Inhaltsverzeichnis
P-702
Narrow field direction finder P-702, Bech NP-1; manufactured by R. F. Bech, Zurich.
R.F. Bech, a Zurich based RF electronics company, developed several compact narrow field direction finders in the early 1950s.
Only a few examples of the first set, the NP-1 (P-702), were acquired for the army and were most probably only used for testing purposes.
Technical data
- Principle]]: Narrow field direction finder Bech NP-1: TRF with regeneration
- Frequency range: 3-9 and 7-15 MHz
Power supply
- Batteries: Heater and plate batteries
Dimensions
- mm, kg
Accessories
- Frame DF antenna, support with DF rosette
Operation
The very compact direction finding receiver is built into a metal cabinet, which provided some space for the heating and plate batteries in the lower area.
Technically, it is a TRF (tuned radio frequency) receiver with variable regeneration, it was equipped with DF21, DF21, DF21, DL21 and DK21 valves. The two frequency ranges cover 7-15 and 3-9 MHz.
Technical principle
TRF receiver with variable regeneration
Tube assembly
DK21 (RF amplifier, oscillator), DF21 (IF amplifier), DF21 (IF amplifier), DF21 (IF amplifier, regeneration), DL21 (AF amplifier)
Development
In the 1950s, the company R. F. Bech, Zurich, developed several compact narrow field direction finders; of the earliest set NP-1 (P-702), only about 9 sets were built.
Use
According to the report "Die Fk Kp 7 im II. Weltkrieg", a Bech near-field direction finder was used for reconnaissance of a spy radio network, the illustration also comes from this publication.
