Technical data

The RF-520 is the CSF reference for a 19" rack TTY diversity receiving equipement made of three 2U units:
- Two RT-546 six fixed frequencies receivers,
- One CS-576 TTY variable shift diversity decoder.

Theses units have been designed in the 60's. My receiver schematic blue print design date writes as Novembre 22, 1961, last modification being made on December 8, 1965.
They all use germanium technology transistors such as BCZ11, OC44, OC74, SFT214, SFT229, SFT234, 2N525 or 2N1742 with a ground positive supply power.

Here are the technical specifications:
- Receiving mode:
F1 with -1000, -500, 0, 500, 1000 carrier fixed offset. - Sensivity:
1uV with S/B >= 10dB. - Frequency coverage:
6 fixed frequencies, 3Mhz to 30Mhz using 5 set of coils. - Double conversion design:
1.4MHz 1st FI using a 4 sections LC filter, 50KHz 2nd FI using a 5 sections LC filter centered on 2550KHz, 650 ou 1200Hz bandwith.
Both receivers can be setup to work as stand alone units, or as a frequency and/or space diversity receiving set.
They have been designed to be used with the dedicated AN510 magnetic loop antenna and linked to a TELEX unit such as this SAGEM SPE5.


Full view
Receiver Upper view Receiver Bottom view
Diversity FSK Converter Upper view Diversity FSK Converter Bottom view
Linked to an old SAGEM SPE5
RF-520 Coils TTY Shift converter tuning eye
First try of the full set on DDK2 Hamburg weather

Last revision: 03/04/2005