[R-390] RF deck removal

[Alan Victor]

Hi Craig and all,

Thanks for the input(s) and clarifications. Yes, my take away from the
video seems to be 7+000 is more appropriate than 00 - 976. I managed to get
the panel screws broken and loose so I should be able to readily drop the
panel. I will have all modules out at that time except the PTO and RF/xtal
sub unit. I am not sure the clutch gear PTO interface is exactly centered
as in the video but I suspect that is a minor issue that can be done
latter. As long as I do not do a stupid movement of the PTO shaft.
Currently the CAMs that I can see are reasonably on the mark at 7+000. Of
course I cannot see the rear CAMs as well as the 2 CAMs in the buttom
front.

Alan
On Sat, Oct 11, 2014 at 9:05 AM, Craig Heaton <hamfish at efn.org> wrote:

>  Alan,
>
>
>
> Where Oh Where to set the MC & KC knobs? I have to agree that Murphy is
> lurking in your lab/shack. No matter what, the front panel has to be
> removed in order for the RF deck to come off of the mainframe. Bottom line
> is; “IF the mechanical alignment isn’t right, ain’t nothing right”.
> Presetting MC & KC for (Seven…..Plus……Zero……Zero…..Zero) at the getgo
> enables one to see the cams & index marks ASAP. If all is good, add that
> event to the day’s blessings. If not, you have another challenge in life!
>
>
>
> At that point, don’t let anyone attach a drill motor to the PTO  shaft and
> give it a spin or two. When reseating the RF deck the coupling might be a
> few degrees off. Take caution not to bump the PTO shaft. If for any reason
> the PTO shaft is going to be turned, all is not lost. Quite simple to use a
> sig-gen to input a signal, turn on the BFO, loosen one of the Bristol
> screws on the Oldham coupler, turn the PTO shaft to zero beat. That should
> get you back into the ball park.
>
>
>
> Not sure if Chucks video or the Y2K has the following? With the panel
> down, check/adjust the Zero ADJ device for middle range of movement. On
> Chuck’s website, he at one time had added a last step to the IF alignment
> procedure. Which was how to adjust the BFO; zero beat with a 455KC signal
> injected into the IF.
>
>
>
> The hardware issue: Hams use what is in the junk box!!! With luck the
> threads are okie-dokie and there is a store in town with the correct
> fasteners. Good Luck……………
>
>
>
> Craig,
>
>
>
>
>
>
>
> *From:* Alan Victor [mailto:amvictor at ncsu.edu]
> *Sent:* Friday, October 10, 2014 5:15 PM
> *To:* Craig Heaton
> *Cc:* r-390 at mailman.qth.net
> *Subject:* Re: [R-390] RF deck removal
>
>
>
> Thanks, all good inputs. Nice to know about the backlash spring and the
> ball point pen substitute!
>
>
>
> Actually, before I drop the panel and pull the RF deck out, all the other
> modules will be out anyway. Namely, IF deck (already out) fixed one item
> but may as well look for any other bugs that are obvious. The power supply
> and the audio deck taken out as well. Main reason... I need to move the
> receiver from the lab bench to the workbench. Getting down to about half
> its weight is better for me alone. And of course, the entire mainframe has
> not been cleaned at all, so that is the goal.
>
>
>
> I guess I need to re visit Chucks video on dropping the panel and the
> issue of NOT loosing synchronization. While the Y2K says full CCW on MC and
> KC knob, I was under the impression, I was to set the CAM tips in line as
> it were at 7+000. That is, set MC and KC accordingly and pull the panel and
> RF deck at that setting. Not at 00 -963. Am I missing something again?
> Sorry, but I am a firm believer in Murphy's law. In any case, open to
> any/all comments.
>
>
>
> One last item. *My panel hardware was redone somewhere in its life*. The
> Phillips screw heads on the main panel attached to the mainframe are
> straight head screw and use selflocking nuts. So I suspect the mainframe
> tap is stripped. They are stainless, but not Phillips. So I need room to
> get behind the panel to get them out and replace with the right hardware.
> Another reason to get as much electronics out of the mainframe as
> reasonable.
>
>
>
>
>