The AM Forum

Hi all, I just picked up a Viking 2 last week that's in beautiful condition . It has very little grid current 2 mills until I turn the drive to 9.  Than there is 7/8 mils of current. There are mods instead of 6au6's there are 12ax7's driving a 6cl6. , 807's to 6146 . I made a mistake trying to tune and had the drive to far and plate current and took out the 5v4ca  rectifer . This is mated to a HRO 50t ,also the Viking has a trans relay the coax to the back  of the case and one that plugs into the two small holes at the bottom. This is my first AM transmitter and I don't want destroy it.





 

L,

Welcome back.

You may want to search through this forum to bring you up to speed.

Do you have the manual?? If not, try this.......

http://bama.edebris.com/manuals/johnson/viking2(2)

 The first thing I would do is to add a fuse to the LV power supply, along with a 3 prong power cord to this beast.

gud luck,


klc

Hi,

I'm working on a Viking II also. Page 23 Section 6b suggests checking your buffer or osc tube. Feel free to email me at kd1nw yahoo.com
Good luck with your V2!

73 Kevin KD1NW

So I had another 5v4ga that had the tit broken off but was marked . So I am back to where I was. All tubes test good . Does anyone know about the mods whit the 12ax7s in ace of the 6au6s in v 1 v2 and the 6cl6 in v5 in place of the 6aq5 ?

I would not consider any mods until you get the transmitter up and running per the factory specs. You may not need any mods. My Viking II has been running stock since 1954 and with some of the original tubes.

I think the radio has already been modified.
You might think about making it stock, or rather use the stock tubes.
Otherwise you would need to trace out everything and draw a diagram so you know what is going on.

The mods that were done MAY be improvements, or not, but something is not working right.
Test all the resistors and pots, maybe the drive pot is bad or its an audio taper.
Check voltages on tubes.

What are you using, vfo or xtals?

Why do they call it a Viking 2 anyway?

   Why do they call it a Viking 2 anyway?



http://amfone.net/Amforum/index.php?topic=10006


73

/Dan

Agree.  Get it running FB before doing anything else

Happy New Year all, Al

I know a lot of people changed the front end of the audio section and installed a 12AX7, you might Google Viking II audio mods, I think that is how I found it several years ago.

The mod your talking about is a popular one.  The stock Viking 2's or 1's for that matter do not have a lot of mic gain. If you use a mic that has not that great output level, you will run out of mic gain.   The most popular one is replacing the first audio stage with a 12AX7 which give the transmitter more mic gain.

I would go by the manual tune up procedure and see how things turn out.  The manual is your friend!  Just going blindly into one of these transmitters is creating a disaster waiting to happen. 

Some mods are good!  So wee what you have and go from there.

Have fun and be safe.

73,
Joe-W3GMS   

Yes, I see the one and the two, but why Viking?
I thought everything Johnson made was a Viking/
Viking ranger, Viking Valiant, Viking 500.
Was there a Viking 0 (zero)?
Or was a Viking 1 the first transmitter they ever built?
Why call it a Viking 1 then?

Maybe the product and/or the marketing manager for the product line was of Norse origin.

You can also investigate why Heathkit named a number of their receivers and transmitters after Indian names.  :D
Why do some manufacturers (Hallicrafters, Gonset, Ten-Tec, etc.) use model numbers and a "unique" name to identify their models.

All of this is obviously a task for people who have lots of time on their hands.

Manufactured in Minnesota as in the Minnesota Vikings who probably will kill the Packers Sunday night?  The founder was named Johnson which is Scandahoovian.  They had a mail order radio parts company in the '20s.  They built a lot of police communication gear and their entire manufacturing output went to the government during WW2.  The first ham transmitter was the Viking 1 made in 1949.

Ok, but why Viking 1 if it was the first transmitter, I would think it would just be the new Johnson Viking transmitter.

I believe it was originally just called  "Viking" by Johnson.  But after the Viking 2 came out, people referred to it as the Viking 1 to differentiate it from the newer model. 

As far as I can find, it was always labeled as a Viking 1 in the product brochures and on the 3 original manuals I have.

However, the original Viking Ranger was never labeled as a "Ranger I". It was just called a "Ranger". Likewise with the original Valiant. They weren't labelled Valiant I. Moving forward, we eventually had a Ranger II and a Valiant II.

Lots of useless info here, but great info for cocktail parties as fill in information when the conversation gets bogged down.

Actually if you look at pictures of this particular xtr, the front decal actually says Johnson Viking 1 so they must have had a model 2 in the works or planning stage from the get-go.

Thanks for correcting me, Pete.   Sometimes when voicing an assumption, I learn the facts quickly from the folks on the forum.  I have had a Viking II for years, but never looked closely at the predecessor.

Probably after they used up all their surplus procured 4D32's. Someone once told me that in the mature life cycle of the Viking I, they actually started producing these transmitters with 6146's. Johnson probably also saw the money value in producing hardened versions of the original design with the Viking II and the CD version.

