It's all Fred's fault...

[AE1PT]

About a month ago, I was thinking about the need to add a sweep generator to my bench. There's a thread here on the subject. Every time I post a gear or some other stuff query, Fred always comes back "eBay's yer friend." Indeed, that has been the case.

So in amidst the looking about for this sweep generator--and remember that I had set a budget of $250 for this little project--eBay friended me with a few little treasures. The irony? The sweep generator was the last piece I got just yesterday... Take a guess what might have happened here--there are some of you know that once I get an idea to do something 'improvement' or gadget oriented--it never seems to happen in an understated way...

http://ae1pt.com/photos/imh/newgear.jpg



Gigatronics (Fluke) 6060B RF generator deck
Advantest R3261A spectrum analyzer
HP 5328A frequency counter & RF voltmeter

B&K 4040 sweep/function generator



That's a handy-dandy HP 202C low frequency oscillator peeking out the right of the frame. At 40 years old, that thing is still rock solid after a 15m warmup...



Only the 465B is original to the start of this adventure... :cool2: Oh, the budget went completely to hell as soon as the idea of a spectrum analyzer got stuck in my head.

[KG4CGC]

Oh, cool toys.

[PA5COR]

Congrats with the new toy ;)

[NQ6U]

Nice going, Pat. I hope to score a spectrum analyzer one of these days.

[N8YX]

Golfclap.jpg

I have the big brother to that scope sitting here - Tek 468. It was obtained in trade for working on a buddy's Cubic Astro 103.

Also need to get more test gear - spectrum analyzer in particular, and a network analyzer would come in handy if I can source one at a reasonable price.

A set of these are next on the list:

7869

Tektronix TM series. Mainframes and plug-in modules let you configure an instrument for a role. Aim is to get four frames then equip one for power and analog signal generation, another for digital signal generation, a third for signal measurement and a fourth for as-needed duplication of the above functions.

[WX7P]

Golfclap.jpg

I have the big brother to that scope sitting here - Tek 468. It was obtained in trade for working on a buddy's Cubic Astro 103.

Also need to get more test gear - spectrum analyzer in particular, and a network analyzer would come in handy if I can source one at a reasonable price.

A set of these are next on the list:

7869

Tektronix TM series. Mainframes and plug-in modules let you configure an instrument for a role. Aim is to get four frames then equip one for power and analog signal generation, another for digital signal generation, a third for signal measurement and a fourth for as-needed duplication of the above functions.

The LAST thing you need is more gear...:mrgreen:

[N8YX]

The LAST thing you need is more gear...:mrgreen:

What I need to do is to get rid of the excess-to-my-needs radio equipment then use the money and space to flesh out my test bench. Tinkering is fun, but tinkering with a decent lab setup as an assistant is more fun.

Think I'll keep two 7-lines, the '301 projects I'm now in the middle of restoring/converting, the FT-980s, all the Ten-Tec stuff and one, maybe two each Astro 103/150/151/D lineups. The 726Rs and CPI CB rigs along with the Icom stuff stay as well...and the Astro-DR rack and two Mackay receivers mounted above the Cubic equipment.

All else is going out of here and that includes most of the Kenwood gear, all of the FT-90x lines, much of the Drake and Cubic equipment.

It's all great stuff but simply doesn't figure into my long-term shack vision.

[WØTKX]

Yea, I need to add more bench toys myself. Working on it.
Get by with a small frequency counter and the MFJ analyzer.

A little crude, but it works.

I do have a decent 4 channel Tektronics scope.
Leave 2 channels hooked up for TX monitoring.

[AE1PT]

Scoring a spectrum analyzer is the difficult part. If you are ready to shell out $900 upwards to a factor of 10--it's pretty easy. Anything below that is likely to be industrial scrap. I spent two weeks bidding on around a dozen of them--using my super secret last 3 seconds body slam system. In each case except for this one it failed--and the winning price always went above $500.

What I see going on in the Bay is a business dominated by industrial electronics specialists. Nice equipment (albeit decades old) that might go for a reasonable price is being snapped up at prices that drives the casual hobbyist out of contention. Those doing this snapping have tens of thousands of feedback score--and this is the arena where they play the game. Whatever might have gone for a few hundred is bought, cleaned up and/or calibrated--and sold for a thousand dollars or more over the initial price. One has to be persistent and patient.

