Schematic Check Print 813 Deck

[KB7HTV]

cleaned up the HV transformer
labeled as follows:
1500
1250
1000
0
1000
1250
1500
so my max voltage with a bridge is 1500
a smudge over the label cleaned off to read 500ma
If I used a full wave bridge I could raise the HV voltage
somebody mentioned using a 810
plate voltage would be out of range of the 811 modulators at 2 KV I think
half an amp, at 1500 volts, wow, does seem like a waste to just use 1 tube
what is the output of only 1 813 at 1.5KV

I will fix the mumbo jumbo bias supply for Fred it was my fault, I drew it wrong.

oh, the power supply caps are 470uF

what else,  oh I have a bunch of large wattage resistors I will be able to cobble together the bleeder or maybe lower the valve of the capacitor bridging resistors
I am catching up, but still way behind you guys though.

this is like skipping high school, and going to college courses taught by a bunch of broadcast engineers, my tube theory in college was a long time ago, and I don't remember it as well as I would like. but it is coming back, Thanks to all for the time you have taken to comment.

HTV

[KB7HTV]

Added some photos of this animal for reference

HTV

[KA2DZT]

WoW!!  didn't know you had some of the rig already build.  I thought you were still in the thinking and planning stages.

FB,  I think your plate xfmr might be a UTC S series judging from the three plate voltage levels  Maybe a S-48, IIRC that one is rated at 500ma, most of the others are rated at 300ma.  I have a S-49 that has higher voltages but only 300ma.

Stancor plate xfmrs usually had only two voltage levels BUT the ratings as marked on the xfmrs are the DC voltage output after two stages of filtering.  The AC terminal voltages are higher.

If it is a UTC S series you probably can not use it with a full wave bridge rectifier.  The ceter tap may not be able to handle the high voltage above ground.  With a FW bridge your max voltage would be 3KV not 1.5KV like you say.

With a full wave rectifier you will only get about 1250-1300 volts DC after a choke input filter.  There is an easy way to bring that voltage up 300-400 volts, 1500-1600 volts is a good level to run the rig at considering the 811's

Fred

[KB7HTV]

Thanks fred,
I went back out a looked at it it indeed is an S48 you were right.
I don't even want to ask how you knew
secondary hipot is 4500V but I suspect you are right, may not want to subject the thing to 3kv or even 2kv on the center tap
so I have gobs of current but am limited for HV, I don't have the modulation transformer for 2 tubes, there is a 125 watt on ebay but I suspect I need a bit more for 2 tubes,.
the ART-13 Mod Transformer seems small, It is smaller than the 60 watt transformer in my viking 1
How do I boost the output of the HV trans without doing a voltage doubler circuit?
maybe the smart thing is to add a second tube and run 1250V and find another modulation transformer would the multimatch on Ebay work?

73 HTV

[KC2ZFA]

you can still use the ART-13 mod xfmr. See

http://www.amwindow.org/tech/htm/shuntfedmod.htm

[KA2DZT]

Simple way to bring up the final plate HV;

If you have another power xfmr in the range of 300-400 volt,  (700-800VCT) with a current rating in 250-500 ma current range,  do the following.

Using the xfmr with a set of solid state rectifiers just exactly as if your were building a small PS,  connect the output from the rectifiers directly to the center tap of your plate xfmr (S-48).  This will bring your final HV up by added amount of the smaller supply.

Remember, just the output from the FW diode rectifiers with nothing in between the diodes and the CT of the S-48. (no chokes, no caps) You could put a fuse in between if you wanted, that would be OK.

This will bring your CT voltage up 300-400 above ground but most any xfmr should be able to handle that without any problem (always check the CT terminal with an ohm meter to make sure it is NOT internally grounded).

This can be done with any xfmr you have on hand.  The small xfmr can be a FW bridge diode rectifier output,  same thing, just connect output of the FW bridge diodes to the CT of the S-48.  Even if a HV xfmr (not your S-48) was using FW bridge rectifiers, you could do the same thing,  the output from the small xfmr diode rectifiers would be connected to the diodes on the HV xfmr (the junction on the FW bridge rectifiers that is normally grounded) and you will get the same results.

