310: Difference between revisions

4,057 bytes added ,  26 February 2013
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Image:Tek 310 on base.jpg|310 on fan base
Image:Tek 310 on base.jpg|310 on fan base
File:Wellenkino 310a.jpg|310A
File:Wellenkino 310a.jpg|310A
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This is a nearly true pure elektron tube scope,
but in the power supply there are some silicon rectifiers
and in the circuit is one germanium point contact diode.
Its bandwith is 4MHz.
It is sometimes very usefull because it contains a 1kHz calibrator output with up to 100V level combined with a step attenuator.
Early examples of the Tektronix Type 310A used commodity 3WPx CRTs.  At some point in production,
they switched to a Tek-made CRT, part number 154-366, which is compatible with the [[3WP2]].
Unlike later Tek instruments, where the incremental model designated by an “A” suffix
only occurred with a significant specification or performance enhancement,
the original 310 and 310A were essentially identical. 
They even shared the same manual and schematics. 
The main difference was the wiring construction. 
The original 310 pioneered the use of circuit board construction,
rather than the trusted ceramic strip point to point wiring. 
The circuit boards were two sided, however plated through hole technology
to interconnect the layers had not been invented yet. 
Rather, all of the holes for component mounting and interconnect contained a rivet
which was expanded in a press before the components were installed in the board. 
The rivets themselves were not soldered to the copper foil traces, and relied on
the pressure from the crimp to make contact. 
This proved to be extremely unreliable, with many intermittent connections
resulting in high warranty and after warranty failure. 
The 310A model essentially used the identical circuit design,
but returned to the trusted ceramic strip construction method.
The 310A also replaced the [[selenium rectifiers|selenium plate rectifiers]] in the power supply with silicon diodes. 
Tek offered a retrofit kit, to be installed in the service centers, to upgrade older scopes with selenium rectifiers.
During the lifespan of the 310, Tek evolved its color scheme. 
The original 310 scopes had a case painted with a blue metallic hammer tone color. 
Later units moved to the crinkled “Tek Blue” color still in use today.
The scope cabinet was hinged to allow it to be opened like a book and operated for access to the circuitry for service purposes.  The 310 and 310A were convection cooled, and required free access to air through the cabinet vent holes to avoid overheating.  It contained a thermal cut-out to protect it from damage if the supply of cooling air was inadequate.  The scope has feet on the rear panel to allow it to be operated on the floor with the front panel facing up, but the manual warns against prolonged operation in this orientation.  Shortly after introduction, Tek offered a Fan Base accessory, which the scope would sit on and provide forced air for better cooling.  While the scope had universal primary wiring options, the fan base did not.  Separate models were available for 115 VAC or 230 VAC operation.
Like most old Tektronix devices the mains transformer holds a indefinite(!) warranty, so hold an eye to that.  The device goes away on ebay here often for 30€ to 60€.
Fun on
*But its not quite clear what the "indefinite" means, live long for the device, the first owner, the company (Tek), the universe, or the transformer itself? ;-)
Fun off
* http://bama.edebris.com/manuals/tek/310a/
* http://w140.com/tek_fcp/tek_type_310_factory_cal_proc.pdf
* http://w140.com/tek_fcp/tek_type_310a_factory_cal_proc.pdf
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Image:Tek_310A.jpg|310A Front view
Image:310A_right.jpg|310A Right internal
Image:310A_foldoff.jpg|310A Folded off internal
Image:310A_left.jpg|310A Left internal
Image:310A_top.jpg|310A Top internal
Image:310A_bottom.jpg|310A Bottom special slot to access sweep trigger tubes
Image:310A_back.jpg|310A Rear view
Image:warranty.jpg|310A indefinite warranty to the Tektronix manufactured transformer
Image:310 1.jpg|310 right front
Image:310 2.jpg|310 front
Image:310 3.jpg|310 rear
Image:310 4.jpg|310 model
Image:310 5.jpg|310 right rear
File:Tek 310 base.jpg|fan base in '57 catalog
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