7A19

The 7A19 is a one-channel vertical plug-in for 7000-series scopes.

The 7A19 has no variable gain control. An option (#4) was available that added a variable signal delay (± 0.5 ns implemented using a mechanically variable passive delay line), intended to match timing between multiple channels.

The pre-charge setting on the input coupling switch is intended for situations where there might be residual charge on the input coupling capacitor that could overload the input. To use it, one sets the switch to PRE-CHG before connecting the input signal, then waits two seconds before switching to AC (LF point is 1 kHz). The PRE-CHG setting also serves as a ×100 attenuator having a 5 kΩ input impedance in series with 2 μF, extending LF cutoff down to 20 Hz. In the AC GND position, the input is disconnected from the amplifier and terminated in a capacitively coupled 50 Ω load.

Key Specifications

Input impedance	50 Ω
Bandwidth	600 MHz (500 MHz in 7904)
Deflection	10 mV/Div to 1 V/Div, 1—2—5 sequence. Pre-charge circuit may be used as a calibrated ×100 attenuator.
Maximum input	2 W average or 50 Div, in AC mode 100 V DC+peak AC
Variable delay (Opt.4)	-0.5 ns to +0.5 ns

Internals

The 7A19 uses the 155-0068-00 amplifier IC.

Pictures

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  7A19 without option

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  7A19 with Opt. 4 (Variable Delay).

Earlier model

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  Left side (early model with Weinschel attenuator, without Opt. 4)

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  Right side (early model with Weinschel attenuator)

Later model (B030000+)

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  Left side (Opt.4 delay line enclosure in front)

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  Right side

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  Front right, Tek-built attenuator

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  Rear right

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  Front left

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  Front right

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  Top view

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  Attenuator switch contacts

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  Contacts detail

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  Contacts detail