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

[Bob kb8tq]

Hi

Welcome !!!

There is no single “right” way to do this. I would replace the capacitor of death and put in 
new electrolytics. Past that, I’d clean things up and look for visually obvious problems. If
I didn’t see anything, I’d cautiously fire up the radio. Do a few quick checks and then move
on to troubleshooting. The R-390A does not have quite the wholesale parts issues that 
some other radios have. There is less need for shotgun / wholesale parts replacement. 
In some cases replacing a part damages something else (maybe that’s just me). If you 
create a couple of issues in the same radio, it is a lot harder to get the whole thing running.

Lots of ways to do it ….

Bob




> On Oct 17, 2017, at 4:11 PM, Thomas Hoyer <thoyer1 at verizon.net> wrote:
> 
> 
> 
> 
> 
> -----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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