This is a great video been working on electronic communications for many years and I still learn things but your explanations are easy to understand and will help many, including me!! Well done. Maybe another video on combiners would be worth it thanks.
Excellence !!!!! The tune is the black art no one is willing to teach anyone and it's probably the absolute most important step when it's all said and done. TY Sharky
Quite difficult, but tried to keep following it, Thank you for the video and the good information I think you tried really hard to make us viewers wiser! like to keep doing? keep going!? Healthy and Friendly Greetings from the Netherlands! Rob
Awesome explanation in understandable terms. Keep it coming. I see you bumped up to nano vna-F ver.3.1 w/buttons. Mines has the thumbwheel [ver. 2.3] I need to upgrade. Again Great job!
One of the best video's I've seen on this topic in quite a while. Also a joy to listen to the tone of your voice while explaining though stuff, very relaxing, down to earth and convincing at the same time. Thanks much, I've learned a lot this time! 👍
I'm reminded of the crystal radio from the late 1800s-early 1900s: - antenna - no source of power - a crystal - headphones that was it. They were also called "trench radios" since they were assembled in the ww1 trenches by soldiers RF introduces complexity! You did a great job, thanks. .
Awesome video... Really enjoy trying to learn and understand rf...like the way you keep in some what of Layman terms. I want to build myself a amplifier someday... keep the videos coming...
Beautiful video brother.....It took me prbly 4 years into this hobby of amp building u till I learned that the brass tube in conjunction with the front and back copper board lol. It was almost like a light bulb went off. The compensation capacitor on top came a lot later. You can't always have that perfect turn ratio like you mention cause we are stuck with the 1 to something lol. It is always cool how there is more then 1 way to skin a cat as they say.....when I got into this it confused me so much how a 4 pill can work with so many different wrap and compensation capacitor values until I learned this. Wish I had the intelligence that you have sharky. The Motorola handbook as they call it along with each year of the ARRL especially the older ones have been a life saver to me.. I am one of those type of guys that aren't happy with just knowing 75 percent of why an amplifier works.....I want to understand it all.. its more like im an addict to the knowledge lol.. same way i was growing up with computers back in the old school dial up era and designing software to do this and that lol....Would love to chat with ya sometime brother.. Your fellow builder from the South!! Gatekeeper Keep on going! I love your videos!!!
In reference to your statement "brass tube to copper board front to back" are you trying to point out the difference in conductivity or velocity factors between the two metals?
Great Video !!! You did a good job putting it into layman's terms that everyone can understand better .. About the only thing I'd add is that those adjustable caps can have a tendency to falter over time or when a lot of power is put though them . Personally I like to adjust them to where I need to get them and then remove them from the circuit after adjusting , measure capacitance , and then replace them with a good fixed cap.... keep the videos coming and great job of sharing knowledge !!
MudDuckSharky Watching this piece of gold again! Could you someday explain the difference of feeding the power at the output transformer center tap, versus feeding it through a bifilar choke to the transistor collectors as BBI does? This change has me totally stumped.
I don't fully understand that part yet, but one thing I can say is that feeding the center tap loads up the ferrite more and can make the transformer hotter. As far as power output goes I haven't seen much difference between them.
@@MudDuckSharky That may be it! If it makes the transformer hotter, than it is perhaps messing with the B-H curve, perhaps like a DC shift, at least for the bias part? Thank you for your experimental observations. (Sorry for the email, I didn't think you would see this comment...) :thumb up:
Most all solid state mobile amps, back in the early days of the MRF-454 and 455, had tunable transformers. Someone, along the way, decided to measure the tuned padder cap, and replace it with an equivalent value using a silver mica cap or caps. Now, they're using surface mount silver micas. However, knowing that copycats are out there, who don't really design anything, they merely copy what others have done, and do not know how this came about, nor how these values are determined. It's why they produce splatter boxes. I'm not for sure if Arco is still in business, as that is who supplied us with padder caps years ago. DigiKey doesn't list them anymore.
