The next best-kept test equipment series

Putting it all together - from the most simplistic to the most flexible.

If you're going to use just one single-width instrument at a time, it's entirely possible to do this with a TM501 (single width) power module then swap counter or DMM in as required. Do so with the power off, please. Otherwise, get hold of a TM502 or larger power module with which to run your accessories.

General-use:

DM-501A, DM-502A, DM-504A or DM-511 plus DC-503A, DC-504A or DC-505A

Communications service work:

DM-501A, DM-504A or DM-511 plus DC-501, DC-505A, DC-510 (with DP-501 Prescaler or an R-Y-O equivalent) or a DC-508/A.

Engineering and calibration lab work (requires TM5006 power module):

DC-5010, DP-501 Prescaler and DM-5120 DMM.

The combination listed immediately above can fetch north of $1200 if you're not a prudent shopper and south of $500 if you are. Make them an offer they won't refuse. I got all three modules for $450, albeit via separate sales.

Bump.

A couple weeks ago I made a heckuva score on the 'Bay:

SG5010 synthesized audio generator (ultra low distortion; does sine/sawtooth/square waves from 0.1Hz to 168KHz...and offers CCITT/SMPTE/burst functions)

AA5001 audio distortion analyzer - this one does THD and IMD testing, as compared to my DA4084 which is set up for SINAD tests

DC5009 Counter

DM501A 4 1/2 digit autoranging DMM

TM5006 mainframe

All for roughly the 'reasonable' price of an SG5010 by itself. At the higher end of the scale, these generators have been fetching upwards of $2100. Crazy, as I can buy a new stand-alone audio generator for less than half of that figure.

The SG5010 shows an Error 319 on powerup but this can be cleared and the instrument still functions. And the DC5009 has a digit with a burned-out segment but parts are inbound as I type this. Some day I'll get around to ordering the service manual for the '5010 and fix it but the instrument is fine for use as-is.

I have another DM501A in one of my TM506 mainframes. Swapping it into the '5006 in place of the DC5009, one now has an instrument capable of simultaneously measuring the performance of both channels of a stereo audio amplifier.

Just put one of these plus an SC502 in a TM515 case for a portable 16ch logic analyzer. Folks, if this is still available it's a very good deal:

http://jerseyshore.craigslist.org/ele/3661392080.html

Bump again.

Eddie graciously sent me a 1985 Tektronix Products catalog. Described therein are all the TM500 and 5000 series modules you could ever care to read about - with the exception of the discontinued stuff of the early 70s-early 80s and the modules of the 90s which had yet to be designed when the catalog was released. The AFG5101/5102, PFG5105, PG5110, CG5010/5011 and SG5030/SG5050 all come to mind.

What's really valuable is the accessories listing on each page: Which probes, leveling heads and other options went with each module.

We're going to study it intently so 'DSG knows what to look for at Dayton. :lol:

I noted in the Swap Meet area that I had a TM503 plus a few accompanying modules for sale. Will get pics of it posted when the weekend is settled.

Quote:

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Originally Posted by N8YX

Bump again.

Eddie graciously sent me a 1985 Tektronix Products catalog. Described therein are all the TM500 and 5000 series modules you could ever care to read about - with the exception of the discontinued stuff of the early 70s-early 80s and the modules of the 90s which had yet to be designed when the catalog was released. The AFG5101/5102, PFG5105, PG5110, CG5010/5011 and SG5030/SG5050 all come to mind.

What's really valuable is the accessories listing on each page: Which probes, leveling heads and other options went with each module.

We're going to study it intently so 'DSG knows what to look for at Dayton. :lol:

I noted in the Swap Meet area that I had a TM503 plus a few accompanying modules for sale. Will get pics of it posted when the weekend is settled.

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Lots of opportunity to find lots of test equipment there.

Quote:

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Originally Posted by X-Rated

Lots of opportunity to find lots of test equipment there.

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Fist full of dollars in hand, I'll be waiting.

I hope they have all of what I'm after. Tek 500/5000 stuff is hit-or-miss. Another area ham buddy of mine commented that there was a lot less of it available during the past two events than in past years.

Am going to start selling off a lot of my duplicate items. Occasionally I'll buy a loaded power module just to get that one piece I need and end up with multiples, so I'll pass them on.

Bump again.

Today we discuss the AM502 differential amplifier and what it can do for you:

Attachment 9811

A differential amplifier allows one to examine the difference between two applied voltages or waveforms. This model has a usable bandwidth of DC to 1MHz...not much, right?

Wrong!

To stimulate groupthink, let's say that Pat ('MHZ) somehow coughed up half the contents of his garage to the Island membership and we all came into possession of items in various stages of repair, most of which are double or triple conversion superhets. Or maybe Pat himself decides to restore his collection en masse and address some of the design deficiencies inherent to a number of models of gear from the the 70s and 80s.