If you want to lower your plate voltage, you just shut off the small xfmr and the voltage will just drop back down to just the S-48, NO need to disconnect anything, just shut off the AC to the primary.  Turn it back on to get the higher voltage.  You can do that while the supply is in use.  You could shut off the S-48 and you would be left with just the voltage from the small xfmr.

This method allows you to increase your HV by a smaller amount of added HV, instead of the double-the-voltage you get when going from FW to FWB.  You also mantain the full current capacity of the HV xfmr.  Normally when you go from FW to FW bridge you have to half your current load on the xfmr.

The current capacity of the small xfmr would normally have to be the same as the HV xfmr.  If you use a power xfmr that has filament windings, you can draw more than the rated HV current by not using the filament windings.

A note about diode strings,  You need to use enough diodes in each string to handle the PIV.  Xfmrs in the 350-400V range I use two 1KV PIV diodes in each string.  Xfmrs in the 1500 volt range I use seven diodes in each string.  When using this stacking-of-PS method like I described, there is NO need to increase the amount of diodes normally used for each xfmr.

Let me know if you have any questions about this.

A test on this subject matter will be given on Friday

Fred

[KX5JT]

you can still use the ART-13 mod xfmr. See

http://www.amwindow.org/tech/htm/shuntfedmod.htm

That's pretty neat... what kind of audio response can one expect with an ART-13 mod txfrmr?  Can one approach Hi-Fi or is that asking too much from them?

[The Slab Bacon]

you can still use the ART-13 mod xfmr. See

http://www.amwindow.org/tech/htm/shuntfedmod.htm

That's pretty neat... what kind of audio response can one expect with an ART-13 mod txfrmr?  Can one approach Hi-Fi or is that asking too much from them?

Chris (W2JBL) runs one like that (ART-13) somewhere around 200+w out and it sounds real good.

[The Slab Bacon]

Simple way to bring up the final plate HV;

If you have another power xfmr in the range of 300-400 volt,  (700-800VCT) with a current rating in 250-500 ma current range,  do the following.

Using the xfmr with a set of solid state rectifiers just exactly as if your were building a small PS,  connect the output from the rectifiers directly to the center tap of your plate xfmr (S-48).  This will bring your final HV up by added amount of the smaller supply.

Remember, just the output from the FW diode rectifiers with nothing in between the diodes and the CT of the S-48. (no chokes, no caps) You could put a fuse in between if you wanted, that would be OK.

This will bring your CT voltage up 300-400 above ground but most any xfmr should be able to handle that without any problem (always check the CT terminal with an ohm meter to make sure it is NOT internally grounded).

This can be done with any xfmr you have on hand.  The small xfmr can be a FW bridge diode rectifier output,  same thing, just connect output of the FW bridge diodes to the CT of the S-48.  Even if a HV xfmr (not your S-48) was using FW bridge rectifiers, you could do the same thing,  the output from the small xfmr diode rectifiers would be connected to the diodes on the HV xfmr (the junction on the FW bridge rectifiers that is normally grounded) and you will get the same results.

If you want to lower your plate voltage, you just shut off the small xfmr and the voltage will just drop back down to just the S-48, NO need to disconnect anything, just shut off the AC to the primary.  Turn it back on to get the higher voltage.  You can do that while the supply is in use.  You could shut off the S-48 and you would be left with just the voltage from the small xfmr.

This method allows you to increase your HV by a smaller amount of added HV, instead of the double-the-voltage you get when going from FW to FWB.  You also mantain the full current capacity of the HV xfmr.  Normally when you go from FW to FW bridge you have to half your current load on the xfmr.

The current capacity of the small xfmr would normally have to be the same as the HV xfmr.  If you use a power xfmr that has filament windings, you can draw more than the rated HV current by not using the filament windings.

