Tektronix 665 manual

Welcome, Guest. Please login or register. Did you miss your activation email? This topic This board Entire forum Google Bing. Print Search. Pages: [ 1 ] Go Down. Ishmael Contributor Posts: 7. Hello everyone! There's hardly a scratch on this thing. The front cover is included as well as the pouch. I was testing it and it seems like it needs repair. The signals on the display look blurry and out of focus.

Everything else works fine. That makes a huge difference. The techs don't disassemble the units. A lot of repairs are new crystals, or reprogramming the synthesizer, or replacing a bad LCD display which is done before a tech sees it.

Also, they do large runs of the same unit, then do a different model. Also, some only need a few pieces of the case replaced, and the password cracked so it can be reprogrammed in the field. They have service contracts where someone ships a pagers or cell phones and they repair what they can in a fixed time. They either return the bad units, or replace them with their own stock of repaired units, depending on the contract.

We were talking about repair and service equipment, not consumer items. A consumer item is expected to have a short life-cycle, and repairability is often not a concern.

OTOH, everything inside was reachable and easily repairable. If that MHz scope can be built to have a reasonable cost to lifetime ratio, then it could be considered a consumer item, and a non-repairable investment.

A very good analyzer series, but generally still priced out of the hobbyist market. Reasonably portable, and ruggedly built. Performance is generally a bit lower than the x series, but still very respectable. Much more useful than a hobbyist-affordable analyzer, and easier and more versatile than an older analyzer. Unless your needs are exotic, the x series will be a good industrial choice. For the spectrum analyzer part, the best a hobbyist can usually afford is an HP, with a few plug-ins IIRC, they offered a total of 6, collect the whole set!

And you will need some other basic and decent lab gear scope, counter, DMM, sig gens to do the job right. Sorry, but I can't comment on any Network Analyzers. If you cannot see the relationship, then you need to stretch a bit. Everything in electronics, test equipment especially has grown in complexity and performance, as it has been reduced in size. Some of the reductions are there to make it possible to fit more test equipment in a given space, and some are there because of necessities of the new technology eg.

Was your life, as a technician that is, made better or worse when that same 4 man lift SA was reduced to one that you could carry yourself with one hand, while carrying your 1G scope with the other? How about performance? How about your 30MHz scope that is now 1GHz? Did you notice that the prices went DOWN? How about the heat generation? Have you ever worked in a lab that had no effective air conditioning, and also had a herd of Tek series scopes whirring away?..

I have, and I am quite happy not to do it anymore. We saw temperatures as high as F at times. No windows, one door, lots of fans. Turn off the equipment, and the AC did quite fine. And finally, how about the space savings? Does it help you or hurt you to recapture that floor space the old SA, and scope, and signal generator used?

Tiny little custom component ridden hard to service test equipment made it possible to move away from that kind of scene. You cannot be serious. Most of this stuff is so finely calibrated that it would be beyond the capabilities of anything but an expert calibration lab to accomplish the task. Just having the standards necessary takes a whole lab I know this because I tried to set up a NIST traceable cal lab for my business, and eventually concluded that for me to do that, cal would have to become my exclusive business.

I still have all the standards and equipment, but no time to put them to use No money to keep them in cert with NIST. It is FAR cheaper to send the stuff out and get it calibrated. The "consumer grade" goodies in the test equipment market don't really need more than a simple calibration checking. I cannot tell you the last time my little Fluke DVM needed recalibration Has something to do with the little fidgety custom components that are inside it.

Same goes for my Tek scope. This might be a bit off the exact topic but I have a friend who has a HP and the horozontal display scan has shrunk and folded over on top of itself. Having never worked on test equipment, I could only offer generic possibilities, Voltages, deflection transistors, caps? Is there are common part failure that can cause this to the best of your knowlege? Thanks, Dave. You keep mixing the needs of an enterprise with those of a hobbyist.

True, many of the people on the groups of this thread are electronics professionals who also have an electronics hobby interest. My comments have all been aimed toward the hobbyist. If you have a B scope one of the finest analog scopes I have ever used , then you are one extremely wealthy hobbyist, and the economic constraints most everyone else lives by must not apply to you.

