View Full Version : The best-kept test equipment secret of them all...
Looking to put a decent bench together on a budget?
Be on the hamfest lookout for Tektronix 7000 series mainframes and plugins. Until late last year I had absolutely no idea what this series of gear was all about and it's too good not to share.
Tek made a number of different oscilloscope chassis and measurement plugins in the series from the early 70's until the mid 90s. It was expensive as hell at the time, fairly affordable at present as surplus - and the best part is that a piece from the 70s will work with a piece from the 90s.
Mainframes: Bench and rackmount models were offered. Most came with an on-screen alphanumeric display (which I'll get to in a moment). Of the benchtop series, the two I would look for are the 7603 (a 100MHz unit with a wide CRT) and a 7104 (1GHz; widest bandwidth of any analog scope ever built).
8855 8856
The key to these instruments' flexibility are the many plugins which are offered. The 7603 (at top) has a spectrum analyzer installed while the 7104 underneath it has a standard vertical amplifier/timebase complement.
In subsequent posts I'll discuss each plugin type and any associated quirks, hints and needed accessories.
First, a further word about the mainframes and what they do. There are a number of them from which to choose; with the exception of the 7104, the 7600 series and above are probably the most desirable as they offer bandwidths greater than 100MHz. Both storage and non-storage variants were offered. If one is planning to use the chassis for housing a curve tracer, multimeter or similar readout-based plugin then any of them (including sub-100MHz B/W models) can be pressed into service.
Tek incorporated an on-screen alphanumeric display which was facilitated through a custom character generator/display board. Depending on age of the scope there are two versions of the board. They're interchangeable can can be retrofitted to a scope which came from the factory without one. The readout enabled display of operating parameters, and - by way of the various plugins discussed in subsequent postings - turned the chassis into much more than a simple oscilloscope.
As with all vintage electronics, the main failure point of these instruments are the power supply electrolytic capacitors and the numerous tantalums which are used for de-spiking purposes on each board.
Do yourself a favor and shop the hamfests before turning to eBay for a 7000 series mainframe. Most offerings these days are from commercial gear dealers whose overpriced wares sit for months if not years...and the estate liquidators following suit.
You may catch a deal on a complete setup from time to time but shipping charges will often equal the price of your purchase.
While a number of custom ICs were used in the equipment, they rarely fail - and there are so many surplus units available that donor parts are fairly easy to acquire.
X-Rated
02-12-2013, 10:20 AM
Yes. Those are oldies but goodies. I used one of the bench models back in the early 80's with the spectrum analyzer plug-in. 10kHz? to 1500MHz? I don't remember. It had a beautiful display.
Anyway, looking at pictures on the web, it was a 182T and an 8558B plug-in.
http://www.surplus-electronics.co.uk/urchin/assets/images/_mod/20111215_163014.7903.209.400.-1.85.jpg
X-Rated
02-12-2013, 10:27 AM
Now I have an HP ESA-L1500A that is incredible. (at work) It has a built-in frequency counter that allows you to count the frequency of the signal under the marker to 1Hz resolution. 1Hz may not sound that good, but some of the 900MHz carriers seem to be pretty accurate and 1Hz at 900MHz is about a part in ten to the ninth resolution. (1ppb) Also, counting a signal in a crowd of signals is a pretty nice capability.
Now I have an HP ESA-L1500A that is incredible. (at work) It has a built-in frequency counter that allows you to count the frequency of the signal under the marker to 1Hz resolution.
I had to do a bit of searching for the model you mentioned and upon checking it out will segue into an observation about Tek plugins:
No matter how nice they are, they're NOT worth more than a stand-alone, single-purpose instrument of the same basic capabilities.
Thus...we begin the discussion with timebases. If a given seller asks more for a timebase than an entire scope with an equivalent vertical amplifier response is fetching, simply walk away.
