80
DETAILED INFORMATION
6.30 30 dB Rear Panel Attenuator Output.
The 30dB attenuator output on the back of the COM3010 can be used for a variety of external
hookups such as spectrum analyzers, modulation analyzers, and other test gear. It can also be
used to loop back into the receiver input on the front to obtain good frequency counts during
power testing.
The Receiver Input on the COM3010 is a sensitive circuit which is sent not only to the
Receiver, but also the Frequency Counters. It is recommended that the input is never driven
with more than +20dBm (100 mW) of signal. When keying a 100W (+50 dBm) radio into
the COM3010 power meter the 30dB attenuator will have about +20dB of signal on the
output; this is right at the limit of the Receiver Input.
The 30dB power attenuator is nominally 30dB of attenuation over the 100kHz to 1GHz band
of the COM3010.
The RF signal from the RF OUT jack to the 30dB attenuator output passes through cables,
connectors, the main PCB, a relay, and the attenuator before it reaches the output jack on the
back. This chain of connections has a predictable amount of loss from front to back, and is in
part used during the power meter calibration in the lab. The following table will help if using
the 30dB output jack in another method of measuring power.
Take the dBm reading at the output of the 30dB attenuator and the frequency under test, and
look up the closest value in the attenuator table below. Add this value to the result to find
the level present on the RF OUT jack. This will allow measurement of power and signal levels
lower than the COM3010 will display, which is limited to 0.1W.
MHz Atten MHz Atten MHz Atten MHz Atten MHz Atten
10 29.60 220 30.20 440 30.59 660 30.93 880 31.24
20 29.62 240 30.22 460 30.63 680 30.99 900 31.41
40 29.71 260 30.26 480 30.68 700 31.01 920 31.31
60 29.78 280 30.30 500 30.71 720 31.03 940 31.35
80 29.84 300 30.35 520 30.75 740 31.12 960 31.39
100 29.89 320 30.38 540 30.72 760 31.15 980 31.36
120 29.98 340 30.43 560 30.80 780 31.17 1000 31.54
140 30.03 360 30.46 580 30.79 800 31.23
160 30.09 380 30.48 600 30.85 820 31.21
180 30.12 400 30.51 620 30.89 840 31.30
200 30.17 420 30.57 640 30.90 860 31.29
Attenuator Table
Property of Ramsey Electronics, Inc.
Do not reproduce or distribute.
To Next Page
Loading...
Need help?
General