Great job as usual, but don't you also have to take the extremely high input and output capacitance for the power fet into consideration when determining the drain to drain capacitor size?
Is this also necesary for Transmission Line transformers? Those capacitors are there to compensate for leakage is it? To measure leakage you could short the transformer and measure the leakage inductance. Put it in simsmith and calculate the caps.
Thank you for explaining how it works, it was very helpful for me. I assembled the same circuit, but when setting it up, I got a capacitance of 1600 pF on the primary side and 270 pF on the secondary side with an impedance of 5.5+0j. I think this is too much capacitance; on your diagram, the values are almost 5 times smaller. What could be the reason for this?
Great video. Just one question. I have looked at a few pairs of Zetagi B300P they have 6x power level positions. What i found is that each power position has a slightly different reflected power back to the radio, each position passes via a different group of resistors mounted near the power level switch. However when in position 6 which bypasses all resistors i see the highest reflected signal to the radio. SWR at the radio jumps up 2 or 3 times worst. What I'm thinking is that they tuned the amplifier with fixed capacitors for an average taking into account the effect of the attenuation resistors. But the problem is that at full power the reflected power is the worst. I'm thinking the best is to add variable power to the radio, keep the linear always at full power and try to tune the transformers for less reflected power at full output power. I think I will tune with variable caps then remove them and measure the value then add fixed caps of that value in place. Keeping the variable caps for the next amp tuning.
Excellent demonstration! I was wondering if you could have put 5.5 ohms where the transistor goes and feed the NanoVna into the output? Probably just a different way to skin a cat. Great Job!
Yes, you CAN put a resistor in place of the transistors and tune the transformer. The problem there is that a resistor is not a good representation of the transistors, and without further test&tune the performance would likely be pretty bad.
Hi. Thanks for the great video. Would be very (and completely) useful if you could post in the comments the specific Motorola ANs that you are refering to. Thanks in advance.
Thanks sharky , you used a brass tubes , instead of copper for the single winding , is this to drop the Q or did can’t buy the red copper tubing Thanks in advance for answer
How many watts will the LDMOSs transistor do on 27MHz. U peeked my interest and knowledge. I grew up working on Tube type TVs. Dad worked on them in 50s through 80 but now im interested in power transistor’s
If in doubt use a door knob cap. Short length TC 12 coax makes an indescribable cap too. Iv used these on 50 88-108 and 144 mhz. No experience with 10/11m.
Nice job, am a hobbyist trying to work on rf amp on high frequencies like 90mhz on the FM band. Always end up in low gain, high swr etc. But you've done a great job explaining this in simple terms, can you please make a tutorial like this on the FM band will appreciate if you could do that thanks.
I have a datasheet for the transformer I'm using but still can't figure out how to get the values for Simsmith. The amp is working through trial and error but I'm just trying to learn. I have 1 winding inductance and leakage inductance. It's a 2 x 2sc2879 amp.
Couldn't you bias a transistor ON, connect the VNA to the input and perform the same test until you get a match? Maybe start with a 1:1 transformer with the transistor biased ON to find the Impedance of the transistor at the frequency of operation?
port 1 of your nano vna has 50 ohm coax attached to the primary of the output transformer. WOULD THE READINGS CHANGE IF THERE WAS 25 OHM COAX? OR 75 OHM COAX ? OR IS THE COAX TAKEN OUT OF THE EQUASION WHEN YOU CALIBRATE THE NANO VNA?
There are a handful of reasons why neither of those will work well. Best method I have found is to tune the transformer into the ballpark and then fine tune with trimmers based on the amplifiers performance at various power levels.
for 27 MHz operation only, why not ditch the transformer -just use a ~80 nH series inductor (tied to drain ) feeding into a 300 pf shunt... This should match ~5 ohms to 50. You would then need 3600 pf (or greater) at the output to block dc.
That's done quite often in single transistor amps, and would also work for transistors in parallel. I don't recall a push pull design like that, no doubt it's at least been attempted.
@@MudDuckSharky Yes the circuit topology with the push pull would be an issue. Also check out W6PQL.com for his 6 meter mono band design. Very low in harmonics... hmm, could that be scaled for 27 MHz?
