TEKTRONIX 485, DUAL TRACE, CALIBRATED, REFURBISHED, 41 TANTALUM CAPS REPLACED, US $730 – Picture 0

TEKTRONIX 485, DUAL TRACE, CALIBRATED, REFURBISHED, 41 TANTALUM CAPS REPLACED, US $730 – Picture 1

TEKTRONIX 485, DUAL TRACE, CALIBRATED, REFURBISHED, 41 TANTALUM CAPS REPLACED, US $730 – Picture 2

TEKTRONIX 485, DUAL TRACE, CALIBRATED, REFURBISHED, 41 TANTALUM CAPS REPLACED, US $730 – Picture 3

TEKTRONIX 485, DUAL TRACE, CALIBRATED, REFURBISHED, 41 TANTALUM CAPS REPLACED, US $730 – Picture 4

TEKTRONIX 485, DUAL TRACE, CALIBRATED, REFURBISHED, 41 TANTALUM CAPS REPLACED, US $730 – Picture 5

Tektronix 485, Dual Trace, Calibrated, Refurbished, 41 Tantalum Caps Replaced

US $730

Tustin, California, United States
Jan 29th

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TEKTRONIX 485, 350 MHz, DUAL TRACE OSCILLOSCOPE CALIBRATED -- WARRANTED The 485 is an Analog, general purpose, environmentalized, high performance, portable, wide band oscilloscope which has a dual channel vertical amplifier with selectable input impedance. The bandpass is DC to 350 MHz with 50 Ohm input impedance and DC to 250 MHz with the 1 MOhm input impedance. The 485 has a 1 nS/DIV to .5 SEC/DIV sweep rates, stable triggering to well beyond 400 MHz and calibrated X-Y capabilities. The Delayed sweep has calibrated delay time, can be triggered after delay and can be displayed with the intensified main sweep in an alternate sweep switching display. Additional features are X1, X10 and X100 probe scale factor readouts, 8 DIV (vertical) X 10 DIV (horizontal) graticule area, small spot size and high writing rate. A 20 MHz bandwidth limiter, 1 MHz and 1 KHz fast rise calibrator and auto focus are also included. The 50 Ohm input is automatically disconnected from excessive input voltage applications. An external trigger view is also provided. The 485 will operate from 90 to 136 VAC in the 115 VAC mode or 180 to 272 VAC in the 220 VAC input mode, with input frequencies from 48 to 440 Hz and at elevations up to 15,000 feet. OPENING BID IS $467, NO RESERVE, A 10 DAY AUCTIONTHE $467 OPENING BID PRICE IS FOR THE COMPLETE OSCILLOSCOPE PACKAGE THIS PACKAGE CONSISTS OF THE OSCILLOSCOPE, THE 1.7GB SERVICE MANUAL ON A DVD DISK, A XEROX COPY OF THE ORIGINAL OPERATIONS MANUAL, TWO NEW X1-X10 100MHz PROBES AND PREPAID PROFESSIONAL PACKING Saturday, November 29, 2014; 4:39:31 PM < ===Time flies like an arrow, is your bid in yet?==<< THE OLDER TEKTRONIX OSCILLOSCOPES We admittedly live in a throw-away society. If we happen to have a VHS device and it goes bad we immediately think of purchasing a new one rather than repairing the old one. I think this is because the industry advances so rapidly that it does not pay to repair an old VHS device since the cost of a new one, with new features and technology, approximates the repair costs of the old one.Such is certainly not the case with the older Tektronix Oscilloscopes. The 4XX series of Tektronix Oscilloscopes has easily repairable circuits and technology that is as vibrant today as it was the day it was designed almost 20 years ago. The oscilloscopes of the older Tektronix 4XX series are a joy to use . The analog response is around 1 to 3 nS, a figure that deserves respect even by today's rigid standards of performance. The crisp FET and tunnel diode triggering and bright display of these older Oscilloscopes will stand up to the best that are on the market today. Sure, the band pass of some of the newer Tektronix Oscilloscopes exceeds that of the older 4XX Oscilloscopes, but just how often do you encounter a signal over 300 MHz on your test bench that you must view? The older Tektronix Oscilloscopes did not use Large Scale Integrated (LSI) circuits. Almost all the circuits use transistors that are easy to obtain and are in sockets. Most of the transistors used in the Tektronix 4XX Oscilloscopes are available for about a dime each today. Trouble