134Ghz Equipment
Transverter
No photo's yet..........under construction!
The PLL LO's
The basic 116MHz OVCXO 's are shown above lashed together. These are based on the well known G8ACE design and are controlled as VCXO's with the Cupido PLL locked to 10Mhz, in this case from a GPS source. Two oscillators are used one at 116.666Mhz for the LO to produce a 145Mhz IF and the other as a Tx source at 116.79Mhz, using the LO as a straight through multiplier. The sources are switched into the following multiplier chain on transmit and receive.
This photo shows the other side of the LO box which contains the multiplier chains from 90Mhz to 11.8Ghz. This comprises a G8ACE x24 multiplier stage which accepts the 116MHz from the OCXO and procuces an output at 2800Mhz. This is then further multiplied in a G3WDG x4 design (not a X5 as shown), to produce an output in the 11.2Ghz region.
This then goes into a X2 stage with an output at 22.4GHz at 30mW. This in turn is used to drive a beam lead type diode as x6, very similar in design to that shown in the 76GHz section of this website, to produce the 134GHz output at a few uW! A small amount of audio applied to the LO produces an FM signal. On receive the same diode multiplier is used as mixer too, fed with a different frequency LO to, to produce a 145MHz IF. In this configuation it can also be used as a linear transmit converter by having SSB applied at the IF frequency. However this produces less output power than straight multiplier configuration, but effectively can gain by using an SSB detector instead of an FM one at the receiving end.
Antenna comprises a Procomm dish with splash plate type "penny" feed...(maybe it should be "2p" feed these days?!)