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
4 -a very effective noise limiter
5-both line and carrier meters
6-mechanical frequency counter
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
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
Noise Floor 137db
100khz blocking 130 db
Sensitivity .2 mV
LO noise spacing 130 at 2 khz
Front end selectivity A+
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
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.
all sorts of people are in
there looking for answers ,and giving some of their own away on these
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
A copy of this manual is very
inexpensive at $10 .00 in the USA, and can be found by emailing
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
Fair Radio in Lima ,Ohio.
Rick Mish of Miltronix
Miltronix - Rick Mish
E. Manhattan Blvd
Now I found out he has his
own website. Go here to see what services he offers.
Chuck Ripple in Florida
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.