meanwhile out in the garage ...

[Shadetree Mechanic]

The people that say it can't be done should not get in the way of the people that are doing it.

The more you know, the more you realize you don't know. Because you don't know what you don't know.

Wizdom comes from experience and experience comes from when you didn't get what you expected.

There is never time to do it right. But there is always time to do it twice.

Measure once, cut twice. I cut it twice and it's still too short.

A goal without a plan is just a wish.

 

[kopcicle]

 

[TheRealPorkchop]

Looks like you’ve flatlined

 

[kopcicle]

That was the before pic of the trash that was coming out of the 1011C

 

[kopcicle]

I'm in a bit of a quandary. Suffice to say this has been a long rebuild/restoration with the end in sight but ...

Some here have already heard/read/seen the carnage I was presented with. The bandswitch was meticulously rebuilt from Oak parts and #2-56 hardware. It looked like it had been hit by lightening, or a small nuke. Two of the doorknob capacitors had been blown off the chassis. The HV filter has been re-built from scratch. Both the lid and plunger interlocks were repaired. Several tries at the fan got it from "box of rocks" to near silent. Appearance wise it's at least 80% if not better on the outside and in all but a few areas as new inside. It really is worth fixing. And to those uninformed naysayers, the 8122 although not ubiquitous is not rare and unavailable. I'll admit it helps to have broadcast connections for pulls and a NOS resource that doesn't break the bank. In short I'm okay for tubes (unless someone offers a killer deal on 8072's as well as 8122's , I'm a fair machinist so a sink for the 8072's is doable)

1) Plate voltage metering. The bottom 1.66 Meg Ohm is a collection of 2 Watt resistors totaling 1.44 Meg Ohm. I'm now 4.76 Meg Ohm away from the 1800/2500V line instead of 4.98 Meg Ohm while I wait for the proper resistor.
2) Power on and after the 1 minute delay the plate lamp lights when the plate switch is depressed. There is no plate voltage indication.
3) The plate voltage metering circuit has been verified end to end. The meter deflects to half scale when my multimeter is place across the terminals in diode mode.
4) Primary wiring has been verified from the house panel to the terminal strip on the amplifier.
5) Bias supply is verified and adjustable.
6) I have power at and through both fuses.
7) Mode switch does not affect zero indicated HV.


Left to do

1) Indicator lamps #1445 & #1826 meter lamps
2) It would be nice if I could find color code for the main transformer
3) Some means of verifying plate voltage other than out of the case with the interlocks disabled.
4) Some way of testing the overload relay.
5) apply some drive...

It's out of the case now and I'm playing "physical graffiti" with the wiring. That is as you would with an old point to point wired chassis. Identifying each circuit by eye and comparing it with available schematics.
Anything in that vast experience here that you think may help would be appreciated. Anyone you can think of that might be able to help, please send them my way. I really don't want to experience fireworks of the 2.5Kv nature.

 

[Handy Andy]

Interlocks ok?

 

[kopcicle]

I was about to update ...

from a well known member

"The NCL I'm looking at right now is serial # 71 4044. The center section of the antenna relay has a blue and an orange wire on the normally-open center pole. Both wires lead to the front-most two lugs of a tie strip just behind the center of the front panel, alongside the socket for the time-delay relay.

The orange wire goes to the next-to-frontmost lug, where the anodes of the screen-voltage bridge diodes are connected, the '-' side of the screen-grid bridge at CR3 and CR6. A 1 meg resistor R50 goes from there to the adjacent front-most lug, where the blue relay wire, one end of the 15-Watt resistor R35 and a black wire that leads to the negative end of C31, the 80uf screen-grid filter cap. At the other end of the black wire, the 20.5-ohm screen-meter shunt resistor R16 goes from there to ground along with a yellow wire to the meter switch and the negative lead of C31."

I wish I was color blind. This mess looks like a Denny Had "build with what ya got"
The descriptions were correct but the colors are , well not even close :-( .

I did get a few good pics from you know who and a few more from I doubt you do ...

It would be a damn sight easier if I didn't have to disassemble the input pad every time I went in there .

 

[Handy Andy]

Well, if they tried to run it with the hood off. Well, then the Interlocks are 'prolly in a trash bin or landfill by now...

Ok changes the dynamics a bit...

Ok, you know it runs a "Delay Fuse" so that at least you can recite the Lords Prayer at least once before you "Push To Test - Release To Detonate" function - at least you get a ready lite in the process...

I just hope like Hades' you're telling the truth because this thing with all it's safety features, if they've been defeated and you get hurt - I'd never hear the end of the Laughter from TRPC/Rabbi Tour group and The opening act of the Grave Digger 5 band...Solar powered or not...

