Tektronix DSA602A Digitizing Signal Analyzer Part 1
I recently had the opportunity to purchase one of these units, and I am thoroughly enjoying the process of checking its operation and getting to know how to use it. This unit is a laboratory grade, very accurate digitizing oscilloscope from about 1990. From the Tek Wiki entry:
3 amplifier bays, up to 12 channels (using 11A34 plug-ins)
8 bits; averaging of N acquisitions increases by log2(N) up to 14 bits
DSA601, max 1 GS/s; DSA602, max 2 GS/s (one channel, left plugin)
512 to 32768 samples
50 ps/Div to 100 s/Div
7.2 bit up to 10 MHz, 6.3 bit @ 250 MHz, 5.7 bit @ 500 MHz, 4.5 bit @ 1 GHz
magnetic deflection color computer monitor, 10″ diagonal (130 mm × 168 mm), 552×704 pixels, 22×11 infrared touch-screen grid
90-132 V or 180-250 V, 48-72 Hz, 465 W (DSA601A) / 585 W (DSA602A)
Automated signal measurements (rise, fall, period, frequency, width, delay, phase, duty … Read More »
Tektronix Scope-Mobile Cart Repair Part 1
I was lucky enough to obtain a Tektronix 202-2 Scope-Mobile Cart.
Upon examining it, I found that the scope tray was loose and the tilt mechanism did not function properly. The cause for this was broken trunnion mounts on both sides of the cart as follows:
Three of the four bosses were fractured with the fracture surface indicating tensile overload. I suspect that the bolts were overtightened and the bosses fractured. Overtightening loaded the bosses in tension by trying to compress the box frame member. Unfortunately this type of polymer (some type of hard thermoplastic) is not good in tension.
Other mobile carts I have seen use cast aluminum for these trunnion mounts, which is a better choice for strength and durability. The cart I have for my 556, a 205-2 (triple wide), uses cast aluminum trunnion mounts.
I … Read More »
Tektronix 556 Dual Beam Oscilloscope
I had recently the unique opportunity to acquire a complete Tektronix 556 Oscilloscope setup. This comprised the oscilloscope itself, the matching scope cart, original manual, probes and 12 plug-in units. This in itself is rare enough, but in addition, this particular scope has the optically desirable blue phosphor CRT and Tektronix C-27 Camera Bezel. This 50 MHz bandwidth oscilloscope was the state of the art when it was introduced in the mid 1960’s: Tekwiki Tek 556
This will be the first of many posts and updates as I work my way through checking and restoring this beautiful scope.
And now some images:
Tektronix 7904 Oscilloscope
Here are some images of one 7904 mainframe with a 7A24 vertical module and a 7B92A horizontal module. The scope screen shows the pulse from an S52 pulse head; the rise time is about 850ps which translates into a bandwidth of about 412 MHz. Since the 7A24 plug-in is specified at 400 MHz, this is about right.
This is the same pulse from an S52 pulse head but using an S4 sampling head instead of the 7A24 vertical amplifier
Tektronix 7000 Series Equipment
I am doing some testing on recently acquired Tektronix 7000 series equipment. Involved in these images is a Tektronix 7904A mainframe using a 7S12 TDR/Sampler plug in with an S52 pulse generator and S4 sampling head.
The rise time on of the pulse is about 32ps which translates to a bandwidth of about 11 GHz; all this for a few hundred dollars.