MiniCircuits kits (2023 Update)

On a sunny day (Thu, 10 Nov 2022 09:49:15 -0800) it happened John Larkin <jlarkin@highland_atwork_technology.com> wrote in snipped-for-privacy@4ax.com:

It will make you very depending on their products.

MiniCircuits has been pretty good. Parts lifetime is a chronic problem in our business.

Yeah, you can still get the SBL-1 mixer, which I used in my first engineering job (1981-3).

And I agree that that pHEMT kit is super useful--I have one taped to the inside of my binder of fast transistors that lives on the shelf above my bench.

Nobody else (with the possible exception of Skyworks) still makes 6-GHz discrete pHEMTs, so the lock-in problem is pretty well moot. ;)

Cheers

Phil Hobbs

I love the SAV parts. Enhancement mode makes it easy to drive the gate from CMOS logic and then the drain switches stuff fast.

SAV-541 has Rds-on about 2 ohms. Why don't RF data sheets specify Rds-on?

Am 11.11.22 um 00:10 schrieb Phil Hobbs:

At least interesting: CE3512K2 by CEL; There is a 20 GHz version, too: CE3520K3 AT least they survive Idss.

If you need a little bit of negative gate voltage: Vishay VOM1271 and friends. No switcher noise.

Cheers, Gerhard

They don't know what ON and OFF mean. ;)

Cheers

Phil Hobbs

I have some of the 20-GHz parts, but haven't ever tried using them.

Cheers

Phil Hobbs

On a sunny day (Thu, 10 Nov 2022 13:07:11 -0800) it happened John Larkin <jlarkin@highland_atwork_technology.com> wrote in snipped-for-privacy@4ax.com:

Sure, but in my time we needed at least one second source for components we used. Mil would require that too over there?

An other thing that makes me wonder is the 50 Ohm issue At 1 GHz the wavelength is 30 cm If this was to sort of 'appeal to people to just chaining blocks together on a PCB with 50 Ohm transmission lines in between' then its silly.

In many of not most cases the parts can be more efficiently used with a different coupling impedance when a few mm apart even more so. Then it is RC times or LC[R] coupling (thinking RF now) that can be optimized. Done it many times . So who is it for, the RF clueless? LOL and you cannot even spice <do you have a spice model for these?> it! Seems all a bit .well not snake oil, those thing will work, but lemme say "strange target audience..."

No, it's for broadband amplifiers, (near) constant gain over GHz bandwidths.

Jeroen Belleman

On a sunny day (Fri, 11 Nov 2022 08:24:45 +0100) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <tkktbt$v5s$ snipped-for-privacy@gioia.aioe.org>:

Ever looked at the Y amplifiers of a modern GHz scope?

Not in detail, no. How do they do it?

Jeroen Belleman

On a sunny day (Fri, 11 Nov 2022 09:14:16 +0100) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <tkl08o$394$ snipped-for-privacy@gioia.aioe.org>:

Google tektronics circuit diagram

Lots of vintage circuits, which I *did* see before. Interesting, but not modern. Can you be a more specific?

Jeroen Belleman

On a sunny day (Fri, 11 Nov 2022 10:56:19 +0100) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <tkl683$k9q$ snipped-for-privacy@gioia.aioe.org>:

In those vintage circuits did you see any minicircuits like stuff? Max frequency was?

We were talking about mini Circuits RF gain blocks, easy to throw together. There's nothing silly about that. You brought up scope Y amplifiers, which have a completely different purpose and a completely different architecture. Now what was your point, exactly?

Jeroen Belleman

In the days of discrete design, there were multiple sources for pretty-similar 2N2219. There are no multiple sources for FPGAs and uPs and complex parts like that.

MiniCircuits is adamant that they will NEVER have Spice models for their parts. Since we work in time domain, we measure things that are not specified and hack our own models. Not complete models, but good enough for what we are doing.

I build instant-start Colpitts oscillators with the SAV551 phemt. They behaved very badly until I put a 499 ohm (not a typo) resistor in series with the gate. Guess we didn't model the wire bonds right.

Lunatic fringe electronics is fun.

MiniCircuits has fabulous MMIC amplifiers. GHz bw, simple, and would be a bargain at 10 times their price. And when they say "unconditionally stable" they mean it.

But the data sheets are full of silly things like s-parameters, and are vague about biasing.

On a sunny day (Fri, 11 Nov 2022 15:14:56 +0100) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <tkllcv$1juo$ snipped-for-privacy@gioia.aioe.org>:

Well twist all the way you want, you said: it's for broadband amplifiers, (near) constant gain over GHz bandwidths

Bit decent analog (call it 'vintage if you like) scope vertical amps do that WITHOUT silly secret blocks and with discrete components, most of those still available today.

I remember in the early seventies 'Elektuur' (think it is 'Elector' now) published the V amp for a 300 MHz Tek analog scope, it used BFY90 IIRC, I immediately went to work and build it, to drive my 300 MHz East German CRT,,, Much later when I worked for Tek I met the guy who gave Elektuur that circuit, he got quite a bit of head wind he told me because he published that circuit... BFY90 is still available (ebay)... 42 years later,,, There are many faster transistors now, same circuits should work, Have a good look at those old circuits!

Vertical amps now just feed an ADC. They don't need to drive a delay line and swing a hundred volts into deflection plates.

The last-gen Tek analog scopes were full of full-custom ICs in the vertical path. Both of Jim Williams' analog circuit design books have chapters about Tek scope amps.

I can lift my 500 MHz 4-channel color storage scope with one hand, and it barely runs warm. It does pretrigger display, signal averaging, measurements, FFTs, and I haven't replaced a tube yet.

Opamps and mosfets would be great for a CRT-based scope, but it would need an expensive distributed-deflection CRT to get the bandwidth of a cheap modern digital scope.

I love my 11802 sampler, but it's a digital scope with a CRT display, in fact magnetic deflection vertical raster scan.