[R-390] Question 1

[John Lawson]

On Sat, 28 Aug 2004, Charles B wrote:

> Hi all,
>
> I am a new owner of an R-390A.  I have a question about the speaker and ear 
> phone socket.  Is there a connection on the rear of the receiver that will 
> allow me to hear the speaker without earphones, but when the ear phones are 
> plug in, the speaker cuts out?  Just like modern receivers do?
>


  Hi Chuck - I'm a newcomer to this list, but have had several (6) 390s 
over the years, as well as many other Boatanchor radios.

   If you envision one of the roles of the R-390 - a multiple reciever 
set-up - say, on board a destroyer - you might have ten of them in a rack. 
Some would be feeding teletype circuits, some receiving crypto, some 
hearing voice or SSB - all feeding their respective outputs to the various 
'users' via audio circuits.

   You, as the attendant of the radio room, get a call that Channel 6 is 
fuzzy and not readable. You walk up to the rack, plug your headphone into 
Radio 6, and discover that the sending transmitter is off it's assigned 
freq. You nudge the dial a bit, now the signal is clear. You check the 
output meter, reduce the LIne Gain a bit to bring the output level back 
near a 'zero', and unplug the headphones.

   Now - if the headphone jack interupted the Line Audio feed - and, let's 
say that it was feeding a crypto set - you would have just caused a loss 
of sync, or a garbled line of the TTY. That's why the two outputs are 
seperate. You can monitor without disturbing the feed.

   To do what you want to do, the easiest (IMHO) would be to just turn the 
Line Gain down when you don't want the speaker on. And I *know* it's a 
mismatch to hook a speaker up to the Line Outs on the back, but it works 
well enough for most applications - you can always use a transformer, or 
an external amp if you wish...  I don't.  Then you can use the Local Gain 
to control your headphone volume.

  Alternatively, you can hook a 'normalled' jack up to the Line Out, and 
when you plug your headpones into that, it will interupt the speaker feed. 
However, I find it very convenient just to lower the Line Gain pot when 
I'm using phones with the 390.

   Hope this helps...

Cheerz

John KB6SCO