The AM Forum

This is all I can find as far as differences:
1) Rack Mounting: Viking I is easily, Viking II is not
2) Tube Lineup: Viking I has older/rarer tubes, Viking II has newer/more common tubes
3) Power: Viking one has slightly less power output, Viking II has slightly more power output
4) Shieldinig: Viking I produces more TVI, Viking II produces less TVI
5) Cosmetics: Personal Preference

What am I missing (I am sure it is more than I have found above)?

I've had both (still have viker1) You've pretty much covered it all.
Later viking 1's had shield kit standard (mine does), Viking 1 uses a Budd cabinet
(henceforth rackable) Viking 2 has own dedicated cabinet. Vik 1 uses 4D32 for final, Vik2 uses 6146's. The 1 is a little more scarce, 2's are common as dirt. Both are good reliable transmitters. If I had to voice a preference it would prolly be the 2 just because 6146s are cheap and plentiful, 4D32's are a little more scarce amd pricier. Also some of the 1s had 829Bs for finals as well.

                                                              the Slab Bacon

I think the V1 has negative feedback in the modulator doesn't it.
They are pretty easy to work on. I think I would like to get a V1 and drop an 813 in the final.

That pretty much hits the nail between the eyes guyz.

Having both transmitters in the lineup right now, I like the Viking 1 better for its rack mounting ability. I have half a mind (yawl new that) to make a new front panel for the V2 or get an old V1 panel for it to rack it up.

The V1 lends itself to more mods in the final stage. Being a 1 holer there's gobs of tubes that could be dropped in there to replace the 4D32. I now have a 4CX250B in my V1. I've been toying with the idea of putting a 4-65A or 4-125A in the V2.

Have fun. These are great transmitters to work on/modify.(or is that oddify)
As i once told Frank(GFZ):
If your mod breaks a Viker its easy to repair it !!!

One more note on the Viking I, my first AM tx, back in 1977....
that one had a factory authorized mod in it replacing the 4D32 with an
829B. Much easier tube to come by for a 16 year old AMer in those days!
Now, a 4D32 & 829B cost about the same $$.
The last pages of my Viking I manual outlined how to do the mod, someone
before me had taken care of it ...
OH, and mine had the shielding for TVI....which probably helped, but
it sure wiped out stuff!
73 steve

Bud,
The 4CX250 works at lower voltages. The  4-65 and 4-125 have a wide base.
I looked into the 4-125 socket and it is pretty big. Also these tubes like high voltage where the 4CX250 has specs down to 500 volts. I think you made a good choice with that tube. So what you need to move air.

Frank,
         I have actually been pondering doing that to mine. Seems that great minds think alike! For now it is a shelf queen awaiting my tinkering

                                                              The Slab Bacon.

The 4D32s are very easy to find these days and don't cost any more than a pair of brand new 6146s. I've bought several for $20. They will put out just as much power as 6146s too. I don't think you can go wrong with either the V1 or 2, since they are the same radio inside, plus or minus some RFI mods and a shielded cabinet. The V1 is cooler looking to my eye.

My PDM viking was well hacked when I got it so don't mind going at it. I was looking for a v1 when the V2-CDC came along. It is clean so don't want to mess with it too much. The problem with the pdm rig is that it chews up 6146s every few years because of the modulator power.
An 813 with maybe a 5763 driver would fix it forever.

For sure. Deano put two in a DX-100, so one should fit in a Viking no problemo.

Dean told me he replaced the hv transformer and choke with a higher voltage unit.
Mike WU2D ran a test for me one night and found you need 1 KV on an 813 to make 100 watts out. At 750 volts it was down around 85 watts. I don't think a pair of 813s will fit so the voltage needs to increase.

How can I spot the TVI shielding kit and/or shielded cab visually?  I assume part of it will be a cover over the back of the meter.  Anything else?

The whole chassis inside the cabinet will be enclosed in perforated sheet metal.

