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)

Repair HP8640B

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.

Repair PreAmp 8640B (pdf)