Mystery object #5
This is some sort of infra-red detector device. it was encased in a very heavy aluminium casting, with a label saying "Mullard Infra-Red Detectors" and VX8578-01. The base connections are made by four 33-way flexi-print cables, onto which are soldered fine wires which dissappear up the middle of the inside of the tube - this is filled with resin and so hard to see exactly how the wires get inside. Height is 150mm.
From Ed Gisske : In all likelihood a thermopile IR detector with a Gadolinium lens. Gadolinium (and Germanium too) will pass IR but not visible light. A thermopile is a number of dissimilar junction thermocouples connected in series to increase the voltage for very small heat rise.
Mystery object #4
This is some kind of sensor. The large cylindrical base (7cm dia) contains some electronics. amd has a circular 7-pin connector on the underside. It is obviously intended to screw into a bulkhead, and when I got it, it was screwed into a small sealed box with a removable clear lid. The PCB has 3 chips, 3 multi-turn trimmers and several precision resistors, and the overall construction suggests a high-performance device, being very solid, and mostly made of stainless steel. The finned end part unscrews, and appears to be a heatsink. The use of stainless steel suggests it needs to be resistant to corrosion or chemicals. The underside is sealed with a large amount of white silicone sealant.
Below the fins (removed) is a brass cylinder, the outer and inner surfaces of which have a rough appearance, and the low weight of the cylinder suggests it may be made of sintered powder, and therefore porous. (if anyone cares to calculate the density, outer dia is 20.9mm, inner dia 17.9mm, height 11.6mm (=1060mm2) mass 5.35 grammes. The second picture below is with the cylinder removed. This shows two wires entering the top secton, and a red plastic sleeve which contains a thermocouple.
View on removing top section. There are two holes in the base on the left, through which a LED and photodetector are visible, set at a 90 degree angle between them. The upper assembly (right) has what looks like a peltier cooler bonded to it. The second image shows the PCB removed from the base. On the left is a photodetector, containing a large-area photodiode, and an internal chip. This device is marked OSI 5K Centronic KN. The LED on the right lights up red, but appears rather dim, so could be a near-IR device. The stainless tube contains a thermocouple and what appears to be a ceramic heater.
My guess is that it is some sort of moisture/humidity/vapour content sensor
From Geoff. Sweet : You are right it is some kind of moisture sensor. It is in fact
a dew point sensor. The electronics control the temperature of a mirror using the Peltier
cooling device you found. Light is directed on to the mirror, and when moisture forms on
the surface, at the dew
Mystery Object #1
Below is a clear 2.5 x 3.5 x 1" encapsulated plastic block containing what appear to be the component parts of an item made by a company named Collins.
My first thought was that it's something like an LVDT position transducer, but I don't think this is the case.There are two coil forms, each containing two series windings of fine enamelled wire, with a 1.5mm hole through the middle of them. these appear to fit in the ends of the upper tube, which consists of two brass cylinders, joined by a series of 9 silver-coloured rings or discs (can't see which), supported by longditudinal wires spot-welded to them. The terminal/endcap assemblies below the coils look like they fit into the ends of the bottom tube, but the 2mm tube on the right-hand terminal cap is NOT central, and so cannot pass through the centre of the coils (it would be too thick anyway), or through the top brass/silver tube.
Update (from Radiomatt) : A Collins Radio Co (Cedar
Rapids, IA)(now Rockwell Collins) mechanical filter
From David Stockton : It is definitely a Collins mechanical filter. Coils
operate magnetostrictive transducers in early versions, then conventional magnetic
transducers in later versions, discs work as filter resonator elements, wires provide
support and coupling. Japanese company Kokusai did a copy but used piezo-electric
transducers. Collins redeveloped to lower the distortion of their transducers. 455kHz is
most popular centre freq, I've seen 100kHz and 45kHz... But
From Rich Oliver : Collins Radio Corp. of Cedar Rapids, Iowa was a premier
manufacturer of fine radio equipment. Their gear exhibited state-of-the-art performance
due in part to two devices they developed to a very high standard of performance. Your
Mystery Object #1 is one of them, a mechanical filter. A transducer at one end converts
the electrical signal to a mechanical, torsional force at the end of the resonator stack.
Precisely machined discs are positioned down the central rod of the resonator; each is
resonant at a slightly different frequency. At the far end the torsional motion is
converted back to electrical energy. The result of this is a filter with excellect
characteristics - a very flat passband with very steep skirts on the edges. These
mechanical filters are typically used at intermediate radio frequencies, most commonly at
455 kHz or 500 kHz for Collins gear. You appear to have a display piece showing the
"guts" of the filter. The other Collins device I referred to is the Permeability
Tuned Oscillator, or PTO. Unlike the typical RF oscillator with a fixed coil and a
variable capacitor, these units vary the inductance. A precisely machined leadscrew moves
a slug within the coil changing its inductance. Collins was able to produce oscillators of
exceptional accuracy and stability in this way.
