ICOM IC-7610 S-Meter Tracking

Having been checking the S-Meter for my prefered software solutions  (SDR) I thought it might be a good time to also (re)check the S-Meter in my ICOM IC-7610. The setup is the same as for the previous two checks. Below is the result of my checks for my IC-7610. A quick graph of how well my ICOM IC-7610 S-Meter is tracking using the IARU Standard of 6dB steps (6dB/S-Unit).

Setup:

• Signal generator: XG3
• Level: -34.8dBm @ 13.8V
• Att: HP-355C & HP-355D (38dB for approx. -73dBm level)
• Frequency: 14.175MHz

Result:

Table 1

Graph 1

The graph shows a pretty linear S-Meter for the IC-7610 down to S4 with a 6dB step per S-unit. The above graph is based on the measurements at 14.175 MHz (20m) with the PreAmp off. However, enabling either preamp we can see from Table 1 that the measurements deviate quite a bit. So for the times that I'd use either of the preamps I need to do a bit mental arithmetic. My measurements show a 6dB increase for PreAmp 1 and a 10dB for PreAmp 2. But please note, even though the data in Table 1 looks spot on, the measured values are rounded up or down to the nearest integer. However, we are talking about an Amateur device not a professional Field Strength Meter. So I'm quite happy with the result.

Here are some older 40m graphs.

Graph 2

Graph 3

Graph 4

Below is my cheatsheet for S-Unit vs dBm vs µV.

Graph 4

CLICK on a graph for a better view.

NOTE: Even though the above graph is displayed with 3dB steps, it is 6dB per S-Unit!