Hardline RF Power Divider v2.0

[@suncrafterspielt9479]

I really love how you are more aktive during corona. Thank you :D

[@rexjuelz7229]

A tip : you can watch movies on flixzone. Me and my gf have been using them for watching all kinds of movies recently.

[@torincarl7934]

@Rex Juelz Yea, been using flixzone for months myself =)

[@RobertResearchRadios]

On an overlay to the screen at (8:23) you show -20dB return loss equal to 2:1 VSWR, -10dB return loss (power units as usual) is VSWR = 2:1. -20dB in power units is VSWR = 1.222:1. If it were in voltage units on your spec-A which it does not appear to be, then the -20dBV is -10dB (power units) which would have been VSWR = 2:1 and a standard return loss values of -10dB.

[@Dabodizafa]

I have no clue what you're doing. I sub'd the channel for the basic solder and such, but I am powering through in effort to influence the algorithm. I enjoy the way you teach and/or narrate.

[@smartups1]

Why you not make more videos. I want to see you 🥺 your explanation awesome.

[@joostjepek]

If in open air and there are no spacers used, the velocity factor for air in a coaxial line is 1.001. So one takes 1.0 as the factor in: VF= 1/sqr Er (Er being the Dialectric Constant of a material, air in theis case). therefore VF becomes appr 1.0

[@andyourbirdcansingfrankrya1280]

I'm gonna subscribe just because of the shirt! RIP Lux Interior!

[@AmRadPodcast]

That is a good enough reason in my opinion.

[@SkyGravity1]

Now that you've checked with your spectrum analyzer, did you test again with the nanoVNA again to check if it still had a bad/offset result ?

[@digitalradiohacker]

This. I don't mind using cheap junk PROVIDED I have some way to verify the results. I have an older mechanical movement SWR meter, and I treat it as my standard. It produces the same results year after year when I repeat the same test, boosting my confidence that the instrument hasn't changed. I can't get verifiable numbers, but I can get comparative numbers with a high level of confidence. Spectrum analyser VS VNA!

[@AmRadPodcast]

SkyGravity1 haven’t yet, but I’ll make a new video once the EME station is up and running

[@squelchstuff]

It would be very scienticious to see the nanoVNA results compared with your previous endeavour. I'm intrigued to see which of the variables you have changed made the most difference. Would you be prepared to share some empirical results? I'm sure we could all learn something from that. Great stuff, and I've only just discovered your channel. "Warts and all" making is the most satisfying to share in my opinion. Keep up the good work.

[@РадиоОдинЭфЭм]

hello, possible to get video about how to make dipole for fm radio transmitter, and power splitter divider. thank u

[@George-gz5zm]

I'm ok thanks. How are you Derek? I like these RF videos. If you are making things and can shoot a vid then why not eh? I recon the more detail you can put (time permitting) the better.

[@julesinspaaace]

#question What was the process like to get your ham licence?

[@AmRadPodcast]

GreenCoat a bit of studying.. there are a wealth of resources online, hamexam or hamstudy comes to mind. When/if you’re ready, the ARRL has a website that lists locations and dates for VE (volunteer examiner) testing sessions near you... though I don’t know how they’ll handle such a thing now with social distancing. Normally, you go with $15, a pencil, calculator, sign in and take the test and they grade it right there. If you pass you get your certificate of successful completion and it’s filed w the FCC (in the states). Keep checking the fcc.gov site and once it shows your callsign you can start transmitting.. it’s a bit different for people upgrading

[@jafinch78]

Neat to see the update! Awesome, was wondering about using copper as I made a comment regarding on the Hackaday article somewhat related. Just received the noise source in the mail also yesterday, or two days back, I think. Figured I better invest in the noise source for the ~450MHz yagi antenna instructable since I noted as a cost effective way to test with a RTL-SDR and a tap or directional coupler with Spektrum. Wondering what all else can be done to improve performance? Thanks for sharing!

