KC908 Spectrum Analyzer

Introduction

KC908 is a wide-band sweep receiver, it is capable of measuring radio frequency spectrum and field strength as well as demodulating and monitoring common signals like AM FM SSB YSF D-STAR and DMR. As for uncommon signals, KC908 can record the raw IQ signal and save for later analysis.

KC908 is based on SDR theory. Different from other SDR receivers, KC908 integrates complete digital signal processing unit and user interface, so there is no need to depend on a computer. KC908 supports SDR software like HDSDR and is able to connect with GNURadio.

As a reconnaissance equipment, KC908 is capable of sweeping swiftly and discovering signals. Being different from traditional sweeping spectrum analyzer, KC908 obtains spectrums of certian width using FFT and then splice them together to acquire a panorama. In this manner, KC908 reaches a speed of 3GHz bandwidth per-second with a 10kHz precision, which is equivalent to 120,000 25kHz channels. As for specific radio stations within 300-500MHz, it takes less than 0.1 second to finish. We’re proud of such a decent performance on a micro-size hand-held equipment.

KC908(10.8/18.6GHz model) comes with 2 receiving channels. It can measure the amplitude difference and phase difference between two channels. Also, it’s equipped with signal generating function to output the CW/simple modulated signals and play IQ files. With GNURadio connected, KC908 is even capable of outputing relatively complicated digital modulating signals.

Feature

Basic Function

1. Spectrum analysis

2. Field strength measurement

3. Signal generator & IQ play

Useful Functions

1.Better than 15KHz frequency measurement accuracy with any sweep span, a single measurement can get the accurate frequency.

2.Comfortable monitoring with multiple squelch mode

3.Automatically log strong signals for reconnaissance

4.Storing up to 999 channels

5.Waterfall figure display

6.Record IQ and audio to TF card

7.Level tone function for tracing on foot

8.Analogical demodulation with high volume audio for noisy environment

9.Digital signal demodulation ( required to install the option)

Main Performance

Item	Min value	Typical value	Max value	Note
Frequency range	9kHz		10.8/18.6GHz
Real time bandwidth	1kHz		15MHz
Analysis bandwidth	1Hz		2MHz	can be set to 8MHz
Demodulation bandwidth	150Hz		300KHz
100% POI(note 3)			210us	Where SPAN=15MHz
Level measurement range			+20dBm
Level measurement uncertainty		1.5dB		Receiver only
Noise floor		-120dBm		@12kHz BW, avg
Instrument noise coefficient		13dB		With max gain
Third input Intercept Point		-42dBm 46dBm		REF=-70dBm REF= 20dBm
First image suppression	50dB	60dB
IQ image suppression		50dB
Residual response(note 4)		-110dBm -90dBm		Port N.C With whip antenna
Spurious response		-50dBc
Battery life		4h
Weight		900g

Note:1. This table just shows the parameters that user are concerned about, for detail please see the technical parameter table in the user manual.

2. Performance is measured with the right port. The receiving performace on the left port maybe inferior to the right port.

3. We define the intercept in POI as accurate measurement.

4. KC908 will transmit EMI during the measurement. If the antenna is close to KC908 it will receive the EMI. This parameter is measured by a 0.2m whip antenna, 1m from the KC908 in the microwave anechoic chamber.

Sensitivity(note 1)

Item

Condition

Typical

Max

Note

Normalized noise floor(note 2)	3MHz-500MHz	-162dBm/Hz	-155dBm/Hz	All refer to with max gain. REF=-70dBm, others at auto. Average value detection mode.
	500MHz-6GHz	-163dBm/Hz	-153dBm/Hz
	6-10.8GHz	-160dBm/Hz	-147dBm/Hz
	6-18.6GHz	-150dBm/Hz	-140dBm/Hz
FM demodulation (note 3)	3MHz-500MHz	0.3uV		12kHz BW
AM demodulation	1MHz-500MHz	1uV		9kHz BW
SSB demodulation	1MHz-500MHz	0.15uV		3kHz BW
CW demodulation	1MHz-500MHz	0.1uV		600Hz BW

Note: 1. Ambient temperature 25℃, neglect influence by residual response or other factors.

At frequency below 3MHz, noise floor would rise obviously.
Sensitivity indicators relevant to demodulation are all refering to the situation in which SINAD is approximately 12dB. The modulating signal is 1kHz single tone, FM modulation frequency deviation is 3kHz, AM modulation 80% depth. CW as non-modulated carrier. PRE AMP, AGC turned on.