Pacific Antenna
Affordable QRP Antennas and Kits at exceptional value


N2CX Accuprobe Plus

The N2CX Accuprobe Plus is a descendant of the common diode RF detector. It uses a special operational amplifier with a compensation diode to cancel out non-linear diode characteristics at low RF input levels. This allows accurate measurements down to about 50 mV rms as compared to several volts for ordinary detectors. This translates to a very low QRpp level of about 50 microwatts. The upper end of the range is 5 V rms or 1/2 watt. A second uncompensated range is provided to allow measurements up to 35V rms or 24-1/2 watts. Compensation is not needed for the higher voltage range since the detector is linear for high input levels.

The Accuprobe is used as an accessory to a reasonable quality digital multimeter. It provides a DC output voltage that gives a DMM reading calibrated to the RMS value of the Accuprobe RF input. On the LOW range the DC is read directly while the DMM reading is 1/10 the RF input of the HIGH range.

The Accuprobe is AC coupled so it can be connected directly to biased circuits with voltages up to 50V without upsetting circuit bias or inaccurate readings due to presence of DC. Its high input impedance and low capacitance allow it to be used with minimum loading on high impedance low-level circuits.


Printed circuit board dimensions:1.8 x 1.9 inches
Power: 12 VDC at approx. 1 ma using a standard 12-volt battery
Input levels: LOW range - 50 mV rms to 5V rms (usable to 20 mV)
HIGH range - 5 V rms to 35 V rms
Frequency range: 100 kHz to 30 MHz (upper end not tested but should extend to VHF)
Outputs: DC - compensated to rms input
LOW range - 50 mV DC to 5 VDC (Uncalibrated readings to 20 mV)
HIGH range - 5 VDC to 35 VDC (1/10 RMS input)
Output accuracy: approx. 10% of reading decreasing to 25% at 50 mv
Supporting Files and Documents

 Accuprobe Assembly Manual (3/17/13 update)

Ordering Information

To order this kit, use the buttons below. (you do not have to have a PayPal account to pay for items using a credit card)

Use Add to cart buttons to add an item to your shopping cart. Use "Continue Shopping" tab to go back and add multiple items to your cart. You can view shipping charges before making payment. Payment can be made by Credit Card, Debit Card or by Paypal. Selecting "Checkout" in your shopping cart will allow you to use a credit card rather than Paypal Please be sure the address you supply is correct. We receive an automated notification when you complete payment. Your order will be shipped as soon as possible unless otherwise stated. Thanks for your support!

Accuprobe: 50.00
View your shopping cart: 

Back To Top

Page last updated: 09/12/2017, 12:48:43
Page Maintained by:
Copyright © 2001-2016 Pacific Antenna/QRP Kits, All rights Reserved.
Pacific Antenna Return Policy