The FMC 108-28 converts the FM broadcast
band to the shortwave range. The FM range of 87.5 - 108MHz is converted to 7.5
- 28.5MHz. Conversion is crystal stabilized, ultra-linear and non-inverted.
Screenshot of the total local
FM band taken with PERSUS HF-Span 0-40MHz:
In this way the receiving range of
shortwave Software Defined Radios (SDR) is extended to the FM broadcast band range.
Besides the reception of conventional FM radio stations it is also possible to
receive the new digital radio standard DRM+.
Sophisticated input and output filters
provide high selectivity and high out-band rejection. A discrete constructed double-balanced
mixer in combination with an ultra linear broadband amplifier provides good intermodulation
In the following some screenshots
taken in combination with the SDR receiver PERSEUS.
Reception of a FM modulated radio
station at 95.5MHz converted to 15.5MHz:
In waterfall spectrum mode:
The peak-to-peak deviation of +/-75KHz
depending on modulation level is clearly recognizable.
(Preliminary specification 04/2010,
all data are therefore subject to change without notice)
Input Freqency Range: 87.5 - 108MHz
Output Frequency Range: 7.5 - 28MHz
RF Connectors: BNC sockets
Max. Allowed Antenna Level : +0dBm
Output Third-Order Intercept Point
IP3: +10dBm (@ 100.0 & 100.1MHz)
Overall Gain: 3dB typ.
Amplitude response: +/- 1.5dB
Frequency Stability (15min. warm-up
period): +/- 10ppm typ.
Image Rejection: >35dB (52.5 -
Combined Output Selectivity: >55dB
(0 - 60MHz)
Power Supply / Connector: 7 - 15V
DC max.100mA / 2.1mm DC power socket (positive inner)
Operating Temperature: 0 - 40°C
Dimensions / Weight: 112 x 71 x 31mm
High Output Selectivity for 0
Converter received in perfect conditions
and successfully tested. Excellent performance also in my difficult local FM band,
full of strong signals with very narrow spacing between adjacent channels. I'm
using a discone antenna and a Perseus receiver with WRplus software. The FMC108-28
is a good converter for FM DXing.
F. M. / Italy