The AM Forum

I am resurecting an old R390 NON A model.  It was a mess.  Owned by a CH6 guy.  I know this because when I got it, It was tuned right into CH 6 CB.

I found some bad tubes. Checked them all tonight with the TV7.  I need one IF tube.  6bj6.  Its reading 20 on the scale. The others are reading 80.  $3 at tubesandmore down the street.

I popped the covers off the pots and sprayed Deoxit. That fixed the pots. Nice and smooth no crackle anymore.

Someone took the 3TF7 ballast out and stuck in two resistors. Seems to work.. Should Try to find one? Anyone have one?

The set is now working FB. I had to calibrate the BFO. It was way out.  Its sounding good.  

I noticed that the wire in the picture is not hooked up.. I have no idea where it goes. Can someone help and identify its location?

I am going to have to align the thing. On some bads the readout is up to 6 KC off. Seems simple enough.  I will do this once I get the new IF tube.

BIG problem that I need help with. BOTH this R390 and my R390A do NOT turn off.  Even in the off postion, The Receivers lights stay on. I studied the switch. I dont see anyway to adjust it. Can someone help me with this?


Parts needed: 

Top and bottom covers.
3tf7 ballast tube.
5! large size tube shields
6! small size tube shields
Correct power cord with plug for back of set!

THanks!

Clark

Don't bother with a new 3TF7.  There are several ways around this.  Look in the receivers forum here for some of them.  One is to plug in a 12BY7 or similar (requires socket rewiring) another is to replace the BFO and PTO toobs with 12BA6s then short two of the 3TF7 terminals.

The microswitch on the power switch assembly is bad.  Needs to be cleaned/replaced.

So first off Clark, is this a R390 as the subject line says, or a R 390 NON A? The latter is much harder to find parts for!  ;D

All joking aside, a similar approach is to use a.... (searching memory banks).....47 ohm 5 watt resistor between pins.....2 and 7 of the ballast socket, no other changes needed. Been a while since I did this workaround, but the 3TF7 is basically a resistor used to absorb voltage changes in situations of poor line regulation, not something we often encounter in civilian life these days.

Essentially the same thing as John's 12BY7 recommendation which actually looks better since there's a real toob in the socket. Just another option depending what you have in the junk box for parts.

Ok. I will leave the resistors in place then. 

Anyone have any idea about this wire???

C

Hard for me to make out in the photo, but the location tells me it might have gone to the the diode load located on the back panel. Navy versions of this receiver brought the diode load connection out to the front panel for easier access (instead of having to remove the receiver from the rack onboard ship) during regular use and maintenance. If there's a small plastic socket near the headphone jack, that would be the clue, though some owners swapped panels to get rid of the 'unoriginal' hole.

Missed it in your original post, but the power switches on these things are notorious for welding themselves shut over time. Very common failure point, unless you've owned one for years and never had a problem, in which case I'm making it all up.  ;D I'd try googling R390 switch or something similar to see what comes up for possible sources of replacements Someone had a stock of NOS a year or so back, Fair might have some as well.

The more you play with these great sets, the more intuitive it all becomes. The R-390 is especially fun, and most rewarding. I especially like the cast aluminum criss-cross support in front.

That jack on mine is the headphone jack.  It could go to one of those contacts. I cant tell. It just looks like it was broken off over time. Someone please flip there R390 over and see.. Its a solid White wire. 

I will just put it on a power strip like the others. Its a 2 to 3 hour job to get to that switch and they are $75.  LOL

C

If it is the same switch as the R-390/A, Fair Radio use to sell them for ten bucks,

Craig,

I need to call them anyways.. Thanks for the tip

C

I got almost all of these parts from Ron and Gary at Fair radio.  Spent more then I wanted but I got this radio cheap and its going to be damn nice when its done.

I do need:  7 medium sized knobs and both large size knobs. This radio has an odd ball knob set on it. 


Clark

Clark: I have R-390A knobs. Email me of list.
Regards,
Gary...WZ1M

Thought you guys might want to see what I have been doing all day.. :)

This R390 came cheap but it also came with about an inch of Grease and Grime all over the damn thing. The worst I have seen in a long time. 

