[R-390] Interesting find in my Cosmos PTO
n4buq at knology.net
n4buq at knology.net
Wed May 17 13:09:08 EDT 2006
On Wed, 17 May 2006 12:22:24 -0400, "Tim Shoppa" <tshoppa at wmata.com>
wrote :
> Bill asked:
> > Wanna tell us how you took those pictures?
>
> N4BUQ replied:
> > I have an inexpensive digital camera (Nikon Coolpix 3000 I think it
> is).
> > It's a 3MPixel model. It is a pretty crummy camera in most respects,
> but
> > the macro option seems to work well. I have some other closeup shots
> of
> > the rest of the PTO I planned to use to help me reconstruct it in the
> case
> > where I do decide to rebuild it. I may post those too.
>
> Certainly it'd be interesting to do that and some other locations too.
> The shots you've already made are way above average.
>
> Your 2.2K seems to be more deeply buried than in my Cosmos PTO's.
>
> There are some truly amazing techniques I've seen used to
> document complex mechanisms with Macro photography that
> uses progressive lighting/variable focus to do some truly
> amazing things with seemingly infinite depth of field. I'm not
> volunteering to apply these to my 390A's
> but if they could be done the results are STUNNING.
>
> > I'm really curious if lifting this lead away from the chassis
> > will have an effect on the thing. I checked continuity to
> > ground from that point and it shows infinity; however with
> > about 200VDC and an RF signal on that lead, who knows...
>
> I'm guessing that if it shorted to ground that you would have
> blown a fuse (or sacrificed a wiring harness) but it doesn't look
> right and it looks like you can do this at the same time as the
> 2.2K.
>
> Tim.
Yeah, I figured it wasn't making contact as I'm getting correct plate
voltage and the 2.2K isn't burned, etc., but it's amazing it isn't as close
as it is. I'm going to try to slide a feeler gauge underneath it just to
see how close it is. Like someone else said, it's probably a pretty good
capacitor the way it is.
I picked up both a 1/2W and 2W 2.2K resistors yesterday. Their 1W versions
were much larger than the 2W version - go figure. The 1W probably wouldn't
have fit, but this 2W looks like it will. I have the 1/2W just in case it
won't though.
I have some closeup shots of my IF deck's innards I should post too. They
turned out pretty nice. I do notice that PTO1.JPG shows up a lot brighter
on my laptop's monitor than it does on one of my other CRTs here at work.
Weird. I was just happy there was a small hole in front of the PTO that
allowed me to get that shot. The flash was partially blocked, though,
because I was shooting through that hole and I had to adjust the brightness
a bit.
Thanks,
Barry - N4BUQ
More information about the R-390
mailing list