HP 185B - First 1 kMc Sampling Oscilloscope

HP 185B - The Kilomegacycle Sampling Oscilloscope

Just two years later, the HP 185B was introduced in the March 1962 issue of the Hewlett Packard Journal.

The 185B mainframe with the 187B drawer combination, extended the equivalent bandwidth of the previous model HP 185A to the Gigahertz region. Thus giving the Journal the opportunity to title its article with the nickname "The Kilomegacycle Sampling Oscilloscope".

Brief specifications of the 185B when used with the 187B Dual trace Amplifier were: DC to 1000 mc passband with a rise time of less than 0.4 nanosec. Sensitivity from 10 mv/cm to 200 mv/cm in 1, 2, 5 sequence. Input impedance 100 K shunted by 2 pf, nominal.

HP 130C Oscilloscope

The 130 Series

The 130 series of oscilloscopes had many versions during the beginning of the 60s. The 130 series were not designed for high performance but rather to offer various solutions where and when an oscilloscope display had to be integrated into an electronic test system.

They are general-purpose oscilloscopes designed to fit the needs of the industry in the low frequency, audio and vibration analysis.

Inside the HP 130 series, the 132A was the only HP Dual-Beam Cathode Ray Tube oscilloscope ever produced.

HP 140A Mainframe with 1415A Time Domain Reflectometry Drawer

The 140 Series,
and the 1415A, First TDR

The first oscilloscope of the 140 series was the HP 140A mainframe, which appeared in the 1963 catalog.

The choice of the Mainframe-Drawer solution probably came from the competitive challenge with Tektronix. None of the many drawers developed for general purpose oscilloscopic measurements would be a significant technology advance compared to the oscilloscope market of the time. But HP quickly included many new products in the 140 series counting on their technology leadership... Sampling, TDR and Spectrum Analysis. The result would be that by the end of the 60s, a complete product line including a scope with 20 picosecond rise time and spectrum analyzers up to 18 GHz.

The birth of the Time Domain Reflectometry at HP came also with the 1415A drawer in the 140A mainframe, introduced in the September 1963 of the Hewlett Packard Journal:

"High-resolution time-domain reflectometry measurements are made practical by the Model 1415A TDR plug-in for the Model 140A Oscilloscope. Time domain reflectometry is a relatively new impedance-measurement technique which gives accurate, quantitative, easy-to-interpret information about mismatching, loss, reflection coefficients, and other parameters of electrical transmission systems.
The technique, analogous to the pulse-reflection principle used in radar, has been used for some time as a means of locating faults on long electric power and telephone transmission systems. The extremely fine resolution available in the Model 1415A, however, enables application of the pulse-reflection technique to systems with much smaller dimensions. The Model 1415A plug-in with the Model 140A Oscilloscope displays cable discontinuities separated by only fractions of an inch."

For an in- depth understanding of Time Domain Reflectometry two important Application Notes were published. The AN-62 printed in 1964 was dedicated to the basis of "Time Domain Reflectometry", and the AN-67 printed in May 1968 was titled "Cable Testing with Time Domain Reflectometry". Copy of the originals of these two application notes have been added to the AN Page of this web site at the same time this Oscilloscope chapter was inserted.

The 140 Series

At the beginning of the 70s, with its 5 different mainframes and 22 high-performance plug-ins, the 140 oscilloscope system provided the largest measurement spectrum to choose from: Wideband, Sampling, High-Sensitivity, Time Domain Reflectometry and Swept Frequency.

The performance of the various configurations would be progressively supplanted by the next generation of oscilloscopes growing all through the 1970s. But many of the most popular configurations, associating a 141T mainframe and 855X spectrum analyzer drawers are still alive today, and they offer low cost access to high performance Audio and Microwave spectrum analysis to many enthusiasts.

The link below gives access to a copy of the 30 page original short-form catalog. PDF format (13.1 Mb)

HP 140 Series Technical Data. March 1971.

