[R-390] question

[Flowertime01 at wmconnect.com]

Tim,

Good response to Radio52.

Think this receiver use to work.
It was moved.
Now it does not work?
There fore something come adrift. (IT BROKE)

A place to start is with the eye balls.
Pull the top cover off if the receiver has one.
Pull the Utah RF deck cover off (so named for its shape) the RF deck.

Under 8Khz is the first crystal osc V702 a 6ak5 or 5645 tube.
Is it lite?
As this is a new receiver to you. you need to locate the 
HR 202 crystal oven.
This is a round can on an 8 pin crystal socket off on the right side rear 
corner.
It should have two springs and cross clip holding it in.
Slip the clip over to one side.
Pull a couple tube to get some finger room and pull the can.
The cover comes off the can with little screws around the base.
Then there is another cover on the oven can inside.
Its a press fit and slips off.
Inside the can should be two crystals.
Check that they exist and are seated.

We Fellows believe in a product called DeOxIt. clear liquid in small bottle 
that cleans out crud from contacts. You may need some between the crystal and 
the contacts in the oven can and between the can and the octal socket contacts.

Put that all back once you know you own those parts.
Make sure the two crystals are in the correct location in the oven.
You can have cal tones with swapped crystals.
A Fellow would know the symptom of swapped crystals but only from experience.

Check V202 a 6C4. Is it lite?

Grab the MC change knob and roll the dial from 00 to 08.
Watch Z213-1 ,2, 3 This is the back corner left set of three cans under a 
slug rack.

As you go through the MC change steps the rack steps up 
00 is slugs in the cans 07 is slugs out of the cans.

As you run the KC dial from -000 to +000 the rack should move up slowly the 
small amount of a step between the MHZ steps.

Look to see that all three slugs are moving and the rack follows the cam and 
does not hang up some where on the rails. Mostly a slug hangs in a core and 
the rack does not follow.

Set the dial to 7+000 and check that all the cams line up close to the 
mechanical alignment point.

You may have to use the zero adjust to get some small adjustment on a cam or 
two. 

If all the cams are not close then look for a loose or broken clamp in front 
of a gear. That's a whole another mail subject.

Do not worry about dial over run being exact or zero adjust being exact at 
this time. They should be close unless something come loose in the mechanical 
stuff.

The next visual check is the RF band switch.
As you run the MC knob from 
00 to 01
01 to 02
02 to 03
03 to 04
07 to 08
15 to 16

You should observe the band switch changing position.
You can see the shaft gears in the front once you learn where to look.
If you actually have to adjust this gear, shaft, switch timing, you need to 
pull the RF deck and do the adjustment by eye. You want to ensure maximum 
switch contact at all bands on each of the switch segments. Its a look at the whole 
problem and select the best average for the longest switch life. Your 
receiver may have a burnt corner on a switch contact from pass life experience and 
you may need to adjust the switch around it.

You have eyeballed,
Two tubes.
Two crystals
The cam alignment
The rack motion
Three slugs
The band switch motion.

Time 10 minutes. (you pulled a can and looked inside it)

Run the tubes through the tube tester.

If this has not brought you back to life the work starts.

Next stage of work is to pull the slug rack and the three IF cans.
Slips the two springs off the slug rack.
Lift the rack out of the cans.
Do the slugs all look the same color and have the same length?
Broken springs can be soldered back end to end with acid core flux.
Broken slugs can be glued with super glue (out of the can and with care).

A good small dia number 2 Philips screw driver will remove the machine screw 
in the bottom of the slug tubes.

The cans will then unplug from the RF deck.
Push the two side clips in with care and the can covers will slip off the can 
frame.
Inside is the coil winding on the tube, the trimmer cap and maybe some fixed 
caps.

The clip can be slipped off the bottom of the trimmer cap and it will 
disassemble.
The cap parts can be cleaned with soap and water.

Hear again you are looking for crud in the contacts where the cans plug into 
the RF deck.

Check for a broken wire between the can frame contacts and the tuning coils.

This is all still mechanical inspection and eye ball with cleaning.

You should check the tube socket pins for crud and clean them as you go.

After you pull the IF cans apart this far and put them all back together you 
can expect you will need to realign the whole stage.

You can do the alignment of the IF stages using the cal tones, an AC volt 
meter and 600 ohm resistor on the local audio output on the rear terminal of the 
receiver. Panic Not about taking these cans apart for inspection.

If this amount of visual inspection and cleaning did not restore operation on 
the receiver below 8Mhz, your next venture is going to be pulling the RF deck.

As this is your first venture into your new to you receiver it will take you 
some time. Fear of doing things will slow you down. Fear not you have no idea 
how many young GI's have had their hands in that receiver and did it no harm.

The receivers are not bullet proof but are very tolerant of being petted.

Tim is right, 
If this shot gun eye ball does not disclose a problem, its time to start the 
signal injection and voltage tests in the TM. 

You need to down load a copy of the Y2K manual and burn your self a CD for 
reference. If you do not have a fast net line, A Saturday afternoon at the 
library will be in order. (Or from work.) Scope out the environment and come back 
with the media you need in hand to save a copy. The old TM is also on line for 
reference.

The options are
a prior owner let some tubes go to the point of burning things under the 
deck, 
Or moving the receiver Jared something loose including old solder joints.
Or age has allowed crud grow a contact open.
Or a tube has gone bad.

I think you need to inspect for problems from this list bottom up.

Let us know how these inspections go and what you find.

We love to read the stories.
We all learn.

Post everything out to the r-390 at mailman.qth.net so it gets shared with 
everyone.

Roger L. Ruszkowski AI4NI

P.S.

You boys just go play with the toys you have and enjoy your selves.
Lets not be dragging your school colors out and waving the flag for your 
preferences in front of the new people. Lets help them solve their problems and 
give them a day or two before we get to the philosophy.

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