813 Transmitter coming to life

[W7SOE]

Thanks again to all for sharing your experience and wisdom.  I finally believe I have enough rudimentary understanding to fire this thing up. 
From a previous thread:

--->SNIP

Last night I decided it was time to fire this thing up!  :-O

Both the plate and mod HV supplies had been brought up slowly on the bench.
I connected a my JVII to the input and a dummy load and scope probe on the output.

I left the modulator HV off, filaments on.  I fired up and tuned the JVII at 3870 Mc and I was able to peak the 813's grid current using the RF input tuning and grid tuning controls.  I set the 813 grid current at 20mA.  I adjusted this using the grid drive of the JVII, it takes VERY little to get sufficient drive, the JVII grid drive is close to zero.  Really not sure if this is the way to do it.....

The plate HV is on a variac, fired it up and put about 50mA on the 813 plates.  I was able to tune the plate tank for a minimum nicely.  There is an antenna capacity switch as well as an antenna loading control, I adjusted these for a minimum plate current, is this correct?
I then re-tuned the JVII tank.

I slowly increased the B+ until the 813 plates were drawing 300mA.

The screen current came up to about 35-40mA.

At this point I am really sweating!  No sparks or smoke, just a lot of impressive humming.  The output looks good on the scope, a smooth sine wave, and it is bigger than the one made by the Viking!
I let it run like this for about 5 minutes and the shut it down.  My dummy load is one of those MFJ dry 300 watter's and it was beginning to smell.

I only hope this was somewhat close to proper operation.  Very exciting, weee!

-->SNIP

I am very interested in making sure that I am operating this rig correctly, any comments on the above would be appreciated.

Rich

[WD8BIL]

Nice Job Rich. Do you gots a wattmeter ?

That'll tell ya the story.

Again, nice job. Looks like you're on the right track.

Just one thing though. That don't look like no kit transmitter.
How'd you do it

[W7SOE]

Just one thing though. That don't look like no kit transmitter.
How'd you do it

I didn't build it, but I sure wish I knew who did.  It is a beauty.

Rich

[KB2WIG]

Looks perty....

put a cheep fan on the dummy load kep it a bit cooler.

Ya really need these tube caps..........

[WD8BIL]

Ya got it runnin' though !! Stand up Man, be proud !!!

[WA1GFZ]

GREAT !!!!!!!!

[ka3zlr]

YES, very well done OM,  Now address your grounds well..and RUN that thing...

Even has the rf shields on the metering..Kewel...

[WD4TC]

     Rich, Great to see the transmitter come to life. I saw it when it was for sale and I wanted  it But there was a Small thing of being 3000 miles away here in NC. I almost had arragements made by a trucking co here to pick it up and bring it back..Once again Looks Great and I know all your effort and time will be well rewarded when you get  to put it on the Air..  Great Score....Tim...WD4TC...

[W7SOE]

I modified the JVII to output 500 ohm audio which is fed to the HB rig.  All looks well with the modulator, whew!

Now I need a tuner than can handle some power..

Rich

[N3DRB The Derb]

great to see the pix of another rig being saved and put on the air.

[KA7WOC]

Rich,
You might consider a trip up to Prosser, Washington for the annual winterfest.  Last weekend of this month.  Details are at W7JHS's website.  Google the call.
Lots of swapping, selling, lying goes on there.  It would be a good place for you get information, insight and tips.
Bob ka7woc

[W7SOE]

Rich,
You might consider a trip up to Prosser, Washington for the annual winterfest.  Last weekend of this month.  Details are at W7JHS's website.  Google the call.
Lots of swapping, selling, lying goes on there.  It would be a good place for you get information, insight and tips.
Bob ka7woc

Bob,
     That sounds like a good time,  I will try to make it if I can.  Chances are I will not though.     My time is in HIGH demand these days.

Rich

[W7SOE]

     Rich, Great to see the transmitter come to life. I saw it when it was for sale and I wanted  it But there was a Small thing of being 3000 miles away here in NC. I almost had arragements made by a trucking co here to pick it up and bring it back..Once again Looks Great and I know all your effort and time will be well rewarded when you get  to put it on the Air..  Great Score....Tim...WD4TC...

Thanks Tim!

[W7SOE]

I went ahead and broke out 500 ohm audio from the Viking II as per their manual (minus the mistake in their schematic).  I was able to test modulation and it works just fine.  I am seeing some ripple when the audio is on but quiescent.  I think this is because I left out a series VHF choke that they called for, I just have a decoupling cap.  Perhaps a load resistor will help.  I will play with it when I can.

Another issue is that the Viking II is way to lightly loaded when driving the beast.  Perhaps I need to add a loading resistor but I am unsure of the value.

Rich

[WA1GFZ]

A way to increase the output from the V2 would be to add a load resistor on the 813 grids AC coupled to ground. This will also help to tame the 813s against taking off.