Ameritron Al 811 Repairs - Popping, Bulbs, Fan
ฝัง
- เผยแพร่เมื่อ 7 ต.ค. 2016
- WARNING: Working on amplifiers is very dangerous, take extreme caution. Follow at your own risk.
Meter Bulbs, Capacitors And Fan
First it was the meter bulbs that burned out, then the amp started making a popping noise. After fixing those items finally the fan began to make noise.
I have it together now and back on the air.
See my website for all of the details: www.k0pir.us/ameritron-al-811-...
UPDATE: I eventually had to replaced one of the bleeder resistors.
WARNING!!
DO NOT ATTEMPT TO PUT THIS AMPLIFIER IN SERVICE WITH THE COVER REMOVED!
CONTACT WITH VOLTAGES INSIDE THIS AMPLIFIER CAN BE FATAL! ALWAYS
DISCONNECT THE AMPLIFIER FROM THE POWER MAINS AND WAIT FOR THE FILTER
CAPACITORS TO DISCHARGE BEFORE REMOVING THE COVER.
As an added precaution: Remove the cover and connect a jumper wire from ground to the
anode connection of the tubes.
Thanks for watching, bet of luck, 73. - Rich, K0PIR - วิทยาศาสตร์และเทคโนโลยี
The 50 k bleeder resistors checked out good.
u have a bad bleeder resistor.mine drains the caps in a little under 30seconds .
Dude, you have one or more open bleeder resistors. First the resistor goes bad then it ruins the cap. If you realize the resistor is bad and replace it right away the caps will not go bad. The first inkling the resistor (s) are bad is that the HV does not bleed down to zero rather quickly. If the HV meter hangs up at the bottom and holds voltage for more than normal bleed time, you have bad bleeder(s).
Hi Lou, Nice to hear from you and you nailed it. Look at my website, thanks for the input. Best 73 - Rich, K0PIR
@KG2RG It's nice to hear from you and thank you for commenting. It is www.k0pir.us Vry73!
very nice suggestion 👍🏻
Have you had any problems with noise from the led light you installed? I tried to go the the link you had but no longer works,
Great question and no problems with noise. Look for miniature LED 12v bulbs. I'll try and update the link. Thanks for the heads up! 73 de K0PIR
I had the 811H version of this amplifier. I ended up trading it in after three years because of the problems I was having. I got an Alpin 100 mk3, which is far better!
Thank you for commenting. Initially mine had some problems, but it has been good to me for years now. They have poor quality control at Ameritron. I would love to have an Alpin, maybe someday. Best 73's - Rich, K0PIR
I have a Amertron 811 (3 tubes) and for some reason the amp started blowing the two 12 amp fuses. I replaced the the 3 tubes and made one short contact. Everything looked ok. HV ok and 60 ma idle current ok. After running for about 5 minutes after the one contact the fuses blew again. I wasn't keying the mic or anything. I heard the fan stopped running because the amp had shut down. I think that I should replace the caps like you did. Also, I read where the D1 diode goes bad - if I can locate it. Please give me your opinion.
Hi Jack, It’s great to hear from you and thank you for commenting. Good to hear from you and thanks for commenting. First, the voltages and currents in there are Lethal! I just had to get that out of the way. I would suspect a bad tube blowing the fuse but you already replaced them. I called Ameritron tech support and they were helpful troubleshooting mine. I would call them and they can also tell you exactly where D1 is because I don’t see it. Another good source is Groups.io see groups.io/g/MFJSHM GL and stay safe. 73 and good DX!
Just a note about the bulbs. To give them longer life, place a five ohm resistor on each one positive wire. OR better solution, use a ninety ohm resistor with your choice of LED colored lamp replacements The LEDs make it pretty. That's all. Plate current / voltage meter is blue. Grid current meter is a very pretty violet. Still, dollar for dollar, the cheapest and the very best amp out there for mid level RF power.
Thank you for the info!
are you using an inrush-controlling device when you turn on the AMP?
what brand and voltage of the Fan are you using?
Sorry for the delay. I didn’t see this and now I’m on the road traveling. I got my fan from Ameritron and don’t have the specifics, but they were very helpful. 73 and good DX!
Can you put a link for the LED bulbs? I bought this amp used... The guy said it was in perfect order... Both the Fan & Bulbs are busted!