I have a Viking2CD with a Viking1 front panel,(bolts up fine). I was thinking about a PL177 in the final modulated by 572s with a common 1500V power supply.Should make about 150w of carrier with plenty of audio........Patrick,WA4QJU

Thanks to cable TV, we don't have to worry about all the TVI crap these days.  I don't have any special shielding on any of my rigs, and never have a complaint.  Most complaints I get are about getting into telephones.  The only thing in the house that my rig bothers is the computer audio.  Every computer I have ever tried to operate here picks up my signal loud and clear. 

I recall reading somewhere that only about 15% of the public still uses off-the-air TV, and many of those have cable, but pick the signal off the air with extra TV's in the spare bedroom, etc.

Has anyone reported how well the new digital TV system, scheduled to replace analogue TV in a couple of years, is immune to ham and other radio transmitter TVI?

Well, I just secured a Johnson Viking I.  It's an non-TVI/unshielded one with a big old (fresh) 4d32.  I appreciated Frank, KB3AHE's sound advice to go for the Viking II because they are cheap and plentiful, but I ended up going for the 813 final upgradability of the Viking I based on Frank, WA1GFZ's post.

I also just secured a Johnson Matchbox as well, and while I am keeping an eye out for a Johnson 122 VFO, I think I have a 3880 and a 3885 crystal to get it on the air.  All I have to do is go through it.  My plan, after securing a schematic, is the following:

 1) Pull transmitter out of cab
 2) With shorting stick Short/Discharge all caps
 3) Check for and fix broken parts/components, look for loose solder joints and fix
    3.1) Consider re-capping all paper/electrolytic caps
 4) Remove all tubes and insert crystal
 5) With a variac and an AC ammeter
    5.1) Bring up voltage slowly a stage at a time, watching for current spikes
    5.2) Power down and insert tubes a stage at a time
    5.3) Repeat until all tubes are inserted
 6) Connect to dummy load
 7) Tune up transmitter
 8) Connect to antenna
 9) Tune up antenna
10) Transmit

Am I missing/forgetting anything?

Get it working in stock condition before you replace the final. I'm also thinking of changing the driver tube to a 5763.
I get 760 VDC with the power supply changed over to solid state rectifiers and added a second 8 UF filter cap. the voltage would sag about 100 volts during peak modulation. Now it barely drops 30 volts.
Please report your results. The V1 has a socket similar in size of the 4D32 so may not need metal work. May have to sub mount socket an inch or so to get the plate hight right.
I bet if you are careful the old 4d32 socket comes out in one assemble making it easy to swap back if you need to. BTW 813 needs 10 volts 5 amps to light it up so you need to mount an additional fil. transformer.

Test fire it into a dummy load first. Check outpoot for specs. And check mod levels with a scope while still on the dummy load.

Also If the 4D32 is good, leave it in place until it goes soft. Why make extra work if you dont have to?

All of this talk ov V-1's might be enough for me to pull mine off the shalf and mess with it!

                                                                                   The Slab Bacon

Frank said:
Hell why not! I did. Now I have to fix my aerial! :-[

When powering up with the variac, you should just yank the rectifier toobs.

After this is (hopefully) successful, insert the rectifiers.  Leave all the other toobs in place when you're testing.  DO NOT remove them all and start testing stage by stage by inserting toobs in succession.  The PS capacitors may experience overvoltage due to no load (no toobs) and blow to smithereens.

Ask me how I know this  ::)

My, My, My, Once bitten, twice shy!! ;D ;D

Ah, yes, I dont pull all of the toobz either (I'm lazy)

Many of the older table top boat ankas use the class a static draw of the lower stages for voltage stabilization of the low B+ supply. That is why the toobs still continue to wear down even when left in the "standby"  mode. The Invader / Invader 2000 is so bad with this that they actually wear the 12BY7 rf driver toob out while "resting" in "standby"

                                                                           the Slab Bacon

                "Ask me how I know this  ::)"

A little dog told you????      .... ..   klc





( ...and your little dog too..)

Note,
My CDC was acting weird a couple night ago. Turned out the SO239 RF output connector was not making contact to the PL259. I went in with a small screw driver and bended the socket contacts so it would contact the PL 259. Might need to do this every 20 years or so.