<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:12pt"><div><span>None of the HP-23- series of power supplies has a switch for "bias"! The HP-23 and HP-23A have fixed bias and a variable bias. The HP-23B, HP-23C, and the PS-23 have only fixed bias. The HP-23A and HP-23B have a toggle switch to switch between 250 VDC and 300 VDC. The HP-23, HP-23C, and PS-23 require an internal connection to determine if the lower B+ is 250 VDC or 300 VDC.</span></div><div></div><div> </div><div>Glen, K9STH<br><br></div><div>Website: http://k9sth.com<br> <div style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"> <div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> Dave Edwards <kd2e@comcast.net><br> <b><span
style="font-weight: bold;">To:</span></b> heath@puck.nether.net <br> <b><span style="font-weight: bold;">Sent:</span></b> Tuesday, April 23, 2013 10:18 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [Heath] SB-110A<br> </font> </div> <div class="y_msg_container"><br><div id="yiv0978939986">
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Some of the old Heathkit HP23's had a toggle switch on it to switch
bias voltage. ...Not sure if it was the 23 or 23A.<br>
Newer ones did not, and had to be hard wired. <br>
Just make sure you have the right setting for your rig.</div></div></div> </div> </div> </div></div></body></html>