BNC connector

The stable LC oscillator contained in the WTW Dipolmeter mentioned in Exp. 29 can be used if that equipment is available. The oscillator circuit shown in Fig. 29-2 is probably not sufficiently stable it lacks an amplifier stage to isolate the oscillator stage from the output load. A very stable solid-state LC oscillator for operation at about 1.5 to 2 MHz, constructed inexpensively from a published circuit diagram, has been found to be satisfactory. This should be built in a metal box (which will serve as an electrical shield), with two BNC connectors—one for connecting with the cell and one for the output connection... 

Fig. 9 Photograph of two narrowbore probeheads. a aluminium jacket sealing the double helix used for thermo stating b high pressure vessel c platform carrying the autoclave d capacitors e capacitor platforms f tuning rods g high pressure connector h thermocouple i BNC connector j Pt-100 connector k copper tubing and 1 widebore adapter.

Figure 2. Photograph of two narrowbore probeheads a) aluminum jacket sealing the double helix used for thermostating, b) high pressure vessel, e) platform carrying the autoclave, d) capacitors, c) capacitor platforms, f) tuning rods, g) high pressure connector, h) thermocouple, i) BNC connector, j) Pt-100 connector, k) copper tubing, I) widebore adapter.

Figure 3-3. Typical targeting system (top)[38, reprinted with permission, 1987 American Chemical Society] and irradiation cell for pulse radiolysis system (bottom)[39, reprinted with permission, 1977 Radiation Research Society] (Q quartz cell body B BNC connector, P paraffin gasket M mica window E electrical tape gasket. A aluminum frame S standard taper joint).

A wide range of attenuators is available for the commonly used SMA and BNC connector systems. Power splitters are available for splitting a signal into 2, 3 or 4 outputs. The signal amplitude at the outputs is 1/2, 1/3 and 1/4 of the input amplitude, respectively. Unused outputs of a power splitter must be terminated by 50 resistors. Attenuators and power splitters of satisfactory bandwidth can be made by soldering small 0805-size surface-mount resistors directly between the pins of SMA connectors. 

Here, Cp is a parasitic capacitance stemming from the combination of fhe coaxial cable. Bayonet Neill-Concelman (BNC) connector, printed circuit board (PCB) trace, lead frame, bonding pad, electrostatic discharge (BSD) cell, and input-pair transistors of the core amplifier. A(s) is the amplifier s transfer function, Aq/(1 + s/cOq), where Aq and cOq are its open-loop gain and bandwidth, respectively. 

Loss in connectors is negligible, except for small (SMA and BNC) connectors at frequencies of several gigahertz and higher. Small connectors used at high frequencies typically add 0.1 dB of loss per connector. 

The signal output — this will need a cable with BNC connectors and usually of 93 ft impedance. It would be stamped RG 62/U. Systems matched to 50 ft or 75 ft would require different cables (see Table 11.2). It is important that cable of the correct impedance is used, particularly if long cable runs are necessary. 

The HV cut-out cable - this is a logic level and the specification of the cable is not critical. It wiU need BNC connectors. 

The signal electrode is a 34-inch long aluminum "dryer pipe" which is suspended from the drum lid and insulated from the lid by an acrylic disc, which also forms a seal so air must flow into the bottom of the electrode. This electrode is connected by a wire to a BNC connector which penetrates the lid of the overpack drum. 

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