tek 454

jechentau · 26th September 2009, 10:12 AM

"it is broken" ;p

no screen "dot", does that ring a bell to a narrow often occurring error to someone perhaps? i don't dare messing or mearuring yet.

i also have a old US mine detector from the 50s afaik, US army corps of engineers. microtone, minnesota. when i got it the filaments of all 1l4 1u5 were open. afaik nothing else fails, needs a 1.5V glow, and 90V plate, with button contacts.

i also have a philips tube autoradio, with Ex4X tubes (rimlock), and a octal connector, for a vibrator, and OT, i presume.

anyone any remarks, trivia, questions etc? ;p

the oscope i would really like to have fixed.

it has nuvistors, and tunnel diodes.

HollowState · 26th September 2009, 05:25 PM

Quote:

Originally Posted by jechentau

"it is broken" ;p
no screen "dot", does that ring a bell to a narrow often occurring error to someone perhaps? i don't dare messing or mearuring yet.

Is this scope one that you've had for a while and was working, or is it a newly acquired one that doesn't work? In any event, the "A sweep mode" switch must be in the "auto trig" mode to get a trace without an input signal. There are many reasons for no trace and you must be an experienced trouble shooter to repair these with knowledge of how they work. Something that is not quickly learned. And you will definitely need the service manual.

Some of the more common causes for a lack of trace are:

Low voltage power supply problems. (There are multiple outputs.)
High voltage power supply problems.
Defective triggering circuits. (including the tunnel diodes)
Deflection problems driving the trace off screen. (vertically or horizontally)
Defective CRT.

Unfortunately diagnosing this much further is beyond the scope of this forum.

jechentau · 26th September 2009, 07:07 PM

ah, i see, thanks.

no, i got it in this state.
i just tried again, but still no trace.
i could not see any activity on the screen, turned some other controls, several indicators lit and such. the mains power configuration box i found interesting, and opened up as well for curiosity, and the fuse for the range here had a piece of alu foil inside from one end, endcap falling off while i tried to examine it further. unless the good fuse was taken, this one to me seems blown and tampered with. so bad sign in any way.

and i could not hear any inverter or smps come on or such at least, nor see a filament come on, with a lid off (not sure if either supposed to detectably such though)

i did have one manual already.

but, what nicely built it is

that mine detector too btw.
it has a large alu can, where the frame with all the stuff, slides in. strong smell of the varnish. no dust inside. reminds me of a satellite somehow ;p

those tubes seems to be sourceable last time i saw, and may build a psu one day.

it is such kind with 2 oscillators one with external detecting coil, a mixer, headphones basically. where one apparently hears a beat tone if something is there.

but, best chance of me getting the scope functional again, seems practical help or having it fixed perhaps.

26th September 2009, 10:12 AM	#1
jechentau diyAudio Member Join Date: Feb 2005 Location: Gelderland	tek 454 "it is broken" ;p no screen "dot", does that ring a bell to a narrow often occurring error to someone perhaps? i don't dare messing or mearuring yet. i also have a old US mine detector from the 50s afaik, US army corps of engineers. microtone, minnesota. when i got it the filaments of all 1l4 1u5 were open. afaik nothing else fails, needs a 1.5V glow, and 90V plate, with button contacts. i also have a philips tube autoradio, with Ex4X tubes (rimlock), and a octal connector, for a vibrator, and OT, i presume. anyone any remarks, trivia, questions etc? ;p the oscope i would really like to have fixed. it has nuvistors, and tunnel diodes.

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26th September 2009, 07:07 PM	#3
jechentau diyAudio Member Join Date: Feb 2005 Location: Gelderland	ah, i see, thanks. no, i got it in this state. i just tried again, but still no trace. i could not see any activity on the screen, turned some other controls, several indicators lit and such. the mains power configuration box i found interesting, and opened up as well for curiosity, and the fuse for the range here had a piece of alu foil inside from one end, endcap falling off while i tried to examine it further. unless the good fuse was taken, this one to me seems blown and tampered with. so bad sign in any way. and i could not hear any inverter or smps come on or such at least, nor see a filament come on, with a lid off (not sure if either supposed to detectably such though) i did have one manual already. but, what nicely built it is that mine detector too btw. it has a large alu can, where the frame with all the stuff, slides in. strong smell of the varnish. no dust inside. reminds me of a satellite somehow ;p those tubes seems to be sourceable last time i saw, and may build a psu one day. it is such kind with 2 oscillators one with external detecting coil, a mixer, headphones basically. where one apparently hears a beat tone if something is there. but, best chance of me getting the scope functional again, seems practical help or having it fixed perhaps.