[R-390] Varying gain [WAS: Filters] and archives

[quartz55]

Thanks for all the replies.  I was beginning to figure out most of what has been said.  I thought maybe I was missing some search feature I couldn't find.  Seems for some reason some of the pdf files I get aren't searchable, but maybe if I save them it will work.

I'll look into the Z503 before I go buy one.  I suppose I could clean out the junk from my old one and re-wind it if I can find any litz wire.  I'm about to break into one of the chokes that is bad (L603) and see if I can re-wind that.  I'm sure it's just wound with enameled magnet wire which is readily available and I have some.

I've been through most of the Y2K stuff, but it gets pretty interminable reading through all the stuff and yes I've seen the 'Pearls'.  I have most of the items that interest me on the hard drive.

As far as the IF caps, I do have the OD in the filter in and out coupling caps.  I was going to use the metalized for the rest of the bypass and coupling, and since they are 800V, I'm hoping they won't have any 'pimples'.  I did use Xicon Poly Met 400V axial ones in the AF module, mostly because of their small size.  The ODs just won't fit on the AF board TB601.

Another filter question.  I have pulled the input circuits off the 2 and 4K Collins filters and at least the input seems to measure pretty good on the Fluke, around 50 ohms across the terminals, and about 34Meg to ground.  I haven't checked from in to out yet, but should get to that today.  Seems like the filters measure good with the ohmmeter, but don't act right, and the rest of the circuit components seem fine.  Need to check the switching though.  I'm not adverse to pulling the filters apart to see if I can work on them, but don't want to if not necessary.

N3DT