[R-390] Yet another R-390A rises from the dead... (long)

[AdamAnt316@aol.com]

    What follows is a relative newbie's journey into the R-390A world. The 
story behind my getting an R-390A is a long one. For over 20 years, the back 
room of the electronics shop at the technical high school I used to go to held a 
small collection of older boatanchor radios, including an R-390A/URR, an 
R-392/URR, and an R-48/TRC-8. All three were said to be in nonworking condition, 
including the R-390A (in fact, there had apparently been two more R-390As there 
at one time, which were said to be in working condition, but they disappeared 
over the years, leaving the nonworking one). I discovered this cache of radios 
during my second-to-last year at the school, where I was able to simply 
fiddle around with the nonworking receivers, but wasn't allowed to take them home 
at that point. This year, due to an upcoming renovation of the school, the shop 
needed to get rid of over twenty years worth of junk. I showed up there one 
day, and the first thing they asked me was, "Did you come for these radios?" I 
then proceeded to load all three boatanchors into the back of my Dodge Spirit, 
and the rest was history. After years of putting up with mid-end shortwave 
radios, I finally had a decent HF receiver.
    
    The R-390A was in relatively good shape; missing it's top cover, as well 
as two of it's 5814As and their WPM tube shields, which I soon replaced 
(though I could only find two small 9-pin IERC shields; anyone have any spare medium 
9-pin WPM tube shields? TIA), but otherwise complete, including the meters. 
Upon examining the 3TF7, I discovered that one of it's filament strands had a 
small gap in it, so I bought one to replace it (thanks to Dan Arney!), and also 
made a 12BY7A sub for it which would go in it's place much of the time. 
Perhaps a bad ballast tube was what kept it from working all those years, I thought 
to myself. I then decided to go through with the standard preventative 
maintenance, which would allow me to power up the set without the threat of 
fireworks. After restuffing the can capacitors and replacing both C-553 and C-549, I 
decided that it was time to try the set out for the first time in several 
years. I hooked the 390A to both a Variac and a device which would allow me to read 
it's current draw with a Simpson 260 VOM, connected the output to a stereo 
receiver through the diode load jack on the back, hooked a long piece of wire to 
the balanced antenna input through a twin-pin plug, I then began running 
tests on the set.

    After confirming that the microswitch attached to the function selector 
was doing it's job, as well as finding that the standby mode doesn't like to be 
run at very low voltage, I then began bringing power to the set slowly with 
the function switch set to AGC, during which I began to see signs of life come 
from the receiver. After reaching 120V on the Variac, I listened for signs of 
reception, but didn't hear any until I turned up the RF gain, upon which I 
began to hear static coming from one of the stereo receiver's speakers. I then 
proceeded to tune around, and I soon received my first signal, which was WBCQ 
(though I received it several KC from where it should've been). I continued 
tuning around on several bands, on some of which I managed to pick up 
foreign-language broadcasts (one of which had a musical station identification, which came 
booming through the speaker). I then did some tuning around on the AM 
broadcast band, where I picked up several stations close to where they should've 
been, though tuning seemed to be shifting around (turned out later that I had the 
zero adj. knob screwed in, when it should've been unscrewed). I considered my 
test to have turned out to be a success! I had had a feeling that a bad 
ballast tube might've been the reason that this set hadn't been working in years, 
and possibly the only reason that it lingered in the back room of that 
electronics shop for as long as it did, and I was correct. 

    Later on, I lengthened my antenna wire, printed out some pages from the 
manual to help me better understand how to operate the receiver, and decided to 
take another go at using the set. This time around, all the stations appeared 
in the general area of where they should've been. I then began using the dial 
calibration procedure to sync the set to the 100KC calibration points, and 
everything managed to fall into place. I was able to get WBCQ at 7,415KC, as 
well as BBC World Service (which I'd been unable to receive well on my other 
shortwave radios since they turned off their North American transmitters) right at 
5,975KC. I also managed to pick up Radio Havana, as well as a station in 
Czechoslovakia (which seems to be my benchmark when it comes to picking up 
long-distance SW signals; whenever someone asks me how far away I've received 
shortwave signals from, I usually tell them that "I picked up a Czechoslovakian 
station once."). The set appears to be working quite well in most respects, though 
I need to figure out why the carrier level meter never seems to go below 60dB, 
even with the RF gain control turned all the way down. 

    I must say that, so far, owning an R-390A has been an exhilarating 
experience for me, especially since I'd never really used a high-end receiver before 
I got this set (most of my shortwave radios have been old radios from the 
'40s, although I also have a few Zenith Trans-Oceanics, as well as a 
Hallicrafters S-118, which is a step or two above the S-38/S-120). Once I build a wooden 
case for it, I'm going to put it in place of the S-118 in my bedroom, where I 
do most of my shortwave listening. My thanks goes out to those who guided me 
along the way, as well as those who have put up web sites about how to restore 
the R-390A (especially Chuck Rippel and Walter Wilson, whose detailed pages on 
component replacement were extremely helpful). For more on my R-390A saga, see 
my 390A page at <A HREF="http://www.angelfire.com/ma2/AdamVon/r390a.html">http://www.angelfire.com/ma2/AdamVon/r390a.html</A>.
-Adam

Adam Vaughn 
Collector of old computers, video game systems, radios and other electronic 
equipment... 
Visit my page at
http://www.angelfire.com/ma2/AdamVon/index.html


--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---