Your clear and concise explanation has allowed me to get a useful start to understanding and using the Smith Chart.. I am also in need to build an L network for a remote tuner so this is priceless information you have presented. GOD bless your Sir!
Thanks for making and sharing this interesting video. If you make additional videos on this subject I think it would be helpful to demonstrate how matching circuits are used to interface to loads having a complex impedance (resistance plus capacitive or inductive reactance, or Z = R +/- jX). Antenna matching circuits would be a good example since they almost always have non-zero reactance that needs to be cancelled to effect maximum power transfer. Thanks again! - Jim (KK7CSC)
I just viewed your video 3X. This is in reference to your final demo. When the shunt capacitive element is in parallel with a higher VNA source impedance, 50 ohms, your circuit will transform the impedance downward to the lower impedance load, 25 ohms. While your lab setup is correct for what it is intended to do, it does not faithfully reflect the drawing that you showed of Professor Long's network. Professor Long's network is drawn to transform a higher impedance load down to a lower impedance source. I suggest that you revise the notebook drawing that you present to reflect what you are demonstrating in the lab. It generates confusion for the viewer. If you would like to see it presented correctly, please watch W2AEW's lesson #276.
At the end of the movie, you did not explain where the additional 25ohm pure resistance came from. Did you endure reactance and pure resistance was connected ???
Another informative video RF Man! I'm curious, and maybe it requires a video to answer, but when would you use an L-network or T-network vs. a transformer? What I am driving at is, for a 1/2 wave end-fed antenna, we use a 49:1 unun, but why do you see 5/8 wave antennas using a T-network instead of a transformer? And is there a rule for when to use which method?
There is no rule that I am aware of. Most antenna matchers will use either a Pi or T network. Both LC networks can be tuned to match a wide range of impedances. The combination of LC can be considered infinite. A transformer has a fixed impedance ratio limited by the number of turns in the primary and secondary. The ratio is a fixed or finite value and can not be tuned. This may be necessary if the antenna is not resonant at the high or low end of the band.
@@rfmanchannel6915 Thanks RF Man; I thought that other than for small tuning adjustment, getting the impedance to match at 1.5:1 or more, using an LC arrangement of any kind was very lossy in some way, even when done at the antenna feed point. I had in my mind that a transformer would be more efficient and after that, just use minimal LC to get the match "perfect". Would you say that's true, or can an LC arrangement be just as efficient to match impedances for power transfer?
@@louisseaman8455 I agree with your point. I have a video where I use a 9:1 Unun and an antenna tuner/matcher with a long wire antenna. This arrangement works best. Regards
RF Man, I really appreciate you sharing this insight. RF Man I have seen some 1/4 wave antennas for cb radio using a L-Match Network for a 11 and 10 meter. Can you please share how this is accomplished? Thank you, excellent video.
Finally I find a video made by someone that explains this that I can understand.
Bless you Sir and many thanks!
I'm happy you found my video helpful!! Regards
I really like the way you demonstrated this. It is perfectly clear. Thank you.
Your clear and concise explanation has allowed me to get a useful start to understanding and using the Smith Chart.. I am also in need to build an L network for a remote tuner so this is priceless information you have presented. GOD bless your Sir!
Excellent, I would like to see more of these videos. I leaned a few things. Please more on how you match the LDMOS devices.
Thanks . Now i understood smith chart thanks to you❤
Thank you
Thanks for making and sharing this interesting video. If you make additional videos on this subject I think it would be helpful to demonstrate how matching circuits are used to interface to loads having a complex impedance (resistance plus capacitive or inductive reactance, or Z = R +/- jX). Antenna matching circuits would be a good example since they almost always have non-zero reactance that needs to be cancelled to effect maximum power transfer. Thanks again! - Jim (KK7CSC)
I just viewed your video 3X. This is in reference to your final demo. When the shunt capacitive element is in parallel with a higher VNA source impedance, 50 ohms, your circuit will transform the impedance downward to the lower impedance load, 25 ohms. While your lab setup is correct for what it is intended to do, it does not faithfully reflect the drawing that you showed of Professor Long's network. Professor Long's network is drawn to transform a higher impedance load down to a lower impedance source. I suggest that you revise the notebook drawing that you present to reflect what you are demonstrating in the lab. It generates confusion for the viewer. If you would like to see it presented correctly, please watch W2AEW's lesson #276.
At the end of the movie, you did not explain where the additional 25ohm pure resistance came from. Did you endure reactance and pure resistance was connected ???
Thank you.
Very helpful.
Very informative : Thank you
Another informative video RF Man! I'm curious, and maybe it requires a video to answer, but when would you use an L-network or T-network vs. a transformer? What I am driving at is, for a 1/2 wave end-fed antenna, we use a 49:1 unun, but why do you see 5/8 wave antennas using a T-network instead of a transformer? And is there a rule for when to use which method?
There is no rule that I am aware of. Most antenna matchers will use either a Pi or T network. Both LC networks can be tuned to match a wide range of impedances. The combination of LC can be considered infinite. A transformer has a fixed impedance ratio limited by the number of turns in the primary and secondary. The ratio is a fixed or finite value and can not be tuned. This may be necessary if the antenna is not resonant at the high or low end of the band.
@@rfmanchannel6915 Thanks RF Man; I thought that other than for small tuning adjustment, getting the impedance to match at 1.5:1 or more, using an LC arrangement of any kind was very lossy in some way, even when done at the antenna feed point. I had in my mind that a transformer would be more efficient and after that, just use minimal LC to get the match "perfect". Would you say that's true, or can an LC arrangement be just as efficient to match impedances for power transfer?
@@louisseaman8455 I agree with your point. I have a video where I use a 9:1 Unun and an antenna tuner/matcher with a long wire antenna. This arrangement works best. Regards
Really useful, thank-you. When would I use an L network compared to a Pi match... does the Pi match have any advantages?
RF Man, I really appreciate you sharing this insight. RF Man I have seen some 1/4 wave antennas for cb radio using a L-Match Network for a 11 and 10 meter. Can you please share how this is accomplished? Thank you, excellent video.
Very useful video... thankyou sir 🙏
Thanks for your comments. RF Man
very cool, I'm an amateur trying to wrap my brain around all this stuff so I can build a qrp L-match tuner for 28Mhz
Ok play back speed at 1.5 fast ahead , and he sounds like a normal person talking .
Beautiful, thank you 👍.
What A Supercool Video :)