference of the capacitor or the potential difference of the inductor is what is causing the time/phase delay. A Resistor doesn't have a potential difference on both sides of the resistor component but when you apply a voltage/current to it but when applying a voltage/current to a capacitor or inductor the potential difference takes TIME or a time interval for the potential different to be ZERO or equal on both sides of the component . This Potential difference is what is causing the phase angle?
Very helpful, thank you!
Hello sir hope you are fine , please make a video on noise figure measurement .
3:33 The smaller heat shrink tubing didn't need to be put on before the BNC male connector?
Perfect, thank you! This helps a diy guy a lot :) When measure a heaphone output that can have something between 1 and 30 Ohms, will it fit when using 50 and 100 Ohm resistors and do the third type of measurement explained in the video?
Great video, sir. I have a doubt about how to find the inductance value for 100 ohm resistor or any resistor in high frequency. Because at high frequency it behave like inductor how measures please acknowledge me
The parasitic inductance of a resistor is highly a function of the resistor construction, lead length, etc., and is typically quite low. You would need an analyzer that tests at high frequency, such as a Vector Network Analyzer to test this.
@w2aew S sir, we have vna in lab. Can u tell me the procedure? I will check tomorrow.
@@Sheikshameer. This video goes through the measurement in detail. kzread.info/dash/bejne/gqidmqerp8Kxm8o.html
@@w2aew thank u sir
sir, how to calculate the inductance for a resistor? at high frequency it behaves like inductor.
Sir, How leakage is related to frequency ? While measuring Cp -Rp it is found that Rp decreases with frequency. Please tell me why Rp changes with frequency . I meassure DC resistance and it gives few Giga Ohm, but, while measuring Cp - Rp , it is found that Rp comes down to 500 ohm only at 300 kHz. Please explain . 🙏🙏🙏 N Das from INDIA
Thank you, excellent explained, great video.
How is the antenna/VNA connected to the tuner
Both are the normal coaxial connections.
nice, clean fixture and excellent explanation
🙏🙏🌹🌹🌹🌹
Where do you get the RG316 with the common mode choke built in?
I got mine from ABR Industries: abrind.com/shop/cable-builder/amateur-radio-coax-builder/ www.hamradio.com/detail.cfm?pid=H0-017956
I watched a presentation of some amateur radio club and the the presenter said that tuners suck up radiating power and when doing QRP, one absolutely doesn't want to use tuners....I became quite incredulous when I heard this. Being new to the hobby, Is this something worth pondering over next time I take my IC-705+ random wire and AH-705 tuner for a walk?
The presenter was ill-informed. A well designed tuner has very little loss. There may be some additional loss in the coax when the antenna is non-resonant, but often is of little consequence. I have well over 5000 QRP contacts operating 5W with a tuner into non-resonant antennas as evidence that says that using a tuner is just fine.
Pure Gold ❤
হিরো ?
To Correct the 90 degree phase angle in capacitors and inductor to make it "0" degrees would need a power factor of "0" which should shift the phase from 90 degrees to 0 zero degrees?
Capacitors and inductors have a 90 degree phase shift which the phase shift will waste energy & applied power, any reasons why the phase shift will Half the power?
🙏🙏🌹🌹
Hi have you tried an OA79 point contact Ge diode? I have a bunch of them and since it is very old, I could not find data sheet spec on timing.
Never had one to try. Give it a go and let us know what you find!
Really helpful and clear explanation! I hope you will continue making videos, you're a great teacher
Hi Alan ... I have an old 260 8 series (mirrored scale, protection feature and roll top case) that I used for troubleshooting for many years. When I first got it, I was really disappointed about the reverse jacks (The plug (male) is in the meter, and the jack (female) is in the test probe. With my previous 260, it was the other way around. I called Simpson and complained about it, as I only use it for low voltage work (other than the 70 Volt Line from distributed audio systems and I didn't typically work on those live anyway, everything else was typically 50V or lower.). And then I use a set of Pomona 'mini-grabbers' with them. Well, I got them to send me a pair of adapters. These were made specifically, and I still use them Their part numbers were 6-112685 and 6-112686. One of them is a little bit loose, so I've been looking for a replacement for them. Unfortunately, I've not been able to find them. Supposedly, they have a test lead set that was quite pricey #00043. I got a set just to have them. I really appreciate the info you shared, and I'm going to try out both solutions you suggested. 73, Neil, K7WK
How do you modify this circuit for PNP transistors?
I just don't understand one thing. I connected the antenna using one of the cables supplied with nanoVNA. Whenever I move the antenna everything change on the screen. Question is how to properly make all the measurements?