The 1200 Series

The 130 series oscilloscopes were replaced progressively by the 1200 series by the end of the 60s. The main improvement was the full-transistorized design providing reliable, low maintenance operation with less frequent calibration requirements.

The 1200 series oscilloscopes are low frequency, all solid-state instruments matching the needs of production line testing, system applications and classroom or laboratory instruction.

Every oscilloscope of the 1200 series uses an HP rectangular CRT with parallax-free internal graticule.

The link below gives access to a copy of the 8 page original short-form catalog. PDF format (4 Mb)

HP 1200 Series Technical Data. February 1972.

HP 1200A

The HP 1200A

All solid-state, low frequency 1200-series oscilloscopes offered advanced performance with operating features previously available only on much wider bandwidth, and more expensive instruments.

The HP 1200A was the basic instrument in the 1200 series. It was a dual trace oscilloscope with a 500 kHz bandwidth, and a very high sensitivity of 100 microvolts per division on the lowest of its 17 input ranges.

Other characteristics rarely found on oscilloscope of that era were a very low drift, and a very high common-mode rejection ratio of 100 dB on the lowest deflection factor of 0.1 mV/div, over a DC to 10 kHz frequency range.

The 1200A, and five other members of the 1200 series were introduced at the same time in the 1969 HP general catalog.

The 180 Series, Short-Form Catalog

The salesman's message to his customers for the HP 180 oscilloscope family was the following:

"Whatever you're looking for in a general-purpose lab scope, you can find it in the 180 System. A choice of mainframes, plug-ins, and accessories lets you "custom design" the scope system that best suits your needs, selecting bandwidth range, screen size, writing speed, sweep, sampling, TDR, and storage capabilities, as your requirements demand. And because all elements of the 180 System are fully compatible with each other, you can expand your scope's capabilities as your needs change."

The link below gives access to a copy of the 16 page original short-form catalog. PDF format (6.8 Mb)

HP 180 Series Technical Data. October 1971.

HP 181T Mainframe with 8558B Spectrum Analyzer Drawer

The HP 8558A Spectrum Analyzer

The HP 8558B Spectrum Analyzer is certainly the largest diffused instrument of the 180 series. It is still today a very low cost, good performance solution, frequently found in general purpose RF workshops.

The HP 8558B Spectrum Analyzer is a fully calibrated spectrum analyzer designed for simple operation. It is a plug-in which fits into any HP 180 Series oscilloscope mainframe.

The analyzer has a frequency range from 100 kHz to 1500 MHz and a digital LED readout for more accurate frequency measurements. Absolute Amplitude calibration enables accurate voltage and power measurements to be made.
Through the use of coupled controls, the instrument can be made to operate using only three knobs. A simple three-knob operation means the inexperienced user needs very little training.

Reduced cost and portability opened the 8558B to a very large diffusion as a bench and on site service instrument, mainly in the telecommunication and CATV applications.

HP 1818A TDR Drawer in 181T Mainframe

The HP 1818A TDR

The 1818A was the lastest evolution and the most sophisticated Time Domain Reflectometer of the 180 series.

The 180X/1818A combination is a completely integrated wide band system for testing transmission lines, strip lines, cables, connectors, and many other devices in high frequency systems. The front panel controls provide accurate direct distance calibrated displays of up to 300 meters. Thus allowing to quickly determine the magnitude and nature of each resistive or reactive discontinuity in coaxial components such as attenuators, cables, connectors, and delay lines in microwave or pulse circuits. Faults such as shorts, opens, loose connectors, defective tap offs, splices, and mismatches can be located and identify with measurement resolution as close as 2.54 cm.

AN/USM-339 Ruggedized version of the 1700B

The 1700, Ruggedized

The device shown in the pictures on the right, and below, is certainly not the most representative of the 1700 series of oscilloscopes. But it is nevertheless an interesting and symbolic example of the HP special production responding to military requirements.

