Challenge Thread: The fastest breadboard oscillator on the mudball

[joeqsmith]

The mixer would be the choice if the goal is to shatter the record.  If you have easy access to the other SA, it's more than enough to take the lead.

We are fortunate to have distributors here like DigiKey who will sell small numbers of parts and carry a wide selection.   

Hopefully your parts will show up soon enough that you don't loose interest.   Personally I am glad to see you putting your equipment to use.  Here, it's very easy to get your hands on older equipment, but it's rare to see anyone actually use it. 

I gave away my old 22GHz HP SA from lack of use.   That 20GHz mixer and DRO was about the best I could come up with without buying a new SA.   My old counter isn't very sensitive and getting a strong enough signal to drive it was a problem.  You're in a much better position.     

26.5GHz or bust!   

[avlijas.sladjan]

Today I found some transistors (for +20GHz) and ordered them. But I will need to wait, maybe more than 20 days for shipping.

To be honest, I was very happy to have instruments to play it. It was very hard to find and buy here, but I saved every money to buy these instruments. And now after regular work I have a small lab for playing.

[RJSV]

I like this! Kind of mad scramble, for what? A, la, the classic movie, "It's a Mad mad, mad mad World", you gotta dial-in some GREED, there: How about one Philly Steak, per day, free. Now, I'm in!
  I'm thinking Opto-Microwave, seriously; an optical gate or modulator, actuated by microwave, and that responds / reacts to light. Then, your OSC will flash a light, very fast, 'ruining' the gate coherence. Even tho, that gate was really supposed to be microwave actuated. Wrong way, wrong way, but possible to OSC way fast. (?)

[SilverSolder]

I like this! Kind of mad scramble, for what? A, la, the classic movie, "It's a Mad mad, mad mad World", you gotta dial-in some GREED, there: How about one Philly Steak, per day, free. Now, I'm in!
  I'm thinking Opto-Microwave, seriously; an optical gate or modulator, actuated by microwave, and that responds / reacts to light. Then, your OSC will flash a light, very fast, 'ruining' the gate coherence. Even tho, that gate was really supposed to be microwave actuated. Wrong way, wrong way, but possible to OSC way fast. (?)

Make it run on a breadboard and show us!

[joeqsmith]

Today I found some transistors (for +20GHz) and ordered them. But I will need to wait, maybe more than 20 days for shipping.

To be honest, I was very happy to have instruments to play it. It was very hard to find and buy here, but I saved every money to buy these instruments. And now after regular work I have a small lab for playing.

Maybe while you wait, you can bring home the faster SA. 

After playing around with different parts, it seemed as far as making them oscillate and what frequencies could be achieved, I could push them far past the data sheets.  I think the part I used at 6GHz, was only characterized to a couple of GHz.   With it just needing to oscillate, I took the just try it and see what happens approach.  Most of the transistors I tried cost under 50 cents so I wasn't out anything if they get damaged.   Shipping was more than the parts so it made sense to buy a few different ones. 

Good luck.  I'll polish up my crown for you! 

[RJSV]

A single component, I'm loosely suggesting, would properly be interfaced by a 'micro-wave' input (port) but the test would be to ignore that, and start using a pulse of light. It's in the realm of parasitic response, utilized (instead of avoiding the light being there at input region).
  But I gotta read the rules better, as I meant a MEMs device, having a visible light port in and out, plus a micro-wave actuated control input. The control causes disrupted or 'ruined' coherence, eliminating light output emission. Suggestion is try go outside usual device interface, but I guess a try could be made, still within (this) contest.
  A public contest can be where some really smart Humans will shine their best!
  I am wondering, is there a region where a waveguide / active MEMs and RF transistor start losing 'trace' wiring and become wholly independent (200 GHz?).
And, of course that's called a 'Radio'.  Duhooh

[ogden]

I gotta read the rules better, as I meant a MEMs device, having a visible light port in and out, plus a micro-wave actuated control input.

Don't worry, rules are flexible here. As long as breadboard is part of DC suppy circuit for oscillator - your entry most likely will be accepted. Could you elaborate more about your MEMS device with visible light input and output plus a micro-wave actuated control input?

[RJSV]

Ogden, the idea bears similarity with the 'garden' light analogy, pointing an LED light, at the photo-panel. So since the little solar cell drives the switch, any increased light (i.e. from unusual pointing set-up) will cause lamp shut-off.
  Then, such LED shut-off allowing the garden light to come back 'on' thus a circular situation (perpetuates.)
  This is the basis for further speculation, with additional thoughts regarding hysterisis, and time delays, often extending timing range / stabilizing function.
  So, you have bought a few surplus micro-optical 'modulators' and the two ports for optical / infrared laser beams are in / out, looking reasonable. But then, a short instruction / spec. sheet lists: "Novel control port uses 110 nM pulsed maser"...
   What did that mean ?
  Well, apparently, without that micro-wave arriving, the modulator distorts, and output goes mostly internal reflecting uselessly.
  Key to all this, apparently, MFG. Sez the unit must be light shielded, as light will also 'mess up' your coherence, (whatever that is).
  So that is your key: Just take a bit of that infra-red, feed it back around to your 'RotoPhotator' or whatever it's called; The light-pulse, disrupts the means that sent it.
  It's all the simple paradox of any OSC, really.
  Trick and skill really gets going, when Tech person has a handle on timing dynamics, and hysterisis.
  Kept wondering, why the data sheet note insistent on 'shield any nearby source of visible light'

[RJSV]

