[R-390] RE: New R390A owner with some questions.

[Cecil Acuff]

Hi Paul,

        Congrats on your being a new owner of a couple of R-390A's.  I 
probably won't be able to answer all of your questions fully but I can 
comment on a few.

The dead bands may be caused by problems in the Crystal Osc. deck.  There is 
a cover on the top that contains the assortment of crystals and an 
associated heater.  I would check to be sure all crystals are present and 
accounted for and are seated well.  You may need to clean some of the 
sockets.  Good thing is you have two radio's...always a recommended 
practice.  You can barrow the crystals in question from the non-working 
radio and try them in the somewhat working radio.  The next thoughts might 
be a dirty switch that selects the crystals.  It is accessible from the 
bottom of the crystal deck.  Not too hard to get out.  Beyond that the posts 
of others will probably be of  more help with the dead bands.

As far as the Sharp filter setting...my experience is that it has a bunch of 
attenuation in that position and it appears that the world went away when in 
fact more volume and better centering of the signal usually brings things 
back.  It is possible of course that yours is broken.  I've not seen that 
mentioned as a common problem area so I would have to refer to the schematic 
to form a game plan.

As for identifying your radio...that's a tough one.  The tag may have come 
from anywhere.  There are several suppliers of re-pop tags even.  I would 
pull a few of the easy modules and check their markings...if you are 
extremely luck and they are all marked the same you probably have your 
answer.  Sometimes you can see whose name is marked on the Veeder Root 
counter (mechanical digital readout mechanism) and tell the origin.  I've 
seen Electronic Assistance Corp. stamped on the back panel and you can 
sometimes look for the inspectors stamps on the main chassis and tell a 
little from that.  Some are marked SW, some EAC etc inside of some shape 
such as a triangle or a square.  The ITT thing is a little unique 
though...you may have something there....another Helena Rubenstine 
(spelling?)


On my radio's I have just attached the green wire in your new 3 wire cord to 
the nearest convenient place and the other two to where the power normally 
lands.  Be sure not to plug into a GFI protected outlet as there are 
problems usually with leakage current that will trip those.  Another 
story...

Anyway...

Good Luck and Welcome to the group!

Cecil Acuff....


----- Original Message ----- 
From: "W4QG" <W4QG at CFL.RR.COM>
To: <R-390 at mailman.qth.net>
Sent: Sunday, January 16, 2005 4:27 PM
Subject: [R-390] RE: New R390A owner with some questions.


>
> Hello All,
>
> I have been lurking around for a while on the
> list, my complements to all for this great resource.
> This is my first post and I have a few questions for
> the newsgroup.
>
> I recently acquired 2 R-390As.
>
> One is a mostly functional Stewart Warner radio.
>
> While twiddling knobs I have discovered a few things:
> Radio works on all bands that I have tested so far
> except 1000kc to 2000kc. Seems stone dead on that
> band. Any ideas where to look first for problems?
> The radio appears to be very clean and so far I
> have not found any obvious modifications
> (still has a functional ballast tube).
>
> Also, engaging the sharp position with the audio
> response switch seems to kill the audio no matter
> what mode it is in.
>
> I am in the process of downloading/printing the
> maintenance and operators manuals today. Any other
> documentation I should be thinking about acquiring?
>
> The second radio is somewhat of a mystery.
> Not operational yet but it does power up.
>
> The nameplate says "ITT Electro-Physics Laboratory".
> I did find a list on a website of the dozen or so
> R-390A manufacturers and ITT was not listed. So, I am assuming
> that someone else made this one and ITT just put their
> label on it. My question is, how do I go about finding out by who and
> when was it made?
>
> Finally, I am planning on making the inrush limiter modification,
> and changing both radios to a three prong plug. Is there a preferred
> way to handle the 2 wire to 3 wire power cord change?
>
>
> Thanks!
>
> Paul W4QG
>
>
>
>
>
>
> _____________________________________________________________
> Win a new Icom IC-756PROIII and help QSL/QTH.net
> Details at: http://mailman.qth.net/index.html
> _____________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe: http://mailman.qth.net/mailman/options/r-390
>