A Wiha nutdriver set later and I'm in: https://goo.gl/photos/SDHtvgFmftQq6vYJA
See the last two pictures. I will disassemble the board stack and work out some schematics next. Thanks everyone. -ch 73 de AI6KG On Nov 20, 2016 5:19 AM, "J. L. Trantham" <[email protected]> wrote: Christopher, Enjoyed the pictures. You might want to look at these items on theBay. 381408412092 311736541103 I've had the same issue and broke down and bought a set of these small nut drivers. Good luck. Joe -----Original Message----- From: time-nuts [mailto:[email protected]] On Behalf Of Christopher Hoover Sent: Saturday, November 19, 2016 11:45 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Inside of FT1200-100 tl;dr: I've made some progress and have the1200 oscillator core out of the dewar: https://goo.gl/photos/SDHtvgFmftQq6vYJA I got some 5 thou brass stock and worked it between the rubber sheet and the dewar. That seemed to help but it was insufficient free things up -- I busted off the unused solder lug trying to pull the core out with it. Having not a lot to lose, I took a chance that the screws going into the TO-23 went into threaded holes (rather than being clearance holes with nuts inside). This was indeed the case. With two 6-32 threaded rods into the TO-23 threaded holes and and an appropriately machined piece of mild steel bar stock suspended across the case <https://goo.gl/photos/1pfiN2GX3WxYCSbg8>, I was able to easily get the oscillator core out of the dewar by evenly tightening the the nuts on the bar. Really easily -- I might have been able to pull it out by just pulling on the bar stock. I don't know if the shim stock shenanigans were even needed. Despite running out the three sloted screws on the "top" around the circumference, I'm not into the inside yet. I don't have the right thin-walled socket to remove the nuts at the opposite end. I found an epoxy covered hole on the top. It is/was under the green blob midway between 1 and 2 o'clock in this picture here <https://goo.gl/photos/ iHbSbqwBiKD7NRfJ6>.. There was something blue and at this point crumbly underneath it. Not sure yet what, if anything, is beyond all of that. I'm hoping for a trimmer cap. :-) -- Christopher. 73 de AI6KG On Mon, Sep 26, 2016 at 9:24 PM, Chuck Harris <[email protected]> wrote: > Back when I was going to work on mine, I was thinking of prying the > rubber away from the aluminum oven with something like a feeler gauge, > but also using some naptha (lighter fluid) to help release any > adhesive... I didn't get around to doing it, but that was the way I > was going to progress. > > -Chuck Harris > > Ed Palmer wrote: > > > > > > On 2016-09-26 10:00 AM, Christopher Hoover <[email protected]> wrote: > >>> > > >>> >You might be able to slide something like a feeler guage down > >>> >between > the > >>> >oven and the rubber blanket to break the oscillator free. The > >>> >oven > on mine > >>> >is a plain metal cylinder. This way, the rubber sheet should > >>> >protect > the > >>> >Dewar from your feeler guage. On mine, the mounting bolts for > >>> >the > 2N3792 > >>> >transistor both have ground lugs. I think I see them on yours. > >>> >You > could > >>> >hook something through the ground lugs and use that to pull the > oscillator > >>> >out of the rubber sheet and then remove the sheet later. > >>> > > >> Thanks Ed, > >> > >> I think the rubber sheet on mine is against metal. I haven't yet > >> seen > the > >> glass dewar. > >> > >> The adhesion is huge. > >> > >> Do you know if the holes opposite the 2N3792 are threaded? If they > are, I > >> might try running the screws out and using those holes with longer > screws > >> as my pull points. I can't pull on the lugs hard enough -- I've > tried. > >> > >> -christopher. > >> 73 de AI6KG > > > > Yes, you have seen the Dewar. The silvery ring that's outside the > rubber is the top > > of the Dewar. What you have to do is unstick and unfold the rubber > starting from the > > open area in the center. Work your way outward. The rubber is only > > 2 > or 3 mm > > thick. Once you completely clear the rubber out of the way, you'll > > see > the edge of > > the oven. The TO-3 transistor is mounted on top of the oven assembly. > Once you can > > see the edge, you have to slide something like a long feeler gauge > > down > along the > > edge of the oven to break it free from the rubber. Work your way > > all > around the > > oven. It's about 85 mm long. It'll still be stuck on the bottom, > > but > you might be > > able to pull it free. > > > > When I took mine apart, I ended up tearing off all the rubber at the > > top > and then > > cutting out that ring of hard foam to get at the Dewar so I could > > smash > it more. I'm > > guessing you'd rather not do that! :) But sacrificing the rubber on > > the > top might be > > okay, if you have to. > > > > Sorry, but I don't know if the mounting holes for the transistor are > threaded or > > not. In any case, since the oven and Dewar are bonded to the > > rubber, > you're pulling > > on the Dewar when you pull on the oven. Not a good plan until you > > break > the oven > > free from the rubber. Those Dewars are built in a rather fragile > manner. Your > > typical home Thermos is much more robust. > > > > Ed > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] To unsubscribe, go to > > https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow > the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