shooting the older Tektronix Oscilloscopes is fairly easy as Tektronix published outstanding manuals that makes trouble shooting a dream. All the circuits are DC coupled so trouble shooting is merely a matter of taking DC readings at critical points and comparing the measurements to the values published in the service manual. The next generation of Tektronix Oscilloscopes after the 4XX series was the 2XXX series. The 2XXX series uses a lot of LSI circuits, notably in the horizontal and vertical outputs. These LSI devices are subject to high power dissipation and do not hold up well. Replacement of these LSI devices is practically out of the question as Tektronix no longer supports the 2XXX series of Oscilloscopes and the supply of the Tektronix made replacement parts has pretty well dried up. After the 4XX series was discontinued in the early 1990s, Tektronix began building oscilloscopes with many custom VLSICs (Very Large Scale Integrated Circuits), shoddy mechanicals, and overall lower quality. The 4XX series of Tektronix oscilloscopes are the last oscilloscopes that can be fixed by the average electronic technician using readily available, off the shelf components. These oscilloscopes were once fairly common, but are now becoming rare. It will soon be hard to find an American made metal chassis analog oscilloscope of this quality in excellent condition. So if you are considering a quality Oscilloscope with a proven track record of performance I urge you to consider investing in a superior instrument that has many years ago passed the early infant mortality failure rate of modern electronic devices. In 50 years of working with Tektronix Oscilloscopes I have found them to be the instruments on the market with the best design. All the resistors are power over-rated by at least 100%; voltage ratings on filter capacitors is at least double the voltage applied to them; diode breakdown voltage is usually double the applied voltage. In short, the 4XX series of Oscilloscopes was designed to give many years of faithful service and that service period has yet to expire. FEATURES OVERVIEW Calibrated to Tektronix specifications, power on aged for 100 hours and calibration rechecked Unlimited warranty for 30 days No questions asked return within 5 days of receipt if not delighted. Restrictions apply, please read section on Return Rights. Front panel switch selectable input impedances of 1 MOhm or 50 Ohm 350Mhz Bandwidth (1 nS risetime in 50 Ohm input impedance), 250 MHz at 1 MOhm input impedance 1 nS/DIV to .5SEC/DIV calibrated sweep ranges 5 mV/DIV to 5V/DIV calibrated Vertical Sensitivity Very fast, stable patented FET and tunnel Diode triggering functional to well beyond 500 MHz Very high timing accuracy: under +/-1% on center line even at 1 nS/DIV A/B Trace Separation Control and Separate B Intensity Control Extra high acceleration voltage (21 KV) used in CRT to give higher writing rates Distributed vertical deflection plates with characteristic terminations for maximum frequency response Rarely used controls located on rear apron to reduce front panel clutter (FOCUS, ANSTIG) 1X/10X/X100 auto probe detection Built-in power supply two for P6202 FET active probes (probes not supplied) Very small (10"X16") footprint, takes up minimum test bench space THE REFURBISHING PROCESS The refurbishing process I have developed is rather extensive. The procedues used are as follows:Receive the oscilloscope and inspect every PCB and mechanical component. Replace worn or frayed power cord. Remove all the hardware from the case. Completely clean it, remove all traces of labels, sand it, mask unpainted surfaces and spray paint it the factory Williamsburg Blue color. Clean the instrument. I use compressed air as I have had bad results cleaning with water based products. Remove and inspect all the knobs and the set screws. Clean all the knobs, replace legends