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