For any of the 100MHz platforms, a 7B50 (non-delaying), 7B51 (delaying) 7B53A/AN or 7B70/7B71 works just fine. 7B80/85/87s work to 400MHz, 7B90/7B90P, 7B92 and 7B92A to 500MHz. For the 7104 you'll want a 7B10 or 7B15, the latter being a delayed sweep. Pay no more than $100 or so for the fastest units and at most hamfests they'll go for considerably less.
Good info, Fred, thanks. I'm headed out to the Yuma Hamfest this weekend, I'll keep an eye out for some of this. A spectrum analyzer would be a nice thing to have.
Carl, an area friend scored an entire setup (7844 dual-beam unit w/ all plugins) for the princely sum of $25.
No, I'm not kidding...and it all works.
Vertical amp time:
There are a bunch to choose from. Be on the lookout for the 7A11 (single-channel, 250MHz), 7A12 (two-channel, 120MHz), 7A18 (two-channel, 75MHz...great for pairing with a curve tracer or other low-bandwidth module), 7A24 (two-channel, 400MHz), 7A26 (two-channel, 200MHz), 7A19 (single-channel, 500MHz) and 7A29 (single-channel, 1GHz).
A number of specialty vertical plugins exist. Most of these sit on dealers' shelves, never to move because they're far overpriced.
I just scored a nice late model 7A13 (100MHz differential amp) for $40. Of course it's "as is" and uncalibrated but one of the very first things I did when the 7000-series gear came rolling in was to buy any needed calibration fixtures. Thus, I can service and calibrate any of the stuff (including 500/5000 series plugins) to Tek standards.
You use this particular plugin for comparing two voltages and displaying the result. A typical example is tracing an AGC voltage through a receiver: Look at the AGC Amp output with one channel and the pathway through each sub-module or connector header with the other.
Since Carl touched on the need for a spectrum analyzer, I'll delve into those.
Tek offered several in the 7000 family: 7L5 (20Hz-5MHz), 7L12 (100KHz-1.8GHz), 7L13 (1KHz-2.5GHz), 7L14 (10KHz-1.8GHz; w/ storage) and 7L18 (1.5-18GHz; 60GHz with an external mixer. Also has a storage function.)
The most useful to the amateur (in order) would be the 7L14/7L13/7L18/7L5, though if you can snag a 7L12 for a song by all means do so. It doesn't have a digital center frequency readout but is a great addition to the bench nonetheless.
It's easy to blow the mixers in the units if you transmit full power directly into them. If at all possible, examine the prospective purchase when it's powered up in a mainframe and looking at its internal calibration generator signal. Of course, these can be fixed so don't let the "as is" part put you off if you spot one going for less than a C-note.
Pricing...the HP unit Jerry mentions is currently fetching ~$3K and is in many ways far advanced beyond the Tek equipment. That doesn't matter to the average hobby user or low-volume repair lab except where cost is concerned. Kindly remind clueless sellers that there's no way a 30-year-old analyzer should fetch the same amount as its new, state-of-the-art equivalent. You should realistically spend no more than $400 for a 7L13/14 or $500 for a 7L18.
X-Rated
02-12-2013, 05:52 PM
I mentioned 2 HP units. One from the 1990's that you quoted the price, and the other is from the 1980s and would be much less expensive. The 182T, even relatively new, I tried everything to keep it operational well, but I remember now having to pull the plugin and re-seat the connector in the slot. I didn't like that, but the calibration was fair and the trace was excellent. I just had the spectrum analyzer plugin.
I would agree that Tek is better than HP at least until the 90's. HP had issues. For the most part, HP/Agilent had cleared up and became more competitive.
I mentioned 2 HP units. One from the 1990's that you quoted the price, and the other is from the 1980s and would be much less expensive. The 182T, even relatively new, I tried everything to keep it operational well, but I remember now having to pull the plugin and re-seat the connector in the slot. I didn't like that, but the calibration was fair and the trace was excellent. I just had the spectrum analyzer plugin.
I would agree that Tek is better than HP at least until the 90's. HP had issues. For the most part, HP/Agilent had cleared up and became more competitive.
