[R-390] Before you attach power to your newly acquired R-390A

[Raymond Cote]

Good post Tisha!  Everyone should print this out so it is visible and reviewed occasionally. Many do not bruise the list daily so an occasionally posting is warranted as a reminder. 
Can anyone point me to where the most needed fixes that should be done before power-up?
Thanks. Love the group
Ray
KD9CCZ

Women and cats will do as they please, and men and dogs should just relax and get use to the idea. 

-Robert Heinlein

> On Apr 25, 2016, at 08:06, Tisha Hayes <tisha.hayes at gmail.com> wrote:
> 
> There are a few steps that you absolutely must do before you power up any
> untested R-390A receiver;
> 
> 1.  Replace C553. This is on the IF deck and keeps B+ off of the mechanical
> filters. When this cap shorts out it will blow out the input coil on the
> mechanical filters. As quick as you would rotate the bandwidth switch you
> would destroy every filter in turn. You should never-ever see B+ on the
> filter side of this capacitor.
> 
> 2. Check the power supply filter capacitors. These are the plug-in can-type
> capacitors on the audio deck. and are several capacitors inside of each
> can. These age badly (wine turning in to vinegar) and while you may have
> some success in reforming the capacitors so they do not draw excessive
> current they will never come back to their full capacitance or ESR values.
> If your radio has the B+ fuse mod (in an external holder on the back) the
> bad caps will keep blowing out this fuse. If you do not have a B+ fuse you
> can end up burning up a transformer, rectifier or power supply choke.
> 
> There are at least another dozen steps you should be taking before powering
> up the radio. These first two are ones that keep the components from
> releasing their "magic smoke packets" and making what could be a fairly
> easy restoration turn in to a major rebuild/ overhaul with unobtanium parts.
> 
> *Ms. Tisha Hayes, AA4HA*
> *"*There are many who live in the mountains and behave as if they were in **the
> town; they are wasting their time.*
> * It is possible to be a solitary in one's mind while living in a crowd;
> and it is possible for those who are **solitary to live in the crowd of
> their own thoughts.*"*
> **-Amma Syncletica of Alexandria**
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