A hobbyist doesn't send anything "out" for calibration; they rely on the ability to cross-check their various gear with everything else in their collection. Sometimes, they might be able to compare one of their items with a professionally calibrated and traceable item. Or maybe they buy a new DMM, that's rated for 0.

My point is that old equipment is repairable. Your point is that newer equipment is chock full of value, more reliable, and is easier to lift. There's no contradiction between these positions. BTW, your DVM always "needs" calibration, even if it is still within tolerance every time it's checked. Nice to know that it's stable, but nothing lives forever.

As for "fidgety little components", should you ever apply a few watts of RF to the input of your , you'll find it very difficult to repair by yourself, and the Tek bill for the job could very well approach the replacement cost. If the same had happened to a , then you would just be replacing a few small, precision resistors. Look at the 2W resistors and the output transistors in the output deflection stages for a start.

What I am NOT doing is trying to mix the needs of the hobbiest with the realities of companies that build for professionals. You are lamenting the fact that the newer gear is hard for hobbiests to maintain. That argument will go soft on HP or Tektronix, or any of several dozen other equipment manufacturers that make equipment for professionals. The simple fact that your abilities at repair stop at thru hole, technology, doesn't mean that devices that use hybrids, and surface mount technology are not repairable.

The hybrid front end on the is quite repairable, but requires a little optical help, just like watch repair, an 's tecnology. From what I have heard, most of the parts in the hybrid are standard off the shelf surface mount faire I have no direct knowledge of whether this is actually true.

I did find it to be the case with the output hybrid in HP's A sweeper plugin. There would be no more point in taking your busted to Tek for repair than there would be for your , they won't work on either. Checked is not the same as calibration. The case doesn't even get opened for "checked". And to your assertion that I am a rich hobbiest, I am not an electronics hobbiest at all!

I am a self-employed electrical engineer, and I use the test equipment I own to earn a living. Sadly, for me electronics died as a hobby when I started getting paid to do it. The happy part is I truly enjoy my work! Old tube gear, and old minicomputers. Way too new! Things that have absolutely no practical use ;- -Chuck. BTW my Trash 80 was a real Trash S said it was uneconomical to repair, read out of warrenty replaced a bad ttl chip and away it went. A friend reworked the firmware to get rid of the infamous keyboard and cassette problems we rescued 8 of them from that dumpster.

That's a good one! I spent too much time using the original TRS to ever really want one. In one of my first consulting jobs I wrote a bunch of drivers for a customer's Z80 controlled instrument using the customer's TRS as the development system. It worked just fine, I guess Good for you! Shoulda kept it? Still have that little pocket version with 4k RAM, though. It'll come in handy someday :- -Bill M. Sorry, I never had much use for TRS's. And, considering that it has a built-in monochrome monitor, it qualifies as a genuine boat-anchor, since it glows in the dark.

A commercial calibration implies no warranty of future reliability. It just means that the unit was inspected, by a lab with traceable standards to NIST , and that equipment parameters were found to be within the specified tolerances or some adjustments we made to allow for proper performance.

Every equipment should be on a periodic schedule of calibration, possibly 6 months or 12 months. The interval is determined by the original manufacturer's declaration, or from the class of equipment is it a resistor or a function generator or an oscilloscope , or from the accumulated record of a device's calibration history. A Metrology professional can make a case for shorter or longer intervals, based on a review of the calibration history.

The calibration is valid as of that date only, although it's reasonable to expect that the calibration will be valid for some time to come unless the shipper dropped it as it went out the cal lab's door!

All that said, a traceable calibration is an indication that the equipment has been treated in a professional manner, and I would view that as a definite plus when considering a purchase. That's my opinion. Do I care what Agilent or Tektronix thinks? Gee, do they care what I think? And why are YOU worried about their feelings? Sounds like your nose if pretty far up somebody's butt! Sorry, I don't do watches.