What was the bandwidth of your 182T analyzer plugin, Jerry?
FWIW...my area friend (who got the deal on the 7844) has a couple 182Ts and swears by them. IIRC, one's going to be coming up for sale - it's a 500MHz B/W unit. I'll check with him this weekend if anyone is interested.
90s era HP - would love to lay my mitts on a 4396A 1.8GHz network/spectrum analyzer. Besides a few remaining Tek 5000 pieces plus a 7934/7104 mainframe combo, that's really all the bench still needs in the way of equipment. With an average retail used price of $6500 it'll be a year or so before fundage permits.
X-Rated
02-12-2013, 06:24 PM
The RBW was 1kHz to 3MHz.
wa6mhz
02-12-2013, 06:54 PM
I just checked, and we have 2 of the 7104s and a 7608 with misc plugins. 7A29,7B10, 7A26, 7P15? 7D10. Never turned them on, don't know if they work. Will nab them if they ever have a FIRE SALE and the plant closes.
XE1/N5AL
02-12-2013, 11:35 PM
Probably, the 7P15 is actually a 7B15, which is often paired-up with the 7B10 plug-in. With the 7A29 vertical amp and the 7B10/7B15 plug-ins, you can use the 7104 up to 1GHz. As Fred said, its the fastest analog scope ever marketed. As I recall, the 7104 has such a fast sweep that it requires a very bright trace. There is some kind of mechanism which dims the display after a short period of time to avoid screen burn-in. It's been a while since I used one, so I can't remember all the details.
BTW, There are also TDR/sampler plug-ins, for the 7000 series scopes, that let you see repetitive signals up to 14 GHz.
X-Rated
02-13-2013, 01:20 AM
Probably, the 7P15 is actually a 7B15, which is often paired-up with the 7B10 plug-in. With the 7A29 vertical amp and the 7B10/7B15 plug-ins, you can use the 7104 up to 1GHz. As Fred said, its the fastest analog scope ever marketed. As I recall, the 7104 has such a fast sweep that it requires a very bright trace. There is some kind of mechanism which dims the display after a short period of time to avoid screen burn-in. It's been a while since I used one, so I can't remember all the details.
BTW, There are also TDR/sampler plug-ins, for the 7000 series scopes, that let you see repetitive signals up to 14 GHz.
You're not at Continental in Guadalajara, are you?
As I recall, the 7104 has such a fast sweep that it requires a very bright trace. There is some kind of mechanism which dims the display after a short period of time to avoid screen burn-in. It's been a while since I used one, so I can't remember all the details.
The "Micro Channel" CRT. Certain types of plug-ins should NOT be used with a 7104 as they'll damage the CRT. Best to throw in a pair of 7A29s, a 7B10 and 7B15 then use the thing for its intended purpose - a scope with microwave bandwidth. For everything else I have the 7603s.
BTW, There are also TDR/sampler plug-ins, for the 7000 series scopes, that let you see repetitive signals up to 14 GHz.
One of those is the 7S14; usable to 1GHz I just made a seller a realistic offeran offer he couldn't refuse and have a specimen inbound.
The '14 uses a bias battery on each of the input channels and the type has long since gone out of production. There have been a number of published workaround mods for replacements; if your plugin isn't working the battery is the first thing to check.
Unlike the 7S11, the 7S14 requires no sampling heads. It's wholly self contained.
8871
I just checked, and we have 2 of the 7104s and a 7608 with misc plugins. 7A29,7B10, 7A26, 7P15? 7D10. Never turned them on, don't know if they work. Will nab them if they ever have a FIRE SALE and the plant closes.
I would definitely keep those on the short list, Pat. Might want to power them up from time to time to keep watch on the aforementioned capacitors. My first 7603 had two bad ones: An electrolytic in the LV power supply and a tantalum on the vertical deflection board's 5V rail, near the input header.
