This thread is intended to document the reconstruction of R 390A power supply capacitors from start to finish. I haven't found any good sources explaining "how to" do this exactly with any significant level of clarity and step by step detail. So I am creating this thread as a reference for those wishing to rebuild their power supply caps in their cherished boat anchor rigs. This information is not only limited to the R390A, but could be used to demonstrate how to rebuild caps in any boat anchor for that matter. It would be great if we could all go out to Radio Shack and buy direct replacements for our boat anchors but since this is not possible, we are required to rebuild them ourselves. I recently picked up an R390A on the cheap. It was in good physical condition. Super clean inside but the seller said it didn't power up so I got it at a rock bottom price. With a little knowledge and know how, it is possible to save a lot of money buying non working boat anchors and restoring them to work again. So I brought it home and threw it on the bench to see what was wrong with it. Tried to power it up but no go. No tubes were lighting up and it appeared dead. So the first thing to check are all the fuses. I grabbed the Fluke meter and pulled all the fuses and they checked out ok. Then I remembered that the R390A has a quirk with the power / standby switch on the front panel. There is a micro relay switch located on the back of this switch and it sometimes sticks preventing the rig from powering on. The micro switch sticks because the relay contact arcs inside and they recommend never placing the rig in "standby" because of this quirk. So to get the micro switch working again, you have to use some old fashioned and unconventional technology to fix the problem and here is the solution... You simply use a small hammer and a wooden dowel stick. Yes, you heard me right. Now locate the power on / standby micro switch behind the panel of the R390A and rest the dowel on top of it. Give it a light tap or two and Viola! The R390A immediately powered up just like magic! So the result is now I have an R390A that was apparently sold to me a few hours ago as completely dead as a door nail for a $100 bucks. It is now powering up and working again thanks to Mr. hammer and wooden dowel. All the tubes were lighting up so all the modules inside the R390A were getting power. This one already had the solid state conversion done to the power supply so that's good. I suspect this one is also a "depot spare" rig that never seen much use at all since it was originally first decommissioned and here's why I have come to this conclusion. It's clean as a whistle inside! Even the gears are spotless and they have no wear on them. There is also no grease on the gears at all. Incidentally, the depot never greased any R390A gears when servicing them. It wasn't listed as part of the service schedule. There is still evidence of the yellow stripe on the front panel of this R390A. They did this to all R390A's when they were decommissioned from service. Most of the stripe has been removed by it's previous owner but it doesn't look like any attempts were made to do anything else whatsoever with this rig since it was acquired. The meters are "still missing" Again, more evidence absolutely nothing has been done with this R390A since it was first decommissioned. There is clear evidence it was serviced at a depot before. It has a Stewart Warner RF deck, The IF deck is an EAC. The panel has been repainted before. There is a small scratch about a 1mm in size on the bottom corner of the front panel and it was filled in and painted over and it's not a touchup job. Same goes for where screws were previosly used to hold the front panel inside a rack. Small "circle rings" are evident but were painted over. Looks like it was repainted by a depot in the past. The solid state conversion to the power supply module has already been completed. The rectifier installed inside is "green" military grade with military numbers stamped on it and it's been "professionally" wired and mounted to the chassis. The old tube rectifier holes in the power supply have been plugged and the entire solid state conversion looks far too professional to be anything else but a depot repair service job. I also have an "original" copy of the R390A manual. It is not a reprint, but 100% original. The only place an original manual for an R390A would come from is a service depot. This also suggests the rig was stored inside a building along with the manual which is in the same physical condition as the R390A itself. So moving along I powered up the R30A hooked up an antenna and my 600 ohm headphones to the phone jack on the front panel. I tuned it into to listen to WWV. I noticed the the frequency display was right on the money. Then I tuned around and heard brother Stair Put it on 40m and played with the BFO on SSB signals and listened to a few DX'ers calling CQ. So it seemed like it worked. However after a few minutes a "hum" was noticed in my headphones. I tapped on the power supply caps with my wooden dowel stick and this would make the hum disappear and come back again. So it was evident the power supply caps must be leaking and in need of replacement. Of course they are probably quite old and need replaced anyways. If you don't do anything else with your R390A, at the very least you should rebuild the power supply caps. So let's get started rebuilding the power supply caps shall we? . These caps are located on the AF chassis on the bottom of the rig. Marked on the AF module as C 606 and C 603.