Ameritron AL-811 Repairs – Popping Noise

Boy, where to start on my Ameritron AL-811 repairs? It started a couple of months ago when I replaced the tubes.

I took the cover off, replaced the tubes and one of the meter bulbs went out. So I took the cover off again just to look at it and when I put the cover back on and fired it up, the other bulb went out! That's where the troubles began.

So I've been running it without lighted meters; it's not too bad, but I like the lights.

Just recently though I heard a popping noise coming from the amp. This needed immediate attention.

Ameritron AL-811 Repairs - CapacitorsAmeritron AL-811 Repairs - Capacitors

After checking the forums I decided to take a look at the capacitors and check for leaking or damage. I found one capacitor was leaking and ordered a replacement from Amazon. Total cost for one capacitor = $29.98 at Amazon. The picture on Amazon showed two, but that's not what I got and that's way too expensive. I found later the cost at MFJ is a lot better and even at RFParts.com. The shipping is a little high, but they still only come out to approx. $15 per cap if you order four.

I replaced the one that was leaking and what do you know? It still popped when I tested it. So I order 4 more capacitors at RFParts.com.

ameritorn al-811 repairs - blown capacitorI replaced all four capacitors and again the same popping. After taking the cover off and removing all of them I discovered one of them had blown. A brand new cap went bad.

Luckily I had an extra, so I put it in and got it working.

UPDATE: Eventually, I had to replace one of the bleeder resistors and I haven't had any problems since.

ameritron al-811 repairs - lampsAmeritron AL-811 Repairs - Bulbs

While I was waiting on the capacitors to arrive I ordered some  LED bulbs.

I just soldered one in and wedged it between the meters (See video).

Ameritron AL-811 Repairs - If It's Not One Thing It's Another

Just as I thought I had everything working, the fan started making noise. I blasted it with canned air and tightened the screws; so far so good.

Here's a clip I made so you can have a good look at it.

YouTube player

CAUTION!!
WORKING ON AMPS IS VERY DANGEROUS, PLEASE TAKE EXTREME CAUTION. FOLLOW AT YOUR OWN RISK. 

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

What's your experience with Ameritron amps? Thanks for coming by. Best wishes, 73 - Rich, K0PIR

K0PIR

I'm an Amateur Radio enthusiast. I love the hobby and experimenting with radios, antennas and software. On my YouTube channel I upload videos on the Icom 7300 and Icom 7610 along with Ham radio software programs. I hope to inspire people to try new things in Amateur Radio.

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Marc
6 years ago

Excellent YouTube video and website. I was wondering if you or anyone has had issues with this amp with the IP meter dancing around? I can touch the meter, wiggle it, and the needle dances around all over the place. If I rock it back and forth it will sometimes function normally. Any help would be appreciated. 73, Marc VA7MNM at Yahoo dot com.

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Tom Tobiassen
6 years ago

I just bought a brand new Ameritron AL-811 from the Denver HRO (4/2018) and, right out of the box, it’s making a loud snapping sound shortly after turning on the power. I sent a note to Ameritron tech support and they say it’s probably “one or more” of the HV filter caps but offer no help on a warranty repair. I’ll chat with HRO today.

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Tom Tobiassen
6 years ago

Hi Rich,
Thank you for your comments and for your service to our ham radio community! I dropped by my local HRO shop yesterday and since the unit was a recent purchase, they advised that I return it for another unit which I did. The new unit is working fine. The fan in the new unit is also much quieter. I heard from Rob at Ameritron and he offered to help me troubleshoot and send any necessary parts. In the end, I am satisfied with the amp and the extremely helpful service at HRO and Ameritron. The folks at the Denver HRO are awesome!
Best 73,
Tom, N0BZ

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Ken
6 years ago

I have an Ameritron Al811 and when I key mic it makes a buzzing sound what could be the problem ?

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Mike Gibbons
6 years ago

I have and 811H ..it’s making the same popping as yours was. What is the best way to discharge the 4 capacitors so they are safe to change?
Thanks
Mike
W4GIB

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Nicholas B
6 years ago

Can you share exactly what kind of LED you purchased from amazon. I am having a hard time finding a comparable LED

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Lee
1 year ago
Reply to  Nicholas B

You can also get different colors. I use red.

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Larry
5 years ago

HI Rich, Maybe you can help me with a question. I was recently given an AL-811 (not H). I am planning on selling or trading it so I opened it to see if it was clean inside before testing it. It looks great but there is a wire that was deliberately cut on the input board. Without taking it apart more I do not know what it does. Any ideas? I can send you a picture if you like.

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Jim Styck
3 years ago

KD5JDS back. I bought these LED’s. Should work, they are 5mm, 5volts to 15volts, internal resistor. Should work. LED Light Cool.
Jim

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James Forsythe
1 year ago

Have an 811h doing just the same thing,

what bleed resistors do i need and who would be the go to for them.

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Layne
9 months ago

Just setup my AL-811H with my FT-950 on FT8. There is a noticeable high pitch beep just before the transmit cycle ends. The pitch is about 2000 hz. It disappears when power is below 250 watts. Curious~
Layne AE1N
(see my QRZ page for a chuckle)(

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