Mystery Object #2
This is a stainless steel cylinder about 4" long by 1.5" dia, with an octal plug base on one end, and a single electrode, mounted in a ceramic insulator on the other. The label reads ' E.I ? Vibron'. The plate which retains the octal base has the number 9654 engraved on it. The unit is very well made, and looks as if it was very expensive.
The single electrode is retained by a screw-in ring. Inside, the electrode is fixed to a 19mm dia highly polished gold plated disc 1.5mm thick, with a chamfered edge. There is an identical plate in the bottom of the cavity, and when assembled, there is a spacing of approximately 2mm between the plates, determined by the size of a rubber o-ring which the end cap rests on when the retaining ring is screwed down.
Removing the base reveals a large adjustment grubscrew with a locking nut. Further dismantling reveals a coil, two spring discs and the plate which appears at the bottom of the cavity seen above, attatched to a shaft which passes through the centre of the coil. It appears that the coil is intended to make this plate vibrate or move towards the top disc.
My guess is that it's for testing piezoelectric materials.
Bill Conrad writes : Mystery object number two is an electrically
variable capacitor, One applies a current to the coil to move the plates closer together.
I found two of them is some strange test equipment that compared
Salty Dog writes : In my career, I worked for EIL (Electronic
Instruments Limited) at
Mystery Object #3
OK, this is a real hum-dinger - a Nobel prize is due to anyone who figures this one out!
This is a small glass tube, 18mm dia, with a metal base bonded onto one end, which has wires emerging and a pip for evacuating. On the other end a circular translucent red-orange disc has been bonded on. The disc initially appears to be glass, having a very smooth polished appearance, but can be scratched and cut with a sharp knife, but in a way unlike any plastic I've encountered - there's a 'squeaking' noise as you cut, a bit like a heavily filled polymer, and tapping on the surface with a hard blunt object leaves slight indentations. Maybe a crystal ?
Inside, there is a small coil containing a pellet, which looks like a small length of 2.5mm dia. copper tube crimped nearly closed at each end, containing a white powder. I suspect this may be something like a getter, used to remove traces of gas after evacuation.
At the disc end are four sharp points facing the disc, the tip to disc spacing being about 4mm. Each point looks like a 7mm length of approx.0.75mm wire, the end of which has been filed to form a wedge-shaped point, Two of the points are gold in colour, and two silver. All four are black for about 1mm at the sharp end, either coated, plated or burnt. They seem to be mounted in mica blocks 1 x 3 x 3 mm, clamped into a metal frame by two very small screws. A wire from the base is soldered to the base of one of the points, on the other side of the mica block. Two other wires connect to the metal frame, but these appear to be for mechanical support.
There are a few flakes of a white substance (presumably from the copper tube), and two 1 x 3mm pieces of gold foil, each blackened on one side, loose inside the tube.
The construction suggests that this is a hand-made experimental item.
Duncan Cadd provided the following suggestion: The Mystery Object number 3 looks like it may be an ion source. The small copper tube containing the flakes of white stuff is meant to be heated by a current passed through the coil, and an ionising/accelerating voltage applied to the sharp spikes. The orange disk I think would be removed when the thing is installed, or perhaps drilled with a very small hole. It looks like the sort of source which might have been used in an early caesium atomic clock or such like, but that's just a guess. Get the bits of white stuff analysed (stick some in a clear, colourless flame and see what colour it gives) and find out what kind of ions it was meant to produce! With the pellet inside the coil it's much more likely to be an ion source than a getter IMHO. Getters are usually heated in a relatively uncontrolled fashion with rf, and it doesn't matter if the metal goes all over the glass envelope. Ion sources need to be heated in a regulated way to control the number of ions produced, hence the coil for a variable heating current. That's my best guess anyhow.
Frank Gilliland wrote : About your Mystery Object #3. I took the pic
to an old mentor of mine (I don't know if he wants his name public, so I can't give it),
who said that your tube is "nothing more than a lamp".
John Garmendia writes : I concur that it is a spectral source,
and suggest that the red material may be an optical window, if I understand the
construction properly. Likely it was hand-built to support some special instrument,
though some of the "professional" stuff made years ago looked pretty
rough, as it was buried within instruments, and aesthetics were secondary to function and
It is difficult to state with assurance, but I suspect that the
electrode structure you describe for Mystery Object 3 might be as follows: The
coiled wire surrounding the "copper tube" is just a resistance heater, used to
raise the temperature of the "copper" tube enough to vaporize some of the white
powder within. The ends are crimped only enough to contain the solid phase of the source
material. (It is likely some specially-compounded substance, having a desired specral
emission) It may