A "little optical help" isn't a magnifying lens in a fluorescent work light. BTW, turn on your spell checker, a 's technology. Well, don't let lack of direct knowledge slow down your opinions. I wish you enjoyed reading the thread as well. I said you were either a professional or a very rich hobbyist as you had declared ownership of some nice gear.

OK, you are a professional. Do you hear me now? Well, that's a good sign, as we have been yakking about this in the boatanchors and more group. This is a hangout for hobbyists and very frugal professionals.

What it actually means is anybodies guess. It could be actually calibrated, it could be that the guy bought it surplus, turned it on, and it lit up. The words "fresh calibration" without an express warranty are worthless. Most anything Tektronix or HP made will stay in calibration to close enough for hobbiest use for years. A real bonifide business won't be comfortable using test equipment that is out of calibration for anything very important.

It is their assurance that all of the functions should be working properly. You should care. Unless you suddenly start building your own test equipment, you are going to be "stuck" with using equipment geared toward professionals, and manufactured by companies like HP Agilent or tektronix. OBTW, can you think of a less vulgar way of expressing your opinions? I have no financial interest in any test equipment manufacturer. They don't give me special favors, or punishments for stating my opinions.

I don't think so!!!!!!!!!!! The "average hobbyist" once made complete radios from hunks of rock, metal and wood. A pretty extreme feat for the time. Now if it requires a little study, or the acquisition of some special skill, or tools, it is deemed impossible. At least when I post, my spelling is the result of my own efforts. Yours, apparently, comes from the efforts of a machine. I don't think it hurt your eyes all that much to stumble over one of my very few typo's.

When you type at over WPM, a few will sneak in now and then. The parts in these hybrids are very large compared with mechanical watch parts. A cheapy stereo dissection microscope works very nicely Back in the days of yore, adjusted to today's dollar, a soldering gun cost as much.

You have some direct knowledge that says differently? I know that there will be some parts that are special, but I doubt all are. I have several friends that do a good business repairing these "special" hybrids, they aren't great big companies, just individual hams that saw a market.

I haven't needed to go inside the hybrids on my , mostly because I don't put my scope into positions where it is likely it will get zapped. If you have a B scope one of the. It is a hangout for people with an interest in boatanchors, nothing more, nothing less. I work on SMD all the time. I go down as far as components, which look like sand, and have replaced pin QFP chips without problem. BGAs are where the hobbyist becomes incapable of working on them.

Ball Grid Arrays. Yes, and I came within one day of throwing one down some stairs to put it out of service so I could get a laptop at work. Figure Block Diagram B and Above.

Figure Graticule References. Figure Test Hookup for Functional Tests. Figure Horizontal Adjustments One. Figure Horizontal Adjustments Two.

Figure Horizontal Adjustments Three. Figure Gain and Voltage Test Setup. Figure Trigger Level Test Setup. Figure Bandwidth Test Setup. Figure Timing Test Setup. Figure Dual Delay Test Setup. Figure Video Trigger Test Setup. Figure Location of Boards for Adjustments. Figure Horizontal Output Calibration Setup. Figure Factory Vertical Calibration Setup. Figure External Trigger Calibration Setup. Figure Vertical Adjustments.

Figure Adjusting Vertical Gain and Centering. Figure Attenuator Compensation Test Setup. Figure Analog Board Adjustment Locations. Figure Oscilloscope Orientation.

Figure Internal Modules. Figure Cables and Cable Routing. Figure Knob and Shaft Removal. Figure A1 Analog Board Removal. Figure Location of Display Driver Board. Figure CRT Removal.

Figure Power Button Shaft Disconnect. Figure Power Supply Removal. Figure Fan and Fan Mount Removal. Figure Cabinet and Rear. Figure Front Panel Assembly. Figure Chassis. Figure Circuit Boards. Figure Accessories. TableStandard Accessories. TableOptional Accessories. TableAvailable Languages. TableNominal Traits Triggering System. TableNominal Traits Cursors. TableNominal Traits Mechanical. TableWarranted Characteristics Triggering System. TableWarranted Characteristics Video Triggering.