A note about diode strings,  You need to use enough diodes in each string to handle the PIV.  Xfmrs in the 350-400V range I use two 1KV PIV diodes in each string.  Xfmrs in the 1500 volt range I use seven diodes in each string.  When using this stacking-of-PS method like I described, there is NO need to increase the amount of diodes normally used for each xfmr.

Let me know if you have any questions about this.

A test on this subject matter will be given on Friday

Fred

Or just simply change the filter to cap inpoot (C-L-C).
I know you loose some regulation.........blah, blah blah..................
But you gain a noticable increase in plate voltage, even under full load.

Yer takin the long way around the block again, Fred! ! ! ! ! ! ! !

Also, dont run an old piece of iron FWB unless it's rated for it!! I didnt listen and had to learn the hard way, I blew up a handful of them that broke down at the center tap to ground or center tap to the primary! ! !

[KB7HTV]

Thanks Fred for staying with me on this, you are of great help.
You opened this up for questions so here goes.

I have seen resistors used across the diodes in solid state power supplys.
if the PIV of the diodes is high enough can these be omitted?
If indeed I need this precaution how are these sized?

Back to my mumbo jumbo bias setup, should I split the bias source some from fixed and some from a resistor, or delete the fixed bias entirely and risk the tube.
I could use the bias transformer for control relay voltage, or get that from the filament winding, allthough 10V may not operate a 12V relay.

I understand the concept of the small transformer and rectifier on the centertap of the Main HV transformer. I suspect that I do not have a small transformer with  the current capability, but I may I will have to look. I do have a large variac I guess I could use that on the primary of the HV Trans. Some folks seem to discourage the use of variacs in HV supplys though.

I want to confirm a basic assumption, In this circuit it is assumed the exciter is always on and the HV is always on, Keying the rig is done by removing the bias from the centertap of the filament transformer.

Today I will scrounge around my shop looking for  relays transformers and the small chokes I need I know I have them I just need to find where I put them.

I will put up a corrected schematic again soon after I correct the errors.
73
HTV

[KA2DZT]

Thanks Fred for staying with me on this, you are of great help.
You opened this up for questions so here goes.

I have seen resistors used across the diodes in solid state power supplys.
if the PIV of the diodes is high enough can these be omitted?
If indeed I need this precaution how are these sized?

Back to my mumbo jumbo bias setup, should I split the bias source some from fixed and some from a resistor, or delete the fixed bias entirely and risk the tube.
I could use the bias transformer for control relay voltage, or get that from the filament winding, allthough 10V may not operate a 12V relay.

I understand the concept of the small transformer and rectifier on the centertap of the Main HV transformer. I suspect that I do not have a small transformer with  the current capability, but I may I will have to look. I do have a large variac I guess I could use that on the primary of the HV Trans. Some folks seem to discourage the use of variacs in HV supplys though.

I want to confirm a basic assumption, In this circuit it is assumed the exciter is always on and the HV is always on, Keying the rig is done by removing the bias from the centertap of the filament transformer.

Today I will scrounge around my shop looking for  relays transformers and the small chokes I need I know I have them I just need to find where I put them.

I will put up a corrected schematic again soon after I correct the errors.
73
HTV

To start with, don't listen to Frank KB3AHE, here's a guy that doesn't know much of anything about radios, thats why he has blown up so many xfmrs .  Frankie, I love ya.

Even though a lot of folks will tell you that with modern diodes you no longer need to use them, I still use them.  A 470K 1/2w and a .01 1KV disc ceramic across each diode.  I just feel better using them and I use 1N5408 3A 1KV piv diodes.

I would not use the bias supply as I mentioned before, but if you insist, your grid voltage should be around 170 volts total.  So, if you have say 80 volts of bias supply you then need another 90 volts of grid leak bias.  Figuring 13ma of grid current, 90v/.013a = abt 7K of grid resistor in series with the bias supply.  .013x.013x7K = 1.18w, so, use at least a 2W or larger resistor.

As far as your design for keying the xmtr into standby, I am completely against using the high-bias-resistor-relay setup.  It creates too many problems (in standby) that you're not seeing.

