[R-390] First R390A - let the adventure begin

Tue Oct 17 17:34:59 EDT 2017

Hello Tom, 

Getting your R-390/A back up to snuff isn't that difficult. I see you have started in the correct direction, kudo's to you. If the seller can't demonstrate all is well, the best road is to take a look under the hood before plugging the receiver into an outlet. The Y2K R3 is your bible, keep it close, print it and life will be good.

The last few chapters has a wealth of info in the Y2K. Chapter 6 (six) is a beauty. 

I've sent a MS document in another email, use as needed. 

There are others on this reflector that lived radio and have much to add in the theory end of things. My work was more practical, get it fixed and fly to the next location. So, to prevent you & others from chasing their tails; get the caps first (all of them). Check a resistor here and there. Clean switches, clean pins on IF & RF transformers. While the modules are out in plain view, check for modifications and someone's better ideas. Test the tubes, etc. The idea is to catch the easy items first.

Get the mechanical alignment next, then Chapter 6 and the electrical alignment. After that chase the bugs, good chance there will be a few. Someone here on the list has been there already and can/will help.

Regard,
Craig
WD8KDG 

-----Original Message-----
From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net] On Behalf Of Thomas Hoyer
Sent: Tuesday, October 17, 2017 1:12 PM
To: r-390 at mailman.qth.net
Subject: [R-390] First R390A - let the adventure begin

-----Original Message-----
From: Thomas Hoyer <thoyer1 at verizon.net>
To: r-390 <r-390 at mailman.qth.net>
Sent: Tue, Oct 17, 2017 10:25 am
Subject: First R390A - let the adventure begin

Picked up my first R390A fora reasonable price at a local hamfest this past weekend. It was dirty with afair amount of surface mold but seller said it was operational and would giveme my money back if it wasn’t. Local guy so I went for it.

Once I got it home I decidedthe best course of action was not to plug it in and turn it on, but to removethe modules, clean and inspect everything then determine a course of actionfrom there.

>From what I can tell, eachmodule appears original with the exception of the IF module where the filterarea was definitely worked on and a couple were replaced along the way.

I took to the internet andstarted researching the R390A radio. Talk about information overload! Lots andlots of info out there. I downloaded the MIL TM manuals and the Y2k document(wow, tons of research and effort put into that document!). 

After finding this wealth ofinformation I have decided to walk through each module, replace the black/brownbeauties and other suspect caps as well as test the resistors and replace themas needed.

Last night I did a baselinearchive of each module recording part numbers / serial numbers and takingpictures. All of this babbling leads to my question for the start of thisproject…….

I’d like to know if thefollowing module part number / serial numbers align with the radio or if theymay have been swapped out over the years. This is probably old hat to most ofthe experts out there but this is my first rodeo with the R390A so here goes:

Radio SN – 4067, Contract 8719-P-55

PTO – Type 70H-12, SN 2529-D

Crystal Osc - PN 540 7609005, SN 4139

IF Module – MFP 1330 (whatdoes MFP mean?) BFO inside – Collins 70J-3,SN 6751

Filters:
F455 N 160;  PN 526 9162 00;  SN 10 M 2
F455 N 80; PN 526 9167 00;SN 10 M 2
F455 N 40; PN 526 9160 009;SN 10 V 2
F455 N 20; PN 526 9163 009;SN 6451

Audio Unit – PN 540 7553005, SN 4151 (MOD 1)

RF Deck – PN 540 7909 005;SN 4053

Power Supply – PN 540 7545004, SN 4056.

Judging by all of this itlooks like the Audio Module was changed along the way?

Thanks, 

Tom
W3TA

PS: I have experiencebringing other receivers /  boat anchorsback to life, Hallicrafters, Hammarlund, Collins 51S-1 and have lots of testequipment so I’m good to go there……….

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