@@jimsmith8389 PQLs design could be but of course the values are just different. Note while most CB amps run 61 material , PQL is trying to cover the whole ham HF spectrum plus 6 Meters so he's undoubtedly using 63 material ... Which does suffer at higher freqs and may present a problem ... I haven't looked to see if he has a stand alone 6 meter version , because I haven't been on his site in a while.
What we call transformer, is not really a transformer, and the imprecision, the lack of perfection, is not the real explanation, i believe. What we call transformer, is in fact.... how should i put it... communicant storages. When you realize this, you understand that it is not far from perfection, but in fact quite close to perfection. When we consider communicant storages, there can be no symmetry. It means we should not work with sine waves, but only with transitional. Then it is completed, a better word than compensated, i believe, with storage elements that are the capacitors. That too, is not about working with sine waves. It is about trading storages, in order to push it toward symmetry. Again, it is not about some imperfections of a real world transformer! The ideal transformer, as a perfect model, is not ideal for the job, and can never be. The perfect model, is imperfect use. Perfect "transformer", what i call perfect co-inductors, combined with perfect capacitors, are used to optimize response for desired signal, with better results than just ideal "transformer".
I could just picture me after taking a break and a glass or two full of champagne, hell guys with this wimpy ass little two pill job we're going for the moon 50,000 Watts
Heads up. Mark Sherman has his eyes on you for "copying" other amplifier builders. He is already going after RF Man. I think you are next man. He just hasn't sent his trolls over yet but the word has been given.
You must learn how to make a video on the topic you want to talk. Connecting the unbalanced 50 ohm side of the nanoVNA to the balanced 5.5 ohm side of the output transformer is itself a big blunder. The output transformer (or the input transformer) characteristics can be studied/evaluated or optimised using the nanoVNA only from the 50 ohm unbalanced side using an 1:1 CMC choke. Or else you can use two identical Transformers connected back to back to guarantee that the they're well built and optimised; but again the first transformer will have to be made/studied only from the 50 ohm unbalanced side using the nanoVNA. After all the nanoVNA can work correctly with a 50 ohm unbalanced impedance system only. You may want to reconcile your understanding and knowledge on the topic and make a revised video. Viewers should not be misguided. False information should not be disseminated anymore. De VU2RZA.
For the principle Professor Sharky was demonstrating, the test setup was adequate. Please note that both the NanoVNA and the 50-ohm load were isolated from any "ground" reference.
@k7jeb I think you want to study what it means or referenced to 'balanced' or 'unbalanced ' in the first place. The nanoVNA is by design a 50 ohm impedance system, meaning any trivial deviation will result in false readings; more the deviation more the inaccuracy. I strongly believe you may want to have a basic idea of how the nanoVNA or any VNA is working. Have a good day. De VU2RZA
next time you do a video of this type. Do Not keep moving the item your talking about. your hand and fingers were like a I don't know annoying. your talking about this device and your not showing us what your talking about. STOP Moving that item and hiding what parts look like. I notice One End is linked together. and the other end is cut? Bad talking about stuff that is not necessary. Boring NOT RELATED TO THE TITLE OF YOUR VIDEO.. Thank you for your idea of trying to Teach. And you did a Great job once you got on the computer and ran the sim program. now that was spot on. Learned this stuff back in High School. many many moons ago. :) Thanks🤙
I think Mr. Sharky learns by doing. So, hopefully he has had some time to review this video and learn a bit about the value of preparation and organization before delivering a lecture. The teachers and professors one has had all made it look so easy when in front of the class -- guess what? it wasn't. There was a lot of time spent behind the scenes before the presentation.
Even the experts get things wrong and often. You win or you learn. Excellent work!
Thank you so much for making this video, it definitely helped point me in the right direction on tuning in 2879's. You rock, sir!
This is a great video been working on electronic communications for many years and I still learn things but your explanations are easy to understand and will help many, including me!! Well done. Maybe another video on combiners would be worth it thanks.