First, your assumtion that the exciter is always on, is wrong.  The exciter is OFF on standby.  If you left it on, to begin with, you would have so much of your own signal in your receiver you would not hear anything but your own signal.

Leaving the HV PS on during standby conditions is never a good idea and IMO poor engineering.  It may be done all the time with linear amplifiers but not too good an idea with plate modulated AM xmtrs.

Because you're using a series dropping resistor for the screen voltage, on standby the HV PS voltage will rise, without any current flowing through the screen resistor the voltage on the screen could rise to the full PS standby voltage.  This may cause the 813 to arc over inside the tube.  Frank, KB3AHE, correctly pointed this out in a previous post (only time he ever came up with a good point)

Another thing is that this same HV will appear on your meter switch circuit.  Most likely exceeding the voltage rating on those disc ceramic bypass caps, in addition the meter switch may not be the right type to handle such high voltages.
Another point about the meter circuit for the screen current, you want to avoid too many bypass caps on the screen because you may begin to bypass too much of your higher freq audio.  It's better to meter the screen voltage than the current, you then don't need the extra two .001 bypass caps.  

There is probably other issues with leaving the HV supply on during standby.

Leaving the HV on during standby, in general, just waste energy, you're heating up bleeder resistors for no good reason.  It also can be dangerous, one can walk away from the station for a minute or so and forget the fact that there is a 2KV power supply left on.  Someone else (not you) may get hurt.

It's better to shut off the HV power supply on standby and key it up on transmit with a step-start circuit.  This is not hard or difficult to do and it eliminates a whole series of issues.

Fred

[KA2DZT]

You asked about using a variac on the HV xfmr.  The UTC S-48 is rated for 115VAC on the primary.  It is also rated to produce 1300VDC after a single choke input filter.  It is rated for 500ma.  These plate xfmrs like most plate xfmrs are designed to be run with choke input filters.  Using a cap input filter (CLC) will bring up the DC voltage output of the supply.  But, it increases the VA load on the xfmr and you must reduce the total current drain by about 30%.  CLC filters are not as stable as a choke input filter.  Under light loads the voltage can increase close to the peak AC voltage.

It is not recommended that you try to run the primary at a higher voltage than normal AC line voltage, which in most areas is around 120VAC.

You can easily bring up the DC output voltage by using the extra xfmr and diode rectifiers like I described previously.  IMO, a few hundred volts on the CT of the S-48 should work fine.  This method is far less stressful on the xfmr CT than using the xfmr with a FW bridge rectifier.  With FW bridge the CT is operating at half the total AC voltage of the secondary. So, that would be 1500VAC if using the full 3000 secondary AC voltage.  There a big difference from a few hundred volts to 1500 volts.  Using this method also mantains good voltage regulation.

It would be good if you can tell me what choke you have to use with the supply.  Some choke are better than others, even with chokes that have the same ratings.

Fred

[KB7HTV]

Fine Buisness Fred, Might as well do it right, I may have this thing for years.

The choke I have is unlabled about 8" tall and 7" wide with traditional End caps It is not a potted style. (has 2 wires coming from the windings #18 with cotton rubber insulation) in good shape weighs 30 LBs. don't know what value or if it is a swinging choke, hard to calculate critical value when you don't know the size of the choke

I need to study how a stepstart circuit works, If the bias is all passive either off the HV supply of derived from grid leak and the hv supply goes away along with the exciter, no harm done to the tube, But the exciter (a millen 90800 with a separate power supply) is going to turn off quicker than the caps on the HV supply will discharge, I need to study this. Analyzing what happens during this process is something I have never done.

