[Johnson] Newby Valiant Owner questions

[Glen Zook]

The article on the 6146 family of tubes that appeared
in Electric Radio a while back can be found on either
of the websites that are listed at the end of this
messag.

Next, tighten ALL of the machine screws, nuts, etc.,
that go through the chassis.  If your particular
Valiant has rivits instead of machine screws holding
the tube sockets, etc., in place, then you are going
to have to drill them out and replace them with
machine screws, try to add very short ground wires to
where you can get a good ground (going to be very
hard), or, possibly, use a punch to tighten up all of
them (hard, but can be done).

All of the grounds in the transmitter are made through
these connectors.  Over time they become loose, build
up corrosion, or both.  I usually can fix at least 90%
of "screwball" problems in "boatanchor" equipment by
tightening all of these.

For example, my Collins 75S-3A receiver started doing
"strange" things a few weeks ago.  Now this receiver
has been in approximately the same position for about
30 years.  When I put in on the service bench I found
that almost every machine screw in the receiver had
worked its way loose.  Remember that every time you
turn on a piece of tube type equipment that the unit
goes through a pretty good temperature cycle. 
Eventually that causes the hardware to work loose.

I tightened up all of the hardware and the receiver
again works correctly.

Also, if you have already done so, clean all of the
switches in the unit.

Glen, K9STH

--- John Lawson <jpl15 at panix.com> wrote:

I replaced the rectifiers with the IR plug-in stacks
and bought a nice set of 6146Ws for it - quasi-mil
tubes, should be twice as good, no?
 
Okay - first Valiant lesson: 6146s!! Maybe "A"s....
 
After replacing the finals with 6146As - I have the
problem that running thru a BIrd into a dummy load
-the rig plate current 'runs away' on any band lower
than 20M.  (I never tried 10) 40 holds for 30 seconds
or so, 80 starts climbing right away, and 160 just
won't resonate at all.

Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco

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