Ok, starting to hit my stride, (or stagger), but here is continued direction, of last post:
  I would, first, create a 'Contest Goal', that being first one to reach 200... That's 200 GHz.
  Now, addressing the hypothetical 'optical' switch / modulator, I believe this was, still, a switched signal, at say, 2 Thz (terra-herz), being switched at 200 GHz. That means you get a few cycles (about 5 cycles) of the faster signal, per each, that's typical modulated, but maybe needs (lots) of wiggle room, to call it a Sine or nearly so...
  Thanks to T3s14co1l (Tim) for the discussion re: optical signal speeds / voltages / probes reality, a contortion act to comprehend those issues...
How about X-rays, next.  There, maybe have to keep particle physics, not wave.
I make any sense, here ? Some

[ogden]

Ok, starting to hit my stride, (or stagger), but here is continued direction, of last post:
  I would, first, create a 'Contest Goal', that being first one to reach 200... That's 200 GHz.
  Now, addressing the hypothetical 'optical' switch / modulator, I believe this was, still, a switched signal, at say, 2 Thz (terra-herz), being switched at 200 GHz.

Why don't you take that 200GHz oscillator, throw your 2THz source with modulator in the bin and win 200GHz contest?

[RJSV]

Attached photo features a MEMs block, that sits above bread-board, uses 10 VDC supply, but I see my faulty plan: That laser, for switching, was to provide the 'substance' being switched, kind of was supposed to be more of a 'DC' potential, for more common OSC.
That is, a comparator or OP amp switches DC, to create the waveforms, so right there, FAIL... on my effort.
  But, idea there, is a MEMs device, requiring the side control port be shielded, from visable light. Which I immediately violate. See the run of optical fiber, to bring some (light) into the CTL port, in disregard of Spec. So correct, you have an oscillator, but that feedback fiber created that. However, not done there, as the 'ruby' laser violates the contest, being an assumed 300 Terra-hz.
  Keeps me thinking.

I searched on 'Optical Modulator has micro-wave control's and got some good results. Plz see Keyang Photonics.
Research gate had some papers like; 'RF signal port, to phase-modulate Optical 633 nM output'.
A good article, Q.A.Duong, has 2018, called 'Suppression of residual A.M. in microwave controllable field-ready module.'

  So a little un-focussed, but the OSC basics still apply, that is to use a bit of output, for feedback. I'm using feedback dynamics, but 'negative resistance's, got to be there,... just not explained (here).
  Now waiting, while study Tim's comments here.

[ogden]

I see problem in your plan: you connect optical output to microwave input.

[RJSV]

Yes, and that is why I try make a schematic, I can see my own goofs.  Right now, I've an interest, in making a non-linear spectrum scale:

  For EM Spectrum base lines,
  10 T
    9 T
    8 T
    7 T
...
    1 T
      900 GHz
      800 GHz
...
      100 GHz
         90
         80
...
         10 GHz
            9 GHz
 
  Looks boring, but I need self-educate. The diagram should include 10 khz, a low low Rf
More edu, less speculation.

[ogden]

More edu, less speculation.

Right. Best way to educate yourself - take breadboard, some transistor and make oscillator of any frequency you can reach.

[AnalogueLove1867]

Hi, a bit late to the party!

Can't believe nobody here hasn't just made a cm or mm long spark-gap bipolar antenna as an oscillator.
Then the capacitance of the bread-board won't even matter.
Spark gaps can go well into the 1 to 100 Ghz microwave zone.
You could even put the miniature antenna into a piece of scap tubing as a wave guide and then measure the radio noise out the other end.
I don't have the equipment for measuring anything beyond 200Mhz so hopefully somebody here can do it instead haha.

ALSO

If you  put a breadboard on top of a sheet of aluminum foil that is directly connected
to the positive terminal of its own power supply an NPN based astable multivibrator will sometimes
 resonate at over 100 times its natural frequency.
Don't know why this happens, and once again hopefully somebody else can try this out with superior equipment.

[buta]

Also attached is a picture is showing the the final version of the tuning network.

zoom_10.JPG

The attached picture zoom_10.JPG shows the tuning network is a motorbike, is it correct?

[KE5FX]

Hi, a bit late to the party!

Can't believe nobody here hasn't just made a cm or mm long spark-gap bipolar antenna as an oscillator.
Then the capacitance of the bread-board won't even matter.
Spark gaps can go well into the 1 to 100 Ghz microwave zone.
You could even put the miniature antenna into a piece of scap tubing as a wave guide and then measure the radio noise out the other end.
I don't have the equipment for measuring anything beyond 200Mhz so hopefully somebody here can do it instead haha.

Extremely small spark gaps are kind of interesting. From that thread:

I tried cutting a slot in the top layer of a copper PCB strip using
a scalpel, the idea being to pinch it shut manually until it fires
somewhere near the bottom of the Paschen curve:

http://www.ke5fx.com/microgap/gap.jpg (closeup)
http://www.ke5fx.com/microgap/10x.jpg (test setup for HV edge)
http://www.ke5fx.com/microgap/50R.jpg (test setup for 50 ohms)

Driving it at -350V through a 100K resistor makes the gap fire somewhat
randomly at about 100 V/ns, limited by the probe and various strays.
The recovery time is also swamped by the scope probe RC:

http://www.ke5fx.com/microgap/mso_10x_probe_1us_div.png
http://www.ke5fx.com/microgap/mso_10x_probe_1ns_div.png

A 50-ohm series tap is faster, but likely still limited by strays:

http://www.ke5fx.com/microgap/mso_50R_1ns_div.png (MSO6054A, 500 MHz BW)
http://www.ke5fx.com/microgap/tds_50R_1ns.gif (TDS 694C, 3000 MHz BW)

I did see some edges closer to .35/3000 = 117 ps, but 164 ps was the
fastest one that I saved before the PCB strip finally broke.