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Author Topic: Ameritron AL-800 or Acom 1000?  (Read 55957 times)
PA3HGT
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« Reply #45 on: February 21, 2016, 10:27:59 AM »

You have to produce 4 times more power to get 1 s-unit better....so the difference is minimal between 1 Km and 1,5 Kw but all slight changes will help.

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KK4YDR
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Posts: 673




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« Reply #46 on: February 22, 2016, 05:28:08 PM »

Ameritron/MFJ will send you the amateur band modification instructions if you send them a request with a copy of your license.

Regarding input attenuation, recall that part 97 FCC regulations limit the gain of a commercial amplifier to no more than 15 dB. However, for 26-28 MHz, the maximum gain is 0 db. So the input attenuation has nothing to do with CB use of the amp as has been suggested. It is more likely there to protect the amp's input circuits or final(s) and keep your transmitter in a preferred operating range.

The internal attenuator is preferable to substantially turning down the output power of the transmitter since many transmitters have significant ALC overshoot when their RF output power is dialed back by 50% or more. This can negatively impact IM metrics and cause increased amplifier transients. A good target range in which to operate your transmitter is 70-80% output when driving the amplifier.

So before you bypass the attenuator, make sure you know the characteristics of your transceiver - a few radios exhibit good ALC behavior at significantly reduced output but most do not.

- Glenn W9IQ

Yeah, I talked to MFJ on the phone. We had a great conversation. At least 20 mins. We did discuss that the intent of the attenuator has absolutely nothing to do with CB prevention. Ameritron could care less about what CB or HAM buys their amplifier. They are in a business of making money. The circuit was installed in order to protect both the amplifier as well as the exciter. So my questions were answered both here (Thanks!) and by MFJ directly. This is a good thread for others to come across during a search though for similar or this particular scenario.
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W4RS
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Posts: 107




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« Reply #47 on: February 28, 2016, 02:23:52 PM »

ok, let me add my 2 cents worth here. I have a al800 it is now abt 20 years old. same tube, same everything. it does what it does very well. it take 3 min to warm up, that is not a problem, it makes power Easley. it does all I want it to do. and I can fix every part in it!
I can get any part I need from ameritron or other sources.
I am in the Philippines so the voltage is not that stable here. the amp has been in the station here for 16 years. still doing well.
I bought it new, put it in a box shipped it here, and plugged it in. I use it with a ft 1000mp and a ic-7200. both drive it well.
its a good solid amp, not fancy, and a few time I have tried to load it in the wrong bandswitch pos, and the grid protection tripped. reset and moved it to where it was suppose to be, and it worked.
about all I can say abt it.
jim du3jh  /  w4rs
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K6CKD
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Posts: 169




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« Reply #48 on: March 10, 2016, 09:37:17 AM »

The AL-800 is the Volkswagen of the ham world.   Parts are plentiful.  Customer service is good and the price is right. Use it for five years or so and you can sell it and get your money back.
Another good investment are the Collins 30L-1s. Lots of them around with the cheap 811As.   Key down on the AL-800 about 1 KW.  Key down on a 30L-1,  about 700 watts.  Both do well on a 120 VAC socket or 230 VAC. Can go wrong. I have both and also an AL-800H and 2 AL-1500s.
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W8JX
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« Reply #49 on: March 10, 2016, 04:30:11 PM »

The AL-800 is the Volkswagen of the ham world.   Parts are plentiful.  Customer service is good and the price is right. Use it for five years or so and you can sell it and get your money back.
Another good investment are the Collins 30L-1s. Lots of them around with the cheap 811As.   Key down on the AL-800 about 1 KW.  Key down on a 30L-1,  about 700 watts.  Both do well on a 120 VAC socket or 230 VAC. Can go wrong. I have both and also an AL-800H and 2 AL-1500s.

You will not get 700 out key down for long on a 30L-1 before plates melt and good 811's are not cheap either. A good SB 200 would be a better bet for the money.
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--------------------------------------
Ham since 1969....  Old School 20wpm REAL Extra Class..
K6CKD
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Posts: 169




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« Reply #50 on: March 12, 2016, 07:21:51 AM »

http://www.ebay.com/itm/MATCHED-QUAD-4-MACHLETT-811A-TUBES-/161776427644?hash=item25aaa0627c:g:w3cAAOSw0vBUedl7

Four 811As,  NEW,  Matched,  115.00 for all four  One year full warranty

Where I live,  that is a cheap price to replace all four tubes in the final. Respectfully,  In some parts of the USA that may seem like a lot of money.  I apologize for that error.
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KK4YDR
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Posts: 673




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« Reply #51 on: March 12, 2016, 12:23:49 PM »

I absolutely love my AL-800H. Out of all the legal limit amplifiers on the market this is the one I settled on the most. It will blow some heat. Do not be fooled, those 3cx800A7s are space heaters on long keydown but they are a lot tougher than people give them credit. For instance on 20 meters at 45 watts with about a 35-40ma Ig I can hit 1850-1900 watts. It is ridiculous. I drop the drive down to around 25 and am getting 12-1300 out no problem on 20 meters. 80 meters I get just a tad bit less with a little more drive it compensates. I am very impressed with the amplifier. And the build quality is also very nice. (troll away MFJ/Ameritron haters).

I honestly tend to run my tubes around 750-1000w range PEP rag chewing on 75 meters, most bands for that matter, and the grid needle barely pulsates off the zero mark. The size of the AL-800H is not much larger than an AL-811 3 tuber, yet it can absolutely blow the AL-811 out of the water in performance.
« Last Edit: March 12, 2016, 12:26:15 PM by KK4YDR » Logged
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