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test&measurementZONE Products for the week of January 7, 2008
B&K Precision says ...
2652: Compact Handheld 3.3 GHz Spectrum Analyzer With Tracking Generator
B&K Precision Corporation's Model 2652 is a compact, cost-effective, handheld, PC-compatible 3.3 GHz Spectrum Analyzer with a tracking generator added, that delivers the performance and features of a full-size bench top spectrum analyzer. Weighing only 4.0 pounds including battery, this small, versatile, easy to use, portable unit is priced at only $6,950 and is an ideal tool for engineers and technicians who perform field measurements in the 50 kHz to 3.3 GHz range. Advanced synthesizer-based design enables the Model 2652 to provide an accurate and detailed picture of the spectrum being analyzed. The included tracking generator can be used to rapidly determine transmission characteristics of two-port RF devices.
The Model 2652 Handheld 3.3 GHz Spectrum Analyzer with Tracking Generator offers a number of outstanding features that facilitate quick and easy measurements:
- Measuring frequency range from 50 KHz to 3.3GHz
- One Button Auto Tuning
- Channel power measurements
- Adjacent channel power measurements
- Min/Max hold
- Average and over write mode
- Peak search
- Marker measurement
- Occupied bandwidth measurements
- Electric field strength measurements (with optional dipole antennas)
- Magnetic field strength measurements (with optional PR 26M)
- Switchable 50 or 75 ohm input impedance
- Save/Load
- Single sideband phase noise - 90dBc @ 100Hz offset
- Fast sweep speed (min 10ms)
- ANL (displayed average noise level) of -110dBm
- Hard copy of display (with optional PT 2650)
- RS-232 interface
The Model 2652's tracking generator provides the capability to rapidly determine transmission characteristics of two-port RF devices. It is ideal for tuning filters, determining the usable frequency range of amplifiers and attenuators, and aligning receiver IF stages. The tracking generator's output frequency is the same as the frequency the spectrum analyzer is tuned to, permitting the user to see the amplitude response of a circuit on the spectrum analyzer screen.
The Model 2652 is extremely flexible and can be put to work, either in the field or on the bench, testing cable TV levels and frequency responses, testing master antenna TV systems, measuring communications transmitter spurious radiation, locating sources of EMI or to measure unwanted RF radiation. The built-in RS-232 PC interface allows the user to either control the Analyzer's settings or to sample signals and then save, manipulate or print the imported signals. A lightweight portable printer is available as an option.
Model 2652 is capable of precisely measuring the magnetic field distribution on an IC or a printed circuit board using the optional magnetic field probe PR 26M. It is possible to measure the electric field strength by connecting a dipole antenna (optional) to the input connector. A dipole antenna that suits the use is available for PDC 800 MHz and GSM 900 MHz band, PDC 1500 MHz band, PHS, W-CDMA and GSM 1800/1900 MHz band and 2.4 GHz wireless LAN and Bluetooth.
Weighing less than 4.0 pounds including battery, and measuring a compact 6.38" wide, by 2.7" high by 10.2" deep," the Model 2652 3.3GHz Spectrum Analyzer with Tracking Generator comes complete with AC power supply/charger, soft carrying case, accessory pouch, fuse, Ni-MH rechargeable battery pack and instruction manual. Optional PC software, antennas, cables, probes, remote stand-alone printer and coupling adapters are available. The Model 2652 is priced at $6,950, quantity one and is available for immediate delivery. The AK 2650 software and interface cable has a list price of $199 and the PT 2650 portable printer is priced at $459.
EN-Genius Says…
This review follows on the heels of the brief I wrote recently about a high-end 75-GHz spectrum analyzer, the Boonton/Willtek Model 9103. This latest B&K Precision battery-powered Model 2652 analyzer, while not in the 75-GHz class of the 9103 portable, costs only a fraction of the Boonton's $17,000 price tag.
 If you're shopping for handheld spectrum analyzers, you may also want to compare B&K's specs, warranty and servicing policies with those of products from Bantam Instruments, Berkeley Varitronics Systems, Rohde & Schwarz, and Anritsu Co.