The AN/USM-339 is the ruggedized version of the HP 1700B. It is a lightweight, portable oscilloscope specifically designed for the rugged requirements of military operations. Operation in dusty environments cause no problem due to the lack of ventilating holes, which allows the 1700E to pass the Dust Test of Method 510. Procedure I of MIL-STD-810. In fact, the 1700E can operate in chemical plants, refineries or many other locations where corrosive or adverse atmospheres may be present. The environmentally designed construction makes it very difficult for any contaminants to get inside the oscilloscope.

This unique ability to operate in an adverse environment is made possible by the extremely low power consumption of the standard 1700 Series oscilloscopes. When operating on ac line power, these oscilloscopes consume less than 25 watts and when operating on dc line or optional internal battery pack, power dissipation is only 18 watts. This means that no vent holes are required and the oscilloscope can be tightly sealed with little concern for internal heat buildup. The majority of the internal components are designed to operate at only 10 to 20 per cent of their maximum rated power which assures high reliability. The lack of ventilation holes also increases measurement reliability by reducing short term dc drift caused by transient ambient temperature changes.

The Model 1700 Portable, Short-Form Catalog

The other members of the 1700 portable family have a slightly less warrior look and feel, but they respond to the same criteria of performance and power consumption.

The link below gives access to a copy of the 12 page original short-form catalog. PDF format (4 Mb)

HP 1700 Series Technical Data. December 1971.

HP 1740A Oscilloscope

The HP 1740A

The first member of the 1740 series was introduced in the 1976 catalog. It was a dual trace, DC to 100 MHz bandwidth oscilloscope which could display the sweep trigger waveform as a third trace simultaneously.

Although a completely new mechanical design was developed for the 1740 series, (see article below,) it was decided to retain some elements of earlier designs when they were of proven performance and reliability. One of these was the cathode-ray tube. The CRT used in the 180 series oscilloscopes had been improved over the years and in the course of building 40,000 or so. By the way it was re-used for this first unit of the 1740 family.

Another technique retained from earlier designs was the trigger recognition circuits. For both the main and delayed sweeps, the new scope uses the same HP monolithic integrated circuits as the 275-MHz Model 1720A Oscilloscope. They provide stable triggering on signals above 100 MHz but require an amplitude equivalent to only 1 cm of deflection at 100 MHz to do so.

HP 1727A Oscilloscope

The HP 1727A,
Fast-Writing Storage Oscilloscope

Combining extremely fast writing rate (2000 cm/µs) with high-bandwidth (275 MHz), the HP Model 1727A Oscilloscope was the most sophisticated storage oscilloscope of the 1700 series.

The 1727A uses Hewlett-Packard's expansion storage technology which combines a precision storage mesh with an electronic lens system that magnifies and projects the stored image on the viewing screen.

The 1727A uses a transmission-line deflection plate structure (see picture below) that appears to the vertical output amplifier as a resistive load rather than a capacitive load. This results in a much higher bandwidth than is possible with conventional deflection plates.

Combination of the HP 1740A Oscilloscope and HP 1607A Logic State Analyzer in a Package Know as Model 1740S

The HP 1740S,
Signs of Things to Come...

The 1601L, logic state analyzer was the first attempt made by HP to extend the field of use of the oscilloscope to the logic circuitry analysis. It was a drawer fitting in a series 180 mainframe, introduced in the January 1974, Hewlett Packard Journal.

The HP 1607A, presented at the same time as the first oscilloscope of the new 1740 family, was a clear sign that in 1976, the classic oscilloscope needed to add something new to its fundamental vocation of Time Domain Analysis: The Data Domain.

The basis of these new Data Domain measurements were explained in detail by Chuck House in an article published in the December, 1975 issue of the Hewlett Packard Journal. (Reproduced below.)

This early and hybrid solution to the growing need of specific logic circuit measurement, would quickly let the place to a new category of instrument, fully dedicated to this task: The Logic Analyzer. As you could see on the selector page that brought you here, a chapter dedicated to Logic Analyzer is planed on this web site. Like the many other to come... It's under construction... Stay tuned ;-)

A listing of the actual collection of Logic Analyzers is visible here: Logic Analyzers