[R-390] alignment assistance for an R-390A beginner

[antero.nordlund@nokia.com]

Dear group,=20

this is the first, but probably not the last time I write to you.

I have just recently acquired an R-390A receiver from Fair Radio. Having =
my background in humanities (linguistics), I chose the "checked" option =
in hope of a working unit. After having paid almost another USD 550 for =
shipping, value added tax and customs duties, I finally have my radio on =
my desk here in my hometown of Nurmijarvi, Finland. I think I got a nice =
receiver: it has an engraved front panel (without a manufacturer's tag), =
one fuse, the PTO is a Collins, power transformer from EAC, AF =
subchassis from Capehart... well, all in all, a nice example of the =
modular construction principle! These all are from the 1960-1961, or =
thereabouts, contracts.=20

I resisted the temptation to apply power to it before I had changed the =
critical capacitors in the IF subchassis (C-531, 547, 549, 553). =
Obviously, I also had to make the necessary changes in the power supply =
for our 230 VAC. Further, I have now changed all the capacitors in the =
AF subchassis listed on KK4DF's homepage.=20

At this point, the receiver is working surprisingly well, taken into =
account the little work I have done so far. Signals are present on all =
bands, random checks into tube sockets show approximately the correct =
resistance and voltage values, and test point E607 provides exactly 150 =
VDC.  In fact, my R-390A receives just about every signal my other =
receiver, a Drake R8B, receives. Not bad, although I do notice that the =
Drake is more sensitive on the medium wave band, at least so far... Of =
course, my R-390A probably has who knows how old tubes and it probably =
is not perfectly aligned, which brings me to, yes, alignment issues:=20

I can at the moment adjust the frequency display to indicate the correct =
frequency as described in the Operator's manual, but I notice that, =
using the "zero adj", I end up at the very limit of the KC knob's range =
of movement without the last three digits of the display changing. More =
specifically, I can't move the KC knob to the right (higher =
frequencies). =20

Further, the mechanical alignment at the frequency reading of 07+000 is =
slightly off, with the cam plates (all of them) better in place at =
frequency reading 07 990. Now, in such a case, the manual suggests the =
remedy is to set the cam plates to their correct position, and then =
manually change the frequency reading to 07+000. In my case, then, I =
would have to add 10 kHz to the reading. But here's where my confusion =
already starts: if I add 10 kHz to the frequency reading, I can't =
correct that using the "zero adj." as I'm already at the limit of its =
range. Further, the nice balance of approximately 35 kHz above and below =
a "XX 000" reading on the frequency indicator will be gone, right?

So, as you notice, I'm a bit confused as to what setting affects what =
other settings and what the correct order of doing things is. Is there a =
procedure described somewhere that corrects the frequency error, centers =
the "zero adj." to the middle of its 15 kHz range, and restores the 35 =
kHz on both sides of a "XX 000" reading? Of course, what I'm after is a =
non-techical description using layman's terminology and definitely not =
using signal generators, oscilloscopes and other equipment that I don't =
happen to own! I have downloaded TM 11-5820-358-10 and -35, and the 21st =
century technical reference, but can't seem to be able to extract the =
information I'm after.=20

Any help you can provide is received with gratitude!

Greetings from Finland,

Antero Nordlund          =20

antero.nordlund@nokia.com
  =20