TableWarranted Characteristics Cursors. TableTypical Characteristics Triggering System. TableTypical Characteristics ZAxis. TableTypical Characteristics Probe Compensator. TableTypical Characteristics Setup Memory. TableTest Equipment. TableDC Coupled Bandwidth. Table ms Dual Delay Accuracy. TableAdjustments and Dependencies. TableExternal Inspection Check List.

TableTools Required for Module Removal. TableEquipment Required for Troubleshooting. TableSymptom Matrix. This manual provides you with both operation and modulelevel service information. Use the Getting Started section to learn about applying power. This section also contains brief examples of how to use the controls. Use the Operation section to learn about each of the front panel controls and how to perform certain tasks to help you understand typical steps involved to obtain stable, usable displays and take measurements.

Use the Theory section to help you understand the operation of the oscillo scope to the block level. Use the Performance Verification section to verify the functionality and war ranted characteristics of the oscilloscope.

You should adjust the oscilloscope if indicated by the Performance Verification procedures. Use the Maintenance section to learn how to perform general maintenance and troubleshoot your instrument to the module level. Procedures to replace mechanical parts and electrical modules are also located in this section. Use the Replaceable Parts section for a list of the mechanical parts and modules.

Use the Appendices section to learn about each of the menus. The Service manual Tektronix part number XX provides extended service information not contained in the Instruction manual. Items included are a detailed Theory of Operation, Schematics, and a complete electrical and mechanical parts list. Safety Summary Please take a moment to review these safety precautions. They are provided for your protection and to prevent damage to the oscilloscope.

This safety information applies to all operators and service personnel. These two terms appear in manuals: H H statements identify conditions or practices that could result in damage to the equipment or other property.

These two terms appear on equipment: H CAUTION indicates a personal injury hazard not immediately accessible as one reads the marking, or a hazard to property including the equip ment itself. Observe all of the following precautions to ensure your personal safety and to prevent damage to either the TAS and TAS Analog Oscilloscopes or equipment connected to them.

Do Not Perform Service While Alone Do not perform internal service or adjustment of this product unless another person capable of rendering first aid and resuscitation is present. To avoid personal injury, do not touch exposed connections or components while power is on. Disconnect power before removing protective panels, soldering, or replacing components. A pro tective ground connection, through the grounding conductor in the power cord, is essential for safe system operation.

To avoid electric shock, plug the power cord into a properly wired receptacle where earth ground has been verified by a qualified service person. Do this before making connections to the input or output terminals of the oscilloscope.

This includes knobs and controls that may appear to be insulators. Use the Proper Power Cord Use only the power cord and connector specified for your product. Use only a power cord that is in good condition. Use the Proper Fuse To avoid fire hazard, use only the fuse specified in the parts list for your product. It must be identical in type, voltage rating, and current rating. This oscilloscope uses a combination of frontpanel buttons, knobs, and onscreen menus to control its many functions.

The frontpanel controls are grouped according to function: vertical, horizontal, trigger, and special. Within each group, any function adjusted often, such as vertical positioning or the time base setting, is set directly by its own frontpanel control.

Many instrument controls and menus are set to a predefined state, providing you with a known starting point for your measurements. Menus Those functions for which control settings changed less often, such as vertical coupling and trigger mode, are set indirectly.

The buttons below this main menu select a function, such as cou pling and displays a sub menu of settings for that function, such as DC, AC, or GND, at the right side of the screen. The buttons to the right of the menu select a setting, such as DC.

The method employed is the same as for selecting a function, except the final selection in the side menu causes the General Purpose Knob to adjust some function, such as the position of measurement cursors on screen. Once you complete a complex setup and then save it in one of the four memory loca tions, you can retrieve it at any time. Saved front panel settings do not include the assignment of the General Purpose Knob. The vertical system provides two vertical channels with calibrated vertical scale factors from 2 mV to 5 V per division.

Both channels can be displayed, vertically positioned, bandwidth limited to either Full or 20 MHz , inverted, and vertical coupling specified. Besides the two channels, a math waveform is available for display. A math waveform results when you add the two channels. There are three horizontal display modes: main, delayed, and XY. The delayed display can be delayed by time with respect to the main trigger.