[@AmRadPodcast]

jafinch78 there are ways to tune it, like adding dielectrics to electrically “shorten” it or using a nylon screw to adjust the center conductor spacing. I didn’t even know hackaday did a write up. Thanks for sharing!

[@jafinch78]

@@AmRadPodcast Just in case: hackaday.com/2020/03/31/shoot-the-moon-with-this-homebrew-hardline-rf-divider/

[@suncrafterspielt9479]

#Question do you have any knowledge in Analog IC design?

[@briandr]

Any plans to adapt the camera point/tilt device from one of the previous vid’s for the antenna array or just an off the shelf azimuth rotor?

[@AmRadPodcast]

Brian Russo a lot more coming on the topic... :)

[@stevencarr6282]

You are way over my head but I do have my Armature Radio Lic and I like that you're doing radio stuff too. Also, I'm a new viewer to your channel.

[@suncrafterspielt9479]

#Question I found your youtube channel due to the detailed audio amp videos (17,18,19). Is there any chance you will return to this field?

[@ramjet4025]

The Velocity factor from the famous Fig 16 graph shows about a 1/2 wavelength to diameter of the conductor ration of about 22, On the graph, it comes out at .945 , slightly less than your figure. If you had cranked up the reflected needle and then tuned across the ban, you should have been able to see where lowest reflected occurred. It would have been good to see the NanoVNA-F or F2 connected and to see what it shows on the smith chart as well as reflected power. My lastest practical experiment with 15.875 mm copper pipe showed a VF closer to 1.0 rather than the theory of a lower number. Not quite sure why but every antenna with that 15.875mm OD seems to be a VF of 1 instead of what the graph shows down to .94 etc.

[@davidpowell5603]

This video was quite interesting, thanks. But the idea of a velocity factor of metal sounds very suspicious to me, a wave in an air-core TEM waveguide should travel at the speed of light. I can understand that there could be length corrections due to something else, such as parasitics. What source did you use for that? Also, do you get better results measuring frequency response with the noise source if you do video averaging before taking the reference measurement.

[@sleeve8651]

Perhaps I missed it, but I don't think you mentioned changing the material used for the center conductor ? Just a curiosity, but how significant, if at all, was the conductivity difference, between Brass and then Copper ? I have read that Brass is something like only 28 % as conductive as Copper ! Something I don't think you considered, this being equivalent to being the dielectric constant ? And how vital to the end equation might that have played ? Interesting project, true to Life experience ! I must say, I went Head hunting for your 2.0 version, after being led down the rabbit hole, so to speak, from your beginning video ! Lol ! Thanks for following thru ! '73 !

[@George-gz5zm]

Question: whats your job role for TI?

[@mattmoreira210]

Q: what's your opinion on self-oscillating DC/DC converters? Are they any good?!

[@williammarkley1037]

It’s looking good though

[@jbx907]

did you test this out on the nanovna and get bad result that you did it in your spectrum analuzer? is hte nanovna bad? why didnt you even try on this video?

[@williammarkley1037]

I dont think that wires has to be there as long as you touch the tube with center of pl 239,s or whatever your useing and have it soldered that’s all that matters

[@williammarkley1037]

As long as your soldered inner conductor to tube you should be good

[@Marr_SC]

Thank you!

[@leedlbo9949]

Great video but a ham needs to build there own to insure we know what were doing. Thanks again.

[@williammarkley1037]

But you can make the that way too

[@paulziminskin2ghr282]

A weller soldering gun works well for this ..

[@davidpowell5603]

This video was quite interesting, thanks. But the idea of a velocity factor of metal sounds very suspicious to me, a wave in an air-core TEM waveguide should travel at the speed of light. I can understand that there could be length corrections due to something else, such as parasitics. What source did you use for that? Also, do you get better results measuring frequency response with the noise source if you do video averaging before taking the reference measurement.