Pretty much forget about anything recent with an Agilent or Tek label on it...

[W5GA]

All that stuff looks really cool. Too bad I wouldn't know what to do with any of it. :irked:

[KC9ECI]

All that stuff looks really cool. Too bad I wouldn't know what to do with any of it. :irked:

Doorstops?

[N8YX]

It's all Pat's (and Steve, a local buddy's) fault.

This thread finally galvanized me into getting hold of some of the test gear - specifically, those TM-series pieces - that I've been contemplating.

The darned things are like potato chips: You cannot have just one!

First acquisition was a TM-515 (5-bay portable case) which included an SC-502 (15MHz scope), DM-502 (DMM), FG-502 (11MHz sweepable function generator) and a DC-502 (80MHz counter). Just what I needed to work on motorcycle electronics in the drive!

...except the scope doesn't power on. Back to eBay and find another; make the guy an offer he won't refuse...

...then an LA501 logic analyzer appears and I snag it for a song. And a quartet of DD501 delay units; I paid as much for the entire lot as 5 new OEM latch knobs are fetching!

Undaunted by my success, I place a couple Wanted ads. Soon I have an AA501 distortion analyzer (a rare and desirable piece), a pair of AM503 current amps and an SG502 generator...all for less than the eBay price of the analyzer alone.

And a ramp generator. Need one of those to turn an FG or an SG into a sweeper, "...so I made 'im an offer he couldn't refuse...". Thus, there's a nice RG501 on my workbench. Another is inbound next month.

About that broken scope: I can buy a Tektronix extender board for $600 or I can spend the princely sum of $100 for a TM-501 and TM-502 mainframe, each of which can have the covers removed to facilitate single or dual-width module servicing.

Several other companies made TM-series plugins. A Metrotek MR-106 receiver, MP-702 Pulser and MG-701 Gate are now inbound...the latter two in excellent shape and for $20/ea.

Now things begin to get expensive...time to scrounge Dayton and some of the other venues for the harder-to-find plugins. And the TM-5000 series (GPIB controllable) modules are gonna co$t me a pretty penny, especially the function and signal generator units. I may luck out and find deals on that stuff too.

Doesn't matter that a lot of this equipment was built in the 80's - it's still better than almost every piece of modern "hobby grade" test gear on the market.

So many plugins...so little time...

[N8YX]

Bump.

Finally got a bit of free time over the weekend and fixed 4 of the 6 SC-502 (15MHz dual-channel) scope modules which have been languishing in my to-do pile. Power supply problems account for the lion's share of issues seen with these instruments - and it's either bad tantalum filter capacitors (which are used for de-noising each output stage) or the 5V regulator circuit as a whole.

The other issue arises with the custom ICs which Tek used throughout their instruments. The Internet or a donor scope are it as far as finding some of these things are concerned. I have a few questionable sweep generation ICs in the pile; they load the 5V supply to the point that the scope won't turn on. Luckily, I found a few online and bought them but I won't have enough to fix all 6 scopes.

Not that it matters: The last of the Trigger/Sweep boards on-hand was apparently subject to rough handling some time in its life and had the (unobtanium/riveted-to-the-board) Trigger Channel selector switch broken, presumably by a sharp impact to the front panel. Scope #6 has now become a parts donor unless I can find another of those boards.

Next time I'll look at the two SC-504s (80MHz dual-channel) sitting in the fix-it box. One won't focus its trace - possible problem with the thick-film resistor assembly in the HV section - and the other won't turn on at all.

[AE1PT]

Well done Fred. I had looked at one of the 7400 series mainframes to start plugging things into, then I picked up the Advantest SA and put that idea on the back burner. A B&K 4040A sweeper was bought--and that damned thing is going back on eBay as soon as I can find a Gigatronics/Fluke 6080A. I will also then sell the Gigatronics 6060B as I don't need two RF decks. The next scope upgrade must have on-screen voltage and frequency readout--but replacement is not high on the priority list. It's amazing what one can do with a spectrum analyzer. Have also picked up a few extra antique bench queens suitable for BA troubleshooting. What fun!

Keep up the good salvage work. I am continuously shocked at what can be had of quality lab grade stuff if one can snag it before the industrial electronic resellers try to gobble it up for HUGE profit.