with decals I made if necessary. Repair or replace damaged knobs. Replace any cracked set screws. Remove and clean the faceplate. Clean all the surfaces around the faceplate. Clean every switch with contact cleaner. Test every front panel potentiometer for functionality and smooth rotation. Replace all tantalum capacitors that have a ratio of Vr/Va under 2. See following description. Remove the vertical attenuator switch assembly and clean the switch surfaces and re-tension the switch fingers if necessary. Repair the instrument if necessary. I use only new components when repair is necessary. Tap on every adjustable component and watch for any flashes or intermittent indications. Replace component if intermittent. Calibrate to factory specifications using Tektronix NIST traceable test equipment. Age for 100 hours (5 days) after calibration with power on but intensity at minimum. Recheck calibration to Tektronix specifications after the aging process is complete. Reassemble the instrument and associated hardware and give it a final post assembly test. When I ship the completed instrument I double bubble wrap it and ship in a sturdy carton with lots of shipping peanuts.Tektronix used tantalum capacitors beause they were thought reliabile, stable and were relatively inexpensive. Over time, Tektronix found out that the failure rate was unacceptably high if tantalum capacitors were used where the ratio of the rated capacitor voltage, Vr, divided by the applied voltage, Va, is under 2. If the Vr/Va ratio is equal to two this means that the rated voltage on the capacitor is twice the voltage applied while operating. There are a total of 41 tantalum capacitors used in the 485 that have a Vr/Va ratio under 2.0. All these 41 capacitors have been replaced by new modern components with a Vr/Va minimum ratio of 3, a maximum ratio of 12.5, and a tolerance of +/- 20%, the same tolerance as the original tantalum units. All the capacitors were replaced prior to calibrating the instrument. Number of capacitors replaced by assembly (A#) number and nameAseembly Number/Name Number Replaced A3 Channel 1 vertical preamp 1 A3 Channel 2 vertical preamp 1 A7 Vertical Amplifier Board 11 A8 A Trigger Board 1 A10 Sweep Board 5 A11 Horizontal Amplifier 5 A13 Power Board 17 Total 41 VERTICAL The 485 features dual calibrated vertical amplifiers each with deflection factors from 5 mV/DIV to 5 V/DIV in 10 steps of 1-2-5 sequence accurate to within 2%. The 485 features a sensing circuit to change the display of the vertical sensitivity when X1, X10 or X100 probes are used. LED's light up automatically behind the correct vertical sensitivity setting when the probes are changed. The bandpass of each channel is DC to well over 350 MHz in the 50 Ohm input impedance mode and DC to 250 MHz when in the 1 MOhm input impedance mode. The two traces may be viewed independently using either ALT or CHOP (alternate or chopped) switching; or algebracially added together. A separate switch is used to change the polarity of CHANNEL 2 so the oscilloscope may be operated differentially in the ADD vertical mode. The vernier vertical gain control may be preset to a desired value and disconnected by depressing the center knob on the VOLTS/DIV control. A front panel pushbutton will limit the bandpass to 20 MHz if desired. HORIZONTAL The horizontal deflection system consists of two sweep circuits. These are the MAIN and the DELAYED sweeps. Both sweeps feature calibrated sweep speeds from 1 nS/DIV to .5 S/DIV in 27 calibrated steps also of 1-2-5 sequence. The B or DELAYED sweep may be used alone, used to intensify portions of the A or MAIN trace or be used to sweep at the B rate after an amount of time set on the DELAY TIME POSITION control. A separate TRACE SEPARATOR control is used to adjust the position of the DELAYED trace on the screen. TRIGGERING The 485 features the famous rock steady FET and