Home - Products - Reps - Manuals - Application notes

Model 3440A True RMS RF Millivoltmeter

Product Summary3440a.jpg (15865 bytes)

The 3440A measures the true rms of low level RF and microwave signals to over 1GHz. High rms accuracy, traceable to NIST, is assured regardless of waveshape. Common calibration errors are eliminated through temperature compensation of the probe detector diodes; double shielding protects the interchangeable probes from rough handling and pickup. Relative gain or loss measurements are simplified by a 0 dB reference adjustment. DC output proportional to the ac input is provided for analog recorders and to allow operation as an ac-dc converter.

Product Features

bulletNIST traceable True RMS: 100 V to 30 mV; 10 kHz to 1.2 GHz (usable to 2.4 GHz)
bulletVolts and dB Operation: Measures 100 V to 300 V and -60 dB to +60 dB
bulletAccuracy (1% FS + 1% reading) to 150 MHz, NIST traceable
bulletRF detector probes field replaceable

Product Specifications

Frequency Range

Calibrated to 10 kHz to 1.2 GHz. Usable <10 kHz to >2.4 GHz


True RMS to 30 mV, changing gradually to peak detector calibrated in rms of a sine wave above 30 mV.

Voltage Ranges

1 mV full scale to 3 V full scale in eight ranges: 1/3/10 scale sequence.
Usable: <100 V to 3 V rms.
Optional Model 1340A divider extends range to 300 V.

Decibel Ranges

-59 dBm to +23 dBm in eight 10 dBm steps. Reference: 0 dBm=1 mV into 50 W .
Note Optional Model 1340A divider extends range to +63 dBm. Contact factory for price and delivery on other dB references and scales.

Crest Factor (True RMS Ranges)



3440A with Capacitive Divider

Voltage Range

1 mV

3 mV

10 mV

30 mV

0.1 V

0.3 V

1 V

3 V

Crest Factor



























Signal Frequency

Voltage Ranges

10 kHz to 150 MHz

150 MHz to 700 MHz

700 MHz to 1.2 GHz

1 mV to 300 mV

(1% fs + 1% ind) (1% fs + 3% ind) (1% fs + 7% ind)

1 V to 3 V

(1% fs + 1% ind) (1% fs + 3% ind) (1% fs + 10% ind)

Temperature Effect (Outside 15C to 25C reference conditions)

Temperature (C)

Add to % ind accuracy

0 to 10

10 to 15

25 to 30

30 to 40






Three scales and anti-parallax mirror are provided. Top scale is 0 to 10 and is 4.4 inches long. The middle scale is 0 to 3. The bottom scale is -10 to +3 dB.

Indicator Unrest (1 mV FS range)

Unrest of the meter pointer will be <1% FS above 500 V indication, <2% FS between 300 V and 600 V and <5% from 100 V to 300 V.

Normal Response Time

Less than 1 sec on the 3 mV to 3 V ranges; 3 sec on the 1 mV range. Meter recovers to within 10% of final indication within 1 min after removal of 3 V rms overload on 1 mV range.

Meter Response Time Switch

A front panel switch selects normal and slow response times when measuring input signals that are stable, amplitude variable, or noisy.


A detachable probe containing the RF detector is provided. Accessories provided with the probe are a convenience spring tip adapter with ground clip and a 50 W terminated adapter mating with BNC or Type N connectors. The shielded probe cable is 4 ft (1.2 m) long and terminated in a locking quick-disconnect connector at the front panel.


The VSWR using the probe with the non-loading Tee connector in a 50 W system is no greater than 1.3 from 10 kHz to 1.2 GHz.

Power Sensitivity

The probe requires less than 1.9 nW of input power at 300 V input voltage when used with the non-loading Tee connector in a 50 W system.


The probe input is fully protected to 10 V ac on all ranges and frequencies. Maximum DC input is 400 V on all ranges.

DC Recorder Output

A rear panel set of binding posts provides >+1 V dc full scale deflection on "10" ranges and 0.948 V on "3" ranges into an open circuit. Source impedance is 1000 W (5%). The dc output is short-circuit proof. Output voltage is directly proportional to meter deflection and the rms value of the probe input voltage, which allows for use as an ac to dc converter.

Probe Reference

A REL REF control allows continuously variable reduction of sensitivity by a minimum of 3.3 dB. It permits 0 dB reference level change and is useful in setting the meter to a convenience scale mark when performing relative gain or loss measurements. A detented position is provided for normal measurements.


A fused power selector safety switch and receptacle on the rear panel selects one of four ac operating voltage ranges. Input power: 20 VA maximum.

90 to 108 V (100 V); 48 to 420 Hz, 103 to 130 V (115 V); 48 to 420 Hz
198 to 238 V (220 V); 48 to 420 Hz, 216 to 260 V (240 V); 48 to 420 Hz


Temperature: Storage: -54C to +85C, Oper.: 0C to 50C, Ref.: 15C to 25C
Humidity: 0 to 80% RH to 50C without condensation, 0 to 95% RH to 35C
Altitude: Storage: 0 to 15 Km (50,000 ft), Operating: 0 to 3 Km (10,000 ft)
Shock and Vibration: Complies with MIL-T-28800, Class 3, Style E.
EMI: Meets MIL-STD-461A for CS-01, CS-06 and RS-03 to 400 MHz at 1 V/m
Safety: Meets conditions of MIL-T-28800, Class 3, Style E.

Size & Weight

Height: Case: 133 mm (5.25") Overall: 147 mm (5.8")
Width: Case: 220 mm (8.3") Overall: 220 mm (8.66")
Depth: Case: 280 mm (11") Overall: 306 mm (12")
Weight: 2.7 kg Net (6 lbs) 5.2 kg ( Shipping (11.5 lbs)

Product Ordering Information -
All Pricing for US customers only
Please call for Export pricing

Model Description Order Online -US Price Picture
3440A 10 kHz to 1.2 GHz includes 4340A, 6340A, 34402A Call to Order
3440A-M111 3440A with 34401A Kit Call to Order  
3440A-M113 3440A-M111, with substitute High Precision Probe 34403A Call to Order  
-05 Rechargeable internal battery    
-40 Substitute Hi Precision Probe 34403A    
-41 Substitute Low Frequency Probe 34404A    
1340A 100:1 Capacitive Divider for Probe  

2340A Non-loading probe adapter for N & BNC  

4340A Probe Adapter, Probe Tip  

5340A Tee Adapter, Use w/50 W Coax, Type N  

6340A 50 W Terminating Adapter, BNC & Type N  

31-10189-1 50 W Precision N Term. Use with 5340A  

34401A Kit containing 1340A, 2340A, 5340A, 31-10189-1 and 89-11103-1  
34402A Standard Probe, 10 kHz to 1.2 GHz    
34403A High Precision Probe, 10 kHz to 1.2 GHz    
34404A Low Frequency Probe, 10 Hz to 100 MHz    
89-11103-1 7" storage case for accessories    


Revised: September 30, 2015.

All prices subject to change without notice.  All prices listed are for domestic sales only, please call our offices to confirm price.
312 Old Allerton Road, Annandale, NJ 08801 - Tel: 908-713-7742 -  Fax: 908-713-7743 - E-mail: sales@ballantinelabs.com