I just checked, and we have 2 of the 7104s and a 7608 with misc plugins. 7A29,7B10, 7A26, 7P15? 7D10. Never turned them on, don't know if they work. Will nab them if they ever have a FIRE SALE and the plant closes.If you get both, should the time come, I'd like one of them. Let me know & I'll cover the costs + shipping + something towards what you keep for your trouble.
X-Rated
02-13-2013, 10:45 AM
What was the bandwidth of your 182T analyzer plugin, Jerry?
When you asked this earlier, I was thinking that you were asking what the resolution bandwidth was. The frequency range on mine was 100kHz to 1.5GHz. It was the 8558B, I think. There are several plugins out there. Some will go over 10GHz. I used this one on aircraft transponder test equipment and on DME test equipment.
When you asked this earlier, I was thinking that you were asking what the resolution bandwidth was. The frequency range on mine was 100kHz to 1.5GHz. It was the 8558B, I think. There are several plugins out there. Some will go over 10GHz. I used this one on aircraft transponder test equipment and on DME test equipment.
My area friend's HP analyzer is good to 500MHz. Will have to keep an eye out for the higher frequency versions.
As you guys upgrade to better test equipment, consider those of us without any... and let us know if it could use a good home, rather than sit unused collecting dust.
Just sayin'.
X-Rated
02-13-2013, 12:12 PM
If frequency accuracy is important to you, finding something that will cover the CDMA frequencies. The higher band is under 2GHz. I belong to FMT on Yahoo groups. We try to detect amateur carrier frequencies to within a few parts per billion. Finding cheap ways of obtaining a frequency standard is always a concern.
X-Rated
02-13-2013, 12:37 PM
As you guys upgrade to better test equipment, consider those of us without any... and let us know if it could use a good home, rather than sit unused collecting dust.
Just sayin'.
Ron. I know what you mean. For the most part, I borrow stuff from work and buy things at hamfests. This concept that anyone can outfit their shack with tens of thousands of dollars worth of equipment for a few bucks is stretching it. I know people do that and I am not saying it can't be done, but the risk of buying something that requires discontinued parts is always out there and something I am sure we all consider when staring at those babies on the pickup truck tail gate. The concept of having a thread like this is a great idea. Not knocking any of this great information. I always learn something and putting our experiences out there is always a way for each of us to learn the ins and outs. Finding the equipment really cheap is not that easy. At the last hamfest, I saw a piece of test equipment that I tested in the factory off the assembly line back in 1983 and felt that it was too expensive to walk away with just for the sake of posterity. But I did show it to N8WTF and he seemed impressed even though he didn't know what it did.
The key is vigilance. Do like you are doing by asking people to consider selling their stuff. Ask for something in particular as well as in general. If you see someone at the hamfest with a lot of test equipment, ask them for what you are looking for if you don't see it there and maybe they know of something as well. Keep the dialog rolling.
I have a crystal oscillator at 10MHz I could part with right now for $15 plus shipping. Once set, it will stay accurate to within a part per billion for quite a few months. I can send info on how it works. The link to one similar is below...
http://www.ebay.com/itm/CMAC-10MHz-ocxo-oscillator-square-wave-sc-cut-/180911738566?pt=LH_DefaultDomain_0&hash=item2a1f2e0ec6
What you get here is an SC cut crystal in the oscillator. This is great for stability. Far better than similar AT-cut crystals.
Oh look...
http://www.ebay.com/itm/ERC-Precision-Crystal-Oscillator-EROS-800-NTL-3-OCXO-10-000000-MHz-12V-RF-/140779763586?pt=LH_DefaultDomain_0&hash=item20c720b782
I designed this one a few years back in Kansas. I would recommend getting one with electrical trim for ease of control. In this case, the one I designed that is here on ebay has an "800" in the part number which meant it did not have electrical trim. The way you set the frequency is with a trim cap inside. The electrical trim models had a "750" in the part number.
