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THE CONVERTERS


A MIXER FOR NATIONAL
RF-B60

RF-B60 MODS
2 CB XTAL CONVERTER

BACK TO DRM

ZURÜCK ZU
HOBBY-INHALT

 
A 12 kHz MIXER FOR NATIONAL RF-B60

Simple modification to make a 450 kHz IF Output from the RF-B60

My 5th receiver, a National RF-B60, is a really good and sensitive receiver. It covers the Medium Wave (522 kHz - 1620 kHz) and has three overlapping Short Wave bands (1711 kHz - 29999 kHz) in 1 or 5 kHz steps. The selectivity is exellent and the reception on short wave is excellent. It also has the Japanese FM-Band (76-108 MHz) and the Air Band (108-137 MHz). There are 9 memory channels for every band (45 in all). The receiver shows good performance, the selectivity is good and the sensitivity is excellent, even if you use the Telescopic Antenna.

The internal LR6 batteries do not last extremely long, so it is advisable to use an external 6 V DC adapter. I am using a Friwo 230V / 3 VA adapter set to 6 Volt output..

There is a choice between a telescopic antenna or an external antenna which is connected via a 3.5 mm plug, there is a DX / LOCal switch, but you need to modify the radio to create a 450 kHz IF output which can be used for the a DRM IF converter.


The location of the 450 kHz IF output . . .

Leadless IF Terminals

Fig. 1

Break loose two IC socket pins from a 14-pin IC socket and use for the 450 kHz IF output. Solder these to the IF transformer on the RF-B60 printed circuit board. There is no need for retuning, and the IF output does not impair the reception or decrease its sensitivity in any way.


Close-up of the 450 kHz IF output . . .

Close-up of the IF Terminals

Fig. 2


The finished 450 kHz IF output terminals
Leadless IF Terminals

Fig. 3

The finished IF output. Holes were drilled in the cabinet case and in the lid. The pins are safe against short-circuit as they are hidden in the lid.


The converter circuit

To be continued...


The completed 450 kHz to 12 kHz converter

The finished 450 kHz to 12 kHz converter

Fig. 4