Dale

[W8ACR]

Hi Dale,

Although my previous post was somewhat tongue-in-cheek, I really think you should consider using a triode or triodes in parallel for your final amplifier. 810's 100TH's or 250TH's are all plentiful. If you have two 813's, you could then connect them as triodes and use them as your modulator tubes. A single 1500-2000V ps could be used for both RF final and modulator.
I also recently built my first junk box transmitter, and I used two 254W triodes in parallel modulated with 811A's. For simplicity sake, I built it as a single band 160M transmitter, and it has been working great. I built separate power supplies for the modulator and the RF final. I run the 811A's with about 1400V on the plates, and the 254W's with about 2000V on the plates.
I am attaching a schematic of my next project, an RF deck for 80/40 using 8000's as finals. This RF deck will be used with the same power supply and modulator as my 254W RF deck. This circuit is nearly identical to my 254W RF deck circuit. Only the tank component values are different. I would like to point out that not having a screen supply simplifies the circuit significantly. Also note the simplicity of the bias supply.

Transmit/receive switching is also relatively simple. When I apply filament power, the bias supply comes on and puts about -100V on the grids of the 254W's. This is enough to cut off the tube in case plate voltage is accidentally applied. When I key the driver (a viking I), the receiver is muted and drive is applied to the grids of the 254W's. Because I have the grid circuit metered, I can see that when I apply grid drive both the grid current and voltage go up to approximatelytheir working values. I then hit a foot switch to apply the RF plate and modulator plate voltages simultaneously. At the end of my transmission, I simply release the foot switch, and then turn off the driver.
This is a simple control system, and probably less than optimal, but it seems to be working fine so far. Regarding the use of tetrodes versus triodes, I think the main advantages are less drive requirements for the tetrodes and also some tetrodes may not require neutralization. If you have twenty to thirty watts of drive power available, that should be enough for most triodes. Good luck.

Ron

[KA2DZT]

Fine Buisness Fred, Might as well do it right, I may have this thing for years.

The choke I have is unlabled about 8" tall and 7" wide with traditional End caps It is not a potted style. (has 2 wires coming from the windings #18 with cotton rubber insulation) in good shape weighs 30 LBs. don't know what value or if it is a swinging choke, hard to calculate critical value when you don't know the size of the choke

I need to study how a stepstart circuit works, If the bias is all passive either off the HV supply of derived from grid leak and the hv supply goes away along with the exciter, no harm done to the tube, But the exciter (a millen 90800 with a separate power supply) is going to turn off quicker than the caps on the HV supply will discharge, I need to study this. Analyzing what happens during this process is something I have never done.

Dale

Try to put up a pic of the choke, I may be able to identify it.  30 Lbs seems like a big enough choke, the only thing you need to worry about is the high voltage rating of the choke.  What is the DC resistance of the choke??

The Millen 90800 exciter puts out about 50 watts, you only need about 5 watts to drive the 813.  I think that exciter was designed to drive the Millen twin 812 final.  You'll have to work out some way to reduce the output. and key it on and off with the with rest of the xmtr.  Probably lower the plate voltage to the output tube in the Millen and have a PTT relay to key this voltage on and off.  This same relay (through separate contacts) will control the step-start relays for the HV supply.

You're right about the timing of the driver and the HV supply turning off.  On start up, the step-start delays the HV a bit.  But on turn-off the HV caps will delay the HV from going to zero.

Best way to overcome this problem is to use the 6Y6 clamp tube circuit on the screen of the 813.  With the clamp tube you don't need the grid bias supply and you can just use a grid leak resistor (13K about 10watts).  The 6Y6 clamp circuit is really very simple to set up.  The other thing that needs to be keyed along with the whole xmtr is the antenna relay and the receiver.  What relay are you using for the antenna??  A Dow-Key antenna relay also has extra contacts that are usually use to mute the receiver.

If you design the control circuits correctly, you should be able to control the whole transmit-receive with a single PTT switch.

The step-start usually requires two 120v relays and a power resistor of about 20-30 ohms.  The contact amp ratings have to be large enough for the primary current of the HV xfmr.

We also need to look at your metering circuits, I'm not sure what meters are in the rig.  What meters (exactly) are in the xmtr??

