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Ameritron 811h

Discussion in 'Amplifiers' started by 552fl, Sep 29, 2019.

  1. 543_Dallas

    543_Dallas Sr. Member

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    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.
     

  2. 552fl

    552fl Active Member

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    no foot pedal,,no more ,,wolf installed keying circuit.. in the 811-h for me,,just like the sb220 now,$65.00 well spent..
     
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  3. 543_Dallas

    543_Dallas Sr. Member

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    Did he have to tear the front apart to install a ssb delay switch or something?
     
  4. Tallman

    Tallman W9WDX Amateur Radio Member, KW4YJ EXTRA class

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    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.
     
    #19 Tallman, Nov 19, 2019
    Last edited: Nov 19, 2019
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  5. BJ radionut

    BJ radionut Supporting Member and 6m addict

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    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.
     
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  6. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    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. :(
     
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  7. Ranch55

    Ranch55 Sr. Member

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    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.
     
  8. 543_Dallas

    543_Dallas Sr. Member

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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.
     
  9. 2NC995

    2NC995 DAN

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    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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  10. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    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.
     
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  11. 543_Dallas

    543_Dallas Sr. Member

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    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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  12. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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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
     
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  13. 2NC995

    2NC995 DAN

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    That’s a long way from an 811!

    Nice!
     
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  14. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    My plate transformer alone weighs MORE than THREE times what an entire AL-811H weighs. :) 105 pounds versus 32 pounds for an AL-811H. :LOL:
     
    #29 Captain Kilowatt, Nov 20, 2019
    Last edited: Nov 20, 2019
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  15. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    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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