The Shop > Electronics & IC Programing

First i.c. ??

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John Swift:
Hi Dave  

the relays rings a bell

I think I,ve seen reference to magneticaly  biased relays that have a memory
that have two coils to set and reset them

as an apprentice in the mid 70's i did see the Mullard NORBIT logic moduals
germanium diode / transistor logic constructed on a small pcb and the potted in colour coded epoxy

looked like an overgrown ic

I think am showing my age   !!!


if one junction of the bc108 is ok turn it into a photo diode
before Mullard go wise you could remove the black paint of OC71's  intsead of buying the expensive OCP71's


     John


   have now found a picture

Bluechip:
John

Bit difficult to turn a BC108 into a photo anything. In a metal can, at least mine are .. loads of the things anyway, only about 10p each  :)

Apprentice in the middle '70's??

Just a sprog    :lol: ... I started Jan 9 1960 IIRC ..

07:30 start, allowed 3 mins, otherwise 1/2 hr docked. First rate was 9 1/2d  ( no not pence, the old pennies, ie 1/240th of a £ ) hr.

44 1/2 hr week. Sat AM 08:00 to 12:30 was part of the working week.

You young whippersnappers had it EASY ..  :lol:  :lol:

Dave BC


John Swift:
Hi Dave

               My first wage was £9 10s and I was well off !

I don't think the work prevention job's worths would let you do half the things I did

working on live equipment in a dusty mixing room by week 3 with the sparks

or  working with hot wired glass passing near  your head , while kneeling on broken glass

apprentices got all the good jobs didn't they


all you have to do with the BC108 is cut the top off

if you like you can use the NASA can opener !

for more search for  " tin whiskers in AF116/7 "

   
  John                       


MrFluffy:
Re valves and getting bitten... I was once a g7 ham but used to help a relative out now and again with cb stuff, and he used to use a zetagi bv300 and later a different one I cant remember the name. Only thing was it used to carbon up the changeover relay and the rig would go deaf with time. So I showed him how to clean the contacts and made up a probe with a resistance to bleed it down properly etc. Anyway, he's mid session with some rare station he'd been after for years and it started to go, so he takes off the cover and hits the problem relay with a squirt of contact cleaner while keying up his base mic to open it. His grounded alloy base mic.....
The valve field collapsed up the contact cleaner spray and into him, it took the heart path across his body and down the other arm and the reaction lifted him bodily across the room into a wall behind and melted his glasses frames into a twisted mess. He went the hospital after and was really ill for a few days.

I never knew contact cleaner was conductive, but Id never been dumb enough to find out the hard way.
Its probably the last time I showed someone how to do something to something really dangerous that I didnt trust 1000% to listen...

madjackghengis:
I went through a ham radio phase in the late sixties, as a boy, built a few kit recievers and a transmitter, then moved on to bigger and better things, engines and motor bikes, then went through electronics training for the Marine Corps, in the mid seventies, had tube theory, but was told by instructors not to worry about it, we'd never see a tube out "in the fleet".  I retired out of the Corps in '97, my last tour as Non-Commissioned Officer in Charge of the same exact electronics shop I had for my first duty station, right here in North Carolina, and when I left, we still had half the six hundred odd systems we maintained for communications and navigations were tube driven, with solid state pre-amps and the like.  At the same time, my new techs, checking in to the shop, mostly had never seen a tube and were shocked.  Our radar units were up in the three to six thousand volt range for their finals, that didn't so much hurt as laid you out and got you a visit to the hospital, and two or three days bedrest.  I hit 1500 volts of dc/rf out of a transponder, and had a small hole blown in my finger, right down to the bone, took about a year to heal, and almost six months to even start healing.
    Working with solid state is very nice and much less painful now, I don't need to go back to tubes or valves as you chaps like to call them, over the pond, although they were easier to troubleshoot, and almost impossible to blow up, unlike the touchy little transistors.  Tube amplifiers still produce the warmest sound and are much prefered by the "real audiophile", or so I've been told.

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