Needed an accurate 10 GHz signal source for receiver calibration, antenna measurements etc.. This is very easy to accomplish with two small units manufactured by Leo Bodnar, the Mini Precision GPS Reference Clock (GPSDO) and the Frequency Multiplier by 16 to 10 GHz. Very good is that the units are power supplied from a 5V USB source, e.g. an USB power bank when setting up a portable outside site.
Did a quick test on the kitchen table :-)
1. From a PC the Mini GPSDO´s frequency was set to 648.000.000 Hz and drive to 32 mA when locked to GPS. The GPSDO has a memory for the set frequency so nothing is lost when with no power.
2. Connected the GPSDO to the frequency multiplier. The 10.368 GHz output was measured to be -1.2 dBm.
3. A 10 GHz receiving chain was set-up consisting of a Kuhne 144 MHz/10 GHz transverter MKU 10 G4 (the transverter has a TCXO and the 10 MHz reference input was not used) and an Yaesu FT817 transceiver equipped with a TCXO. The GPSDO was locked to GPS. The GPS antenna was hanging inside the kitchen window.
With USB zero beat the FT-817 display showed 144,000.95 MHz which corresponds to 10,368.000.95 GHz. Very nice result!
4. Disconnected the GPS antenna and shortly afterwards the beat frequency was not changed.
5. The day after I investigated the difference +950 Hz on the FT-817 display. I set the GPSDO frequency to 144,000.000 when GPSDO was locked to GPS. Then disconnected GPSDO from the PC.
6. The FT-817 was started 1/2 hour before measurements. Set the side tone frequency in FT-817 to 800 Hz. Started an Iphone tone generator app (799.1 Hz).
7.
Connected the GPSDO to 5 V with GPS antenna connected. When GPS was locked the FT817 display showed 144.000.020 when heard that the FT-817 CW tone frequency was the same as the iPhone tone generator app. Listen on video above.
8.
Disconnected 5 V and disconnected GPS antenna. Connected 5 V and the FT-817 display showed 144.000.00 when FT-817 tone frequency was the same as the tone generator app. Listen on video above. Why there is a +20 Hz difference for this case I have no explanation.
Conclusion For my use of this FT-817 on 144 MHz the displayed frequency reading is good enough. Most of the +950 Hz reading when using the 144 MHz/10 GHz transverter occurs within the transverter. I believe that when the transverter is fed with a GPSDO 10 MHz reference signal this will change to the better.
Did a quick test on the kitchen table :-)
1. From a PC the Mini GPSDO´s frequency was set to 648.000.000 Hz and drive to 32 mA when locked to GPS. The GPSDO has a memory for the set frequency so nothing is lost when with no power.
2. Connected the GPSDO to the frequency multiplier. The 10.368 GHz output was measured to be -1.2 dBm.
3. A 10 GHz receiving chain was set-up consisting of a Kuhne 144 MHz/10 GHz transverter MKU 10 G4 (the transverter has a TCXO and the 10 MHz reference input was not used) and an Yaesu FT817 transceiver equipped with a TCXO. The GPSDO was locked to GPS. The GPS antenna was hanging inside the kitchen window.
With USB zero beat the FT-817 display showed 144,000.95 MHz which corresponds to 10,368.000.95 GHz. Very nice result!
4. Disconnected the GPS antenna and shortly afterwards the beat frequency was not changed.
5. The day after I investigated the difference +950 Hz on the FT-817 display. I set the GPSDO frequency to 144,000.000 when GPSDO was locked to GPS. Then disconnected GPSDO from the PC.
6. The FT-817 was started 1/2 hour before measurements. Set the side tone frequency in FT-817 to 800 Hz. Started an Iphone tone generator app (799.1 Hz).
7.
Connected the GPSDO to 5 V with GPS antenna connected. When GPS was locked the FT817 display showed 144.000.020 when heard that the FT-817 CW tone frequency was the same as the iPhone tone generator app. Listen on video above.
8.
Disconnected 5 V and disconnected GPS antenna. Connected 5 V and the FT-817 display showed 144.000.00 when FT-817 tone frequency was the same as the tone generator app. Listen on video above. Why there is a +20 Hz difference for this case I have no explanation.
Conclusion For my use of this FT-817 on 144 MHz the displayed frequency reading is good enough. Most of the +950 Hz reading when using the 144 MHz/10 GHz transverter occurs within the transverter. I believe that when the transverter is fed with a GPSDO 10 MHz reference signal this will change to the better.