OSCAR 100 – how to listen to on the apparatus DIRECTLY RTX SSB (USB), about 40 meters ( 7 MHz ), or about 20 meters ( 14 MHz ), or about 10 meters ( 28 MHz or on a CB to 27 MHz ), or on 6 meters ( 50 MHz ), or about 2 meters ( 144 MHz ), or about 70 cm ( 432 MHz ) or any frequency is most comfortable or functional for you. NOT NECESSARY TO USE THE WELDER OR SPECIAL SKILLS, JUST CONNECT THE PARTIES EACH OTHER and everything will work A WONDER, IS ONLY KNOW HOW THE SUBTRACTION.

This Down-Converter can also be used to listen on a HF receiver (0-30 MHz) to 6 meters (50 MHz), 2 meters (144 MHz), 70 cm (432 MHz) and other frequencies up to 4.0 GHz .


  1. Radio frequency generator 35 MHz 4400 MHz cost Euro 27,27   ( LINK purchase ) date September 2019
  2. RMS-11 5-1900 MHz RF up and down conversion mixer passive frequency (IF-OUT – RF-IN – LO-IN) Euro 10,96 ( LINK purchase ) date September 2019
  3. Amplifier Low Noise figure (NF = 0.6dB), high linearity RF LNA 0.05-4GHz for HF, VHF / UHF FM , Euro 4.60 ( LINK purchase ) September 2019

The low noise from 4.60 euro depending on the intensity of the signal amplifier can be used or not. If once configured the system, you do not hear anything on the receive frequency set, then you must put it between the received RF signal to the RF-IN of Mixer.

Signal generation module Geekcreit® 4.4GHz 35M-sheet for the source frequency synthesizer development of the ADF4351 RF signal. The entrance to MUXOUT can be used to send through a GPSDO the frequency to 100 MHz GPS referenced therefore very precise.

RMS-11 5-1900 MHz RF Up and Down converter frequency, passive mixer.

Low figure of Amplifier Noise (NF = 0.6dB), LNA 0.05-4GHz High Linearity RF for HF, VHF / UHF FM.

How do the calculations and configuration to listen Oscar 100, for example on the 144 MHz. The LNB output is admissible directly to 740 MHz SSB (USB), and if we listen to the Oscar 100 QSOs on 144 MHz, just adjust the Radio Frequency Generator: 740-144 = 596 MHz , and that’s it, and so for any other conversion. If the RF signal to be converted, arriving at the frequency mixer is low, that is, we do not receive anything of conversion, then amplify it before sending it to the mixer.

Without going beyond, here is the example of a configuration to receive Oscar 100 on 29 MHz, the radio frequency generator via the blacks buttons should be adjusted as frequency of 740-29 = 711 MHz, the LNB output frequency (740 MHz) less the frequency on which to receive (29 MHz).

Following is the figure that shows the connections to do: I highlighted in the picture above the entrance to send to the radiofrequency generator the output of a GPSDO to 100 MHz. Above the entrance there is a jumper to move if you use a frequency external to the quartz at 100 MHz of the RF generator.Video here the conversion from 740 MHz to 29 MHz, 144 MHz, 432 MHz

Other conversions of Oscar 100, on FDM apparatus Elad-DUO on the band of 40 Meters, 7 MHz.

Receiving Oscar 100 directly on FDM apparatus Elad-DUO to 7 MHz.

Good listening to Oscar 100 with my realization of down-converter, simple to implement and to use for the various frequencies.

73 by Antonio IU8CRI.

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