These are the ones I got. amzn.to/2Cme2p0
Brighter than the originals, but I am used to them now. They have been working good for years. You can see more here: www.k0pir.us/ameritron-al-811-repairs/
Thanks for commenting Nicolas, best 73 - Rich, K0PIR
@@HamRadioAdventures Hey Rich. Commenting 2 years later here. That link to the Amazon LED bulb is broken now. Any way you could provide a new link to the LED bulb you used? Just picked up an older 811H and one of the meter lights is burned out. Thanks so much!
Thanks for the video. Where did you purchase your replacement capacitors? Thanks. Bob KE0JNC
Hi Bob, good to hear from you and thank you for commenting here. I got those at MFJ. Good luck, good DX and best 73!
@@HamRadioAdventures Thanks for the prompt response. I also am planning on replacing the bleeder resistors. MFJ as well? 73
@@bobrademaker6842 RR
Mine has a grid current of 0, the plate current is low. No popping noise. The lamp in the center is not working. what is wrong?
HI, thanks for watching and thanks for commenting. You'd better head over to the Ameritron forum and they can help you troubleshoot it. groups.yahoo.com/neo/groups/Ameritron-Amps/info
73,Rich, K0PIR
Merry Christmas! See ya on 40 meters. The problem was simple, 1 tube was blown, another tube was shorted, and the other was fine. I ordered all new tubes from ebay.
@@letitrotfuckit That's awesome I love it when it's something easy. Congrats on the amp!
I had a friend very recently who got electrocuted working on his amp. It was a good reminder to me to be very careful.
Best to you and yours, 73 - Rich, K0PIR
@@HamRadioAdventures Update: I got it to work, 30 watts drive, 400-500 watts out. After three hours of operation, the reason why it would not start revealed itself, the capacitor between the board on the tall vertical coil in the center, and the board with the big horizontal coil and knobs started to smoke. Do you know what part this is?
How long did you have it before the problems?
Hi Tim, it was at least a few years. Probably four or five. Thanks for watching take care and best 73!
@@HamRadioAdventures Great. I just got a 811H and it is humming along great my first and last amp. Been Ham since 65 I am getting real old.....he he.
Can I transmit in 11 meters with this amplifier? 73
Hi Sergio,
Nice to hear from you, no, this one is not capable of 11meters that I know of. In the US it would not be legal for that operation.
It is capable of 10 meters! Best 73! - Rich, K0PIR
yes you can
Looks like the cap shown in front while they were out is about to pop. The bleeders are 50K and would drain the HV pretty quick. Overall, a decent amp - If it works. I bought one new that self-oscillated on the 20/30M setting. I ended up cannibalizing it. The second one performs flawlessly.
I have a strange fault on mine where the high tension voltage is only reading about 800v instead of 1.6kv , that said it works totally , haven't worked out why so far.
When the METER switch is in the HV position, what does Plate Voltage read? Mine is almost 1.8KV.
It reads about 650v then after it warms it seems to rise up to 700v .
I tried a tune on 20m today and it gave about 500-550w with 60w -65w drive so it certainly works ok.
I took the time to check the meter associated resistors in the vicinity of the meter, they all seem to be ok, R6-11 i checked. I'm wondering whether it could be a tube? the anodes on 2 are not good and burned through. Faster tuning up needed ;-)
Yeah that's a good question. If the meter was jumping and you hear some popping I would say capacitors, but if it holds steady idk. I got a set of Alpha tubes for mine at www.rkrdesignsllc.com/products/transmitting-tubes/matched-triple-three-811a-tubes-glass-triode/
found the fault , it was R6, instead of reading 1M ohm it was actually reading 18.5M ohm, it fooled me because it read 1.25M ohm in circuit and only shown it's true resistance once I lifted a leg out.
That's the way to do it. Thanks for returning and commenting. I got some of those resistors from MFJ, the shipping was about $14, so I ordered some more small stuff. I got a fan too because mine is starting to make noise and will have to be replaced someday soon. Best 73 - Rich
Be sure to visit my website for more important information on this. k0pir.us/ameritron-al-811-repairs/
I'm sorry I bought mine, it's a POS, lasted one month and popped very loud. I thought my bookshelf fell over. Replaced all my caps and it still blows both fuses in the back, what a piece of crap.
Yeah, I don't think you are alone. FWIW, I don't remember if I mentioned it but, I had to go through and re-solder some of it. The band switch was causing problems when I first got this amp. I eventually had to replace the bleeder resistors above the caps. It's been good to me for almost a year now.