Fred

[W4AAB]

I was trying to figure out why there were RFC's going to each control grid on the 8000 amp of Ron's. RFC chokes would be used to keep RF at one end and pass DC only. Yiou would need RF on input and output of the RFC's(maybe they are low value inductor used kind of like a snubber resistor to blow in case there was a short from plate to grid.Usually there is a snubber of 100 ohms, 2 watts to each grid.

[KA2DZT]

I was trying to figure out why there were RFC's going to each control grid on the 8000 amp of Ron's. RFC chokes would be used to keep RF at one end and pass DC only. Yiou would need RF on input and output of the RFC's(maybe they are low value inductor used kind of like a snubber resistor to blow in case there was a short from plate to grid.Usually there is a snubber of 100 ohms, 2 watts to each grid.

Probably small RFC's (a few uh) to reduce any parasitics,  similar in purpose to the parasitic choke that is usually used in the plate lead to the final.

[WD5JKO]

When I apply filament power, the bias supply comes on and puts about -100V on the grids of the 254W's. This is enough to cut off the tube in case plate voltage is accidentally applied.

  I like Ron's method of fixed/grid leak bias. This method with diode isolation was debated on other threads with lots of opposition and misunderstanding. Glad Ron seized upon the advantage, and ran with it.

Jim
WD5JKO

[W8ACR]

Yes, those RF chokes on the grids of the 8000's are small VHF parasitic suppressors. I believe I used about 10 turns of #24 wire wrapped around a high value 1 watt resistor. I believe their value is something like 0.2 uH. One other small correction - all the meters are shunted by a 0.01 uF capacitor.

And Jim, I forgot to credit you for giving me the idea to try the diode isolation circuit in the bias supply. So far it has worked very well. As I said, the grid circuit is metered for continuous reading of both current and voltage. They are both very stable during transmission.

Ron

[KC2ZFA]

Ron,

your grid tank looks strange. With a split-cap I would have used grid circuit
C below.

Peter

[KB7HTV]

Ron
the picture of you're FR deck really looks cool,  fine buisness nice Radio

I am going to press on with my 813 though, I do hope to continue to build stuff after this, as This is a work in progress. I can always add a second tube change tubes whatever, but at the moment this is a challenge for me.
but I am learning

Fred,
 I did not throw an ohm meter on the choke but I will, I studied the clamp tube circuit last night, it was either this or use a  grid cut-off bias scheme using a Bias supply and a relay, so I dug through my junk box and found a 6y6G and a ceramic tube socket and also found a 6.3V filament transformer 6.3V at 3 amps. I even have the parts.
I even have a Greenlee chassis punch the proper size, Lucked out.
The meters on the rig came from an old WW2 Army Signal Corps 6 meter RF deck
1 meter is 1-100ma the other is 1-10ma
I have a matching meter that is 1-300Ma to replace the 1-10ma
they say signal corps on the face inside the glass, also real nice jeweled movement, I will look further for any other stuff like resistance, voltage rating etc.
There is a picture of this I put up on a previous post, I am building the faraday cage you see mounted to it.

Also I have not started wiring yet but I will try to partition the input circuit from the rest of the stuff under the chassis.

I have a Dow key relay with 2 extra contacts and several other open reed relays capable of a fair amount of current, they are old school like what is in a KWM-2 not the modern mini type with the clear plastic box
I have 2 or three that have a 6 volt coil and about the same number with a 120Vac coil

Step Start

What about using the voltage drop across a resistor at inrush to hold in a relay at steady state current it opens up using the normally closed contacts to short across the resistor,taking it out of the circuit the problem is where to put the relay in a 1.5KV line, I wonder if the relay coil could be in the 120V line to the primary of the HV trans.
also what is the acceptable voltage drop across this resistor at inrush

also the discharging HV caps won't hold it closed,

it would be nice to see a second set of contacts on this relay key the exciter
after the inrush current event and unkey the thing and this is as far as I have progressed do I want to unkey the exciter before the HV dies or after I think before, then the clamp tube affair takes over cuts the tube off and then HV has leaked away we start over.
I will keep studying

Dale

[DMOD]

