McIntosh MI-3 Maximum Performance Indicator - Serviced

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General:
The McIntosh MI-3 is a unique vintage oscilloscope designed to measure multipath distortion from stereo tuners. Using the front controls you can also set the scope mode to L+R audio where the oscilloscope then reacts to incoming signals. We do not get these often so when these are set up at our testing bench it is a treat.

They look awesome at night especially!

One of the coolest pieces of 1960's McIntosh equipment, and a perfect addition to any vintage system containing a tuner. Or if you want a super cool light show, it can connect to any system with a a tape or output. This would be a perfect match with a vintage McIntosh tuner such as a MR73.

This particular MI-3 has been serviced where various age affected components were replaced and it is working wonderfully now. This will be shipped with care in an original McIntosh box which is an absolute must for units like this with CRT displays.

SkyFi Cosmetic Notes:
We touched up the glass as needed, Original Panloc text is no longer present. There is also an extremely small burn spot in the middle of the CRT barely visible. Paint stain on the top cover.

Overall condition is good for a unit this age.

SkyFi Technical Notes:
This unit received a power supply overhaul and routine service here at SkyFi. We replaced the aging electrolytic capacitors, replaced the selenium diodes with silicon parts, replaced a couple of suspect paper capacitors, cleaned all of the controls, and verified proper operation in audio and multi-path modes.

Brand Background:
McIntosh Laboratory is an American manufacturer of handcrafted high-end audio equipment based in Binghamton, New York. The company was founded in 1949 by Frank McIntosh. The company designs and produces audio amplifiers, stereo tuners and other consumer electronics products.

Ownership:
Second Owner

Connections:
RCA inputs and Outputs, Captive Power Cord, Convenience outlet

Cosmetic Condition:
8/10 = Very Good. Excellent front faceplate, one minor flaw on chassis side or top. See our detailed rating description here.

Working Condition:
Working perfectly and tested in our lab.

Included:
Unit, Box, Manual, Power Cord

Packing:
Original Manufacturers Packing

Specs:
- CRT Type: 3-inch cathode ray tube (3RP1)
Display Modes
- Oscilloscope
- Relative signal strength meter
- FM deviation meter
- Channel balance meter
- Phase indicator
Sensitivity
- Signal Strength (Vertical): 700 mV
- Audio (Vertical): 20 mV
- Audio (Horizontal): 20 mV
- FM Deviation (Horizontal): ±350 mV
Tube & Semiconductor Complement
- 1 × 3RP1 — CRT display tube
- 4 × 6EA8 — Deflection amplifiers
- 1 × 6EA8 — Voltage regulator
- 2 × OB2 — Voltage regulators
- 4 × Silicon planar transistors

Dimensions:
16.00 in x 5.44 in x 13.00

Weight:
23 lbs.

Approximate Age:
1964

Link to Manual:
Click Here