tunnel diode triggering used on all the higher priced Tektronix oscilloscopes. This oscilloscope will trigger faithfully from DC to well over 400 MHz on vertical deflections as small as 0.4 DIV. Each sweep, A and B, have independent trigger controls variable over the complete span of the vertical display waveform. DELAYED SWEEP The DELAYED or B sweep uses the ALT feature where the first few divisions, determined by the setting of the DELAY TIME POSITION control, are swept at the A rate and the intensified portion of the A trace is swept out over the full 10 DIV on a separate trace which may be positioned by the operator to be above or below the original A trace. DISPLAY The display pictures show one with two waveforms and one with a single sine wave. The single sinewave is swept at 1 nS/DIV; 2 DIV per cycle at 1 nS is 500 MHz, try that on your Heathkit scope. The two waveform picture is the output of a Tektronix 184 Time Mark Generator and a Tektronix 191 Constant Amplitude Oscillator. CALIBRATION AND AGING This oscilloscope has been thoroughly and meticulously cleaned inside and out, a new air filter is installed and the case is spray painted the Williamsburg Blue Tektronix color. Then it is calibrated to within Tektronix specifications using NIST traceable Tektronix calibration equipment. This oscilloscope is then powered on and aged for a minimum of 100 hours (5 days straight) at the end of which time the calibration is rechecked again to Tektronix specifications. This aging process is performed to insure the buyer that this oscilloscope will be stable and reliable. WARRANTY This fine oscilloscope carries an unlimited 30 day warranty after receipt by the buyer providing the calibration sticker has not been tampered with. RETURN RIGHTS This oscilloscope carries a no-questions asked 5 day after receipt return policy providing the buyer agrees to pay all expenses and that the calibration sticker is intact. Since the oscilloscope will be out of my hands for an extended period of time I would not feel comfortable reselling this instrument without re-calibrating it. Therefore, before accepting any returned oscilloscope back for a refund I would have to charge the original buyer a recalibration fee. A refund check, minus shipping, handling and recalibrating fees, will be issued within five days to the original purchaser only. PACKING AND SHIPPING The $467 selling price includes a $17 fee for professional packing. FedEx Ground is the preferred shipping media for shipments in the CONUS but, I would be happy to ship UPS or USPS, buyers choice but might be at extra expense. I will also ship on your account or, you can snail mail me a preapid shipping label. Scanning and emailing a prepaid shipping label does not work as the label cannot be reliabily read by the shipper. Shipping on your account can only be to your registered location, not a secondary location. Overseas shipping will carry additional shipping fees. I use USPS Air Parcel Post for all overseas shipping. However, there is no tracking number available when using USPS Air Parcel Post.The estimated shipping fee posted by eBay is far from accurate. Buyer should include sufficient postage to ship a 31 pound carton measuring 27"X18"X18" from Tustin, California, 92780 to the buyer's location. Buyer can call me at (714) 838-1011 for shipping information. I would be happy to assist the buyer in any way possible. PAYMENT I accept cashiers checks, PayPal and personal checks. Checks will delay shipping until check clears my bank. Credit cards are not accepted, unless through PayPal. COSMETICS Mechanically this oscilloscope is in beautiful condition. The case has been freshly spray painted with a coat of Tektronix Williamsburg blue paint. All the knobs, controls and mechanical components are in pristine condition. ACCESSORIES The oscilloscope does not come with the front mounted travel cover or top