Minolta 16QT 16mm; Fixing Slow Shutter

ic-racer

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The Minolta 16QT is one of my favorite 16mm cameras. It has a nice 3-element, f3.5 15mm lens with zone focus markers visible in the viewfinder. It also has a coupled CDS meter with lights (no galvometer) that does NOT need a mercury battery.

This silver one is in very nice shape, with working meter. However, the shutter speeds are slow.

The 16QT is bigger than the two Minox-film cameras here. However, the QT stands for Quarter-Frame. The negative size of the Minolta 16 QT, 12x17mm, is about one-fourth the area of a standard 35mm frame. Or half of a half-frame 35mm camera. The film area of the 16QT is over two-times that of Minox.
The single-perf 16mm film below is shown with perforations, but the camera works fine with no-perf film too.


 
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ic-racer

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Start by taking the top cover off.
There are screws (of different lengths) on each end of the camera that need to come out (red arrows). There is a little washer on one side (yellow arrow).
There is a screw at the base of the tripod socket that needs to come out with the tripod socket (red arrow).
The shutter button will fall out (blue arrow).
There is a thin black trim strip under the wind thumbwheel that needs to be carefully removed (green arrow).
 
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ic-racer

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After taking the lid off, the screws holding the front of the camera in place are visible. There are two screws to remove (red arrows).
After removing those screws the shutter speed lever (green arrow) comes out.
Be careful removing the lever, as the lever has the red, 'slow speed' indicator flag glued to its end which is visible in the viewfinder.

 
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ic-racer

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Before removing the long shutter speed lever, remove the little spring. The ends are different, note the orientation.
 
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ic-racer

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This is the shutter speed lever, with the indicator flag glued to the end.
 
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ic-racer

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At this point there is nothing holding the front in place except a little bit of glue from the rear trim. Every one of these I have taken apart seems like there is a hidden screw on this corner. In all cases, it is just that little bit of glue that is keeping it together.

 
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ic-racer

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There are a number of wires holding the viewfinder-end of the camera together. These don't need to be removed; just pull it apart gently as shown.

With the front pulled away one can see the escapement (orange circle) and the adjustable end of the shutter's main spring (white arrow).

Also, note the coupling for the aperture wheel (green arrow). This will need to be aligned when putting it back together.
 
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ic-racer

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The escapement is held together with a single slotted screw.

 
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ic-racer

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The escapement is pretty simple. It has only a small inertia wheel.

 
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ic-racer

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On my example the shutter blades were clean and seemed to move freely, so they were not removed or flushed with cleaner.
 
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ic-racer

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In the service manual there is a description of a hole in the back of the camera (under the covering) where a exposure/shutter tester can be used. There is a hole in the middle of the pressure plate. What I have done is film tests and in my other cameras, the spring merely needed to be tightened to the next slot on the adjustment wheel. (white arrow).

 
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ic-racer

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The meter circuit has no adjustment, the only exposure adjustment is with the shutter spring. There were two springs available (weak and strong, 0.32 and 0.35mm).

I did not do this to my cameras, but if I get one with a shutter than needs complete disassembly, you can see there is a little window on the back of the camera, under the covering, that would allow a standard shutter tester to be used.

 

xkaes

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The QT only has two speeds -- 1/250 & 1/30 -- so how slow do you think they were?
 

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The good NEWS is that QT's sell for $20-30 on EBAY.
 
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ic-racer

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This silver one is in mint condition. I got it a few years ago and only now am getting around to using it. I have a black one I got in 1985 and it was even a little rough back then when I got it.

The meter in these runs off the common 3V lithium wafer cells. One just needs to fashion a spacer in the battery compartment.

If the meter does not appear to work, there is a switch on the sliding shutter protector and a switch just above the aperture ring. Check the continuity of both. As I recall the main switch (the one above the aperture dial) has two areas of metal-metal contact that need to be addressed if function is to be checked. It has been over 20 years since I did that repair, but as I recall the button on top touches a pin that touches the metal of the battery compartment.
 
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xkaes

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Lots of people assume the QT has some sort of electronic exposure control, but it doesn't. The benefit is that this model is pretty rugged. Two mechanical shutter speeds and a manually adjustable aperture. Works fine without the batteries. Just tape a small, exposure, cheat-sheet on the bottom -- two shutter speeds & six f-stops.
 
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ic-racer

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The meter is coupled to the shutter speed and aperture but not "Auto." Pretty much the best system.
 

xkaes

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For those interested in the Minolta 16 QT which uses a long-defunct PX-30 battery, you can make one by using two Eveready 825 batteries instead -- fits & works perfectly.

 
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ic-racer

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On the subject of batteries. This Exell battery is just a 2032 lithium cell with a cardboard ring and metal back, held together with shrink tubing. It can be taken apart and the 2032 cell replaced.

 

xkaes

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Works fine if you happen to have an old L30PX battery lying around.
 

bergytone

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Hey ic-racer, I just received a QT and it seems like the ASA setting wheel in front is frozen in place. I can't make it budge. Have you ever seen this? I am pretty experienced with camera repair, mostly on Rollei A110s. I haven't cracked it open yet, I thought I'd ask you first. No signs of battery corrosion. The meter doesn't light up.
 

Bronson Dugnutt

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My primary silver QT has a similarly frozen ASA dial. The meter indicator lights will still function and respond to the aperture selection with batteries installed. It always indicates ~f/11 regardless of conditions, so not of much practical use.

Otherwise, it is mechanically sound so I use it as-is.

The QT metering circuit uses an IC package (maybe a resistor divider network?) in conjunction with the powered CdS cell, attenuated by the aforementioned ASA selector to drive the indicators in the viewfinder.
 
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ic-racer

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Maybe try some solvent, like alcohol, to loosen the dial.
 
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