Ron. I know what you mean. For the most part, I borrow stuff from work and buy things at hamfests. This concept that anyone can outfit their shack with tens of thousands of dollars worth of equipment for a few bucks is stretching it. I know people do that and I am not saying it can't be done, but the risk of buying something that requires discontinued parts is always out there and something I am sure we all consider when staring at those babies on the pickup truck tail gate. The concept of having a thread like this is a great idea. Not knocking any of this great information. I always learn something and putting our experiences out there is always a way for each of us to learn the ins and outs.
Well put, and the usual suspects...errr, enthusiasts are here to help. :lol:
Tek did something slick with the majority of their equipment from the era: All failure-prone semiconductors are socketed, and a lot of it is good ol' CMOS/TTL/ECL. I've only encountered one (1 - count it) failed "custom" IC in the dozens upon dozens of mainframes and plugins which have been across my bench. There are so many of the 500/5K/7K plugins showing up on the surplus market these days that you're bound to find a parts unit for whatever you need.
I also have a huge junk box/parts inventory which frequently grows and am glad to help you folks out with a part...or a full repair.
Of course, a timely word to our sponsors...I mean clueless eBay sellers:
I don't care if it says Tek on the front panel. A beat halfway-to-hell example of something is NOT worth as much or more than a perfectly good unit which is going for fair market value, even if it's being compared to an astronomically priced one sitting on the shelf at some refurb lab.
As you guys upgrade to better test equipment, consider those of us without any... and let us know if it could use a good home, rather than sit unused collecting dust.
Just sayin'.
Did exactly that with a 468B which became surplus to my needs when the 7600s rolled in. He's happy to have a scope; I'm happy to have the space.
Speaking of sampling - here's the next piece to be on the lookout for:
The 7S11. With the appropriate sampling head (reusable in another module which I'll cover later) your 100MHz scope can view repetitive signals as high as 14GHz in frequency. Depending on the sampling head installed you'll need an SMB, BNC or a General Radio (GR) style connector but they all can be found in the 'fest bins.
Anyone who prices sampling heads at $300-500 needs to put the pipe down. Seriously. These things shouldn't fetch much more than $150.
8875
7T11 timebase, for use with the above. One of these along with a pair of 7S11s and sampling heads gives you a 2ch instrument capable of examining microwave signals.
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I just received an S-1 head and a 7S11 in the mail. Total outlay: ~$105.
The S-1 can be used in the 7S12. That's a TDR plugin which can be used for such things as finding bad connectors in your feedlines without having to take said feedlines apart. You would normally run an S-52 (pulse generator) in the right compartment and an S-6 (DC-11.5GHz sampler) in the left, but an S-53 (trigger recognizer) in the right and any sampler head in the left turns the 7S12 into a regular GHz+ sampling instrument.
Three dielectric ranges are provided on the delay compensation control: Air, polyethylene and user-definable.
Pretty. Darn. Slick.
Any of you folks around Springfield, IL or know someone in the area who can pick this up for you? I texted the guy yesterday - he still has the scope but won't ship.
It has a 7D20 in the plugin compartment. That device alone is worth several times the asking price:
http://springfieldil.craigslist.org/ele/3481560382.html
That 7D20.
Just bought one off eBay which is showing a Fault 42 - "Bad U525 A/D Converter". Tektronix built in some pretty slick self test routines which will either display on the scope readout or on the front panel, by way of the Memory Display buttons (they're illuminated in binary code). You reference these in the service manual and can pinpoint down to the (bad) device level.
The part in question is an off-the-shelf ADC but it's not currently on anyone's shelves. I'm going to try subbing an ADC-EK12B (Datel) IC for the spec'd 8701CN. The original device is a 10-bit unit, though the pinouts are identical between it and the inbound 12-bit chip.
8893
Another bump.
Finally dug the 7D20 out of the to-do pile and began looking at a few things. Sure, it's showing a Fault 42 (ADC circuit failure) but when placed in one of my 7603s it was also putting a large draw on the +5V line - this indicated by the scope's pilot light not illuminating at powerup. Inspection revealed a 390uF, 25v radial-lead cap on the +5V supply-board line that had started to ooze electrolyte from one of the terminals.
