BRIEF SPECS

Van der Heem was a radio manufacturer in the Netherlands. They also sold parts like transistors in the local market. I have still no information wether they manufactured other T&M instruments.

Features like the oscillator oven and period/frequency/count capability shows that the counter EC9920 was intended for laboratory use. The circuitry is all transistor, but Van Der Heem used a nice layout of plug-in cards which eases production and service. Van der Heem was folded into Philips B.V. in the seventies and the brand name was not used afterwards.

At the moment the crystal oven control is defective, so I decided to remove power to make it inoperative rather than try to repair. Even without heated xtal the counter is very accurate, so the oven has no high priority. I also replaced the knobs to some which are similar to the original ones. There is no manual and I think I will never get one.