Excellence !!!!! The tune is the black art no one is willing to teach anyone and it's probably the absolute most important step when it's all said and done. TY Sharky
Great video. Looking forward to the "Deeper down the rabbit hole" series! BTW BBI sent me!
Quite difficult, but tried to keep following it, Thank you for the video and the good information
I think you tried really hard to make us viewers wiser!
like to keep doing? keep going!?
Healthy and Friendly Greetings from the Netherlands!
Rob
Awesome explanation in understandable terms. Keep it coming. I see you bumped up to nano vna-F ver.3.1 w/buttons. Mines has the thumbwheel [ver. 2.3] I need to upgrade. Again Great job!
One of the best video's I've seen on this topic in quite a while. Also a joy to listen to the tone of your voice while explaining though stuff, very relaxing, down to earth and convincing at the same time. Thanks much, I've learned a lot this time! 👍
I'm reminded of the crystal radio from the late 1800s-early 1900s:
- antenna
- no source of power
- a crystal
- headphones
that was it. They were also called "trench radios" since they were assembled in the ww1 trenches by soldiers
RF introduces complexity! You did a great job, thanks.
.
your the man sharky! thank you for yet another informative video for us rookies. thank you SO MUCH!!!!!
Thanks Sharky! Great video, learned a lot. When your ready to go down the rabbit hole I'll be ready!! LOL.
Awesome video... Really enjoy trying to learn and understand rf...like the way you keep in some what of Layman terms. I want to build myself a amplifier someday... keep the videos coming...
Beautiful video brother.....It took me prbly 4 years into this hobby of amp building u till I learned that the brass tube in conjunction with the front and back copper board lol. It was almost like a light bulb went off.
The compensation capacitor on top came a lot later. You can't always have that perfect turn ratio like you mention cause we are stuck with the 1 to something lol. It is always cool how there is more then 1 way to skin a cat as they say.....when I got into this it confused me so much how a 4 pill can work with so many different wrap and compensation capacitor values until I learned this.
Wish I had the intelligence that you have sharky. The Motorola handbook as they call it along with each year of the ARRL especially the older ones have been a life saver to me.. I am one of those type of guys that aren't happy with just knowing 75 percent of why an amplifier works.....I want to understand it all.. its more like im an addict to the knowledge lol.. same way i was growing up with computers back in the old school dial up era and designing software to do this and that lol....Would love to chat with ya sometime brother.. Your fellow builder from the South!! Gatekeeper Keep on going! I love your videos!!!
In reference to your statement "brass tube to copper board front to back" are you trying to point out the difference in conductivity or velocity factors between the two metals?
Great video sharky, can you do a video on combiner / spliter design ?
Great Video !!! You did a good job putting it into layman's terms that everyone can understand better .. About the only thing I'd add is that those adjustable caps can have a tendency to falter over time or when a lot of power is put though them . Personally I like to adjust them to where I need to get them and then remove them from the circuit after adjusting , measure capacitance , and then replace them with a good fixed cap.... keep the videos coming and great job of sharing knowledge !!
I learned a lot even at my age. Always loved electronics but never had chance to go to school for it
Great info. Thanks for sharing your knowledge!
Very informative. Keep them coming!
Thanks for the tips! You are great! Im dental tehnician - no electronics studies:)) but i play RF ham radio!! Thanks!!!!!
Very well done, and I am sure it will be helpful to many in this RF hobby. Cheers
Man thank you so much! I hope there is more to come!
MudDuckSharky Watching this piece of gold again! Could you someday explain the difference of feeding the power at the output transformer center tap, versus feeding it through a bifilar choke to the transistor collectors as BBI does? This change has me totally stumped.
I don't fully understand that part yet, but one thing I can say is that feeding the center tap loads up the ferrite more and can make the transformer hotter. As far as power output goes I haven't seen much difference between them.
