My R-390 webpage



Motorola built R390



Motorola-built R-390 Info
  • 1-A very large complement of filters-16,8,4,2,1,and .1 khz if filters for selectivity
  • 2-Manual or automatic 3 stage agc  -slow medium and fast
  • 3-Tracking preselector
  • 4 -a very effective noise limiter
  • 5-both line and carrier meters
  • 6-mechanical frequency counter  readout
  • 7-bfo for single sideband operation
  • 8-squelch for  those noisy utility frequencies  opens up  on a carrier or voice transmission.
  • 9 extremely sensitive  receive section with a very quiet  front end. Usually measured at .5 mV or better.Specifications call for 3 mV ,but this is a  worst case figure.
  • 10-very good  dynamic range and lowest noise floor in any radio I have played with
  • 11-Complete 0 through 32 mhz coverage in 1 mhz band increments.
  • 12.capabilities for use with transceivers with break-in switch *  must have a  proper voltage relay*
  • 13. 32 vacuum tubes( a lotta tubes to replace when retubing)
  • 14. Sharp ,medium,and wide audio filters
  • 15.antenna trimmer for maximum signal transfer from antenna.
  • Some specs for the  R390A version ( these are similiar to the non A version  built by Motorola that I have)..
  • Specifications by Sherwood  Engineering
  • Noise Floor 137db
  • 100khz blocking  130 db
  • Sensitivity  .2 mV
  • LO noise spacing 130 at 2 khz
  • Front end  selectivity A+ (tracking  preselector)
  • Filter  ultimate rejection 85db ( Non A version is different since it doesn't use mechanical filters)
  • Dynamic range (wide spaced at 20 khz ) 81
  • Dynamic range (narrow spaced at 2 khz)79
  • These are of course a very  general description of what the radio is capable of. There are going to be some differences  considering that the one I have is the  non A version,but these specs will give you some idea of what the radio is like electrical performance -wise.

  •  I originally bought this radio out of the Bargain Mart magazine here in Louisville about 6 years ago. I think at the time I gave $225 for it, not knowing a thing about the R390's, except that they were very  good receivers. So far ,since I have got it I have used it extensively  ,except for a period of about 2 years when it was put away in a closet because it quit working. I had no manual, no notes, no nothing on how to use the radio . All I learned was by guesswork.

    At
    R-390@qth.net ,
    all sorts of people are in there looking for answers ,and giving some of their own away  on these   older radios.

    So far with this mailing list I have found out a lot  about this old radio and also have learned a lot about how to do some basic trouble shooting.  One tool which has been extremely invaluable has been a cd rom made by  Jeffrey Adams. This cd rom has the  manuals ,schematics,instructions ,and  just about everything you want to know about working   with ,or repairing  the  R390 series of radios. I believe there were  390A's, 391's and 392's  made  that are various versions of the original Collins R390.
    A copy of this manual is very inexpensive at $10 .00 in the USA,  and can be found by  emailing  this address
    eengineer@erols.com.

    For this price alone,the headaches are considerably reduced when you can read about  the radio  , and most of all, it is clear and legible even after a printout on a Hewlett  Packard DeskJet 600.

    I have done some minor work  on it using these cdrom files and I have to say that  when I first opened it up it was kinda scary. Some of the things that was wrong with it when I took it out of the closet after two years was defective bands,a bad IF  tube, non contacting bandswitch,bad crystals,and a few other things . After digging through the manual I have now fixed it to where it is 99% functional,all bands working,and  all filters operational . The only thing it really needs now is a total alignment to bring back into spec the performance ,but without the right equipment ,that is not something I want to try  at the moment .



    So how does it really work? Well ,I don't have any experience with some of the newer radios such as a Icom R75 ,or Ten Tec RX320.but in my opinion it works extremely well for it's age. I believe that  whoever first said this was one of the finest receivers  ever made was right . Further along in my website ,I have a link to another page where I put some RealAudio files of stations I have heard on it.

    Fast forward the time clock to February 2002..

    I  now am trying it out on a 50 foot or so dipole antenna,strung up behind the building maybe 6 feet off the ground at the moment.It's fed into the radio by way of some  75 ohm tv coax I scrounged up. So far it seems to do fairly well here at the new apartment.Earlier this month I was able to hear Radio Uganda on 4976 khz one night at about an 20  or so on the carrier meter.
    South American stations have been pretty audible as well for the most part here,and early in the mornings I have been hearing the NBC-Port Moresby from Papua New Guinea real clear on 4890 while I've been getting ready to go to work.Europeans have been fairly strong here and the Africans on the tropical bands  kinda have come and gone as conditions permit. Soon as I am able to get a slingshot ,this antenna will hopefully be a bit higher. But for now it's working as best as it can.


    There have been several makers of this radio . Some makers have included EAC(Electronic Assistance Corporation),Stewart-Warner,Motorola,Imperial, and others.Without a doubt ,I have to say I would love to have a basement full of these radios.



    Places to look for a R390 or R390A.
    -----------
    Fair Radio  in Lima ,Ohio.
     http://www.fairradio.com/
    -----------------------------------------
    Rick Mish  of Miltronix
    Miltronix - Rick Mish
         36 E. Manhattan Blvd
         PO Box 3541
         Toledo, Ohio 43608
         419-255-6220
    Now I found out he has his own website. Go here to see what services he offers.
     Miltronix
    ---------------------
    Chuck Ripple  in Florida
      mailto:wa4hhg@amsat.org
    ------------------------------------
    This is just a starting point to locate a working ,and or, refurbished  R390 ,or R390A receiver. To be straight up front ,these radios usually do not  come very cheap,nor are the services performed by these  people going to be  really inexpensive,but it is a time consuming and very hard effort to work on these radios.They do a very good job and have been recommended by many  people in the hobby.


    All in all , the R390 is one of the best radios for serious  shortwave listening I have ever come across.If you can find one of these and  have the  funds to have it restored or brought back to good working order I highly recommmend getting one of these fine radios.



    Now that you have seen a couple of radios,I have  a lot more in here to show you  .
    Click on the link below to go on ,or follow the sign to get back home.

     http://members.tripod.com/~swlchris/index-10.html