Saw your post late in the game 

Here is another 813 design:

http://www.raibeam.com/zl1axb/813_amp.html

Phil - AC0OB

[KB7HTV]

I way overestimated my choke
I weighed the thing at 15 pounds not 30
measures 83 ohms across the terminals
my ohmmeter has a inductance setting said 23 henrys
finally drug it out and weighed it, where's the thordarson company when you need them

might work to isolate the secondary in the Mod transformer

any thought's, I need half an amp for my power supply

this is fun, I am having a blast guys, hey, ham radio this is where it's at
I need a swap meet, HTV

[KA2DZT]

Dale,

I'll wait for the ohm meter reading of the choke, don't forget to put up a pic if you can.

The meters are OK and maybe not OK.  Keep in mind that some meters have a faceplate that is not exactly what the meter movement really is.  You have to look close at the bottom of the faceplate to see if there is any other info.  It may say something like full scale = 1ma, which means the meter is really a 1ma meter that is used with external shunts to make it read the full scale current that is on the faceplate.  If you don't see any such notations then the meter reads directly the current that's on the faceplate.  Many volt meters have these types of notation on them.  Example, a 1000v meter may read, down at the bottom, "1000 ohms/volt", which tells you that you have to add your own external multiplying resistance, in this case 1megaohm in series with the meter.  The meter movement itself is a 1ma meter.  In most cases meters that read small currents and lower voltages (under 1KV) have these shunts and resistances inside the case.  Most all the movements alone are 1ma.

In my HB xmtr I use meters that came out of the military ART-13 xmtr.  The meter has a number of different scales on the faceplate.  At the bottom of the faceplate it reads full scale = 1ma.  I use four of these meters, along with other meters.  The 1ma meters are used to read many different currents and voltages.  With switches and the proper resistors one (1ma) meter can be made to read any number of voltages and currents.

In your schematic you have drawn meter shunts in your grid and screen circuits.  Problem is that your meters are not going to work with a shunt type circuit. (now you'll understand why I mentioned earlier having to discuss your metering circuits)

Your 300ma meter (if direct reading) will work fine to read the cathode current (through the filament xfmr CT) of the 813, you'll need another same to read the 811 current.

To read the grid current you'll need about a 20-25ma meter.  Your 100ma meter could be used but the grid current will read at the very low end of the scale.  The meter would be wired directly inline (no shunts) with the grid circuit.  The 10ma meter would also work but you would have to shunt it with a shunt resistor equal to the resistance of the meter.  It would then read 0-20ma. Meaning that, a 10ma scale reading would really be 20ma.  Problem with this is, measuring the exact resistance of the meter and then finding that exact value resistor to place across the meter terminals.

Reading the screen current will be more problematic and probably could be eliminated as it is not really needed.  With the correct size screen resistor dropping voltage from the plate voltage, the screen current will be within the correct amount and there is no practical way to adjust it anyway.  Metering the screen voltage is better but you need the correct meter to do this.

I"ll describe the step-start in another post, it's not difficult but you"ll need the right relays to do it.  I think you said you have a few 120vac relays.  Don't worry about the discharging of the filter caps.  That will happen rather quickly with the 813 and 811 drawing current.  It's the charging of the caps on startup that you have to think about.

Fred

[KA2DZT]

I way overestimated my choke
I weighed the thing at 15 pounds not 30
measures 83 ohms across the terminals
my ohmmeter has a inductance setting said 23 henrys
finally drug it out and weighed it, where's the thordarson company when you need them

might work to isolate the secondary in the Mod transformer

any thought's, I need half an amp for my power supply

this is fun, I am having a blast guys, hey, ham radio this is where it's at
I need a swap meet, HTV

Glad you're having a great time as we slave over trying to get you to build this xmtr and have it work when you're done

Kinda thought 30Lbs was a little high for a choke that has lead wires on it.  Usually, any of the big chokes have terminals.  Any model number anywhere on the choke??  Most any choke will read high inductance when there isn't any current flowing through it.