HP 5257A Detail
I received a question from Ary Lems about the HP 5257A Transfer Oscillator I tore down a few months ago. He writes,
About this one I do have a question.
On one of the pictures there is a pc board with nr 05257-60211.
On this pc board is an plastic srew and washer placed on a small gold loop.
My question is , is there a small steel ? wire over de goldplated loop in the same shape ? fitted underneath the washer and screw.
As best as I can tell there does not appear to be a steel wire over the goldplated loop in the same shape. I am afraid to remove the plastic washer for fear of damaging the assembly.
Thanks so much for taking the effort to post these high-quality pictures! I took apart the mixer of my 5257A a long while ago because the diodes within are busted (i.e. low-ohmic after a possible overload on the input). Then, I got stuck doing other things and forgot how everything was put together. When I started working on it again, I deeply regretted not having taken step-by-step pictures during the process of taking apart the mixer.
Your pictures (combined with what I haven’t forgotten yet) do help a great deal. And to answer Ary’s question: Yes, there is a small wire that goes through the PCB and gets connected by the washer’s pressure onto the PCB trace.
(I know the post is old, but maybe it’s still helpful for others…)