<div dir="ltr"><div class="gmail_default" style="font-family:tahoma,sans-serif">For frequencies within the HF range the impact of impedance mismatch caused by using the breadboard should not be big. You may start seeing some effect when working closer to 30MHz. However at uhf and vhf frequencies breadboarding can be problematic.</div><div class="gmail_default" style="font-family:tahoma,sans-serif">At higher frequencies you should also start paying attention at the location of the calibration plane, i.e. the location where the vna sees the end of the transmission line. This is the point, to which all measurements will be referenced, and any connections between the vna and this point are becoming "invisible" (as long as they stay the same as during the calibration). <br></div><div class="gmail_default" style="font-family:tahoma,sans-serif">At GHz frequencies using a coupler longer by a couple of mm than what was used for "through" calibration can introduce a noticeable phase shift.</div><div class="gmail_default" style="font-family:tahoma,sans-serif"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif">Jacek</div><div class="gmail_default" style="font-family:tahoma,sans-serif">kw4ep</div><div class="gmail_default" style="font-family:tahoma,sans-serif"><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Mar 24, 2021 at 1:03 PM Alex Fraser <<a href="mailto:beatnic@comcast.net">beatnic@comcast.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<p><font face="Comic Sans MS">I soldered the 6 SMA jacks on the
little nanoVNA test board kit. It was good soldering practice
and a way to assess my current soldering abilities. I went
fairly well. As the fumes from the flux whirled around my head
I had some thoughts...</font></p>
<p><font face="Comic Sans MS">If a made an adapter for the SMA jack
so I could plug it into one of those plastic push pin
breadboards, then could I expect any good reading with the
nanoVNA? Would I calibrate connected to the breadboard for
open, jumpered for short and a 50 ohm resister pushed for
resistance? What would be the frequency limits for using those
breadboards? Are there any tricks as to which way you use the
rows of pin holes to plug in components? </font><br>
</p>
</div>
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</blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="gmail_signature">Given a choice between two theories, take the one which is funnier </div>