My avionics collection.

The combination of flying and Radio amateur

results in a collection of communication avionics.



                    RA-1B Bendix  HF RX                          R1155/T1154                                    ARC-2                                        VHF TRX

                618M-1 VHF com Collins                                    British VHF TRX                                                                                          SARAM

                                ART-13 Collins                                                              ER-104   thomson                       AVC-110  RCA                                



                                    GF11 HF TX                                                                 GF11





 Solving the earth problem of the R1155 - T1154

When connecting the minus of the HV supply to more equipment simultanously and connecting the T1154 earth terminal to earth of the other transmitters/ receivers in the shack, generates a short cut to the negative grid bias circuit of the R1155.

To overcome this problem so you can use only one powersupply for all equipment i made this capacitor which makes a DC block  between the earth terminal of the T1154 and the rest of the shack.  It works well. the capacitors have to whitstand a voltage of 30...40 VDC and the RF current due to transmission. See pictures below.  The chassis of the R1155-T1154 is app. 35 VDC below the rest of your equipment. Use 16 1nF feed thru capacitors made by Stettner &Co.