The proper way is to measure the antenna in the configuration that it will be used in. Antennas are affected by things around them, so this is to be expected in many cases.
thank you so much for this video <3
47KOM слишком много, надо 4,7KOM. максимальный ток маленький.
Should have keyed 'subscribe' at the end 😆
In relation to Early voltage, does the lenght of the line indicate resistence? For example, long line, less resistence, short line more resistence for that current?
No, it is the slope of the line that tells you the resistance.
Is thermal runaway in tubes and transistors caused by an internal positive feedback or internal current leakage? I'm not sure why FETS don't have Thermal runaway issues any reasons why? Thermal runaway is when the tube or transistor is self biasing itself to be hotter and hotter I think due to the leakage current and positive feedback but correct me if I'm wrong
Not sure of the mechanism in tubes. But in bipolar transistors, the base emitter voltage drops as the temperature increases. This causes an increase in base current, which then causes an increase in collector current. The increase in collector current causes an increase in power dissipation of the transistor (Ic * Vce). This increased power dissipation raises the temperature which exacerbates the problem and can cause thermal runaway.
Thanks Allen, very useful
my best teacher
The first new shortwave radio I purchased as a young teen in the late 70s, and I still have it, and the owner's manual! Lot of great DX QSL had with this radio. Nice instructional video, I learned a few things.
I have question to your last section. Where you added voltage to LPF output (VcoIN) and the PLL compensated for that by varying the phase. I understand that it should happen for the transient time of the loop. But the should the PLL compensated for this additional voltage offset that you have added by decreasing its PD output and then bring the PLL to a lock. Why does your phase shifted waveform look so stable. I was imagining more of a jitter.
Got it to work. So instead of what you did where you just added a pull resistor to yank on the LPF output. What I was trying to do is take the LPF output through a summing amplifier where I am subtracting the V(LPF)-V(yank) and then feeding it back to the VCOin. That wasn't working. So instead I connected the LPF out to VCOin back. And just added V(yank) through a resistor on VCOin and it worked as your demonstration. So basically what I need to do is a current source instead of voltage source for my Yank signal.
While I am seeing only Superheterodyne receivers, I'd like to know whether we can make a Superheterodyne transmitter. I think yes. Please let me know if I'm wrong
Most transmitters are superhet designs too. They just operate in the opposite direction. Modulation is applied to some intermediate frequency, and then that is up-converted with a mixer and LO to the final transmitting frequency.
Most excellent !!!
I was just started to studying RF, and i watched so many videos but couldnt uderstand the IQ stuff , thanks to you i can move further, thank you so much sir, u really explained it very clearly.thanks again.
Thanks for the impressively thorough, and well presented video. I just got a litevna and am very impressed with what it can do. I thought I might "need" a better device than this, but it is plenty powerful for everything I currently want to measure.
Nice explanation! Thank you
Still valuable and excellent, and it will be even in two decades from now on. A really outstanding quality in terms of clarity, accuracy and style. Can't thank you enough for your work!
WOW!!!!!!! THANKS FOR WALKING US THRU YOUR NOTES,... EXCELLENT DESCRIPTIONS!!!... GREAT DEMO!!! THANKS!!!
Wondering what the results would be using both at the same time.
Marginally better than either.
Very nice and more informative video, Thanks sir ! 😊😊😊
So does the NanoVNA connect to the tuner and then the tuner connects to the antenna? Presumably once you have it all tuned to the frequency you want to work (as per the video) you disconnect the NanoVNA from the tuner & connect the transceiver to the tuner. Great explanation as it makes it all look so simple.
Yes, the NanoVNA is taking the place of the transceiver for the purposes of adjusting the tuner.
I have never seen anybody assemble a circuit board like this. Very cool, And for how old this video is, you must have had a serious camera.
I love my WRC vertical, but the radials are just so inconvenient -- just ordered the faraday cloth, can't wait to add that to the arsenal.
I am giving power to my LNA of 12 volt but it not getting power power up it is generally stopping at 9.3-9.4 volt how to fix this
I am using ZX60-83LN12+ LNA
Love your ability to explain complex stuff in such a short time Alan, amazing little circuit condenses a lot like yourself!! hihihihi
How could you hook this up to rg8 coax go analyze etc??? The connect looks so small
A small jumper with an adapter to match connectors.
Normally We are using decimals for calc..
I remember a video of a guy (using shf) demonstrating how antennas worked using very tiny antennas. It was pretty amazing. He had verticals, dipoles, beams, loops and so on.