The AM Forum

  I know, I know...
All the strip it down -full on major rework, modernizing circuitry, completely modified and ....etc....mods, mods... until it no longer even is a Viking Valiant anymore.
Thats ok for custom projects, but I want this to stay basically stock.
I have modern equipment already so ...I would like this to sound like,
a well built and nice working transmitter, with reasonable and functional factory type improvements.
So...
What are the time tested standard improvements and necessary improvements for a nice and reliable good working Viking Valiant?
I have heard that the resistor in the VFO should be changed, that some of the high voltage wiring should be changed,  what are some of the things to look at?
This is my first Valiant so it should be a fun project, can't wait to make some contacts with it.  
Thanks for any help, I know this is just old-hat repeat stuff for AMFone,
But its fun for me. I have been searching the archives and looking at Viking mods, etc. interesting stuff.  
Thanks for any help....

P.S.
In my old original manual
it has a "Viking Valiant Information Bulletin #1" , 4-page paper.

AG5UM

Well Now...
A few years ago...
This would have at least got a little help... and response...
There of course,
are many things to research and look at here on AMfone,
And also on "The AM Window",  amwindow.org  ,etc.
If anyone is looking for Valiant mods, etc..
For me...
been having fun playing with vapor  tubes etc...
The Valiant was suppost to be...
 Johnsons response to the Heathkit DX-100...which was I guess Heathkits response to the Johnson Ranger?...so I've heard anyway.
Anyway, much info. out there if we look.
The EF Johnson Valiant is very cool and very fun,
Even though its not a full-on Big-Iron Broadcaster,
 or a homebrew Eimac special...oh-well,
 its an Amateur Ham transmitter, and I like it!!
73

Hey it?s up!

See

https://amfone.net/Amforum/index.php?topic=35841.0

And

https://www.amwindow.org/tech/htm/valiant/valiantmods.htm

Ed

Hello Ed,
Thanks for the links,
I've been looking through AMfone and AMwindow, other things, etc.
Lots of interesting things, fun.
How are those wonderful RCA transmitters of yours doing?
FB I'm sure, very nice.

I have a factory-built Valiant that needed a major cleaning after sitting for what I believe was decades.  Fortunately, no "work" had ever been done to it.   The 6146's all tested very well indicating (to me) it had been operated properly during its early service.

Not knowing who will read this post:  Lethal High Voltage inside these transmitters.  Refer servicing to a qualified technician.  

The following worked for my Valiant.   No guarantees it will work for others.  
 
1.   The famous 18K, 2W resistor in the VFO.  I use 20K, 5 watt wirewound.   I Velcro the old 18K to the outside of the VFO access panel to show the resistor was replaced.

2.   If the VFO does not produce a signal after changing out the 18K resistor:  If the tubes test good and you have 150 volts at the 0A2, the culprit might be the 470 ohm, 1/2 watt resistor soldered to a terminal strip located on the chassis below the 0A2 and 6AU6.  I have found this resistor open on two Johnson transmitters.   Sometimes it is soldered on the access door side of the terminal strip but sometimes on the other (hidden) side.

3.   The VFO reduction drive likely needs cleaning and re-lubricating.  Don't use Lubriplate; the drive will slip. Generic grease is adequate.  There is a flexible coupling on the VFO side of the reduction drive.  It is easily damaged.  

4.   Carefully clean the rectifier tube sockets to prevent future arcing.

5.   Replace the 866A?s with 3B28?s.  Some prefer solid state replacements.  
 
6.   Save your HV power transformer by installing inrush current limiter in series with the primary winding.  

7.   Replace all electrolytic and paper capacitors.

8.   Check resistors for values within tolerance.

9.   I only changed one capacitor's value in the audio string.  With a D-104, it gets good audio reports.  No major audio mods needed, IMHO.

10.   See the manual for bias, clamper, neutralizing, keyer adjustments and alignment.  

11.   WQ9E recommends replacing the 6AU6 tube in the VFO with a 6AH6 claiming it is more stable in the Johnson VFO.  The 6AU6's in both my Viking 500's have been changed to 6AH6's; they drift less on warm up and are very stable afterward.  For what it's worth, the Valiant still runs a 6AU6 and is less stable than the 500's.  It is a credible upgrade.

12.   Note:  The Clipping control setting is counter intuitive.  Setting at 10 = no clipping.   Setting at 0 = full clipping and distorted audio.

13.  Controversial modification:  The old Fused plug and two-wire cord is replaced by a three-wire grounded plug/cord.  Due to the weight of the Valiant, I sacrilegiously installed a fuse holder through the rear of the chassis.  (On my Rangers, the fuse goes inside, under the chassis in a surface mount clip type holder.)  

Note: Terry, N6TLU has a Youtube channel (D-Lab).  He goes through most of the above with Valiants.  It is worthwhile to watch his videos.

My Valiant is switched on at least a few days a week for several hours at a time.  It's been a solid performer for two years now.  

Thanks Russ for this great advice.
Always appreciate the voice of experience. I was just looking over your webpage yesterday,
  www.rtsradio.net
Very nice site, great pictures, equipment and information. 

This Valiant is also a factory build, factory wired, nice condition.
The underside of chassis is very shinny and pretty, even the switches, etc. look like they are brand new.
I started with the manual, the resistance charts, transformer charts, readings, Tube testing.....
 looking everything over and just getting started,
So Far, So Good....






.


 

Sounds like you have a good foundation to work with.

I checked your QRZ page.  Nice anchors!
73,

Russ
KW6T

What I did to mine is still here: https://amfone.net/ECSound/Valntmods1.htm
Just pick what floats your boat. Iver the years I tried about everything.

Keith
WA1HZK

Thanks Keith for the link,
I think I've seen your mods, etc. on AMWindow, or somewhere ?,
Great stuff. Saved the link so I can look at it tomorrow,
alot to look over. You have a lot of information there, I will look it over,
Thanks.