The delayed display can also be set to display at the first valid trigger after the delay. XY mode is useful to measure the phase difference of two signals. The triggering system comprises a complete set of features for triggering the horizontal system.

You can configure trigger for source, slope, coupling, mode, and holdoff. Video triggers are available for triggering on video sig nals. Once you have set up to take your measurements, the cursors can help you take those measurements quickly.

The TAS and TAS Oscilloscopes have two types of cursors for taking measurements on the displayed waveforms: delta difference and absolute. The General Purpose Knob controls the placement of the cursors.

Delta voltage measures the voltage between the horizontal bar cursors. Delta time measures the time between vertical bar cursors. These are delta measurements; that is, measurements based on the difference between two cursors. Absolute voltage measures the voltage position of a single horizontal bar cursor.

The displayed voltage level readout is made with respect to the ground reference level of the channel. The bar cursors remain displayed even if you change the function of the General Purpose Knob. This allows you to use them as reference points or markers to easily identify if measurement signals remain within the parame ters set by the cursors.

Remove the cursor display by turning the cursor measurement off. A description of each option follows. See Table WarrantyPlus Service Options The following options add to the services available with the standard warran ty. The standard warranty appears following the title page in this manual. Option M8: Tektronix provides four calibrations and four performance verifications, one of each in the second through the fifth years of service.

Option 3R: Rackmounted With this option, Tektronix ships the oscilloscope with a rackmount kit, providing all the necessary hardware to adapt the oscilloscope for installa tion into a standard 19 inch instrument rack. Customers with instruments can order a rackmount kit Tektronix part number for conver sion with instructions. Option Front Cover and Pouch With this option, Tektronix ships a protective front cover to prevent damage to the front panel of the oscilloscope while not in use.

An attachable pouch attaches to the instrument top provides storage for the manuals and probes supplied with your oscilloscope plus other additional accessories you may want to keep with your oscilloscope.

Option Additional Probes With this option, Tektronix ships two PB 1X 10X switchable passive probes in addition to the two standardaccessory PB probes normally shipped with the instrument. Option 9C: Certificate of Calibration and Test Data Report Tektronix ships a Certificate of Calibration that states this instrument meets or exceeds all warranted specifications and has been calibrated using standards and instruments whose accuracies are traceable to the National Institute of Standards and Technology, an accepted value of a natural physi cal constant or a ratio calibration technique.

The calibration is in compliance with U. This option also includes a test data report for the instrument. Table 14 provides a list of these manuals. Check that you have the proper electrical connections. The rear label lists power requirements for all possible voltage inputs 2. For serial numbers B and below, check that the Line Voltage Range switch Figure 21 is at the proper setting for your power system.

For serial numbers B and above, no line voltage setting is re quired. Check the fuse to ensure it is the proper type and rating the rear panel provides you with this information. Fig ure 22 illustrates how to open the fuse drawer.

Connect the proper power cord from the rearpanel power connector Figure 21 to the power system. Power Connector Fuse Compartment. Figure Fuse Compartment 5. Be sure you have the appropriate operating environment. Specifications for temperature, relative humidity, altitude, vibrations, and emissions are in Section 4, Specifications.

Leave space for cooling. Do this by verifying that the air intake and exhaust holes on the sides of the cabinet are free of any airflow obstruc tions.

Leave at least 5. Review At a Glance in Section 3 if you want an overview of all controls and connectors. You can display the channels separately or simultaneously.

The following steps demonstrate how to select and deselect channels for display. Power on the oscilloscope and wait for the self tests to complete. Press the CH 1 button located on the front panel. The CH 1 indicator lights, channel 1 is displayed, and vertical controls and menus are assigned to channel 1.

Press the CH 2 button located on the front panel. The CH 2 indicator lights, channel 2 is displayed, and controls and menus are assigned to channel 2. Press the CH 1 button, assigning control to channel 1. In the following steps, you will set only channel 1 on and turn the cursors on. Now two horizontal bar cursors are displayed. The active movable one is a solid line and the inactive one is a dashed line. Before using any probe to take measurements, compensate the probe to match the input channel.