@@MudDuckSharky That may be it! If it makes the transformer hotter, than it is perhaps messing with the B-H curve, perhaps like a DC shift, at least for the bias part? Thank you for your experimental observations. (Sorry for the email, I didn't think you would see this comment...) :thumb up:
Most all solid state mobile amps, back in the early days of the MRF-454 and 455, had tunable transformers. Someone, along the way, decided to measure the tuned padder cap, and replace it with an equivalent value using a silver mica cap or caps. Now, they're using surface mount silver micas. However, knowing that copycats are out there, who don't really design anything, they merely copy what others have done, and do not know how this came about, nor how these values are determined. It's why they produce splatter boxes.
I'm not for sure if Arco is still in business, as that is who supplied us with padder caps years ago. DigiKey doesn't list them anymore.
Just wanted to take a minute, and Say Thankyou Mr. Sharky 🦈. GOT ME THINKING, TO A MORE PERFECTED PLACE. Thankyou
Great job as usual, but don't you also have to take the extremely high input and output capacitance for the power fet into consideration when determining the drain to drain capacitor size?
Could you not use another substance like graphene in place of the ferrous rings if they're unstable
Is this also necesary for Transmission Line transformers? Those capacitors are there to compensate for leakage is it? To measure leakage you could short the transformer and measure the leakage inductance. Put it in simsmith and calculate the caps.
Thank you for explaining how it works, it was very helpful for me. I assembled the same circuit, but when setting it up, I got a capacitance of 1600 pF on the primary side and 270 pF on the secondary side with an impedance of 5.5+0j. I think this is too much capacitance; on your diagram, the values are almost 5 times smaller. What could be the reason for this?
Great video. Just one question. I have looked at a few pairs of Zetagi B300P they have 6x power level positions.
What i found is that each power position has a slightly different reflected power back to the radio, each position passes via a different group of resistors mounted near the power level switch. However when in position 6 which bypasses all resistors i see the highest reflected signal to the radio. SWR at the radio jumps up 2 or 3 times worst.
What I'm thinking is that they tuned the amplifier with fixed capacitors for an average taking into account the effect of the attenuation resistors. But the problem is that at full power the reflected power is the worst.
I'm thinking the best is to add variable power to the radio, keep the linear always at full power and try to tune the transformers for less reflected power at full output power.
I think I will tune with variable caps then remove them and measure the value then add fixed caps of that value in place. Keeping the variable caps for the next amp tuning.
It's easy: measure the primary inductance L and resonate it in the middle of the band f with a cap C. Use f = 1/2pi(LC)0.5
Excellent demonstration! I was wondering if you could have put 5.5 ohms where the transistor goes and feed the NanoVna into the output? Probably just a different way to skin a cat. Great Job!
Yes, you CAN put a resistor in place of the transistors and tune the transformer. The problem there is that a resistor is not a good representation of the transistors, and without further test&tune the performance would likely be pretty bad.
Hi. Thanks for the great video. Would be very (and completely) useful if you could post in the comments the specific Motorola ANs that you are refering to. Thanks in advance.
Thanks sharky , you used a brass tubes , instead of copper for the single winding , is this to drop the Q or did can’t buy the red copper tubing Thanks in advance for answer
How many watts will the LDMOSs transistor do on 27MHz. U peeked my interest and knowledge. I grew up working on Tube type TVs. Dad worked on them in 50s through 80 but now im interested in power transistor’s
If in doubt use a door knob cap. Short length TC 12 coax makes an indescribable cap too. Iv used these on 50 88-108 and 144 mhz. No experience with 10/11m.
Thank you for the chunk of knowledge
Nice job, am a hobbyist trying to work on rf amp on high frequencies like 90mhz on the FM band. Always end up in low gain, high swr etc. But you've done a great job explaining this in simple terms, can you please make a tutorial like this on the FM band will appreciate if you could do that thanks.
What do the capacitors from collector to ground do?
I have a datasheet for the transformer I'm using but still can't figure out how to get the values for Simsmith. The amp is working through trial and error but I'm just trying to learn. I have 1 winding inductance and leakage inductance. It's a 2 x 2sc2879 amp.