mounted equipment pouch. I am currently out of the front mounted travel covers. Some of these items are being offered on some of my other auctions. Contact me by clicking here to send a note requesting information on optional accessories. TRADE IN I will accept a non-cannibalized Tektronix 465 to 485 oscilloscope(s) in trade towards this oscilloscope. Contact me by clicking here for additional information on trade-ins. CALIBRATION AND SERVICE If you have a Tektronix 4XX (465, 465B, 466, 468, 475, 475A or 485) oscilloscope that needs repair or calibration why not click here to drop me a note and lets chat about your problem. I would be happy to offer suggestions about calibrating your instrument. RESERVATIONS Seller reserves the right to reject bids from private or negative feedback bidders. FEEDBACK I take my feedback rating very seriously! I would appreciate the courtesy of you contacting me by clicking here to drop me a note should there be a problem with any item purchased. I will make every attempt to resolve the issue as soon as possible to the buyers satisfaction or your money will be cheerfully refunded. I always leave positive feedback for buyers when their payment is received. Your feedback, once the transaction is completed, would be greatly appreciated. Buy with confidence from a seller that stands firmly behind every oscilloscope that is sold. BIDDING INFORMATION Remember, your bid is your word, please bid responsibly. TEKTRONIX 485 SPECIFICATIONS VERTICAL DEFLECTION (2 IDENTICAL CHANNELS) Bandwidth* and Rise Time (at all deflection factors from 50 W terminated source), -15°C to +35°C 50 W Input Impedance 1 MW Input Impedance DC to 350 MHz, 1 nS DC to 250 MHz, 1.4 nS *Measured at -3 dB. Bandwidth may be limited to approximately 20 MHz by BW LIMIT switch. Lower -3 dB point, AC coupling 1X probe: 10 Hz or less. 10X probe: 1 Hz or less. 100X probe: < 1 Hz Deflection Factor at BW 5 mV/DIV (1X Probe) to 500 V/DIV (100X Probe) 1-2-5 sequence, accurate ± 2%. Uncalibrated, continuously variable between steps and to at least 12.5 V/DIV. LED's at edge of V/DIV knob skirts indicate correction deflection factor for 1X, 10X and 100X probes. Display Modes CH 1, CH 2 ADD (normal and inverted), ALTernate, X-Y, CHOPped - approximately 1 MHz rate. 50 W Protection Internal detection circuitry automatically disconnects excessive signals of up to 50 V. The disconnected condition is indicated by RESET lights and has a manual reset. Maximum Input Voltage 50W Disconnect occurs for voltages that exceed approximately 5 V RMS continuous or 0.1 Watt-second for instantaneous voltages of 5 V to 50 V. CMRR ADDed mode with CH 2 INVerted. At least 10:1 at 50 MHz for 8 DIVision after adjusting CH 2 gain for best CMRR at 50 KHz and 20 mV/DIV. Automatic Scale Factor Probe tip deflection factors for 1X, 10X or 100X coded probes are indicated by three readout LED's behind V/DIV knob skirts. LEDs are off when channel not displayed. Ground reference display selectable at probe (when DC coupled). Maximum Input Voltage, 1 M W Input Impedance, AC or DC. 250 V (DC + peak AC); 500 V (p-p AC at 1 KHz or less) Delay Line Permits viewing leading edge of displayed waveform HORIZONTAL DEFLECTION Time Base A and B 1 nS/DIV to 0.5 S/DIV in 27 calibrated steps of 1-2-5 sequence. Time Base A and B Accuracy, Center 8 Screen Divisions TIME/DIV Switch Setting +15°C to +35°C -15°C to +55°C 1 nS/DIV to 20 nS/DIV ± 2% ± 4% 50 nS/DIV to 0.1 S/DIV ± 2% ± 4% 0.2 S/DIV to 0.5 S/DIV ± 3% ± 5% Horizontal Display Modes A, A INTENsified during B delayed, ALTernate display of A, B delayed. CALIBRATED SWEEP DELAY Delay Time Range 0 to 9.9 times the DELAY TIME POSITION setting of 10 nS/DIV to 0.5 S/DIV Differential Delay Time Accuracy (+15°C to +35°C) TIME/DIV Setting Accuracy 10 nS/DIV and 20 nS/DIV ± 1% 50 nS/DIV to 1 mS/DIV ± 0.5% 2 mS/DIV to 0.5 S/DIV ± 1% Jitter < 0.005% (1 part or less in 