See Compensating the Probe on page Turn all other channels off. Wait one to three sec onds to allow the instrument to adjust all the control settings. The instrument will trigger on the waveform, display at least one complete cycle, and center it horizontally on the CRT. The baseline of the waveform will be at the center horizontal graticule line. The intensity level is increased if set too low for a viewable display.

Before taking any mea surements using a probe, first check the compensation of the probe and adjust it to match the channel inputs. Attach the probe to either the CH 1 or CH 2 input connectors along the lower right of the front panel. Select the appropriate input channel, channel 1 or channel 2, by press ing the CH 1 or CH 2 frontpanel button.

With the probe attached between an input channel and the probe com pensation output of the oscilloscope, press the AUTOSET button on the front panel. Set the trigger coupling to Noise Reject use the following guide. Check that the displayed waveform is a square wave with flat tops and bottoms. See Figure 26 for illustrations indicating proper and improper probe compensation.

Adjust the low frequency compensation adjustment, located in the probe body, for the best possible square wave. See Figure 27 for the location of the low frequency adjustment.

You need to consider three oscilloscope operating systems to obtain the best possible display. Vertical System You can change the vertical components of the displayed waveform by adjusting several features of the vertical operating system.

Horizontal System You can change the horizontal components of the displayed waveform by adjusting several features of the horizontal operating system. Trigger System You can modify the triggering system in a variety of ways to create the best possible triggered display, depending on the components of the input waveform. To reduce the clutter of knobs and buttons on the front panel, many instrument control functions are now menu driven.

The menus access instrument functions typically set once before taking measurements. The front panel controls access instrument functions you might need to adjust during mea surements. The menus are easy to use. This section of the manual illustrates each control and connector and con tains a brief description of its use or function. The power and display controls allow you to cycle the power on and off and adjust the CRT display.

The power switch cycles the instrument power on and off. Frontpanel settings existing prior to power off return at power on.

The intensity ratio between the main sweep and delayed sweep is set in the Utility menu see page A7. A probe compensation signal and a chassis ground contact are also provided.

See page 25 for further information. This connector provides contact with the chassis ground. The CH 1 input connector connects signals to the input of the channel 1 vertical system. A signal connected to the CH 1 input connector produces the horizontal deflection Xaxis when horizontal mode XY is selected.

The CH 2 input connector connects signals to the input of the channel 2 vertical system. A signal connected to the CH 2 input connector provides the vertical deflection Yaxis when horizontal mode XY is selected. The EXT TRIG input connector allows the application of an external signal to use as the trigger source rather than a trigger signal generated from a vertical input channel.

The input coupling is DC and the attenuator factor can be set to either 1 or B Position the waveform created with the ADD function by positioning the added channels.

The channel select buttons determine which channel is currently selected for control. A lighted LED next to the channel button indicates the selected channel. Multiple channels may be displayed but only one channel may be controlled at a time. The menu displayed is dependent on the channel select buttons. See page 39 for menu choices. The LED for that channel will be turned off. The channel label for that channel will be replaced with OFF.

Turning the waveform off for one channel will automatically cause the oscilloscope to switch functions to a remaining channel. Channel 1 will remain selected when all others are turned off unless the ADD function is on. Use the horizontal sweep controls to access the features of the horizontal system for both the main and delayed sweeps. The calibrated main sweep speed is selectable from 0. The calibrated delayed sweep speed is selectable from 5 ms to 20 ns per division.

The MAG button magnifies the main and delayed sweeps by a factor of The trigger controls provide access to the features of the trigger system for both the main and delayed sweeps. Its value is displayed in the readout. The sweep triggers when the amplitude level is reached. A trigger level indicator appears on the display while changing the level and disappears after about five seconds of no level changes.

