[Boatanchors] R390A help

[Roger Ruszkowski]

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