That's a very good question Jason. Most commercially produced radios "should" meet the minimum emission standards of 47 CFR § 97.307. But.....after WWII, many hams purchased surplus military transmitters that were rich in harmonics and caused terrible TVI and harmonics of the fundamental frequency. There are many in use today. Therefore the need for an external LPF. Today, there are many home brew transmitters and linear amplifiers that may require a LPF. See my video where I purchased a DIY linear amplifier kit from China. It definitely needed a LPF. ua-cam.com/video/KTCMJNP9fUw/v-deo.html 73's
@@rfburns3472 That is one of the most helpful responses someone has given me on UA-cam. Thank you so much for replying. I appreciate this so much. Very kind to share your knowledge and time in such a helpful way to a “newer” ham. Thx.
Great informative video! The output of the NanoVNA is square wave so cleaning up that signal is even more difficult. Very impressive.
Thank you RMD for your interesting comment!
Hi, I recently became a member of your channel, the information you provide is very good and useful. Thanks
Greetings from GREECE
SV1SVO
73 👍
I'm so glad you found the video useful! Thank you for subscribing and 73's to you also!
Thanks for an interesting and informative video. This has been useful to me.
Glad to hear that Ace!
Awesome video RFB 👍
Thanks Ape!
Don’t radios already have band pass filters built into them already? Why would you need a secondary band pass filter?
That's a very good question Jason. Most commercially produced radios "should" meet the minimum emission standards of 47 CFR § 97.307. But.....after WWII, many hams purchased surplus military transmitters that were rich in harmonics and caused terrible TVI and harmonics of the fundamental frequency. There are many in use today. Therefore the need for an external LPF. Today, there are many home brew transmitters and linear amplifiers that may require a LPF.
See my video where I purchased a DIY linear amplifier kit from China. It definitely needed a LPF.
ua-cam.com/video/KTCMJNP9fUw/v-deo.html
73's
@@rfburns3472 That is one of the most helpful responses someone has given me on UA-cam. Thank you so much for replying. I appreciate this so much. Very kind to share your knowledge and time in such a helpful way to a “newer” ham. Thx.
@@KD9ZHF Your welcome Jason. Glad to have you aboard!