Thank you very much for the nice video !! For a multiband amplifier, do I need capactor selector switch ?
Please, give us the links to the books. Thanks
Very, very good lesson! I will drink a half glass of vine. No vine, russian vodka.
this is the stuff that keeps me up at night., i just don't have your brain power to understand or figure things out lol.. thanks,
I changed the Toshiba transistors to HG in a texas star dx250. Can I tune it with the transistors in the circuit? I get a high swr when it runs.
I'm building a amplifier what type of binoculars are being used I could only get type BN43-7051
I will build an amp. I will need to use it on 28.000 - 29.700 MHz SSB. Should be in good shape?
Thanks for the video. Do you know what the resistance of a blf188xr is ?
Couldn't you bias a transistor ON, connect the VNA to the input and perform the same test until you get a match? Maybe start with a 1:1 transformer with the transistor biased ON to find the Impedance of the transistor at the frequency of operation?
port 1 of your nano vna has 50 ohm coax attached to the primary of the output transformer. WOULD THE READINGS CHANGE IF THERE WAS 25 OHM COAX? OR 75 OHM COAX ? OR IS THE COAX TAKEN OUT OF THE EQUASION WHEN YOU CALIBRATE THE NANO VNA?
Good question, I don't know.
Thanks for the great video.
Can parallel capacitors both compensate for capacitance and leakage inductance between windings?
Thank you for the informative videos sir.
Hey Sharky have you ever tried to multi band an amp?
Dude, thank you.. I’ve been asking well know tech’s how to lower reflect and absolutely no one could tell me, or would even try..
Wow this was a light bulb moment. Thank you
Hope you had a good Thanksgiving and a good Christmas coming up on that end
hmmm I thought it was more about canceling the reactive values of the transistor impedances and the winding impedance of the transformer.
What's with the 2 adaptors on the VNA? are they to change the gender or as I was thinking just pass throughs to reduce wear and tear on the VNA jacks.
Gender repeater adapters.....Just reduces wear & stress on the Vna connector contacts...
Hmmmmmm......so it's kind of the same principle as tuning a tube amp......? Thank you for your awesome videos!!!!
Really good primer! Thanks
I like your style. Like.
You have a file specified for the L element (on far left) in SimSmith.... Can you specify that file or post your SimSmith files?
If you read from the 50ohm side can you do it with transistor installed or would need to remove it and install a 5.5ohm resistor in its place
There are a handful of reasons why neither of those will work well. Best method I have found is to tune the transformer into the ballpark and then fine tune with trimmers based on the amplifiers performance at various power levels.
muy buen video bien explicado ahora ya entendi bastante de los amplificadores de cb gracias por compartir s u conocimiento
Character In the video It's great, I like it a lot $$
the best tutorial ever i like this
enjoyed the detail
Information rare et très instructive ! Merci !
Excellent video TNX
for 27 MHz operation only, why not ditch the transformer -just use a ~80 nH series inductor (tied to drain ) feeding into a 300 pf shunt... This should match ~5 ohms to 50. You would then need 3600 pf (or greater) at the output to block dc.
That's done quite often in single transistor amps, and would also work for transistors in parallel. I don't recall a push pull design like that, no doubt it's at least been attempted.
@@MudDuckSharky Yes the circuit topology with the push pull would be an issue. Also check out W6PQL.com for his 6 meter mono band design. Very low in harmonics... hmm, could that be scaled for 27 MHz?
@@jimsmith8389 PQLs design could be but of course the values are just different. Note while most CB amps run 61 material , PQL is trying to cover the whole ham HF spectrum plus 6 Meters so he's undoubtedly using 63 material ... Which does suffer at higher freqs and may present a problem ... I haven't looked to see if he has a stand alone 6 meter version , because I haven't been on his site in a while.
Waving Hi @MudDuckSharky! 👋
Think you lot of help.
Wow~! It's magic~! Thanks lot~!
I just heard about you from prime minister
nice effort...
Gud, gud! 😊 Вы молодец
😃😁🥳🤩 thank you very much
Thank you x100!!!!