20,000 of full scale plus 0.2 nS). TRIGGERING A AND B A Trigger Modes NORMal TRIG, sweep runs when triggered: AUTOmatic TRIG, sweep runs in the absence of a triggering signal and for signals below 20 Hz: SINGLE SWEEP sweep runs one time on the first triggering event after the rest selector is pressed. LED lights indicate when sweep is triggered and when single sweep is READY. B Trigger Modes B RUNS AFTER DELAY TIME Starts automatically at the end of the delay time. INTernal, runs when triggered following the A sweep delay time. A Trigger HOLDOFF Adjustable control permits a stable presentation of repetitive complex waveforms. Time Base A and B Trigger Sensitivity Trigger Mode To 50 MHz At 350 MHz DC Int 0.3 DIV deflection 1.5 DIV deflection DC Ext 20 mV 100 mV AC Signals below 16 Hz are attenuated. LF REJect Signals below 16 KHz are attenuated. HF REJect Signals below 16 Hz and above 50 KHz are attenuated. Jitter Less than 0.1 nS at 350 MHz and 1 nS/DIV. External Inputs 1 MW paralleled by approximately 20 pF. Maximum input voltage 500 V (DC + peak AC). Level and Slope Internal, permits selection of triggering at any point on the positive or negative slope of the displayed waveform. External level adjustment through at least ±0.5 V for either polarity (±5 V for EXT/10). X-Y OPERATION Full-Sensitivity X-Y (CH 1 Horiz, CH 2 Vert) 5 mV/DIV to 5 V/DIV in 10 calibrated steps of 1-2-5 sequence, accurate within 2%. Gain adjustable at front panel. DISPLAY Crt 4 inch rectangular tube; 8 X 10 DIV (0.8 cm/DIV) display area. P31 phosphor standard; P11 optional. 21 KV accelerating potential. Graticule Internal, no parallax; variable edge lighting; markings for measurement of rise time. Graticule is dark with illumination off. Auto Focus Automatically maintains beam focus for all intensity settings. (Intensified zone and EXT Z axis are not Auto-Focused). External Z-Axis Risetime 15 nS. Input R=500W. +0.2 V (DC to 20 MHz) blanks trace of average intensity. +2 V (DC to 2 MHz) blanks maximum intensity trace. ENVIRONMENTAL CHARACTERISTICS Ambient Temperature Operating: -15°C to +55°C Storage: -35°C to +75°C. Filtered forced air ventilation is provided. Altitude Operating: to 15,000ft; max allowable ambient temperature decreased by 1°C/1000 ft from 5000 to 15,000 ft. Storage: to 50,000 ft. Vibration Operating: 15 minutes along each of the three axes, 0.06 cm (0.025 in) p-p displacement (4 g's at 55 Hz) 10 to 55 to 10 Hz in 1 minute cycles. Humidity Operating and Storage: 5 cycles (120 hours) to 95% relative humidity as specified in MIL-E-16400F (par 4.5.9 through 4.5.9.5.1, class 4). Shock Operating and Storage: 30 g's 1/2 sine, 11 mS duration, 2 shocks per axis in each direction for a total of 12 shocks. OTHER CHARACTERISTICS Two-Frequency Fast-Rise Amplitude Calibrator Condition +15°C to +35°C -15°C to +55°C 5 V amplitude into 1 MW load 0.5% 1% 0.5 V amplitude to 50W load 1% 1.5% 50 mA amplitude to optional BNC accessory current loop 1% 1.5% Selectable FRequency of 1 MHz and 1 KHz 0.25% 0.5% Dimensions (Portable Model Only) in cm Height 6.6 16.8 Width (With Handle) 12 30.5 Depth (With Front Panel Cover, Handle Retracted) 14 35.6 Depth (Handle Extended) 20.6 52.3 Weights (Approximately, Portable Model Only) lb kg Net (Without Front Panel Cover) 21 9.8 Net (With Front Panel Cover and Accessories) 24 10.6 Shipping 31.0 14 Congratulations, you made it to THE END

Condition	Seller refurbished : An item that has been restored to working order by the eBay seller or a third party not approved by the manufacturer. This means the item has been inspected, cleaned, and repaired to full working order and is in excellent condition. This item may or may not be in original packaging. See the seller’s listing for full details.
Seller Notes	“THIS OSCILLOSCOPE LOOKS LIKE IT JUST CAME FROM THE TEKTRONIX FACTORY. EBay shipping estimates are inaccurate, see Shipping Section below.”