The buttons described here either have a relationship with many instrument functions or perform specific tasks. Use the General Purpose Knob to position the cursors. Figure 32 is a complete map of the menus; it will help you locate menu driven functions and their available settings. Refer to Detailed Menu Descrip tions, beginning on page A1, for operating information about each menu. The CRT displays information about instrument settings, menus, and mea surement values. Figure 33 illustrates where on the CRT you can find the information.

Figure 34 illustrates the types of indicators that appear on screen and what they mean. Figure 35 illustrates the waveform reference indicators and measurement cursors. Repetitive signals have a recurring pattern, where the amplitude and fre quency do not change from one cycle to the next. The MAG button horizontally magnifies the sweep by a factor of ten.

This can be very useful in viewing a fast signal transition. Press the MAG button, expanding the waveform horizontally by a factor of ten. Refer to Figure Video signals contain both horizontal and vertical sync pulses.

The trigger system has modes to identify either of these pulses and produce a trigger. Set the trigger mode to video line or video field use the following guide.

Set the SRC to the appropriate trigger source. Select Rising for inverted video signals. Set the vertical and horizontal controls to produce the desired display. Figure 37 illustrates a typical triggered TV signal. The single sequence trigger mode allows one sweep of all displayed chan nels to occur for each trigger event. Another sweep cannot occur until the trigger circuit is rearmed. Use single sequence mode to display and photograph either nonrepetitive signals or signals that cause unstable displays.

Set the vertical and horizontal controls as desired. Set the readout and cursors display options by pressing the UTILITY button and selecting the appropriate choices with the menu select buttons. See page A7 for a description of the utility menus. The LED will remain lit until the instrument receives an appropriate trigger signal. With this feature you can see the results of adding two signals together or removing unwanted com ponents of a signal.

This procedure demonstrates how to use the add feature of the TAS and TAS Oscilloscopes by solving a common problem of having an AC linefrequency component mixed with another signal. Using channel 1, obtain the signal containing the unwanted AC linefre quency component mixed with another signal. Using channel 2, obtain the AC linefrequency component only. Invert the channel 2 signal use the following guide.

The invert indicator appears in the channel 2 readout display. The instrument displays a third waveform that shows the result of adding the two waveforms together. Figure 38 shows an example of subtracting using invert waveforms. Vertical position of the added waveform is affected by the vertical position of the added channels. Delayed triggering allows you to set a time delay from the triggering event for the main sweep to start the delayed sweep.

This enables you to effective ly increase the resolution of a portion of the main sweep by displaying a segment of the main sweep using the delayed sweep. Turn the delayed sweep on use the following guide. NOTE The intensity ratio between the two sweeps can be set to help differentiate between them.

See the Utility functions on page A7 to set this ratio. Select MORE until you can select the intensity level ratio for the delayed sweep use the following guide.

Adjust the trace separation to vertically separate the main and delayed sweeps use the following guide. This causes the delayed sweep to start after the time delay setting regardless of a trigger. Adjust the delay time move the intensified zone using the General Purpose Knob. Use the following guide. You now have a display that consists of the main sweep with an intensified portion and a delayed sweep of the intensified portion see Figure When the delayed sweep scale matches the main sweep scale, further reduction of the delayed sweep scale also affects the main sweep scale.

When the main sweep scale matches the delayed sweep scale, further increases of the main sweep scale also affects the delayed sweep scale. Figure Using the Delayed Sweep Set the trigger mode to trig after, causing the delayed sweep to start after the delay setting and an appropriate trigger use the following guide.

At this point, the two waveforms are still displayed, since an appropriate trigger signal is available. Adjusting the trigger LEVEL control out of the range of the waveform causes the delayed sweep to stop, since an appropriate trigger signal is no longer available.

Using Dual Delay Dual delay displays two intensified zones on the main sweep, each defining the start point of a delayed sweep. This method more accurately measures time between two points on the main sweep than obtained with the mea surement cursors. Set the trigger mode to runs after use the following guide. Notice that turning a measurement cursor on automatically turns a previously selected measurement cursor off.