What we call transformer, is not really a transformer, and the imprecision, the lack of perfection, is not the real explanation, i believe. What we call transformer, is in fact.... how should i put it... communicant storages. When you realize this, you understand that it is not far from perfection, but in fact quite close to perfection. When we consider communicant storages, there can be no symmetry. It means we should not work with sine waves, but only with transitional. Then it is completed, a better word than compensated, i believe, with storage elements that are the capacitors. That too, is not about working with sine waves. It is about trading storages, in order to push it toward symmetry.
Again, it is not about some imperfections of a real world transformer! The ideal transformer, as a perfect model, is not ideal for the job, and can never be. The perfect model, is imperfect use. Perfect "transformer", what i call perfect co-inductors, combined with perfect capacitors, are used to optimize response for desired signal, with better results than just ideal "transformer".
I could just picture me after taking a break and a glass or two full of champagne, hell guys with this wimpy ass little two pill job we're going for the moon 50,000 Watts
Welcome. I hope you will send me the OMPLI HF 11M in Tunisia. There is not a single store for amateurs' radios 73
Lots of incorrect information plus you never said what material type those ferrite cores are. Ferrite cores of different types work well in VHF.
Make a better video than you crabby person.
Yes, he did say that material was type 61 and frequency was 27MHz. Incorrect? Your comment was incorrect and good for nothing.
Heads up. Mark Sherman has his eyes on you for "copying" other amplifier builders.
He is already going after RF Man. I think you are next man.
He just hasn't sent his trolls over yet but the word has been given.
What a joke
Who is he copying ? If I didn't know better..."and I don't " I'd say you were one of the trolls
@@bparker86 Are you one of Mark Shermans fence riders?
@@taft2422 I despise mark. Tfoh
@@bparker86 Then we are on the same team man! TAFT is an organization that points out that Mark Sherman is a troll, liar, and cheat.
You must learn how to make a video on the topic you want to talk.
Connecting the unbalanced 50 ohm side of the nanoVNA to the balanced 5.5 ohm side of the output transformer is itself a big blunder.
The output transformer (or the input transformer) characteristics can be studied/evaluated or optimised using the nanoVNA only from the 50 ohm unbalanced side using an 1:1 CMC choke.
Or else you can use two identical Transformers connected back to back to guarantee that the they're well built and optimised; but again the first transformer will have to be made/studied only from the 50 ohm unbalanced side using the nanoVNA.
After all the nanoVNA can work correctly with a 50 ohm unbalanced impedance system only.
You may want to reconcile your understanding and knowledge on the topic and make a revised video.
Viewers should not be misguided.
False information should not be disseminated anymore.
De VU2RZA.
For the principle Professor Sharky was demonstrating, the test setup was adequate. Please note that both the NanoVNA and the 50-ohm load were isolated from any "ground" reference.
@k7jeb I think you want to study what it means or referenced to 'balanced' or 'unbalanced ' in the first place.
The nanoVNA is by design a 50 ohm impedance system, meaning any trivial deviation will result in false readings; more the deviation more the inaccuracy.
I strongly believe you may want to have a basic idea of how the nanoVNA or any VNA is working.
Have a good day.
De VU2RZA
next time you do a video of this type. Do Not keep moving the item your talking about. your hand and fingers were like a I don't know annoying. your talking about this device and your not showing us what your talking about. STOP Moving that item and hiding what parts look like. I notice One End is linked together. and the other end is cut? Bad talking about stuff that is not necessary. Boring NOT RELATED TO THE TITLE OF YOUR VIDEO.. Thank you for your idea of trying to Teach. And you did a Great job once you got on the computer and ran the sim program. now that was spot on. Learned this stuff back in High School. many many moons ago. :) Thanks🤙
I think Mr. Sharky learns by doing. So, hopefully he has had some time to review this video and learn a bit about the value of preparation and organization before delivering a lecture. The teachers and professors one has had all made it look so easy when in front of the class -- guess what? it wasn't. There was a lot of time spent behind the scenes before the presentation.
Excellent video TNX