OK, after the delay - what happens? The PNPs' kick on and you get Heater - If K1C portion of the relay or it's ZENER opened up - you have no plate because you have no cathode.

Plate Relay uses Interlock. So if you're not getting voltage - suspect Plate and interlock section - use a 10 foot fiberglass pole to kick off the caps so you don't become Captn' Ahab with St Elmo's Fire and not the Tickle me Elmo kind...Do a Bias Check - see above...

 

[Handy Andy]

Yes, I see you did do a Bias Check but again, Plate doesn't show - so do you have a Cathode to your Plate - then suspect the Interlock...

 

[Handy Andy]

Are all the poles of S4 aligned correctly?

 

[kopcicle]

Interlocks,
This was the first thing I confirmed. I have a history of several vocations where you only get to make one mistake.
Bias,
Grid driven tetrode theory is firmly part of my milk language. It is a known trouble spot with the NCL2K.
Screen,
Even with the screen voltage I observe HV safety procedures.
Plate,
I'll skip the jokes today and mention that I have a HiPot tested (including the lead) High voltage probe , proper gloves, safety glasses, face shield, and I don't work on HV by myself any more than I climb a tower without ground support. I've worked around 7Kv commercial transmitters. The men that taught me all lived to a ripe old age.

On to business. I don't have the pics transferred to the 'puter but it's enough to say that there is less than no room to work on K1 as installed. It's buried under the grid swamp resistor stack. Very nearly all the wires have to be connected to the relay in the right place, in the right order as it gets stuffed in the hole. That is the current problem.

I have the help of a well known member here as well as ...
KEO7U Mike Harrison
WB2WIK Steven Katz
KC5RT Fred Gerken
W7CPA Randy Best
K5AZE Wayne Bradford
K9AXN Jim Liles
AF6LJ Sue Robins
N2EY James Miccolis
PG1310569 Gerry "Otis" Greenfield
and
KM1H Carl Huether

So take you pick. I have extensive experience to draw on. I'll still ask here either for simply documenting the destruction, ermm, construction of this device of mass destruction or because I won't ignore any possible resource.

So if Andy's safety concerns are well and truly addressed we can move on
I would, will post, my safety overkill, in any case, when I get to verify Bias, screen and plate one more time . It is never wrong to error on the side of caution and even better to display and document good procedure. This is well past 2500V @ 250ma so a fair bit past getting bit by a 1Kv sweep tube supply. These voltages are lethal. You only make one , one mistake. Anyone remember the rat trap? If plate over current protection wasn't present there is enough potential here to explode, disintegrate, vaporize, a rodent.

I just have to get a few of the many issues around here to quit causing problems so I can get back to the bench.

So until I get it back on the bench it's my fat fingers and no room to work on on the antenna relay

 

[Handy Andy]

Alrighty then...

With heavily insulated - kid gloves...

Your Plate meter per schematic - locates itself as part of the NEGATIVE return off of K2 the overload Relay.

You Plate meter is dead...if K2 is operational - then Plate Overload relay is engaged - and if interlocks are working - your K2 relay and the HV multiplier - are the "dead" part of the circuit then.

Your "power from the tester" - test shows the meter is functional - you also have a 1 ohm shunt across it - the meter itself. Your NEGATIVE/Ground reference goes to K2 - the POSITIVE AND NEGATIVE that power that meter and serve as the return are at ground potential and are placed on one side of the wind that feeds heaters and lamps - only thing is, the NEGATIVE side pulls from ground - thru that shunt/meter combo - for the HV section. So, no deflection? OR are we just seeing a phase condition - but you have meter lamp - then it tells me the K2 / HV combo - is either engaged protection - see Plate Overload condition - or K2 as a unit - has failed in the winds/wiring. The 2.2 ohm resistor across it should have taught you a poke or two of a lesson in it's own right...you should have seen a deflection across the Plate meter if K2 even was thinking about engaging...you didn't tell me anything about that yet...so again wiring may be your whole problem...

There's several other questions too...

What are the numbers off of Q1 and Q2 - gosh darn it I hope they're not drawn wrong - you get bias yes, but if K2 is either open or out of commission - the HV multiplier section won't ever get power. OR at least it floats at losses incurred around it...so it would have an EMF kick even when the circuit is not completed thru K2.

Like I said, I have reservations on this, over knowing my own throes I've received from my younger Arcade days - so this thing is a widowmaker and appears to be damn proud of it...

I don't need your qualifications - I just want you to survive this ordeal...

 

[kopcicle]

I don't need your qualifications

Only to ease your concern. I can't stress enough the respect I have for HV.

I just want you to survive this ordeal...

Me too!!!

I'll have to look again but I believe you are correct Q1 abd Q2 may be incorrect...

 

[kopcicle]

 

[kopcicle]