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Ameritron 811h

It may have been said already but when you change an amp from 120 to 240 don't forget to change the fuses in the amp.

If at all possible I run amps on 240. In many situations the 120v circuit is already powering the radio, lights, and everything else in the room. Depending on how the house is wired there might be other rooms drawing from the same circuit.

I've always had my mono band stuff out in the garage to keep the blower noise and heat out of the house. If you have a 240v plug out there already it's easy to remotely locate an amp. Watt meters like the palstar 2000am, ameritron awm35 or a bird line section and cheap coax will let you keep an eye on things. Tuning up a tube amp can be tricky but not impossible.
 
So long as your 120-Volt outlet is no more than 8 or 10 feet from the breaker box, wired with number 12 wire you're probably okay. Any farther than that, or if the outlet is fed with #14 wire and you'll get voltage sag under load. The biggest wire it's legal to use for a 120-Volt outlet is number 12.
73

Well I guess I better go get my electrician arrested! I designed the electrical in my garage/ham shack and I specified 10 ga to be used through out the entire building and on the outlets. He kept telling me 10ga was not needed and I said only if you want to get paid! I have two air compressors, and two vacuum cleaners that I use to run my sandblasting cabinet..The vacs clear the atmosphere inside the cabinet so I can see what I am doing. The dual air compressors is for the volume of air needed for sand blasting. They were given to me because they were broken and not working.
I can easily convert any one of those plugs to 220 volt because the are on separate circuits.
 
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So long as your 120-Volt outlet is no more than 8 or 10 feet from the breaker box, wired with number 12 wire you're probably okay. Any farther than that, or if the outlet is fed with #14 wire and you'll get voltage sag under load. The biggest wire it's legal to use for a 120-Volt outlet is number 12.

NOMAD: I think you meant to say. The standard Single outlet or Duplex outlet for home use is rated at either 15 or 20 amp max.
The 15 amp receptacle looks like this: minimum wire size #14 copper
15 amp receptacle.jpg

The 20 amp receptacle looks like this: minimum wire size #12 copper
20 amp receptacle.jpg
You can have larger wire to either, say #10 to minimize the voltage drop to code acceptance.
The distance from the distribution panel is the key to this.
However, what I believe NOMADE made the reference to was this.
Regardless of the wire size the maximum BREAKER size for a 15 amp outlet is 15 AMP!
Same true for the 20 amp outlet, regardless of wire size the maximum BREAKER size to feed that outlet can be NO LARGER than a 20 amp!
There certainly are 120-volt circuits that can be greater than 20 amp capacity.
These, however, require different receptacles. One example 30 amp/120 volt RV outlet, where you wish to keep your RV charged and hooked up at home.
Again by code, this requires at least #10 copper wire and a specific receptacle RATED for that service load plus the correct single pole 30 amp breaker.
However, it is never acceptable to say have 2/20 amp outlets and have a 30 or 40 amp breaker to protect them. Overload, Meltdown or eventually FIRE will occur.
The insurance carrier will most certainly DENY any claim associated with that occurrence, which could be your entire home!
All the Best
Gary

PS: It should be noted now the US NEC FIRE Code now requires a maximum continuous load on a 20 amp receptacle or circuit be NO LARGER than 16 amps.
A good example of this is two or more devices say space heaters totaling greater than 1900 watts, these CAN NOT be plugged into the same receptacle or on the same circuit controlled by a single 20 amp breaker.
The 15 amp receptacle or circuit load limit total is 1440 watts continuous.
 
It may have been said already but when you change an amp from 120 to 240 don't forget to change the fuses in the amp.

If at all possible I run amps on 240. In many situations the 120v circuit is already powering the radio, lights, and everything else in the room. Depending on how the house is wired there might be other rooms drawing from the same circuit.

I've always had my mono band stuff out in the garage to keep the blower noise and heat out of the house. If you have a 240v plug out there already it's easy to remotely locate an amp. Watt meters like the palstar 2000am, ameritron awm35 or a bird line section and cheap coax will let you keep an eye on things. Tuning up a tube amp can be tricky but not impossible.

When I built my own home 30 years ago I specifically wanted a dedicated 240 volt duplex outlet for the eventual addition of an amplifier. My shack is located directly above the breaker panel in the basement. Sadly I am still waiting for the addition of that amp. :(
 
When I built my home 7 years ago, I had the electrician do the following for my radio room,
1) ..... One dedicated 240v 40 amp circuit
2) ..... One dedicated 240v 30 amp circuit
3) ..... One dedicated 120v 30 amp circuit
4) ..... Two dedicated 120v 20 amp quad outlets, each on it's own breaker

I do not have any 15 amp 120v outlets in my house.
I do not have any 15 amp breakers in my panel.
The smallest wire in my house is 12 gauge.
All the outlets in my house are 20 amp quad outlets.
And each room is on it's own breaker.

Glad I did and have never regretted it.
 
When I built my own home 30 years ago I specifically wanted a dedicated 240 volt duplex outlet for the eventual addition of an amplifier. My shack is located directly above the breaker panel in the basement. Sadly I am still waiting for the addition of that amp. :(

Good thinking. I plan to start building the cabinet for my 3000 soon. I found out rack mount cabinets are ridiculously expensive. The thing might weigh 400 lbs when I'm done....I hope. I'm going to put it on 75m and leave room for a band switch later. It should be good for a clean 1500 watts.
 
