[R-390] Tube life/replacement?

[Cecil Acuff]

Well I know many list members that leave there R-390's on 24/7.  They seem 
to be happier that way...the radio that is.  That's 8760 hours a year!  At 
200 hours a year for yours that would be over 43 years of equivilant use.

Now I would expect there would be a handicap for switching them on and off 
as you do as opposed to leaving the thing on so lets say you get 50% and 
round up that's 22 years.  The owners that leave there sets on 24/7 report 
several years of operation between failures.  Looks like tubes only used 200 
hours a year would theoretically last a lifetime.

Of course the thermal shock of switching them on and off may handicap the 
tube life way beyond 50%...maybe more like 90%.

Any additional thoughts from the group!

Cecil....
----- Original Message ----- 
From: <fraserb at quasc.com>
To: <r-390 at mailman.qth.net>
Sent: Friday, December 31, 2004 1:41 PM
Subject: [R-390] Tube life/replacement?


> Since I'm in the midst of my annual winter AM BCB Dxing season, I had a 
> thought about the life of the tubes in my R-390A.
>
> How often were tubes replaced when in service with the various govt 
> agencies?  Were different tubes replaced on certain schedules?  Were tubes 
> regulary tested or just pulled and replaced?
>
> I use my R-390A for probably somewhat less than 200 hours a year.  How 
> long are the tubes supposed to last?  How do you know when tubes are less 
> than the minimum level required?  Are there well known symptoms that 
> indicate a certain weak tube?
>
> Lost of questions to start the new year!
>
> _____________________________________________________________
> 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
>