开云体育

Would you please take multiple pictures out of the box so we can see the winding technique and how things are connected! It appears the secondary is center tapped. Please - out of the bos! Dave - W

Gary - very interesting! I would urge you to also post notice of your work on QRZ.com. There is active discussion of EFHW 49:1 technology in the "Antennas, Feedlines, Towers & Rotors" forum, with

You don't need a cal without the cable. Essentially, calibrating at the end of your test cable makes the cable "part of the instrument"

Ya, I have not looked it over real well, but it does give signal strength, S/N and IF-AGC %. ?Also the station frequency, and physical channel. The signal strength indicator is under, Product

Yep, I have had my Sony TV for 10 years and never saw the signal meter, I finally found it a week ago. Yesterday, I went to pull it up and had do go through the whole search again. it's not clearly

Hi Bryon, If you look further down to the "core size" experiments you will see that I did indeed test 2 FT240-43 cores with 2:14 turns. It is a reasonable choice, and with the large volume and surface

I have made a 50 to 75 ohm adapter for the connectors I need. I used the insulation and center conductor inside the F connector and butted the SMA? panel mount connector center pin and RG6 center pin

I probably wasn't clear, my TV has a good signal strength meter in it, I just wanted more fun trying to measure the impedance.

Ok, but I can't do both, the cal is which ever one I do last. Yes, there are memories, but then which cal means what? Mikek > > > > > -- This email has been checked for viruses by Avast antivirus

OK, this looks easy, I already put a 75 ohm termination on the coax, but I''l go back and calibrate with the 75ohm at the NanoVna output.

Precision not necessary, just trying to get my feet wet again. I'm comparing a couple of DIY TV antennas and thought while I was comparing signal strength, I'd look at impedance. -- This email has

Best answer!! Roger

Most TV's this "SIGNAL STRENGTH" is not a true signal strength but a signal to noise measurement. You could have a very weak signal but if it's channel is free and clear of any noise, co-channel

Remember the 1/4-wavelength 'solution' is a narrowband match. Sweeping from 180 through 610 MHz will require a number of 1/4-wavelength lines. Not a good solution for swept measurements. The SWR of a

Well I suppose you are looking to have fun with your NanoVNA --- but there is likely a much easier way to directly accomplish your goal. Many modern TV's (with digital tuners) have a diagnostic mode

This is what I do to measure 75 ohm loads - build or buy a 50 to 75 ohm minimum losspad. Install on S11 port. My 75 ohm end has a F connector. - fabricate a 75 ohm O S L kit. Calibrate using this kit.

Very nice writeup Gary! I may have missed it, but curious about how using two FT240 cores stacked will behave vs total turns. I built one of these transformers with two FT240 type 43 cores stacked,

Mikek: Unless I am misunderstanding your test intentions, a network analyzer will not give you any signal strength indication. You would need a measuring receiver or a spectrum analyzer to check out

Here is a link that has all you need to know for 75 ohm NanoVna testing. https://volpefirm.com/nanovna-calibration-to-75-ohm-for-catv/ Larry, K4LED

The more windings, the more critical the parasitice become, and the less flat the transfer. Note that you can also buy ferrites that allow for half a winding, or even a quarter. Ferriet Varkensneus