NOMAD: I think you meant to say. The standard Single outlet or Duplex outlet for home use is rated at either 15 or 20 amp max.
The 15 amp receptacle looks like this: minimum wire size #14 copper
View attachment 31968

The 20 amp receptacle looks like this: minimum wire size #12 copper
View attachment 31969
You can have larger wire to either, say #10 to minimize the voltage drop to code acceptance.
The distance from the distribution panel is the key to this.
However, what I believe NOMADE made the reference to was this.
Regardless of the wire size the maximum BREAKER size for a 15 amp outlet is 15 AMP!
Same true for the 20 amp outlet, regardless of wire size the maximum BREAKER size to feed that outlet can be NO LARGER than a 20 amp!
There certainly are 120-volt circuits that can be greater than 20 amp capacity.
These, however, require different receptacles. One example 30 amp/120 volt RV outlet, where you wish to keep your RV charged and hooked up at home.
Again by code, this requires at least #10 copper wire and a specific receptacle RATED for that service load plus the correct single pole 30 amp breaker.
However, it is never acceptable to say have 2/20 amp outlets and have a 30 or 40 amp breaker to protect them. Overload, Meltdown or eventually FIRE will occur.
The insurance carrier will most certainly DENY any claim associated with that occurrence, which could be your entire home!
All the Best
Gary

PS: It should be noted now the US NEC FIRE Code now requires a maximum continuous load on a 20 amp receptacle or circuit be NO LARGER than 16 amps.
A good example of this is two or more devices say space heaters totaling greater than 1900 watts, these CAN NOT be plugged into the same receptacle or on the same circuit controlled by a single 20 amp breaker.
The 15 amp receptacle or circuit load limit total is 1440 watts continuous.

I’d add, also, that you can’t tell a circuit rating by looking at a receptacle, because the NEC allows 15amp receptacles on 20 amp multiple outlet branch branch circuits (but not on a 20amp individual branch circuit).

Seperate from the continuous load requirements, a single 20 amp receptacle on a multiple outlet branch circuit can only supply a total load of 16 amps - whether a continuous load or not. In other words, a single device that draws over 16 amps should be on an individual branch circuit.
 
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Good thinking. I plan to start building the cabinet for my 3000 soon. I found out rack mount cabinets are ridiculously expensive. The thing might weigh 400 lbs when I'm done....I hope. I'm going to put it on 75m and leave room for a band switch later. It should be good for a clean 1500 watts.

I've started on my 3CX3000A7 amp project but so far only have the power supply built. It has a variac on the plate AND filament supplies and will provide 4500 volts with 55 uF of filtering. It also has step-start on the plate supply. I am building it in a 48 inch high Hammond cabinet on wheels. So far just the power supply and cabinet weigh around 215 pounds.
 
I've started on my 3CX3000A7 amp project but so far only have the power supply built. It has a variac on the plate AND filament supplies and will provide 4500 volts with 55 uF of filtering. It also has step-start on the plate supply. I am building it in a 48 inch high Hammond cabinet on wheels. So far just the power supply and cabinet weigh around 215 pounds.

I'm going for a similar size cabinet. I'm going to frame it out of 1.25" angle and sheet metal sides. I will put the sheet steel inside the frame so the angle serves as trim too. The angle will be equal thicknesses to the rack panels so the can sit flush. I hope ot turns out as good as it looks in my head.

The plate iron is 3500vac at 2.5 amps, 109 lbs. I'm not going to mess with a variac but definitely a soft start. 112 uf of filter is probably too much but it was a good deal I don't want any regrets. Got to find a good glitch resistor.

The rf deck will be in a rack mount enclosure with the blower right under the toob. I'm going to try to set it up so the blower pulls a draft across the bleeders.

I do like the idea of a variac on the filament. That way you can bring it up slowly and not have the inrush beat on the filament. Mr bbi built a 3000 and was so proud of the overkill filament transformer he used so the owner could run a 6000. That's one area that overkill is not good.
 
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Cabinet with power supply at the bottom and meter panel.

20170220_162918.jpg


Plate and filament supplies with control relays for each. On the right is a Corcom line filter and the yellow thing on the left is a solid state timer for the plate supply. The HV cannot be turned on until the filament has been lit for a predetermined amount of time. 30 seconds is PLENTY of time since the 3CX3000A7 is almost instant on.

20170211_214722.jpg



My rectifiers. 20Kv at 30 amps forward. Four of these in a bridge configuration. Overkill only begins to describe them. LOL
20161125_122328.jpg


Close up of the meter panel. At least all the meters match.
20170220_161713.jpg


It should be finished by the time I retire in 2028. o_O
 
I do like the idea of a variac on the filament. That way you can bring it up slowly and not have the inrush beat on the filament. Mr bbi built a 3000 and was so proud of the overkill filament transformer he used so the owner could run a 6000. That's one area that overkill is not good.

Good point about oversizing the filament transformer. Filament transformers are designed to be run pretty much at full current load ratings. The inrush current basically saturates the core and provides a sort of self limiting current surge protection. Using a transformer with a much higher rating will cause much higher than normal surge currents in the filament leading to shorter life.
 
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