I started by checking tubes and taking inventory of the parts I was missing.  All those parts where picked up from either people on this forum, guys on the radio or Gary and Ron at Fair radio.  All parts are inbound except the knobs. 

I scrubbed this radio down by hand over the sink. I chose not to put it in the dishwasher or hose it out. Just good old fashioned work with hot soapy water got it clean. Now, the only thing that is left is the Mildew coating the military but on the radio.  The dirt and Grime is gone.

The knobs where Hand scrubbed and soaked in the sink.  The front panel was scrubbed by hand. It needs a repaint. Its now at least clean though.  Who repaints these panels?  I dont feel up to the task..

It turned out really nice.  The goal here is a nice, complete and functional R390 that I can use with my new Transmitter.  304Tls modulating 4-400s.  I think this one will be perfect.  Total investment is going to be in the $350 to $400 range. Not bad for a completed r390.

Here are before pics

And After..  I put the incorrect knobs back on because I dont have the correct knobs yet.. Once they come in, I will install them and it will look complete.

C

ANYONE have the manual for the R390?  I cant seem to find it. 

C

http://bama.edebris.com/manuals/military/r390/

Thanks.. I did not notice the millitary section. I looked under Collins and saw the R390a but no R390.. 

Thanks again

Clark

Ok.. Lots of time spent today cleaning this thing.  I repainted the Meter covers and the Freq display cover. Sanded them down by hand and repainted. They look FB!

With the correct knobs, and covers, This will turn out real nice.  I mounted a hammond 600ohm to 4 ohm Transformer on the back with existing screws.  Fit nicely. 

Now I wait for the rest of the parts to arrive....

C

CLARK
You have your hands full reviving that poor soldier!!!!
Many years of abuse and bad ju-ju.
Looks like it was left out in the weather or a really crumby loaction the last 10 yrs.

Fred

You should see it now!   Its as clean as clean can be.. Just going to do the gear train today.  Then its done inside.  I ordered the knobs.. I repainted the meter covers and freq covers.  Its really comming to life!

C

She is comming right along!

I got some basic black knobs for the radio.  They actualy look and fit great.  I am still looking for the large tuning knobs. I really hate how these look. 

I also painted the meter cover and Freq cover. I put LEDs in the FREQ cover.

The Gear train got cleaned and degreased today. I lubed the sliders, cams and gears. WOW what a difference! It turns sooooooo smooth now. 

Its going to look FB ontop of the T368!

Clark

That rig looks sweet now!  Amazing what elbow grease and determination will do.  I have no idea about that wire, but on my  A ihave a similar wire in a similar place. It appears to have been cut off. The rig always work FB so I never bothered tearing apart the laced bundles to trace it and see what it was.  I figured I'd do more damage trying to fix a non-problem then just letting it be.

Thanks Ed!  Its been alot of work.  But fun and it kept me busy! I just cant wait to fire it up! 


C

All the parts came in today.   The Replacement covers DO NOT fit the R390.  I compared the A to the regular and found that the regular 390 has a double thickness side bracket.  Oh well.  Guess I will send them back. I will mount this radio in a cabinet so it will be covered.

The tubes and tube shields where installed.

I made a new power cord.  3 wire with ground to the ground pin.  Looks really nice and fit right in.

The new ballast tube was installed with a shield.

I mounted the Hammond 600 ohm to 8 ohm transformer on the back using existing screws.

The reciever fired right up.  A wisp of smoke out of the on and off switch indicated this probably should be replaced. 

I had a horrible static sound with lots of microphonics. I traced this down by tapping around with a pen to the Relay on the bottom. I smacked it and it fell deaper into the socket. The noise stopped and the sound cleared up.

I tested all bands with the Sig gen. Its pretty close. 75 is dead on.  10.000 WWV is dead on.  40 meters is 4 KC off. Not sure what to set to bring this back in line.

I used it for an hour or two and listened to the AMI net. Its clear and strong on the RX.  At one point, YEC took the needed to 60 DB and I calibrated that meter :) The audio is about the same as my SP600.  Not nearly as nice as the 28 but I did not expect it to be. Its decent audio though. NO hum and the best noise limiter I have used. It took ALL the buzz right out.

