开云体育

There's a pretty comprehensive document about Q-measurements by Andrew Gregory at NPL.

Back when the The Radio Board was running, an Ebay seller mkmak222 sold a Ring Down Q meter populated pcb that with a couple additions made a complete Q meter. I don't find it on his Ebay sales page

Try https://web.archive.org/web/20130124055831/http://www.ee.olemiss.edu/darko/rfqmeas2b.pdf -- Neil G4DBN https://youtube.com/MachiningandMicrowaves

Thank you. I see your paper mentioned somewhere, but no link was given. Do you have a copy of the paper Darko Kajfez “ Q Factor Measurements, Analog and Digital,” www.ee.olemiss.edu/

Back in the days of arc and spark there was a thing called a decrimeter.? This was a sort of wave meter used to measure the degree of "damping" of a transmitted signal.? ?Really it's bandwidth.

To get 1 mOhm, place five 5 mOhms resistors in parallel (Mouser <https://www.mouser.com/ProductDetail/Bourns/CFN0805-FZ-R005ELF?qs=sGAEpiMZZMvdGkrng054tx4c7YuULGmGRxUjPa6hUc0gwh5pq0zJIw%3D%3D>)

Hi Neil: I have a flyback tester that works by counting the ringing. https://prc68.com/I/ESRmicro.shtml#FBTest Shorted turns kill the Q and so this works quite well. A modified version would simply

Nice! Never heard of it being called that, but it fits.? I guess a bit of code would allow the frequency and the exponential value to be extracted and also make corrections based on calibrations with

This Swiss guy has had an article about the ring down test for Q for a number of years. https://www.giangrandi.ch/electronics/ringdownq/ringdownq.shtml 73, Steve AA7U

Possibly a silly question, but have any Q meters been built that use the other approach of watching the relaxation decay starting with a forced excitation and calculating the dissipation factor??

Cheers So are you saying that the scale on the meter is not linear, so each one was

Someone suggested getting the handbook for the Boonton 260 Q-Meter. Since Boonton did this already perhaps you can get some inspiration from it. Of course its tubes but nonetheless one can use the

Reading that, I do get the feeling that some of the improvements made between the 160-A and 260-A, would not be necessary if an instrument was made with a microprocessor doing some number?crunching.

Hi: The design using a thermocouple was done in ancient history when vacuum tubes all had 4 pins.? They could easily be burned out and were replaced on the next generation Q-meters. The TS-617 is a

Hello everyone, You may want to have a look at this article that I wrote in QEX, ten years ago: Q Factor Measurements on L-C Circuits. http://ve2azx.net/technical/Q-FactorMeas_on_LC_Circuits.pdf

Here is the Q page of W7ZOI with his Q meter method and lots of theory. ??????????????????? Mikek -- This email has been checked for viruses by Avast antivirus software.

This site has a novel way to Counter inductance of the 0.02Ω output resistor, but he still only gets to 40MHz, But maybe you could have two transformers, one for above 40MHz and one for below. At

I also have Boonton 260A. I had series of 5 coils that had Qs over 1000. I wanted to see about coil spacing, On these 6" coils I found 10 to 12 turns per inch got the highest Q using 660/43 Litz wire.

OOps again - I meant 74HC4059 (/10000 capable), not 74HC40102 (/100 capable). Also note that it is easy to force the counters to a known starting state for each measurement with the Kb mode input and

Like most engineering decisions, it depends.? In this case my first though would be negative feedback around an amp.? You can get /almost/ arbitrary reduction of output impedance as a tradeoff for