You now have two intensified zones displayed on the main sweep. Adjust the position of the intensified zones using the General Purpose Knob. Notice that the delayed sweep now consists of two delayed sweeps, each representing one of the intensified zones. When the two delayed sweeps appear as one, the intensified zones are at exactly the same position of the cycle of the main sweep.

Figure shows the intensi fied portions on the main sweep and the delayed sweeps positioned together. This feature is very helpful when you have com pleted a complex front panel setup and you want to be able to recall the setup later. Saving a Setup Use this procedure to save a frontpanel setup.

Select SAVE and memory location 1, placing the setup in memory location one use the following guide. NOTE Selecting a location previously used will replace the old settings with the new settings. Setup locations underscored contain a stored frontpanel setup. Once you have saved a particular frontpanel setup, you can change the settings as you wish, knowing that you can retrieve the original setup at any time.

Recalling a Setup Use this procedure to recall a frontpanel setup. Select the location from which you want to retrieve the frontpanel set tings setup 1 through setup 4. Setup locations underscored contain a frontpanel setup. The oscilloscope returns the frontpanel settings to those in the selected setup location. Erasing a Setup If you wish, you can erase any setup location. Select the location you wish to erase setup 1 through setup 4.

The selected setup location is now empty. Taking Measurements This section provides procedures for taking several different types of mea surements related to time and voltage. Since the cursor measurement system takes measurements easily and quickly, all measurements dis cussed in this section use the cursors. You can take frequency, period, and time between event measurements with the cursor measurement system. The following procedures provide you with quick and easy methods to take these measurements.

Measuring the Frequency and Period Measuring the frequency and period of a waveform are both time related measurements. You measure frequency in hertz Hz and period in seconds. Obtain a stable display with at least one complete cycle of the waveform displayed. Using the General Purpose Knob, move the active cursor along the waveform to a starting point for the measurement.

A good place for this first cursor is midway on the rising portion of the waveform. Using the General Purpose Knob, move this second cursor to the same position on the waveform that is one complete cycle away. See Figure for placement of cursors. After you place the cursors, read the frequency of the waveform dis played in Hz on the CRT. Figure Measuring the Frequency of a Waveform 6. Change the displayed measurement from frequency to time by turning the DTIME cursors on use the following guide.

NOTE Do not move the placement of the cursors. Use the same waveform and cursor placement, as used in the frequency measurement, to measure the period. Read the period of the waveform displayed in seconds on the CRT. Measuring Pulse Width You can measure a pulse width with the time measurement cursors. Use the General Purpose Knob to move the active cursor along the waveform to a starting point for the measurement.

Use the Gener al Purpose Knob to move this second cursor to the place on the waveform where you want to measure time in relation to the first cursor. Placing the cursors at the rising edge and the falling edge gives the pulse width measurement. The time pulse width in seconds appears on the CRT. See Figure to help take these measurements. Set the time measurement cursors on use the following guide. This location is marked on the CRT graticule.

The rise time in seconds appears on the CRT. You can take voltage measurements either as an absolute value or a differ ential delta value. Absolute voltage measurement is the voltage referenced to ground. Differential voltage measurement is the difference between the two cursors, typically referred to as the delta D value.

Only one cursor is active for this type of measurement. Obtain a stable display. Set the cursors to measure the absolute voltage use the following guide. Using the General Purpose Knob, move the cursor along the waveform to obtain the DC voltage level referenced to ground.

See Figure for placement of cursor. The voltage appears on the CRT. Delta Voltage Measurement The delta volts measurement measures the volts between the two horizontal cursors. Set the cursors to measure delta volts use the following guide. Use the General Purpose Knob to move the first cursor along the waveform as a reference point for the measurement.

Use the Gener al Purpose Knob to move this second cursor along the waveform to the point where you want to make the measurement in reference to the placement of the first cursor.

The delta voltage appears on the CRT. Included are electrical and mechanical traits. GND input coupling disconnects the input connector from the atten uator and connects a ground reference to the input of the attenua tor. The maximum value can not exceed the end of the Main sweep.

A default slope selection for TV trigger modes can be entered in the scope configuration menu.