There was a kit that allowed Viking 1 users to substitute the 829B.  Here's one resource link:

http://www.boatanchors.org/viking1.htm (http://www.boatanchors.org/viking1.htm)

Another link: see W1BKZ's comments.  Coincidentally, Peter knew the same W1AVP that I knew back in the 50's who owned a Viking 1  Peter's Viking 1 came with the 829B mod

http://www.eham.net/reviews/detail/4702 (http://www.eham.net/reviews/detail/4702)

Also from this forum:

http://amfone.net/Amforum/index.php?topic=26700.0

 (http://amfone.net/Amforum/index.php?topic=26700.0)

As a kid (15 yrs old) I dreamed of owning a V1 and finally got one.  It is now residing at Steve's QIX lab for some experimentation.

I am currently working on a V2 that looks in pretty good condition

Al

Hello,

Does anyone have an explanation of this transmitter?

It says it is a Viking 2 yet it looks like a Viking 1 yet again it has the insides of a Viking 2.

I have a Viking 1 and a Viking 2 plus this one.  I have only used the Viking 2 the one with the original case that does not have the top lid.  So I don't know how they perform against one another.

Ken

Is this question relevant to OP's problem?  ???

As Pete alluded to, the major difference is the Viking I uses a single 4D32 final, whereas the Viking II has a pair of 6146's.

I own both a Viking I and a Viking II-CDC. I just wish the Viking II-CDC had the 4D32 final.

Just got finished tonight rebuilding a Viking Valiant for a guy  - What a monster; lots of iron and real blue-glow  :D  gas rectifiers and regulators. Three- 6146's as finals.

Phil - AC0OB

Happy New Year from:

Early version of the Viking II using the cabinet from the Viking I. Design changed over to 6146's but if you still have a bunch of Viking I cabinets, why not use them. Silk screen a new front panel with the Viking II designation. I also suspect the later cabinet design was done to provide better TVI shielding and move towards Federal Civil Defense Administration (FCDA) compliance.

If the drive control rotation suddenly increases the drive from 2 to 8mA, could it be open? It is a large 25K pot to the screen of the driver.

This is a common problem with both older Heathkit and EF Johnson transmitters.

The modification is as follows:

1). Replace the 25k 4W potentiometer with a 25k, 5 Watt unit.

2). Add a 10k to 15k, 10W series resistor between LV B+ and the Drive Potentiometer

3) Add a 22 uF, 450 Volt electrolytic at the junction of the drive potentiometer and the New 10k to 15k, 10W resistor.


Below is the Buffer-Driver Stage modification schematic:

It's a Viking 2 that was manufactured on April first   ;D - - - - or was the other way?????

Yo'


In June of 1950 the US started support of the South Korean Government (Ironically created
by the Allied  Coalition at the end of WWII) VS. the Soviet/Chinese who supported the North.
With the “Viking” (Introduced in 1949) originally designed with a 4D32 PA this meant big
trouble.  The USAF bought up ALL the 4D32's overnight making them really expensive.

In response, Johnson had little choice other than to find a substitute tube for the PA.  They
chose the 829B (Probably  because it used the same socket) and similar voltages. It wasn't
until the late 1980's that the USAF “Dumped” thousands of 4D32's on the surplus market.

The Korean conflict pretty much wound down by July of 1953. The Viking II was introduced
in 1952 and was available to 1957 sporting 2 X 6146 in the PA.

https://en.wikipedia.org/wiki/Korean_War

http://www.radioing.com/museum/tx4.html

/Dan

I had almost forgotten about the other solution to the Drive Potentiometer problem
which is found at:

http://amfone.net/Amforum/index.php?topic=32895.0

in case you cannot find the 25k, 5W wirewound Potentiometer.

The transistor can be a TT-2062 or NTE 2300, 2669, etc.

http://www.nteinc.com/specs/2300to2399/pdf/nte2300.pdf


Phil - AC0OB

I'm having to re tube my Viking 2 CDC. It came with no tubes except a pair of 807s. I have a jackson 648 tube tester so I can run some kind of check on what I buy. 

Is there any benefit to using a 6293 in place of the 6146? I know it's basically ruggedized 6146 but as the starting goal is to get this operating as stock per manual will this cause issues? Shoukd I neutralize these tubes? The rest of the tubes seem standard.

6aq5. X2
6au6. X3
6al5
5V4g
5r4gy. X2
6j6

So far this is going fine.  I just need to get some dual caps for the power supply. This seems easier to work on than the Viking Ranger.

I have a number of 6293's and use two Marconi 6293's in mine and they they work just fine but:

Testing the transconductance of various tubes, I find the RCA and Sylvania 6146B's have transconductances of 7500 umho's, whereas all the 6293's all check out between 5800 and 6500 umho's, in deference to the published spec of 7300 umho's.

I have used both tube types during testing and cannot see any real output power differences.

I don't see any problems with neutralization as both tubes have the same interelectrode cap specs.

I would replace the 6AU6's in the first speech amp and the Oscillator with 6AH6's.

Phil - AC0OB