Modification HP8614 und 8616
This modification describes the improvement of the HV-DC-circuit
(supply) of these old GHz-generators.
The original DC-supply (720VDC and 320VDC) is equipped with tubes; the
new one is transistorized.
Please
note: I don´t sell pcb´s for this
project and won´t produce them.
This project is a little bit "crazy", so i don´t recommend
to do it again - but maybe it´s interesting for you
Modification 8614_8616
(pdf)
The
"old" HP8640B is since decades a famous generator and still
very popular.
But with increasing age, these generators suffer more and more under
various deseases (like humans....).
One of my 8640Bs had a total loss of output
power caused by a faulty preamplifier.
This article describes the repair of the preamplifier hybrid module in
a HP8640B.