Scope Sunday 33

A quick Sunday update with two pieces of news:

Bad news: Last Sunday was the July MIT Swapfest. It was pretty disappointing. I left after an hour (which is unheard of for me). I didn't see any interesting test equipment and took no pictures. The summer doldrums are one thing, but it seemed worse than that... The consensus among the sellers and buyers that I talked to was that the flea market is suffering from all the new construction in the area. There used to lots of parking in the area (there were hundreds of spots in the lot on the corner of Main and Portland, and at the Analog Devices plant on Osborn), but now there is virtually none. The lack of close parking is hurting buyer attendance, which discourages the sellers. It's a vicious cycle.

Good news: As I mentioned last September, there is "A Museum of Vintage Tektronix Equipment", vintageTEK.org, near Portland, Oregon. I have finally made plans to visit this coming weekend (July 27th). Watch this space for my upcoming trip report!

I also plan to hit some surplus shops and a bookstore. Here's the list that I have:

• Cascade Surplus Electronics, Portland (website says "shutting down")
• R5-D3 Electronic Surplus, Milwaukie
• Surplus Gizmos, Hillsboro
• Powell's Books, which no longer has a dedicated "Technical Books" storefront, but does still carry technical books in "Bldg. 2"

Are these still open? Are they still good? Are there others?

Scope Sunday 32

A colleague recently asked me for suggestions on getting a transistor curve tracer. This post repeats what I told him: There are three classic transistor curve tracers:

1. Tektronix 575, the vacuum-tube monster





2. Tektronix 576, also a monster, built out of transistors, but still enormous





3. Tektronix 577, the little "desktop" one

You occasionally see a 575 at flea markets (I have several; I bought my last one for $40). However, they are big and bulky, and if they need repair, you've got to find the right vacuum tubes (a replacement CRT is also hard to find). If you're cool with that, it's a great bargain.

I think the 576, despite its size, is the most desirable one. I've never seen one at a flea market. They still command $1000 or more. This one was Jim Williams' favorite; in his second book he wrote:

No analog lab is complete without one of these. The Tektronix 575 is an excellent choice. It is the same size as older Tektronix lab 'scopes and is indispensable for device characterization. The more modern 576 is fully solid state, and has extended capabilities and more features. A 576 is still reasonably expensive (>$1500.00). I winced when I finally bought one, but the pain fades quickly with use. A 575 is adequate; the 576 is the one you really want.

The 577 is the smallest one. I saw one at a flea market once. They go for around $500 (I think). They're pretty nice, although they don't have all the features of a 576.

Where to buy? If you want a 575, you might try the flea market, although you won't find one every month. Your best bet (if you're not in a hurry) is probably to watch Craigslist. Prices on eBay are just crazy.

Did I steer him right?

(Photographs stolen from Barrytech's "Tektronix Older Vintage Oscilloscopes" page.)