Two of the big bugaboos in vintage gear are aged/degraded electrolytic and tantalum capacitors, and (unless the equipment was built to mil-spec standards at the outset) filter blow-by due to improper layout and switching methods.

So...how's an AM502 with its measly 1MHz bandwidth going to help us here? Almost all rigs of that genre use a second IF in the 450-500KHz region and a few (Drake R7, etc) employ a 3rd at 50KHz.

We can connect a reference signal to one input of the '502, the pre- or post-filter signal to the other, adjust the DC offset control and get a good indication of how much IF energy is leaking through the switching circuits.

Moving on to post-detector AF...let's say some bypass caps in the AF stages have gone bad and are coupling hum or other unwanted signals into the audio chain. Supplying a reference audio signal to one input channel, the amplifier output to another and setting the filter adjustments appropriately will allow us to spot the culprit, as someone's not shunting low-frequency components as they should be.

A hysteresis squelch operates on a compare-and-hold principle and this module also makes for a decent tool by which to set the DC reference level of the comparator (if the circuit is equipped with such an adjustment means) or to verify operation in the presence of (you guessed it) suspect capacitors.

Basically, the AM502 is a useful tool for any circuit where you have an LF AC signal component superimposed on a DC voltage and are trying to pinpoint and quantify the source.

You'll need to hook the plugin's output to a scope of corresponding bandwidth. A combination consisting TM503 power module, AM502 and an SC502, 3 or 4 scope will make for a neat little benchtop troubleshooting outfit which doesn't take up a lot of room.

I got hold of a few Video Calibration Fixtures (067-0916-00) about a month or so back, along with the display chips required to fix the only one in the lot whose reference display wasn't fully operational:

Attachment 10372

Does NTSC, PAL, SECAM. Perfect for restoration of old analog TVs, which I understand is becoming somewhat of a cottage industry.

Also scored one of the following. Yes, I had to pay a bit for it but considering this is the third one to be listed in 10 years...well, time is money:

Attachment 10373

The 067-0938-00 Notch Filter is used to calibrate the SG505/SG-5010 series oscillators for lowest possible distortion products. It looks to be service-center-only issue, and since Tek quit supporting this stuff some time ago... I'm/we're it. I was lucky to find mine, after I let another one get away without realizing what it was.

There is another, somewhat rare video test fixture which I have that isn't listed on many of the Tek TM reference sites. It functions as a staircase, dot, comb and blanking generator and is a 2-wide form factor. I'll get it out of my storage area and take a few pics before placing it, a -0916- and a couple other related plugins into a dedicated video-test TM506 rack.

Got ahold of two of the following, an SC502 junker, an SC504 junker and two functioning 7B53A time bases for not much more than a single working SC503 fetches. More winter fixit fun; one's partially operative and the other shows no signs of life:

Attachment 10374

Nuttin' fancy here - just a 2ch 10MHz storage scope. But it's all you need for working with lower IF and AF frequencies. Store a good (no distortion) input signal with the storage function, monitor the output of the device-under-test with one of the channels...overlay the stored and active traces then tune the D-U-T so the two waveforms match as closely as possible.

Some very nice scores. I have some fairly recent test gens for analog/digital tv/monitors and audio surround etc. Needless to say, I don't do a whole lot of that any more. Mostly buy/restore/sell radio equipment. I mostly use either the Marconi or IFR service monitor for that. I actually haven't been at the bench since my wife closed the business in Oct. and we moved everything out here. And we have been getting the building ready to sell, too. What a supreme pain in the ass that whole process has been. I plan to get the shop cleaned up and functional again in the next couple of weeks. I miss the smell of burning resistors, and the feel of hot solder rolling off my bare leg.

With all the TEK eq you are amassing, you are quickly becoming the MHZ version of the test eq crowd; but then you do use most of it and don't just stack it up in the garage. No offense Pat. :stickpoke:

I've got a lot of mine stacked at the moment, Eddie - though it's more of a space constraint issue than anything else. Many of my power mainframes are just doing duty as storage racks. I have a TM5006 and two TM506s along with a TM501, a '502 and a few assorted TM503s/504s which can be set up on the bench as required. I may not need a full complement of video or logic test hardware during any one given week but when I do it's fairly easy to swap the stuff around from its storage spot.

A dedicated service monitor, precision RF/sweep generators with a 2GHz or more upper frequency limit, LCR/ESR/Q meter and a network analyzer with a 1GHz or more upper limit are all on the Wanted list. There's just no space to put them at the moment so I'll sit on the cash instead and wait for better lab quarters.