KW Rig almost complete..

[ke7trp]

Some of you may remember when I got this beast.  I found the Mod iron and pole pig Shorted out.  Lots of work this week....

I got a new Plate transformer from W0VMC.  He sent a nice 220v primary 3600 volt secondary 700MA trans.  Mounted it in the chassis and wired it in.

Also replaced the old Metal Top hat diodes with 5408s.  Cleaned it up and put a new heavy power cord on the unit. 

The mod deck is ripped apart. Not going to use the 810s.  I am going solid state modulator on this rig. We should have the Transformer deck complete soon. 

I tried to fire up the rig tonight as an Amplifier but the Primary relays for the HV refused to close. Probably an interlock problem. Going to trace this down tomorrow. Then, I hope the rig comes to life. 

here are some pics of the PS deck and the overall rig to refresh your memory.


The goal is an AM/SSB amplifier for various rigs in the shack.  Then, I will be able to switch in the Solid state 2000 watt PA amp to modulate the B+.  With some luck, I will see some power out tomorrow..

C

[ke7trp]

More pics

[N3DRB The Derb]

thats a pretty beastly transformer. Who made it? how about a nameplate shot, some hot spread nameplate action? 

I'm weird like that.

[ke7trp]

Electro engineering out of CA.   Says 3600 0 3600 220 Volt primary. 700MA.   Robert used it in a 2X 4-400 rig and had it stand up to full output power.  I am using a Dual gang variac (pictured) to control it. I am guessing I will run 2000 volts most of the time. Maybe less.  I am in a neighbor hood and cant really use the power this supply can dish out.

The only thing I am thinking about is that I used Ten 1000V 3 amp diodes a side.  Thats 10KV. Should be plenty. But for some reason I see others use more.  I have another board assembly exactly like this one with Sixteen a side. It will bolt right in If I want. 10 min job. 

You guys think 20 is enough or should I put in the board with 32?

I really wanted this to come to life today.. But no luck. The control system is not letting the Primary come on.  Probably an interlock that used to be jumped on the modulation deck that is now absent. I am going to have to Ring this out tomorrow. Once I hear the big CLACK of relays, I am sure its going to fire up. 

Clark

[N3DRB The Derb]

put some grommets on them thar chassis holes, yo.  You be living on the edge.

try it with 20, it'll either blow up with big stinky clouds of electronic warfare or it'll sit there and purr like a cat.

Since you gonna run it up on a variac anyway, just dont reach for the moon too soon. See how it does with about 35% scrote.



 

[W1AEX]

Looks like a nice assembly of components Clark. I would agree with Derb, that plate transformer looks scary. I think I saw that same piece of iron wired up to the chair in "The Green Mile".

There's nothing like the first time you throw the switch on something you have built. I think I recall back in the late 70's that Dean "KNX" labeled this phenomenon as "white knuckle syndrome". That phrase has stuck in my mind and pretty much describes how I feel every time I reach for the switch for the first time.

At least the plate and screen variacs you have installed there in the control deck should keep that first power up from looking like the bridge of the Enterprise when the Klingons are attacking...

:O)

Rob

(Note: I use a string of 10 1KV diodes per side for my 1500 volt supply in my mid-power rig, and I use 20 x 1KV diodes per side in my 3000 volt supply in the big rig. They have never failed. If it was me I would use the bigger strings since you have them all made up and ready to go.)

[w4bfs]

plate xfmr looks like one out of Gates BC 1 ... orig choke input ... looks like high pwr fun ...73 ...John

[ke7trp]

I put rubber grommets on both sides.  I also heat shrink wrapped the primary side. Its just hard to see with that picture.

Yep. Two big chokes, Two big caps.  Two huge Load resistors.

White Nuckle.  Yes..   I have it on a Foot pedal with a 10 ft cable.  If it goes bang, It will do it 10 ft from me    

Now to go through this interlock system.

Clark

[KD6VXI]

The only thing I am thinking about is that I used Ten 1000V 3 amp diodes a side.  Thats 10KV. Should be plenty. But for some reason I see others use more.  I have another board assembly exactly like this one with Sixteen a side. It will bolt right in If I want. 10 min job. 

You guys think 20 is enough or should I put in the board with 32?

If they are the same diodes, you'll be fine in either case. 

I've always looked at it this way...  Your Ctune, with no Cblock needs to be 4 times the DC voltage...  Then double that for safety margin.