Replaced, but still no go. Okay...let's replace the ADC chip with the spare I had ordered earlier in the year.
Still no go.
Tore every plug-in board out of the main chassis with an aim to inspect each one and the backplane for shorts - and found that never-popular error known as "off by one". That is, the backplane attaches to the input/preamp board with a set of DIP and SIP headers...and several of these weren't in their corresponding sockets.
More disassembly/reassembly required but upon trying the instrument out, I got a display and self-test messages. Something about 5v Self-Test Failure. A few more power cycles and that went away...now I have a fully functioning instrument.
The plugin had arrived in the misconfigured state from the seller. Perhaps all three things were faulty; maybe it was just the backplane being improperly positioned. Regardless...I now have $100 outlay into a piece of gear which cost almost 100 times that amount back in the day.
A 7D20 essentially turns your 7000 series scope into a 2Ch, 75MHz B/W GPIB-programmable digital setup. You can store and examine waveforms, upload control programming and download captured data. The unit incorporates its own timebase and trigger circuits, an on-screen parameter readout makes it easy for the operator to check settings.
KE0ZU
07-11-2013, 10:22 PM
Don't think there's much a 7K series can do that a 500 series scope can't, although they are admittedly a bit slower. Here is a pic of my old 50MC 547 and the 500MHz 7904.
http://i670.photobucket.com/albums/vv62/mikeinkcmo/testgear/Tek/5XX/P1010043_2.jpg
Don't think there's much a 7K series can do that a 500 series scope can't, although they are admittedly a bit slower.
There are a lot more different plugin types available for a 7K than a 500. As an example, did Tek make a logic analyzer or an in-circuit emulator/debugger for the 500 series?
With regards to speed: The 7104 was the highest bandwidth analog scope ever built. You can use one to examine waveforms into the GHz region and they're currently going for a small fraction of their original cost.
How about a 4-channel, 100MHz scope on the cheap?
Head over to Fleabay or your nearest hamfest and score a pair of these 7A26 dual-trace amps. Going prices are anywhere between $10 and $ludicrous, with $30 being average:
10312
Next, get yourself a 7B53A time base. $25-35 should cover it:
10313
Insert the 7B53A into the horizontal compartment of your (cheaply acquired) 7603 and the two 7A26s into the middle and left compartments...voila! If you're a careful shopper you can get all of these pieces in very good to excellent condition for $100-150.
Let's look at a practical application for such a construct. Say you're working with a stereo AF amplifier or maybe an I-Q modulator/demodulator and want to examine the phase relationships, distortion products and so forth of each of the signal paths. One of the 7A26 amplifiers is used to examine the input waveforms of both channels while the other looks at the output paths. You can adjust the vertical positioning so as to overlay the channel traces and thus get a very good idea of what the device under test is doing.
WØTKX
08-04-2013, 12:49 PM
I would love a 7104. Those are both familiar faces from the past, in the work environment(s).
Currently, I'm pretty happy with my Tek 100 Mhz 2246A 4 channel scope. Cheap, and useful.
KE0ZU
08-15-2013, 10:22 PM
OOPS
KE0ZU
08-15-2013, 11:50 PM
N8YX said;
There are a lot more different plugin types available for a 7K than a 500. As an example, did Tek make a logic analyzer or an in-circuit emulator/debugger for the 500 series?
OH, you mean one of these?
http://i670.photobucket.com/albums/vv62/mikeinkcmo/testgear/Tek/7XXX/7904/7D012_zps9cdd96a5.jpg
SOOOoooo just how many computers were YOU working on in '64? Not many I bet, 'cause ICs, 914s and 923s out there were still 20-30 bucks each. Were you around then?
How about a 4-channel, 100MHz scope on the cheap?
