My 811H did that about a month after I got it and it was a bad tube. After changing fuses I put in one tube at a time until it popped again and found the bad one. Has been fine since.
This happened to me just a month ago and it was a tube gone bad. Tested each tube one at a time to see if amp would turn on and it did until I got to the bad tube. I think I need to change out D16 diode now. Ameritron sent me one but with no instructions.
I have the amertron 811 and it kept blowing fuses found out i had a bad tube so i replaced my 811 tubes with 572b tubes everything works fine but now i cant get any power out when i transmit. Can anyone here tell me whats going on with the amp please?
Not a good idea to power up a device that has been blowing fuses, regardless as to whether the fuse may have been a little off; quite often you will end up creating a cascade of failures. Instead, do a visual inspection of the circuits at minimum, and even a cursory component level check with a meter. Plus, test and/or try a different set of tubes.
Why do you have an antenna tuner after a tube amp that already has an antenna tuner built in? Ive never tried that but, I have a few antenna tuners, so why not put them in series and see what happens.
You must be a newcomer or uninformed. No tube amp I'm aware of has an "antenna tuner" onboard. Many have a pi net output network that is somewhat wide ranging, but still nowhere near not wide enough for some antenna systems such as ladder line fed. Read up. Do some research. Running a tuner as the last box in the line before antenna is VERY common and accepted practice. I myself run a multi band, ladder line fed antenna. The Z of that varies greatly. I was first licensed in 1965 and am 75. I've built or modified and repaired several amps all the way from 811's to 4-1000A and 8877
@@fourfortyroadrunner6701 Nope. As long as your SWR is reasonable (less than about 3:1) the pi network in most tube amps will handle this 'mismatch' without needing an external tuner. But if you're running a G5RV, a random wire, or a big loop, then yeah, an antenna tuner is probably needed. But like everything else in this hobby, 'it depends'. There are very few absolutes.
Thank you Kent. I had 2 811A’s go out in mine and I had a fuse blow. 73’s Jeff, AJ4PL
My 811H did that about a month after I got it and it was a bad tube. After changing fuses I put in one tube at a time until it popped again and found the bad one. Has been fine since.
Have fun with it so far mine has been going fine now for over a years love it.@goinghomesomeday1
This happened to me just a month ago and it was a tube gone bad. Tested each tube one at a time to see if amp would turn on and it did until I got to the bad tube. I think I need to change out D16 diode now. Ameritron sent me one but with no instructions.
D16 is a high-voltage (1KV) rectifier that provides DC power to the meters. D16 a 1N4007 diode, if you have the right designation.
Popped your QRP amp hey Kent!!😅
Test till you see the magic smoke!
W4KG
Figured the QRP king would chime in. Ha!!!
I have the amertron 811 and it kept blowing fuses found out i had a bad tube so i replaced my 811 tubes with 572b tubes everything works fine but now i cant get any power out when i transmit. Can anyone here tell me whats going on with the amp please?
Not a good idea to power up a device that has been blowing fuses, regardless as to whether the fuse may have been a little off; quite often you will end up creating a cascade of failures. Instead, do a visual inspection of the circuits at minimum, and even a cursory component level check with a meter. Plus, test and/or try a different set of tubes.
Why do you have an antenna tuner after a tube amp that already has an antenna tuner built in? Ive never tried that but, I have a few antenna tuners, so why not put them in series and see what
happens.
You must be a newcomer or uninformed. No tube amp I'm aware of has an "antenna tuner" onboard. Many have a pi net output network that is somewhat wide ranging, but still nowhere near not wide enough for some antenna systems such as ladder line fed. Read up. Do some research. Running a tuner as the last box in the line before antenna is VERY common and accepted practice. I myself run a multi band, ladder line fed antenna. The Z of that varies greatly. I was first licensed in 1965 and am 75. I've built or modified and repaired several amps all the way from 811's to 4-1000A and 8877
@@fourfortyroadrunner6701 Nope. As long as your SWR is reasonable (less than about 3:1) the pi network in most tube amps will handle this 'mismatch' without needing an external tuner. But if you're running a G5RV, a random wire, or a big loop, then yeah, an antenna tuner is probably needed. But like everything else in this hobby, 'it depends'. There are very few absolutes.
But why did it fail the first time? The light did flash when first power on..but I think that is normal.
When you turn the amplifier off you do not let the tubes cool first? Just wondering .73 AE4OY William Peacock 🦚 EM-81UF SOUTH EAST GEORGIA
Hello William. No. Have never done that.