The ONLY two problems left are:

1. The reciever wont turn off and a wisp of smoke came out the switch.. TIme for a new one.

2. The break in function DOES NOT work.  I put clip leads on the Breaking screw to ground and operated the switch.  NADA. Nothing. 

The coil on the relay is good.

There is no voltage to the coil ever, no matter the postion of the front switch or the grounded Screw terminal.

The Front switch works, I tested it with the meter.  What ever supplys this system with power is not doing its job.. Any advice on this would be helpfull!

Clark

Those receivers had a selenium rectumfryer that supplied the power for the break-in relay from the filament circuit. The rectumfryer is probably toast (or missing). I have replaced a few of them over the years.


                                                          The Slab Bacon

ahh...   Man, I wish I had the manual printed out. Its killing my eyes to try to look at this Schematic.

C

Not many R390 people on this forum. I would think lots of you have used them or own them.  Getting no help here at all with this one :(

I spent a few hours tracing down the break in problem. The wires are all good. There is no volts comming out of the PS for this rail. What a mystery this one is. 

I ended up clipping on to the relay contacts and then powering off my Mute buss in the shack. It works like it should. One day I will have to get a second PS or rip this one out and figure out why the hell it has no output for that tap.

I also pulled the panel today, Pretty easy really.. About 10 minutes. I took the PS switch apart. Its toast. The contacts are welded. I ordered a new one. When it gets here, I will install it. For now, Its up and running on a Power strip. I just turn the strip off when I walk out the room.

The 390 really matches the T3 nicely.. Going to use it tonight if all goes well!

Clark

Well, I'm one.  I've been reading your posts with interest.  Sadly (?), my R-390 is a "remanufactured" unit built by Rick Mish a few years ago (and was probably a good bit more costly than the radio you're working on, maybe closer to the original government price - and worth it!).  Other than the crystal calibrator (which is a bit flakey and seems to work as a function of how long the radio has been off or on or neglected or stroked, or talked quietly to in a sultry voice), it works better than any other radio on the shelf (a pristine and beautiful Rick Mish 1967 EAC R-390A included, a fine radio which is NOT on the shelf).

Don't know about the funky wire to the diode Load, can't help with the power switch.  I'm an appliance operator when it comes to Mish's radios.

But the point is to provide encouragement.  When you get things working well, they work really really really well.  For AM at least, the R-390 is the ultimate radio.  But do stock up on 6082's -- a couple at least.  I have a lifetime supply -- if I ever sell the radio and my stock of 6082's, it will impact the world market :-)  I've tried a kit version silicon replacement, and tossed it.

Fine radio.  

Grant/NQ5T

Thanks for the pep talk.  Its an old girl and there is just not alot of info on it. Tons of A info but not on this one.

Cherrish that Mish radio! 

Mine is now working. I got the break in working with external power off my relay system.  Works FB.

When I put the new power switch in, then put the thing in the case, Its going to be fine for my shack. 

C

Ok.. More updates.  Got the panel painting done. 

My panel was engraved.  I stopped by Micheals Craft store and picked up some water based acrylic white.  The super cute woman knew exactly what I needed once I explained to her my project.

After many atempts and failures, I came back to amfone and searched again. I found a post where it was suggested to use notebook paper to whipe the excess paint off. This worked FB!   I probably used a 10 pages of printer paper. Tore a scrap, Whipe and in the trash. The paper lays flat and never gets in the grooves. 

I used a .59 cent foam Brush to apply.  Two brushes and the paint cost $1.48!

Here are the pictures.  I have to scrub the white film off in a few minutes.. Some areas I had to go over twice..  Just dab on, Wait 10 seconds and whipe in one motion.

Also.. I found that letting the paint sit on a paper plate for 10 to 20 minutes allowed it to thicken. This made the job even easier.. Just put a huge glob of paint out on a plate and let it sit.

Clark

More pics. 

As you can see, My panel was really bad.  Maybe one of these years, I will repaint the entire thing.  For now, This really made the thing come to life. When its cleaned and polished, I will post another picture.

C

Ok.. Panel and reciever are now done.  I need to find the two large knobs if anyone has any, let me know.

IT came out really nice. It works FB.  I put it in a Bud Case for now.  Once I get the paint that matches the T3, i will paint the case and panel to match.  Redo the Chrome strips and this project is done. 