Why be so cheap, spend less than twice the money and go 5 times as fast.
http://i670.photobucket.com/albums/vv62/mikeinkcmo/testgear/Tek/7XXX/7904/79042_zpsf1e20b70.jpg
Have to agree however, the 7L14 is a nice analyzer, but as you can see by the little red lite the 7104 doesn't like to work with it.
http://i670.photobucket.com/albums/vv62/mikeinkcmo/testgear/Tek/7XXX/7104/7L142_zps2a4455d2.jpg
I've had quite a number of the 500 and 7K series scopes along with most of their plug-ins. They were all enjoyable to use, but after a while you run out of room. I've sold off most all of them and only have a 2465 in the rack, with an old 454 as a back up.
http://i670.photobucket.com/albums/vv62/mikeinkcmo/testgear/Bench%20New/NuTstBnch29_zpsa7d680db.jpg
As for a Spectrum analyzer, I sold the one in the pic, and it never reached its destination intact, a pitiful end. Now I have a couple old 141Ts with a set of plug-ins and tracking generators, Thats plenty good enough for amateur radio work.
Mike
N8YX said;
OH, you mean one of these?
SOOOoooo just how many computers were YOU working on in '64? Not many I bet, 'cause ICs, 914s and 923s out there were still 20-30 bucks each. Were you around then?
We're talking for applicability and use in present day work, not when the equipment was built. Most of us couldn't afford the $10k a 7D01 plugin fetched when it was new but you can easily score one (with the display formatter) for $50-75 these days. Judicious shopping nets the probes and related wiring for the same price.
I did a bit of research on the 500-series scope before posting this follow-up...and neither it or the later 5000 series offerings can match the 7K line for versatility.
Why be so cheap, spend less than twice the money and go 5 times as fast.
Simply put, space. I have a variety of the 7K scope mainframes: A couple 7603s, a couple 7903s and a 7854. (A 7104 is on my Wanted list, FWIW). Of all of these models, I find myself reaching for a 7603 far more often than the others.
At 3312 cu. in., the 4-bay mainframes are significantly larger than their 3-bay counterparts (2376 cu. in.). Then there's the matter of the CRT itself. The larger 7603 display comes in very handy when using a logic analyzer, spectrum analyzer or digitizer plugin. And if you don't need the extra bandwidth, why pay for the extra volume?
Have to agree however, the 7L14 is a nice analyzer, but as you can see by the little red lite the 7104 doesn't like to work with it.
Given the 7104's Micro Channel CRT architecture I wouldn't run anything in it besides a pair of high-bandwidth vertical amplifiers, a 7B10 timebase and a 7A13 differential amplifier...possibly a 7S11/7T11 combination. None of the special display-formatting plugins, however...some of which can damage the 7104's CRT.
I've had quite a number of the 500 and 7K series scopes along with most of their plug-ins. They were all enjoyable to use, but after a while you run out of room. I've sold off most all of them and only have a 2465 in the rack, with an old 454 as a back up.
I'm probably preaching to the choir but you have sourced an extra U800 or two for that 2465, I assume? That's the one reason I bought what I did instead of the later-model stuff: Bad, BAD Tek for inadequately cooling that IC, and bad Maxim for not manufacturing any more of them.
As for a Spectrum analyzer, I sold the one in the pic, and it never reached its destination intact, a pitiful end. Now I have a couple old 141Ts with a set of plug-ins and tracking generators, Thats plenty good enough for amateur radio work.
Mike
Since I fall under the definition of "space constrained amateur" at present, the analyzer plugins are the order of the day - in fact, the modular/space saver aspect is why I started these Tek threads. There is a later-model HP spectrum analyzer which will eventually end up on my bench, along with their I/Q/ESR meter and sweep generator. I can put a 7603 at either end of the existing bench along with a TM506/TM5006 pair and have a pretty comprehensively equipped, mission-adaptable lab at my fingertips.
Yes, Tek should have offered a nice, synthesized TM500-series sweeper plugin or AM/FM-capable VHF/UHF generator built along the lines of the SG5030/SG5050. I don't think they wanted to cut into their discrete-unit market, so such things were never realized.
