RF bipolars RIP

It's a drop in the bucket among the things that are taking up valuable lab space, e.g. HP 8568 spectrum analyzer parts mules, a Tek 466 analogue storage scope that I kid myself that I'll fix one day, .... ;)

There are two Simpson VTVMs on the same shelf as the Avo 16.

Cheers

Phil Hobbs

The Onsemi 50A02MH is an SC70/SOT323 that is rated for 600 milliwatts dissipation. I'm a little skeptical.

IR started the trend to high power ratings with (often without) footnotes about insane lab cooling techniques, like immersion in boiling fluids.

Er, yes. Well you may remember that I have one of those awaiting a fix- up. They've recently become unaccountably popular this side of the pond and as a result I keep losing the ones I see on Ebay to other people who are continually willing to pay more, it seems. Sigh. I only hope the main toob is sound on mine. Everything else that may be faulty I can overcome, but not a main toob!

It doesn't resemble any AVO I've ever seen before I must say.

No, they just state 25C. How you get there is "just engineering".

Simmconn has an affordable LCD upgrade for the 85662 IF/Display unit. Much better than the tube in any condition plus about 10 pounds lighter.

Makes the 8566/68 into a more modern SA.

Regards

Tell me about it. I have four Tek 547s, one 545, and one 535, with about 50 plugins. And a gigantic HP185 sampler with plugins. A big Fluke differential voltmeter. A bunch of GR RF stuff. More misc stuff. I can't bear to just tip them into the dumpster and may never get around to restoring them.

Fortunately we're moving to a new facility with a huge crawl-space storage area. Or unfortunately.

I don't miss analog scopes or instruments with needles. But my Keithley electrometer is wonderful.

Somebody probably hired an industrial designer. Never hire an industrial designer.

One of my customers did that and wound up with an ICCD camera that looked like a cheap rice cooker. They eventually redesigned it to look more dignified.

The On part specifies "on a ceramic substrate" so they probably epoxied it to a block of cold BeO. I don't usually do that; I generally use PC boards.

IR did specify some parts in boiling freon or something. That's how you can get the legs of a TO220 to stand 100 amps.

And 1 kW package dissipation.

Thanks. I have a couple of pretty bright 85662As, and can get another one for the price of those upgrades if I need it. I'll probably branch out into 70000-series territory next, because they have tracking generators. Not till next year, probably.

Cheers

Phil Hobbs

Analogue meters are very useful for tweaking up stuff. For actual measurements they're a lot less useful.

Cheers

Phil Hobbs

What a pack of lies. Specs like that are fairly useless.

So you do know how to do it. What's the problem? ;-)

I was almost looking for the April 1st date.