[Hammarlund] cleaning tube pins

[Rocco Lardiere]

Glen,

Yourr recommendations are very valuable.  Over the years, I have learned to
do the following with regards to tubes when I first take a look at a new
boatanchor:

Remove the tubes and check that the correct tube type is in the correct
socket (and no cheap brands installed)

Straighten the pins on the tubes using my Antique Radio pin straightener

Clean the tube socket areas to get rid of dust and dirt

Spray the pins with DeOxit

Insert/pull the tubes several times in the sockets to provide a wiping
action with the DeOxit

After the radio is more or less operational, I perform a wiggle test to
check for any remaining intermittent pin/socket connections.  I do this with
leather gloves to spare my fingers from the heat and am very careful around
possible high voltages (I don't do this with external anode tubes, of
course.)

For receivers, wiggling/rocking the tubes gently should not result in
serious noise at the output.

If, after an alignment, the performance is not up to par, I replace suspect
tubes with known good ones as needed.  I have a good tube tester but rarely
use it.  All new tubes get the same DeOxit treatment on the pins unless they
are absolutely clean and corrosion free.

I really think that this saves a lot of time tracking down suspect gain and
noise problems, and it's easy to do.  In most cases, an older radio will
immediately show improvement by going through these simple steps, as I am
sure you know from your own experience.  I would never try an alignment
until all tubes, pins, and sockets (and other electromechanical connection
points) have been thoroughly cleaned and checked.

73,

Rocco N6KN

----- Original Message ----- 
From: "Glen Zook" <gzook at yahoo.com>
To: <hammarlund at mailman.qth.net>
Sent: Thursday, February 17, 2005 5:25 AM
Subject: [Hammarlund] Possible problem source


> . . .
> I now plan on cleaning the tube pins, along with
> tightening all of the hardware that holds everything
> in place on any boat anchor that I work on that had
> intermittent problems.  In fact, I really think that
> it would be a good idea to actually clean all of the
> tube pins whenever I work on a unit for someone else.
>
> Corrosion on tube pins is not something that you
> immediately think about when troubleshooting a "boat
> anchor".  But, it certainly can be a source of
> problems.  Often we clean the sockets as well as
> switches, potentiometers, and so forth.  However, how
> often do we think of cleaning the pins on the tubes?!!
>
> Glen, K9STH
>
>