KE0ZU
08-17-2013, 11:53 PM
We're talking for applicability and use in present day work, not when the equipment was built.
Of course the 500s had no digital capability per se, however, in the analog arena, the Alpha and 1 series plug-ins cover just about any function the 7K plug-in offerings provide, and certainly more over all capability than the medical oriented 5K line.
Given the 7104's Micro Channel CRT architecture I wouldn't run anything in it besides a pair of high-bandwidth vertical amplifiers, a 7B10 timebase and a 7A13 differential amplifier...possibly a 7S11/7T11 combination. None of the special display-formatting plugins, however...some of which can damage the 7104's CRT.
Agreed, but at the time, the 7104 was the last of the Mohicans so to speak, and I wanted to get some pics of the analyzer for the ebay listing. I've since found a couple of memory scopes I couldn't refuse, so I still have a few of them to get rid of.
I'm probably preaching to the choir but you have sourced an extra U800 or two for that 2465, I assume? That's the one reason I bought what I did instead of the later-model stuff: Bad, BAD Tek for inadequately cooling that IC, and bad Maxim for not manufacturing any more of them.
Seems most anything built since the introduction of ASICs is doomed to the same fate. For quite some time, I refused to buy T.E. with ASICs or uP controllers, for that very reason, but the need for a good sweeper and the price/performance advantages of newer equipment finally won me over, and I'll just have to live with the prospect of expensive door stops. However so far so good.
...in fact, the modular/space saver aspect is why I started these Tek threads.
I had the opportunity to use a TM5006(?) with a compliment of plug-ins years ago, and had been considering that approach for the same reasons you stated. I was impressed with the performance of the equipment, but the panels were just too cramped for my liking. It may sound silly, but I prefer Rack panels with well spaced, big, easy to use keys and knobs. I'm not a "menu" kinda guy either, so a lot of modern transceivers don't show up on the radio bench either, and I've bought houses for less money than some of the newer offerings cost.
Bump.
I started looking into the Tek 5000 series scopes in a roundabout way: Seems that several companies used an OEM version of those mainframes for various applications. A couple involve scalar network analyzers - the Wiltron 640 and Pacific Measurements 1038 series were built into modified 5103/D10 (5110) chassis.
Since A) I'm cheap; B) I'm crafty, I decided to see about constructing my own 640, using a 5110 as a starting point. Did this ever snowball...I now have a rack-mount 5110, rack-mount 5112 (dual-beam non-storage) and a desk-top 5111 (single-beam storage) scope sitting here. With an interesting collection of plugins: A dual timebase for the 5112 and a pair of 5A14 4ch vertical amplifiers. 8 channels (at 1MHz) on one scope - how cool is that? A 5D10 2ch digitizer...5B25 digitizing time base. A 5B31 selectable-delay time base. A complete collection of Wiltron 640 plugins, so I can build that scalar analyzer setup (some mainframe modification required, of course). A pair of 5A24N user-customizable amplifiers which can drive the scope's vertical and horizontal deflection circuitry. And last...a 5L4N spectrum analyzer. This one is great for audio work as it covers 10Hz to 100KHz. Can also function as a time-domain device in manual tuned mode.
Why the 5k stuff instead of the much more capable 7k line? Low frequency noise. According to the folks who actively use them, the 51xx (2MHz B/W) are very quiet (electrically) at audio frequencies and will allow a user to observe signals in the microvolt region. Thus, my bench has space for both.
I need a few more plugins to round out this line: A 5CT1N curve tracer and a 5S14 sampler...maybe a few of the various differential amplifiers, comparators and whatnot which were offered. And then there's the 544x series (50MHz B/W). One of those with a dual timebase and a couple of 2ch vertical amplifiers will make for a nice, quiet lab scope for IF work.
Another thing to be investigated: Roll-your-own plugins. Tek made blank plugin kits for the TM500/5000 along with the 7000 series and I can visualize a couple handy ones for this line of gear.
Restoration, conversion and repair pics to follow as I get to them.
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