Al811mod.jpg, 80698,, Ameritron AL-811 Amp Mod for 10M. Allband.txt, 2936,, ICOM IC-2AT, IC-02AT Mods. Alr22t.txt, 2203,, Extended frequency rx and tx of the ALR22T & ALR22HT. Aor1500.txt, 16908,, Review: AOR AR-1500 handheld scanner. Aor300pr.txt, 1361, 10-29-. Ameritron als 600 als 500m 10 meter modification. This resource is listed under Radio Equipment/HF Amplifiers/Ameritron ALS-600, at Ameritron ALS-600 ALS-500 10 m mod resource page via dxzone.com ham radio guide.
I have a Ameritron AL-811 that has been converted to use 572B tubes. When I got it it would only do 100 watts so I replaced the tubes, let it sit on stand by for a day and then it would do 800 watts for a while.
But after a little while it would start dropping off on power so I let it sit on stand by for several days and everytime I checked it it would be doing less power and now it only does about 80 watts. So does it make sense that it could go through tubes just sitting on stand? And why would it do that? Could it be that the power supply voltage is too high? I think the voltage sits around 1800 volts according to the meter, but I'd have to check to make sure.
The 572b tubes are a very durable transmitting tube. You have to be very mean to them to make them go south. 1800 volts is probably the minimum you would want to run them at, they run better at around 2500. Check your idling current on the plates. To do this key the amplifier with no carrier or RF input.
You should see around 90 milliamps of current. Then check the current at full output. Autodesk Maya 2013 64 Bit Crack Free Download more. You should see about 500 milliamps, which is a reference which you should not exceed. Watch the high voltage at full out and make sure it is not dropping to low, 300-400 volts drop is about right depending on how stout the transformer is. These are all things to look for if your amp is working normally.
Maybe some else will jump in with some other pointers too. 73 Ed KC0PZE. With 1800 volts and 500mA plate current those 572B's should show no color on the plates whatsoever under keydown conditions.In standby mode they should last a lifetime.As Ed said,check the bias.If it is too high the tubes will draw too much current but should still not be damaged.I would be suspicious of something in the power supply causing a drop in plate voltage but it must be awfully low to cause only 60-80 watts output.How many watts are you driving it with and is it being tuned and loaded properly?