I've always built with that in mind... If RFCplate for SOME reason fails, there is a possibility of RF backing into the power supply deck.  And in plate modulated service, that's some SERIOUS voltage.

Theory may just be a bunch of BS, but that is what I've designed around.  SSB only service, you'd be fine for sure, either way.

Maybe someone else with more knowlege could chime in and tell me I'm an idiot?  Or that this makes some semblance of sense?  Don?  Bueller... Bueller?  Bueller?


--Shane

[ke7trp]

The original config used ten 1 amp diodes rated at 750 volts.  These are 1000 v 3amp.  Should be ok. 


I cant seem to figure out this complex keying system. I have been working on it all day. I can see there is a buss that runs from each deck but no apparent place for it to key.

C

[N4LTA]

Next time take a look at the BY228 diodes. Very heavy duty 3 amp  - 50 amp surge 1500 Volt PIV - tough glass passivated case.  Only about 50 cents each at Mouser. I have never had one fail.

[Opcom]

I had the same thing on the Tucker. A keying relay box of some kind was missing. There was a terminal strip to connect to it, but that is where things ended. Maybe you will have to take the bus by the horns..

[KD6VXI]

Next time take a look at the BY228 diodes. Very heavy duty 3 amp  - 50 amp surge 1500 Volt PIV - tough glass passivated case.  Only about 50 cents each at Mouser. I have never had one fail.

While a bit more spensive (in small quantities), check on the 6A10.

I don't believe their is better... I've used it behind some pretty big cap input supplies.

--Shane

[ke7trp]

Ok. Long day here..  Figured out the keying problem. Thank *** for pictures.. I took about 50 pictures of this thing before taking it apart and on one picture, I found where the brown wires from the RF deck go. These needed 110 volts to the control system.

Now it keys up.  But I have SCreen volts but no plate volts (at the supplies not the tubes).  Probablem one was the Load resistors bank was unsoldered.. Scary.  I fixed that.  Problem two was that some idiot decided a good way to interupt the B+ was to lift the Center tap through an interlock relay.  That made no sense.. I jumped that.

Still no B+ out.  Checked the chokes, caps, wires ect.. Then I decided to short the secondary out.  Rolled the variac to 0.  Rolled it up to 20, then 50 then 100 volts.. NO load. Hmmm.

Finally, I decided to feed the Primary side directly with a seperate 110 variac on the floor. No load and no output from the Plate trans F&&%*#&# #$*$(#$)(#  son of a *Y#$I*Y#.   

[ke7trp]

I had to make a second post.  IE wont let me type more then that in one post.

So there is NO continuity from the primary studs to the Primary winding.  Must have been damaged in shipping.  I will be forced to remove the damn transformer and inspect it with a flashlight. Maybe the wire is unsoldered on the back of the Terminal board. If not, I will have to look for yet another plate trans.

Big thanks to Robert for helping me at late hours.  The guy is a real stand up guy. 

Clark

[ke7trp]

Got it going today guys.  Lots of little problems.  Blow fuses, Bad connections. 

Had it running today at 1200 watts.  The right 4-400 is not glowing dull. The other is dull red.  Probably a weak tube.  I put a couple hundred mills on it for a few minutes.  Plate volts is 3500 under load at 55% variac   Screen has plenty to go. Maybe tomorrow, I will replace the old 4-400 with another I have.  I am sure power will come up on it.

Bleeders are working nicely.   In less then 2 seconds the volts are 0. 

Couple things need to be changed.  In SSB mode, The Rig is keyed and idling in AB.  That produces alot of heat.  I want to set it up to apply voltages when its keyed by the foot pedal or radio in SSB mode.

In Class C am mode, This is not an issue.  I dont have the modulator done so I cant report on that just yet. However, The RIg is producing power with nice stable voltages. 

[Steve - WB3HUZ]

All right! I guess we'll be hearing that big maul this winter.

[flintstone mop]

plate xfmr looks like one out of Gates BC 1 ... orig choke input ... looks like high pwr fun ...73 ...John

YUP Electro Engineering made iron for the good ole Gates TX's

Fred

[N3DRB The Derb]

Clark, Thats awesome!  happy for you because I know you put a crapload of work into it. And I love anytime somebody gets a big maul going.

now I gotta do the same over here. Start with getting my new feedline and ant back up in the air and getting the yasoo back on. Then add Gonset amp. that will get me on while I build.

lotsa holes to be punched out.

[ke7trp]

Yeah. Lots of work    I am also learning along the way which makes things tough.  I have had a lot of help though!


Clark