615
Item nr.


Marconi TF868B Universal Bridge

Measure Resistance, Capacity (with tan delta), and inductance (with Q).

Data for Marconi TF868B
ProductionEngland, 1960.
TubesECC81 (osc), 2xECC83 (amp), EZ90 (rect).
Semi-
conductors
Bridge rectifier.
CabinetSteel. Size 50x30x26cm. Weight 12kg.
PowerAC 20W.
DocumentsManual, Slide deck.

The Design



Obtained8/2025 from Gert van Wee; sn=JA705/062.
Condition8.
DisposedSold 3/2026.

This Object

The inside shows some paper capacitors (Hunts) that could use replacement. I also replaced the metal recifier that supplies the DC for resistor measurement, and smoothed its output with a 220R resistor and 470uF cap.

The bridge now works fine. Some of the controls are a bit scratchy, but the potmeters are all of special quality and are probably near impossible to find in good condition.


Part of Gerard's Radio Corner.
Generated by SiteBuilder on 16/3/2026 by Gerard