Here it is up and running..

C

That matches the T-3 very well!   It looks like you have the original meters on it too.  They were hard toget as they had the radium faces and the gove would removed them as part of the dmil process. 

Nice work getting it back to life!

thanks alot!

Now.. For a POLL


Should I paint the bud case black or should I paint it to match the T3?????


Clark

Black it is!

Sanded the case down by hand. I left the Crinkle finish on.  I just sanded the inside and some areas.  I cleaned with acetone.  Then primer with Auto primer.  After that dried I painted the case satin black.  It seems to have come out pretty darn nice. I took the chrome strips off and hand sanded them and then buffed them back out. They will look FB.

I also painted the patch panel to match.  Tomorrow, I am going to bake it in the sun, that is IF the sun comes out.. Then, I will put it back together and take some pictures.

C

Its done.  I will upload video and more pictures. I got lots of email on this project. Hopefully, it will be of some help. I am not super happy with the bud case, The paint is nice, But its 1 rack unit to tall and the reciever wont fit at the top. So I painted a plate to cover the gap.  Its the best I can do. I cant find the correct case. Maybe one day I will.  Here is the current station.  SP600 JX 12 is rack mounted and running Diversity with the R390.  It works FB!  Sp600 Slays the R390 though. I figured it would.  Back to back tests show the 600 just sounding better and recieving weak signal better.

My Brother took this photo with his Nikon Digital. 

Clark

Clark, thats a good looking station.  8) You put a lot of work in it.

you might dig my setup from 1998~1999, don't think if you ever saw it.

left to right, hammurlund SP-200, Stancor 110-C transmitter ( single 812) driving the homebrew rig on the right, which was pair of united electronics 812H's (carbon plate 812) modded by 805's.

I sold it all off on ebay during one of my "screw it, I hate everything" phases. I was going to use this as a QSL card, but never did.

That is a FB looking station indeed, Clark.

Since ya had the panel off that R-390, that woulda been a good time to paint it Stealth Bomber black  ;D

Very cool man.  I really like it..  To bad you sold it, I have done the same thing in the past.  Did you ever print those cards?

My station changes all the time.  When I find the correct case or at least a case that fits better, I will install it. Then time for new pics. I cant have gear open. Sophia the cat is already laying ontop of the damn thing right now :)

C

Heh, she's a darling. Phoebe cat got into on of JN's 75A-2's n chewed up some B+ wiring all to hell. lucky for her th rx was off and unplugged. She will chew on anything made of cloth or plastic, if she can break it up into bit size she then eats it.  :D

I was mortified to have to show Johnny the kittie's handiwork.

By the way. The R390 and 390A power switches are availabe. 

Robertshaw 224-1594-00  You can get them at Kens electronics.  $5. ITs an AC switch.  Guys are marking these thing up to $50!!!!! 

Clark

nope, never did.

I am going to have new cards made when the Raytheon is installed and everything is in place, rxer, exciter, Matchbox, etc.

As much as I love teh black wrinkle, it 's gonna be nice to break out of that mold with the RA-250. late 40's is a good style time-wise in radio. They kept a lot of the chrome and trim but started to get away from black only or gray only. All the Raytheon was 2 toned brownish themed with lots of trim.

I am SO GAY when it comes to gear, I like all the colors to mix and match and follow the same theme, etc.  Always been that way. I care about the visual appearance of my stuff way too much.

Re: Wisp of smoke and welded power switch.

I'de be curious what the in-rush amperage looks like w/ a cold rig. An analog meter with the range bumped up above the expected values might be interesting. It might help point toward some ghosts in the machine.

I'm not big on the R390's but they are starting grow on me!
The construction is amazing. Nice job.
                                                             D.

That would be interesting. I can measure that.  Every R390 and 390a I have come across does not turn off.  The switch always fails. Sometimes you can bring them back, Sometimes you cant.



C

Clark,

Are you sure that this Robertshaw part no. is an exact replacement for the R-390/R-390A power switch?

If so, that is very valuable information.

