I pulled the classic. I've been working on a Airline 62-345 had everything working and then went and changed out most of the caps in the system. Now it doesn't receive any stations and just whistles at one spot on the dial! I replaced the wax spragues with orange drops. I noticed that the spragues looked like they were polarized but the orange drops are not, is this a suitable replacement? The print doesn't show polarity or call them out as lytics. I have the old caps do I now have to start replacing them?
Help!!!
Russ

The condensers are not polarity sensitive. The reason for the "outside foil" mark on one side of the condenser is because that lead connects to the foil piece that extends to surround the entire condenser. A condenser of this nature is made by placing two pieces of foil at predetermined lengths between pieces of oil soaked paper of predetermined thicknesses. The two foil pieces are staggered so that when the entire arrangement is wound up like a toilet paper roll (without the hole in the middle), one of the foils protrudes out one end and one protrudes out the other end. Since each foil sticks out each end of the roll, a wire may be attached to each end and thus to each foil. One of the foils is usually slightly longer than the other lengthwise, and so once the arrangement is wound up into a roll, this foil is the outermost foil. The two foils wrap around eachother over and over again to form a roll, but the longer foil wraps around the outside of the roll after the shorter foil has finished going around and around. This outer foil can then be used for shielding purposes and such. In circuits where shielding is somewhat critical, and where one side of the condenser will be connected to ground, usually the "outer foil" side is that which is connected to ground. Of course in audio and RF bypass circuits where neither side connects to ground, but instead to a successive stage, this feature cannot be taken advantage of. If one wishes to shield such a condenser, then a separate metal covering must be placed over the condenser and grounded to the chassis.

To see exactly how a paper condenser is constructed, carefully disassemble one and take apart the innards. The foil pieces are aluminum. Do not expect to replicate the soldering of the leads to the foils. Normally it is impossible to solder to aluminum. A special process is done at the factory to overcome this problem. If your Sprague condensers are of the type, however, that is simply a cardboard tube with the ends flanged over a cardboard disc (SPRAGUE 600 LINE), you should purchase the small yellow metalized film condensers from www.tubesandmore.com in diameters that will fit within your old cardboard tubes. This way you may maintain an attractive appearance underneath your chassis. Simply insert the new condensers inside of the old tubes. Perhaps drip in a drop or two of wax to hold each condenser in place. Place the cardboard discs over the new lead wires and reflange the ends of each tube. The Sprague 600 LINE condensers are really attractive.

That your radio does not work is probably due to either a misplacement of leads of a new condenser or from a condenser of the wrong value being selected. If the condensers have codes on them such as 473K, then they can more easily be misinterpreted. 473K would be 47 with 3 zeros in PF or MMFD--47000 MMFD, which would convert to .047 MFD. If a 474K condenser was selected, this would be 470000 MMFD, or .47 MFD. Such a value shift would likely ruin operation except if used in a filtering circuit. The K refers to tolerance. I do not recall the different designations.

Thomas

The orange drops should be just fine and polarity doesn't matter for these caps. Even though many old paper-wax caps will have a polarity stripe on one end, it doesn't matter when replacing them with new modern caps like the orange drops you used.

I assume you've probably already done much of the following but I'll go ahead and mention it anyway.

I would first go back and double check ALL of my work against the schematic and then check each of my solder joints for continuity to make sure there are no cold joints.

After that I would start probing voltages in the radio to verify that they agree with the voltages indicated on your schematic starting on the oscillator side and working towards the output side. Don't expect them all to be "dead on" as called out by the schematic but each measured voltage ought to be in the ballpark. Take note of your schematic Service Notes section as well.

Probing the different voltages ought to help find the offending part(s). It is possible (but unlikely) that one of the new caps was bad to begin with.

You might find that a resistor has since drifted or other previously good part has now failed. Perhaps during the process of soldering the new caps, enough heat was absorbed by a nearby resistor to cause it to drift out of tolerance. It happened to me once.

:I pulled the classic. I've been working on a Airline 62-345 had everything working and then went and changed out most of the caps in the system. Now it doesn't receive any stations and just whistles at one spot on the dial! I replaced the wax spragues with orange drops. I noticed that the spragues looked like they were polarized but the orange drops are not, is this a suitable replacement? The print doesn't show polarity or call them out as lytics. I have the old caps do I now have to start replacing them?
:Help!!!
:Russ

As said before, those condensers do not have polarity. Outside Foil simply means outside foil.

:I pulled the classic. I've been working on a Airline 62-345 had everything working and then went and changed out most of the caps in the system. Now it doesn't receive any stations and just whistles at one spot on the dial! I replaced the wax spragues with orange drops. I noticed that the spragues looked like they were polarized but the orange drops are not, is this a suitable replacement? The print doesn't show polarity or call them out as lytics. I have the old caps do I now have to start replacing them?
:Help!!!
:Russ
Found it. Left one pin ungrounded. thanks for the help.