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I second that recommendation, old style antenna analysers seem to be very expensive for what they are, and will only provide you with limited data. I have a LiteVNA 64, which was an upgrade from an

Absolutely, it's no good unless you can notch out the fundamental tones. My own notches provide about 40dB rejection, which is just about good enough. Regards, Martin

Why not a NanoVNA of the newer generations? regards Fred

Definitely, but without? notch filters for the original 2-tone signals the tiny-SA will become overloaded. It's own IP3 is about +17 dBm. regards Fred

Hi all not really a loopy question, but after a good cheap antenna analyser for future projects over winter. Have a mfj 259b but after something alittle better.. best regards Simon g0zen

Incidentally, I've just been comparing IMD measurements using a Rigol DSA815 and a TinySA Ultra. I've been using my own test source and notch filters, and providing the notched test tones are kept to

Nice loop, but could you state the loop inductance ? Regards, Martin

Are you selling this as a kit or fully made? Or do you have the plans available?

Very nice loop. 73, Steve

I would like to introduce you to my latest loop. Ideally, a loop should be round, but because the production costs for a round loop with a diameter of 1m are very expensive, I decided to make the loop

The noise figure of a transistor from the data sheet refers to a specific test circuit under well defined test conditions. The noise figure of a transistor in a particular amplifier circuit depends on

I was looking for something else and stumbled across an article on designing with new FETS. https://www.interfet.com/jfet-datasheets/audio-electronics-jfet-new-frontier1-2.pdf I know from

Hi Dan, I downloaded your simulation of a one meter diameter loop and was able to run it without problems.? Nicely done!? Your 36 segment structure much more closely models a circular loop than my

I would expect that the noise figure of a transistor would be the same no matter what amplifier you plop it into - but with the provision that it depends on its biasing conditions (e.g., current).?

Discrete RF-Transistors ar becoming more and more extinct. For example BFQ590 BFP196 NTE278 (2N5109 replacement) PZT2222A PXT2222A are currently actively produced and widely available.. The

Thanks Everett and Simon, and to Steve I have found his comprehensive list, I should have searched better. However, are these low measured NFs just for the very low input Z loop preamps like the LZ1AQ

Yes, I swept each of the seven transistors I tried. This is typical, and the gain for the last one, 2N4401, unmarked brand: 0.2 MHz +16.1 dB gain 0.5 MHz +16.3 dB gain 1 MHz +16.3 dB gain 5 MHz

Steve, did you measure the frequency response? The properties of the output transformer and the RFC in the base biasing circuit will of course have influence on the frequency response but I am just

This circuit does not make a good preamp--it overloads too easily. As the info in the Files states, it's for making a test IMD preamp that can be duplicated with a characterized OIP3. Recent posts

Hi John Do a search on here..been covered..alot. I think it was Steve, whom did a very excellent and comprehensive list of suitable transistors exactly as you are asking. The 5551 is very good