Good deal! I remember when I got my 390, there was no green gear and someone had messed with the gear train - probably why the price was right..........
I fought with that mechanism alignment for many hours and kept telling myself that it went together at the factory so I should be able to do it too. Eventually it all came together and the radio works well! Congrats, on to the next item........ Tom W3TA -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Barry Scott Sent: Wednesday, September 4, 2024 7:15 PM To: Jim Whartenby <[email protected]> Cc: R-390 Mailing List <[email protected]> Subject: Re: [R-390] Gear Train Removal Success! TM 11-5820-357-35 (1962), at the top of page 84 (Step (50) (a) states that S206 should be on contact 5 for MC=2 (contact 7 for MC=0 and contact 6 for MC=1). Once I had that in position, then rotating the KC gear eventually brought all the cams into alignment. Whew! Thanks, Barry - N4BUQ On Wed, Sep 4, 2024 at 1:19 PM Jim Whartenby via R-390 < [email protected]> wrote: > Barry > What you have experienced was a know shortcoming of the original R-390 > design and is mentioned in "Chapter 6.0 Recommendations" starting on > page > 79 of the Final Engineering Report. Also mentioned are mechanical > filters and tubes used that could have been upgraded if better tubes > were available earlier in the design. But at some point, the design > work had to stop or it would have never left the engineering phase. > There is a point reached where the design is "Good Enough" aka GE. > Relax and take a breath, nothing you have done is fatal and all can be > corrected. Keep us informed. > JimLogic: Method used to arrive at the wrong conclusion, with confidence. > Murphy > > On Wednesday, September 4, 2024 at 12:43:14 PM CDT, Jacques Fortin > < [email protected]> wrote: > > Ah, also forgot to mention: the RF deck have to be re-installed in > the frame (see procedure chapter 59) BEFORE any re-alignment is > attempted ! > > 73, Jacques, VE2JFE in Montreal > > Barry, some COMMENTS imbedded in your text below. > > 73, Jacques, VE2JFE in Montreal > > Well, I don't quite know how it happened, but I can no longer get all > the cams properly aligned. As I mentioned, I've removed the VR > counter so that's one point of reference that I no longer have. > > AH, DON'T WORRY: I HAVE DONE THE SAME FEW YEARS AGO.... > > I had been rotating the MC change gear one click or two and then back > and no problem; however, I think I lost track of which way I had > rotated it and now I can't get back to where 2.000 would normally be > displayed by the counter. > > FOR THE MC POSITION, JUST RELY ON THE ROTATING DIAL OF THE SYNC XTAL > OSC THAT INDICATE ON WHICH MC POSITION THE SWITCHES ARE. > > I'll mention that I've kept the Green Gear in place and, contrary to > my previous comment, that gear does indeed keep the MC and KC gears > synchronized and, given that, I don't know how they're no longer where > I can get them back in sync. > > IT DEPEND ALSO IF YOU SET THE PROPER MECHANISM POSITION CORRECTLY > BEFORE REMOVING THE RF DECK. > READ THE CHAPTER 59 CAREFULLY AGAIN !!! > THEN, ROTATE THE KC SHAFT AND TRY FIRST TO ALIGN THE 8-16 MC CAM. > IF YOU ARE LUCKY, ALL THE OTHER ONES WILL ALIGN (IF THEY WERE ALIGNED > CORRECTLY PREVIOUSLY). > IF NOT, TRY A FULL TURN AROUND LEFT OR RIGHT (DEPENDING THAT YOU > REMEMBER OR NOT WHAT YOU HAVE DONE BEFORE). > OR... JUST TAKE THE PROPER ALIGNMENT OF THE 8-16 mc AS THE STARTING > POINT AND FOLLOW THE FULL CAMS RE-ALIGNMENT PROCEDURE CAREFULLY ! > > According to the manual, as part of the complete gear teardown and > rebuild (which I still have not decided to do), one is supposed to be > able to rotate the MC gear CW (which I presume is taken to mean "CW as > viewed from the rear"), until it hits a stop point and then, back up > to the nearest notch which should correspond to 0.000. My presumption > is that if I back off to the 3rd click, that should correspond to > 2.XXX and rotating the KC shaft should eventually get the gears (and > cams) in the 2.000 position. > > I found that there is something that causes a "stop" at full CW and > full CCW. I think that stop is happening as a function of the Geneva > mechanism and not the 10-turn stops (which aren't engaged when the RF > deck is removed); however, CW or CCW still won't let me get the > gears/cams in their proper setting and am wondering if I'm now truly "stuck". > > Any help is appreciated. > > Additionally, to avoid getting the transformers' cores wet, I'm > removing the slug racks and transformers while cleaning the gears and, > right off, I found that one of the slugs (for Z2223) was broken. I'm > sure that didn't help performance any. I have it CA glued back > together so that should help when I get this all reassembled. > > Thanks again, > Barry - N4BUQ > > ______________________________________________________________ > R-390 mailing list > Home: http://mailman.qth.net/mailman/listinfo/r-390 > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html > > ______________________________________________________________ > R-390 mailing list > Home: http://mailman.qth.net/mailman/listinfo/r-390 > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
