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Turn off the ANL/NB and turn up the RF Gain knob to full open before you do any of this - BTW..

Yes; ~-106dBm is approximately 1uV.
But this number is used for two reasons 1) it is a signal that any radio can pick up and hear 2) it is the minimum amount that can still be heard in the receiver used so that the 1st IF stage can be adjusted to maximize signal vs distortion ('SINAD').

If your radio cannot hear 1uV; then the receive is far more out of adjustment than you first thought and/or there is a failure in that 1st IF circuit.
More likely that it is just out of adjustment.

Get enough output from your signal generator so that you can just barely hear the signal weakly (with the radio's volume up) but not enough to move the radio's S-meter. Re-tune the receive circuit for max output. Then turn down the sig/gen output to -106dBm and listen if you can now hear a signal. It doesn't necessarily have to be -106dBm because some radios can't hear that; but most can/do. The weak signal is pivotal in re-tuning the 1st IF can correctly. Once the 1st IF can is tuned at that level, go through the receive circuit once again (except for the 1st can) for max sig/noise ratio ('SINAD').

Once you are satisfied with the results; then turn the sig/gen up to 100uV (-67dBm) and then adjust the radio's S-meter VR to read 9 S-units.
That should get you really close - so long as your sig/gen is fairly accurate.

<blockquote data-quote="Robb" data-source="post: 416469" data-attributes="member: 8446">Turn off the ANL/NB and turn up the RF Gain knob to full open before you do any of this - BTW..Yes; ~-106dBm is approximately 1uV.But this number is used for two reasons 1) it is a signal that any radio can pick up and hear 2) it is the minimum amount that can still be heard in the receiver used so that the 1st IF stage can be adjusted to maximize signal vs distortion (&#039;SINAD&#039;).If your radio cannot hear 1uV; then the receive is far more out of adjustment than you first thought and/or there is a failure in that 1st IF circuit.&nbsp; More likely that it is just out of adjustment.Get enough output from your signal generator so that you can just barely hear the signal weakly (with the radio&#039;s volume up) but not enough to move the radio&#039;s S-meter.&nbsp; Re-tune the receive circuit for max output.&nbsp; Then turn down the sig/gen output to -106dBm and listen if you can now hear a signal.&nbsp; It doesn&#039;t necessarily have to be -106dBm because some radios can&#039;t hear that; but most can/do.&nbsp; The weak signal is pivotal in re-tuning the 1st IF can correctly.&nbsp; Once the 1st IF can is tuned at that level, go through the receive circuit once again (except for the 1st can) for max sig/noise ratio (&#039;SINAD&#039;).Once you are satisfied with the results; then turn the sig/gen up to 100uV (-67dBm) and then adjust the radio&#039;s S-meter VR to read&nbsp; 9 S-units.That should get you really close - so long as your sig/gen is fairly accurate.</blockquote>

[QUOTE="Robb, post: 416469, member: 8446"] [I]Turn off the ANL/NB and turn up the RF Gain knob to full open before you do any of this - BTW..[/I] Yes; ~-106dBm is approximately 1uV. But this number is used for two reasons 1) it is a signal that any radio can pick up and hear 2) it is the minimum amount that can still be heard in the receiver used so that the 1st IF stage can be adjusted to maximize signal vs distortion ('SINAD'). If your radio cannot hear 1uV; then the receive is far more out of adjustment than you first thought and/or there is a failure in that 1st IF circuit. More likely that it is just out of adjustment. Get enough output from your signal generator so that you can just [I]barely hear[/I] the signal weakly (with the radio's volume up) but not enough to move the radio's S-meter. Re-tune the receive circuit for max output. [B][I]Then[/I][/B] turn down the sig/gen output to -106dBm and listen if you can now hear a signal. It doesn't necessarily have to be -106dBm because some radios can't hear that; but most can/do. The weak signal is pivotal in re-tuning the 1st IF can correctly. Once the 1st IF can is tuned at that level, go through the receive circuit once again (except for the 1st can) for max sig/noise ratio ('SINAD'). Once you are satisfied with the results; then turn the sig/gen up to 100uV (-67dBm) and then adjust the radio's S-meter VR to read 9 S-units. That should get you really close - so long as your sig/gen is fairly accurate. [/QUOTE]

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