7A16P: Difference between revisions

7A16P (view source)

Revision as of 10:39, 2 September 2020

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 {{BeginSpecs}}
-{{Spec | Bandwidth 1 MΩ | 0 – 150 MHz }}
+{{Spec | Bandwidth 1| DC – 150 MHz at 1 MΩ, 250 MHz at 50 Ω }}
-{{Spec | Bandwidth 50 Ω | 0 – 200 MHz }}
 {{Spec | Deflection | 10 mV/Div to 5 V/Div in 1–2–5 sequence}}
-{{Spec | Input impedance | 1 MΩ || 15 pF / 50 Ω }}
+{{Spec | Input impedance | 1 MΩ // 15 pF or 50 Ω }}
 {{Spec | Features |
 * Two BNC inputs
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 ==Internals==
-The input stage of the 7A16P contains miniature relays switching between the two available input connectors, and selecting the AC and DC coupling modes. Another relay is used to connect a 50 Ω shunt if the corresponding input impedance is selected. Relays then select an optional 10x attenuator before the signal enters the input buffer, which contains an AC coupled MOSFET common drain amplifier and a DC coupled operational amplifier, configured in a feed-beside scheme. Gain switching is accommodated by several junction FETs inserting another 10x attenuator in front of the MOSFET buffer, and to inserting 2× and 5× low-impedance attenuators after the input buffer.
+The input stage of the 7A16P contains [[miniature relays]] that switch between the two available input connectors, and select AC or DC coupling modes. Another relay is used to connect a 50 Ω shunt if the corresponding input impedance is selected. Further relays then select an optional 10x attenuator before the signal enters the input buffer, which contains an AC-coupled MOSFET common-drain amplifier and a DC-coupled operational amplifier configured in a feed-beside scheme. Gain switching is accommodated by several junction FETs that can insert another 10x attenuator in front of the MOSFET buffer, and 2× / 5× low-impedance attenuators after the input buffer.
 The digital circuitry is built around a [[Motorola 6800]] processor with several MC6821 Peripheral Interface Adapters that drive the switches of the analog circuit, and interface with the modified 7000-series internal GPIB bus.
 ==Operation with [[021-0374-00]]==
-When operated with the [[021-0374-00]], the 7A16P's modified GPIB bus is directly connected to the 021-0374-00 through an 18-pin, dual-row pin header and 17 leads. Following the labeling from the 021-0374-00 manual, the cable is connected as follows:
+When operated with the [[021-0374-00]], the 7A16P's modified GPIB bus is directly connected to it through an 18-pin, dual-row pin header and 17 leads. Following the labeling from the 021-0374-00 manual, the cable is connected as follows:
 :{| class="wikitable"
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 |}
-Additionally, jumper P1622 in the 7A16P should be set according to the [[021-0374-00]] manual. This connects the regular +5 V supply on A1 to the lights pin A9. In a [[7854| 7854 mainframe]], this will cause no direct harm if the rear "Control Illumination" switch is not in the "high" position since the [[7854]] uses series diodes to drop the light voltage if set to medium. However, the full current for all plugins will run through the 7A16P, so setting the switch to "high" is recommended.
+Additionally, jumper P1622 in the 7A16P should be set according to the [[021-0374-00]] manual. This connects the regular +5 V supply on A1 to the lights pin A9. In a [[7854| 7854 mainframe]], this will cause no direct harm if the rear "Control Illumination" switch is not in the "high" position since the 7854 uses series diodes to drop the light voltage if set to medium. However, the full lights current for all plugins will run through the 7A16P, so setting the switch to "high" is recommended.
 ==Links==