[Boatanchors] R390A help

[Bill Riches]

Good grief Roger,

 

My email must have become garbled.  I have been restoring and selling R390a,
S line and other boat anchors for many years.  I was inquiring if there was
any one in the Billings area that might be of assistance to a elderly ham
that just purchased a R-390 from me in case he needed some assistance or
simple questions that could be answered with a personal touch.  I am not
trying to pass the buck on and service problems.  Unfortunately he does not
have a computer to obtain all of the info that we all use.

 

73,

 

Bill, WA2DVU

Cape May

 

From: Roger Ruszkowski [mailto:flowertime01 at wmconnect.com] 
Sent: Saturday, May 17, 2014 7:11 PM
To: bill.riches at verizon.net; boatanchors at mailman.qth.net
Subject: Re: [Boatanchors] R390A help

 

Bill,

 

You are posting from NJ looking for help in MT.

 

We counter using receivers older than we are by 

also using education methods younger than we are.

 

There are now lots of pictures on line at R390.net.

And Y2K manuals on line.

And TM 11 5820-358-35 online as a PDF file.

 

Plus lot of other good help and Pearls Of Wisdom for the R390 and R390A.

 

Welcome to the group of Fellows who own these receivers.

 

You can just post any question you have here and get help.

 

Some one or several will reply with references to page and pictures and
parts.

 

As a new R390A owner the first question you want answered about your new
receiver,

relates to C553 a .01UF cap on the plate of V502 in the IF deck.

 

This cap blocks the plate B+ from the IF mechanical filters.

 

The question is, has this cap been replaced in your receiver?

 

The original big fat brown or black plastic caps in the R390A are know to be
going bad

after some 50 plus years. Some day you will want to replace all these big
plastic caps.

But C553 is of priority. If it leaks enough DC it will kill the filters and
the mechanical filters

are getting expensive to replace.

 

Check that cap and make sure it has been replaced.

 

You have to remove the IF deck to make the inspection or your prior owner

made a point of telling you the IF deck caps has been replaced.

 

This bring you around to point Number 2. 

Do you have a spline bit and long Philips screw driver.

If you had a good prior owner he gifted you with these two tools.

 

You will need them to remove the IF deck and make the inspection.

 

As an R390A owner you would like to conduct a semi annual PM on your
receiver

twice a year. (Yea Right) Get yours clean and up to par and this is a once
every few year operation.

 

Back when this preventive maintenance procedure took about four hours to
conduct with

a tube tester, volt meter, signal generator, 600 ohm resistor, spline
wrench, tweeker and screw driver.

We used a couple three different meters so we did not have to move them
around. And frequency counter on the signal generator. The tube tester is
optional. Bad tubes do not work. But the tester lets you get shorted tubes
out of the circuits before they fry resistors. Plus the tester do give you
some clues. Once you have spent six months doing two R390A a day you get a
sense of how the good tubes meter in the tester. And you can kind of grade
them and decide into which socket you want to place the best tubes and how
many tubes you would just like to replace at this maintenance time.

 

You should be able to go through the receiver in about 8 hours on a week
end.

 

Your first shot could take you 16 to 24 hours.

 

There is an inspection list on the web that will step you through the
process in more

detail than you ever though necessary.

 

Do get your hands on the Y2K R390A Manual from the web and read it once, 

just so you know what you now own.

 

Welcome aboard

 

Roger Ruszkowski AI4NI

 

 

 

 

 

 

 

 



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