HG Advanced Spacecraft - Tonnage and Upgrades

[atpollard]

How are you working with Vacuum Tubes and such (TL5-6)?

While I'm interested in hearing their response as well, I have a friend who worked as a tech at NORAD:

He told stories about swaping old (PRE-IC) circuit boards. It seems that custom built systems (like NORAD and Submarines) do not replace the electronics with a newer-better-faster version every 2 years like our desktop PCs.

 

[BP]

...It seems that custom built systems (like NORAD and Submarines) do not replace the electronics with a newer-better-faster version every 2 years like our desktop PCs.

The same holds true for many industrial environments. Even in recent years I have worked with plenty of systems that still use discrete components (and older OS's as well).

Besides proven reliability and avoiding retraining - if-it-ain't-broke-don't-fix it also covers economics of development and fabrication retooling as well as avoiding new mistakes in design and unexpected operational characteristics of new materials/logic.

Premium costs of legacy hardware may be a drop in the bucket all things considered.

(Aside from cheap fans and sometimes too much structural reliance on plastics and consumer mounting of HDs (for intentional pre-MTBF loss) - modern electronics is actually more reliable than many older technologies. The same can generally not be said for machinery and mechanical systems where the concept of profit margin and engineered obsolescence from the auto industry has permeated most of the world's hard goods sectors).

 

[snrdg121408]

Evening Rikki Tikki Traveller,

How are you working with Vacuum Tubes and such (TL5-6)?

I think I could still work on tube and solid state circuits built in the
late 1980s or early 90s. The stuff BP's Dad does is not something I was
trained to repair. If that type of circuit fails you fill out a purchase request
and walk the form through the chain of Leading PO and/or Leading Chief
PO, Division Officer and/or Department, Storekeeper (Quartermaster for
the Army types), and/or Supply Officer onboard. If the part was in stock
you were golden. If not and you were inport or along side a
repair facility then you walked the supply request through the inport
supply deparment and hope they have the part in stock.

 

[snrdg121408]

Evening BP and the other members on the board,

I think I could make repairs on tube and the solid state stuff up
to the late 1980s or early 1990s. Of course I'll need the schematic
and a couple of basic electonics books to refresh my memory :wink: .

The first vacuum tube that came out was called the Fleming Valve
because they work in a similar to a valve. Today they are called diodes
and work by having two plates one with a negative and the other with
a positive charge applied, which allows current to flow. I was trained in
the theory that the current flows from negative to positive. The other
theory is that the current flows from positive to negative. The draw back
of a diode is that current only flows in one direction. So the engineers
started placing more plates, known as grids, that allowed the current
to be manipulated to form amplifiers, timing gates, and other neat
stuff. Of course there are some negatives that go along with tubes. The
first to come to mind is that they are very good heat sources. Like a
standard light bulb they have a tendency to burnout at the wrong time.
Since they are made up of glass, metal, and non-conducting materials
like ceramics or plastics there is a good chance one or more of the
parts can be broken. One of the last ones that I can think of is that they
take up space inside the equipment and storage space.

BP makes a good point that advanced tech could be applied and allow
tubes a limited comeback. On the other hand there are still worlds in the
TU that are still at the tube level of technology. A Traveller party arrives
on such a world and needs a circuit replaced and the only replacement
is a tube circuit. Of course there will be small groups of people that
like tinkering with old technology.

 

[snrdg121408]

Evening atpollard,

You are pretty much on target that, in my experience, submarines did
not replace a majority of systems every x number of year. I recall that
there were lots of small upgrades to the equipment. The biggest item that
was changed out was single chassis assembly. We disconnected wiring
from the old chassis, ran additional wiring, and hooked up the new
chassis. The chassis was about 3' tall, 2' deep, and 2.5' wide made of
aluminium.

 

[BP]

I was trained in the theory that the current flows from negative to positive. The other theory is that the current flows from positive to negative.

I learned electronic theory from older textbooks (1940's probably). Later I began learning TTL circuits and working with Microprocessors (~1983) - I could make things work, but for the life of me every other time I designed a circuit it came out 'backwards'. Especially when working with diodes! I felt I had some kind of mental block in electronics. So I went into programming :wink:

Five years later I learned about Ben Franklin who gave electrons a 'positive' charge - quite a eureka moment for me. Me textbook learning had been from books before the U.S. standardized the electronic and physics flow theories with the electron having negative charge! #@$%! Benjamin ^$%@# Franklin!

The draw back of a diode is that current only flows in one direction.

Some would call that a feature


Back to Traveller -> I'm designing a ship with unique high TL parts - in order to make them serviceable I am using onboard dedicated computers and dedicated maintenance droids. This will allow them to fabricate/jury rig parts for repairs from lower TL components. And characters can be trained from them as well (so they can develop an appropriate Engineering specialty skill level).