The closest competitive products look like the Rohde & Schwarz-designed Model FSH3, priced starting at about $6600, and Anritsu's Model MS2711D Spectrum Master, priced starting at about $6300. The basic Rohde & Schwarz FSH3 spans 100 kHz to 3 GHz, much like B&K's instrument. A second version includes a tracking generator for scalar network analysis. It's priced at about $8200.
Compared with these instruments (and more pricey portables like the Boonton 9103), B&K Precision's instrument may fill the bill in a cost effective manner. Indeed, that's historically been the case with B&K gear.
Although frowned upon by some engineering fusspots, the company's wares are moderately priced and practical, and tend to appeal to hands-on technicians, rather than engineers in compliance labs or design shops. These portables let you store up to 100 pre-established set-ups as well as 100 readings, so they can be useful in the hands of less experienced personnel as well.
An 8.5-GHz Version
B&K also has a version of this instrument that extends out to 8.5 GHz. It's the Model 2658 in the company's Handheld Spectrum Analyzer series.
Both the 3.3-GHz handheld and the 8.5-GHz counterpart's data sheets reflect good specs. As such, if treated with care and respect, you should be able to effectively characterize many 2-port RF devices using these menu-driven instruments. Either the B&K Model 2652 or the Model 2658 should be just about all that's needed to cover Bluetooth, W-CDMA, CDMA, PDC, PHS, GSM, and wireless LAN frequencies, making reasonably accurate and repeatable measurements.
Based on PLL synthesizers, these instruments have a center frequency set-up resolution of 100 kHz. As for noise, it's specified to be at a level of -110 dBm or less, which should give you sufficient dynamic range for most tests. SSB (single sideband) phase noise is spec'd at -90 dBc (at 100-kHz offset). B&K claims low spurs, too.
In use, the center frequency is set at the spectrum of maximum level. Optimum reference levels, resolution bandwidth, video bandwidth, and sweep times can also be set automatically using an AUTO TUNE pushbutton. That can come in handy if you're trying to measure signals with unknown characteristics. In auto-ranging, resolution bandwidth, video bandwidth, and sweep time are set automatically based on a set frequency span.
With one-button tuning, you can use these analyzers to make channel power and adjacent channel leakage power measurements, as well as occupied frequency bandwidth measurements. You can also ascertain field strength, both electrostatic (using an antenna) and magnetic (using a probe). The latter can be used when testing for EMI.
RS-232 Obsolescence
As for the RS-232 interface, even though it can operate at data rates to 38.4 kbit/s, it's passé in this day of Universal Serial Bus. In fact, a lot of PCs don't have serial COM ports anymore (I had to specify RS-232 for my spanking new Core2Duo box, so I could run legacy serial-I/O software). I would hope B&K Precision would address this shortcoming, perhaps with an RS-232-to-USB adapter, or (better) an upgrade.
However you deal with the RS-232 conundrum, connectivity should prove more than adequate to talk to a PC using BASIC-like statements. Writing code for a more Windows-like human interface, perhaps using something like VisualBASIC, should be straightforward.
If you're not enamored with software development, B&K's optional executables will let you make all instrument settings from your PC. Although 251 points of data are displayed on the horizontal axis on the analyzer's backlit LCD, over 1000 points of trace data are actually acquired per sweep. When the optional software package is deployed, all of these points can be displayed at high resolution on a 1024 x 768-pixel (or better) screen.
Using B&K's software, you can continuously sweep and transfer trace data to your PC, and store trace data in text or .csv (comma separated value) files. You can also save a screen to a bitmap file, or to your PC's clipboard.
As you'd expect, you can also generate a hardcopy of the display. But, this isn't done via the PC: rather it's accomplished using an optional lightweight printer connected directly to the analyzer.
All in all, regardless of their RS-232 shortcomings, B&K's spectrum analyzers shape up as nifty products that are worthy of consideration.
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