Text 227, 96 rader
Skriven 2005-02-01 09:19:02 av James Bradley (1:134/77.0)
    Kommentar till text 215 av Roy J. Tellason (1:270/615.0)
Ärende: Monitors nee-But it's ec
================================
01-31-05  12:06, Roy J. Tellason told James Bradley about Monitors nee-But it's
ec

 Well, how do, Roy?

 JB> Turns out to be a "T.V. Post Marker/Sweep Generator" Model IG-57A.
 
 RJT> That's not a pattern generator,  it's one that's used for alignment of
 
 JB> I know that now. <D> Since I shoved it in the rack - some half
 JB> dozen years ago - that's the best recollection of the unit I came
 JB> up with. On the front it has an input for IF, 

 RJT> That'd be an output,  I think.
 
Got me thinkin' now. From left to right, the patch points read:
Bias 1+2, External Marker/Sweep, *IF/RF VSM*, Trace in, Marker out, Scope Vert.
and Horiz.

It's the IF/RF VSM, that had me bamboozled into thinking that could be a raw
test pattern output.
 RJT> I've managed to accumulate junk at a somewhat slower pace 
 RJT> overall,  and haven't resorted to that sort of thing yet.  
 RJT> :-)

In my defence your honor, I was prescribed a pretty nasty narcotic at the time.
<G>
 RJT> the IF  stages.  The "sweep" refers to a frequency modulation of
 RJT> the output,  the modulation also being used to provide 
 RJT> horizontal deflection input to a scope, and thereby 
 RJT> generating a response curve.  The "marker" part refers to 
 RJT> generating a slight intensity variation on the curve so you 
 RJT> know where certain frequencies of interest are.  In the 
 RJT> years that I spent doing tv repair,  I could never quite 
 RJT> justify the cost of such an instrument.
 
 RJT> Sometimes,  with real early stuff,  the sweep generator and 
 RJT> marker generator were separate items.
 
 JB> You know, beside the wonkey pictures you can make with the unit, it
 JB> would be good for little else than to tax or deplete a subsystem?

 RJT> Hm?

Well, beside synching the scope to the sweep... That marker portion would do
what; code secret messages into the blanking signal? <-;
 RE: Linux-386 test generator
 RJT> Not a problem,  mostly.  The tricky part would be to find a video card
 RJT> to use  for generating that output that would have sufficient 
 RJT> flexibility to allow for a wide range of frequencies that 
 RJT> could be tweaked,  rather than a small number of discrete 
 RJT> ones to select from -- this is what one of my monitors here 
 RJT> can deal with,  and I don't recall the specifics on any of 
 RJT> the cards offhand.  I know that the one (ISA) card I have 
 RJT> in this box has several of those little oscillator modules
 RJT> on it,  and seems to generate a whole lot more in the way 
 RJT> of tv interference than the one I was using before that 
 RJT> died.  My antenna consists of a bit of wire,  and I guess 
 RJT> those modules radiate enough hash,  that mixes,  that it 
 RJT> messes things up.  Good thing tv reception in here isn't 
 RJT> that high a priority with me.
 
 JB> I think it was an old Osbourn lug-able, that I pulled a Herc.
 JB> TTL/EGA (If that's the one that used a low density D-plug?) card
 JB> out of. That I could use for test paturns. It's a full length ISA
 JB> board, but maybe only able to draw two colours.

 RJT> Osborne (no u) made luggables all right,  but the ones I'm most
 RJT> familiar with  were the ones that pre-dated most of this stuff,  and
 RJT> ran  cp/m for an operating system.  Their clone machines were 
 RJT> just before the end,  when they went out of business.  The 
 RJT> original machine had only one board in it (aside from the 
 RJT> ones on the floppy drives and in the power supply) and the 
 RJT> Executive (which I have) had a plug-in memory board,  that 
 RJT> was it.  There was one later one,  but I never got to see 
 RJT> the inside of that model.

I'll have to take a second look at the pile of vid-cards, for what you talk of.
Mostly, once the VESA bus came out, I started distributing all my ISA cards,
all but the more bizarre ones that is.
 JB> Me, I just plugged the capture card into a 21" monitor. That
 JB> shielded cable comes in handy to take the reception elsewhere.

 RJT> Capture card?

Ops... No, I guess it would be a TV tuner type unit. I just plugged the coax
into that, which drives the 21". When you mentioned your coat-hanger antenna...



... "Safety first: Time permitting. That is my moto!" -R. Merser

___ Blue Wave/QWK v2.20

--- Maximus 3.01
 * Origin: -=-= Calgary Organization (403) 242-3221 (1:134/77)