Thanks & 73,

Bruce

It is the same.  I ordered one, Paid $50!!! for it.  Got it in the mail. It fits and looks EXACTLY like the original  5 amps 240volt. 10 amps 125 volt.  The guy did not grind off the part numbers.  I typed them into google.. I found them at Kens electronics. The page is confusing.. But it seems its $5 each.  I just wanted to pass this along so others dont spend $30 to $50 on a switch only to find out, The local AC parts house has them for a fraction!

C

http://www.kenselectronics.com/lists/switches.htm


Standard-Size Micro Snap-Action Roller-Lever Switches about 1" (27MM) long
PH30-2080 (15A) replaces GC35-0846 C&K Unimax TMCG40, 2TMA-4 3/16" blade    $5,01
PH30-18236 =CES66-4002 =VA-10022 =Highly VS10N061C roller 10A SPDT switch 1/4" blade    $4,77
PH30-2060 =GC35-0827 =VT16061C2 roller (1/2" out) SPDT switch 15A, 3/16" blade    $5,01
PH30-2060 replaces C&K Unimax MV3004, MV3005, TMCG40, TMCJ40, TMCJD6SA1540C,
3TMA-4, 3TMA154, Cherry E-34, GC35-848, GC35-0874, NTE54-400
      
PH30-2080   PH30-18236 =CES66-4002   PH30-2060
291-0005-00 Robertshaw-Acro SPDT button switch 6A-240VAC solder terminals
206-2405-00 Robertshaw-Acro SPDT button switch 6A-240VAC solder terminals
224-1594-00 Robertshaw-Acro SPDT button switch 6A-240VAC solder terminals
224-1611-00 Robertshaw-Acro SPDT button switch 6A-240VAC solder terminals
209-3008-00 Robertshaw-Acro SPDT switch 2" lever 6A-240VAC solder termin

Is it the shortest arm roller switch that is the correct replacement?

PH30-2080 (15A) replaces GC35-0846 C&K Unimax TMCG40, 2TMA-4 3/16" blade 5.01

My 390A's are not readily accessible but I'd love to order a couple of replacements.

I posted the part number.


C

Yes I saw, Ken's web page is a bit confusing.

224-1594-00 Robertshaw-Acro SPDT button switch 6A-240VAC solder terminals

The above (and the other 4 Robertshaw switches) are posted without a price shown so I'm awaiting a reply to my email as to its availability.  Or was thinking one of the PH30's may work, I'm hoping their listing means one of them is equivalent to the 224-1594-00 or close enough to use.

Oh.. I dont know.. Let us know what you find.  You can also get the switch from local AC parts houses.  You will need to call a Robertshaw dealer.

C

Clark,

Looks like my R390 (plain) has gone to the same place as yours. Mine won't power off. I'm told that there is a Cherry microswitch on the back side of the front panel for AC power on. I hesitate trying to replace it as I'm a bit paranoid with having to pull the front panel. Apparently you have already done this. Please share with us how that went and what problems you experienced. Did you get the power switch replaced ok?

Thanks for the information.

Best regards,

Gary, K7EK

After talking to ke7trp on 40m I found this part number in this old post. I ordered one through Kens Electronic Parts. I received it today. You have to fill out his online order form. The switch was $5 plus $4.95 shipping. As of this date 9/2/14 he has 4 in stock and he told me he won't be restocking them. See pictures attached. de k7iou

  Hey Clark,





      My Micro Switch failed about a year ago, He's
an old one, serial 485 off a 1952 MOT contract. I
have not messed with it yet however one change
I did make to mine was to series a 10 mhy choke in
with the "Bulk HV" to keep the voltage to
6080's(?) down.

     I can't recall the particulars now as I have
had this thing for 30 years, but I seem to remember
the bulk HV was over 350VDC to the regulators which
are set for 180VDC. It really reduced the heat
coming off that thing.

     Find the wire in the Mainframes harness
and break it there, Then you can tack the choke
to the back panel and it stays with the rig. I
think the bulk HV went down to around 250 after
this mod. 

GL with the beast..

/Dan

Also selling on ebay, from a listing: $19.99
NSN 5930-00-250-5089: SWITCH
One micro switch for use in the R-389, R-390, R-390A and R-391 Military Receivers as shown.  The electrical ratings are 5 AMP @ 250 VAC/10 AMP @ 125 VAC.  Identical dimensions to the original switch.  These are genuine military surplus.