20 - Double Balanced Diode Ring Mixer 

Great tutorial on building the transformers. Takes the mystery away. Appreciated.

Great video. Thank you for your valued contribution to amateur radio.

These videos are so useful in learning construction techniques. Simple and clear. TU.

Some people hate winding coils and toroids, but I find it quite therapeutic, after a stressful days work.

Thanks for your video on the diode ring mixer. I was worried I'd get the phasing wrong, but you explained it so well. I've become obsessed with the idea of building an upconverter for my cheap sdr dongle. It doesn't have to be the best upconverter. I hope to keep it as simple as I can. If I can receive some of the shortwave band, I will have succeeded. While I've built many small projects over the years, I haven't used my soldering iron for years now. I agree with what you said about building the mixer rather than buying something. Because you can, and you learn along the way. When I first looked at schematics of diode ring mixers, it looked quite intimidating. With video's like yours, I think I can do it. I hope to build my upconverter completely from parts from my junkbox.

Great Video! Ham radio really needs more people like you. I have always said that it`s ok to go and buy something to save time ONLY, if you know how it works and are very familiar with it. (There is little to learn in this case.) Otherwise you should definitely build! There are a couple of points worth mentioning about this build. 1 The three wires should really be the same diameter, otherwise they will create different impedances. 2 When you measure the impedance of the transformer, you should NOT aim for 50 ohms, rather you should aim for an impedance that is many times higher than your intended working impedance at the lowest frequency of interest. eg. Assume 50 ohm, assume this is a first converter, assume lowest rx freq is 1800khz, a good balun would be 6 x higher impedance, so we get around 50 microhenrys, 560 ohms at 1800khz. (You might need to use a softer grade of ferrite or thinner wire.) 3 The actual working impedance is set by the impedance of the terminations of the RF and IF ports, hence the importance of say a 3db pad at either end. The impedance of the LO port is not usually controlled and generally will see a high swr. I don`t usually find the need for a diplexer to dump the harmonics, I follow the mixer with a band pass filter. Complements from Chris, UK (1977 AM Die-hard).

Thanks for this Nick, the way you mix theory and practice really helps my and I'm sure others' learning curve. Don't know about overdressed, certainly the smartest RU-vid presenter this year so far! 🤣 👍

Nice ..waiting for test video..73

Looking forward to tests.

Nice work as always Nick! I've always been of the opinion that the diode ring is a pretty thing.

I was all set to buy 25 of the 1N5711Schottky diodes when I mentioned to a friend that I was going to build a couple of your DBM's and go through the tedious job of characterizing all of them, not really a bad job, but somewhat slow for me. He got up, left the room, and came back with a bag of 150 to 200 FH1100 surplus commercial Schottky full-wave bridge diode arrays already wired together into compact vertical assemblies, so I'm sure they are already matched, but I'll take one apart and verify that. Long story short, he gave me the whole lot of them, along with 5,000 individual FH1100 diodes from that batch of surplus. It pays to have friends who scrounge surplus parts. I don't know if the FH1100 is better, comparable, or worse than the 1N5711, but they were sure the right price. Now I won't have to get, match, and assemble the diode bridges to build mixers for my projects for quite some time. Next, on to the toroid transformers... :)

Great job Nick - the Vienna Wireless Maker Group is about to begin a direct conversion receiver project and I'm encouraging all to build their mixers for the project. You have nicely collected all the great references, Pete, Alan, and Charlie - how can we go wrong? 73 from Virginia - Dean, KK4DAS

The trifilar wire, 'actually looks quite cool', okay Nick, we think so, but would my daughter? Not so sure😂

Awesome video! I just built a dbm but didn't match the diodes just to see what would happen. It works. kinda. :D Now I have to sit down and do the hard work of matching all of the ones Ive got! BTW "build me diode ring" is an awesome name for a #1 hit single! Great... now I have to write it, don't I?

Hi Nick, thank you for your reply on another video. You mentioned that you measured 43-ohms. My understanding, is that to achieve 50-ohms on the twisted pairs, that they should be wound with a pitch of 5-7 turns-per-inch. In looking at yours, they seemed a bit higher; maybe this contributed to the lower impedance? Anyway, nice construction work and description! 73… 😊

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Que ocurriria,si invierto las señales de entrada,e inyecto la señal del oscilador local,en el extremo donde esta el puerto de ((FI))??,que cambio puede haber en el funcionamiento, y perfomance??.Gracias amigo!!

Can you give me advices how to solder those components i have no clue and i have this project, the copper is the ground? How to do it without soldering pads? Does island cutter work?

Have a look at sprat 144 page 4/5 a design that uses BAS40-04 which is a pair of diodes in a small smt package as they are on the same subwstrate they will be matched. I think your wire is a bit thick for that core, 32swg would be better - the old vero wire prototyping wire would do nicely. Seems to be a bit rare now, but it did come in several colours. Andy

Question is T2 wound in the same direction as T1?

how many wounds or turns did you do in T1 and T2?

how did you determine 50Mhz as the max frequency?

How do I make a 0 gHz to 6 gHz mixer? I would like to build an ultra wide band transceiver.