<p>Hi&lt;br&gt; Just looking for some advice. I recently purchased a TDS 524a scope without probes. I am trying to test it's functionality with a P6100&amp;#160; but am unable to get a trace/signal from the probe calibration output. Is this dedicated to a P6139 probe? If I feed in an external test signal a trace is displayed correctly.&lt;br&gt; Thank you&amp;#160;&lt;br&gt; JK</p>