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- เผยแพร่เมื่อ 1 ม.ค. 2021
- I just wanted to make a quick video showing the tune up process for the Ameritron AL-811H. This tune up process should be the same for most other tube type amplifiers but consult your manual to be sure.
- วิทยาศาสตร์และเทคโนโลยี
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It helps to set the knobs as per instruction manual it really helps and speeds up the tuning Thank goodness for PEP meters they make me feel better.
This is the best tune video I've seem on the 811. Great job.
Thank you!
Very Good instructions
Your sweeping from load to plate to aggressively..the amp exspecialy the 811 can be over heated fast at loading ... U want to couple ... And you can also over couple quickly .. it's a very very good idea to mark your load indicator for each band o do this so I can pre set the cap
I have watched several of these "tune up" videos, and this one is the best. Good job and 73 👍
Thank you for the kind words! I'm glad you like it :)
that ameritron pa does 600watt with 572b tubes, those simply replace the 811 tubes. when signals are weak, the 600watt can make a difference to 450watt.
Thanks for a very informative video, I found the tip about increasing the load to bring down the grid current very useful. I bought mine 2nd hand off Ebay a few years ago and it arrived with a fault, either the load or plate capacitor was shorting out but I was able to bend the the plates slightly to cure it. My amp is very noisy compared to yours, the fan seems to be very loud and fairly obtrusive, in fact yesterday a station mentioned that he could hear it running in the background. Do you have any tips or suggestions how to make it quieter please? I placed it on a sound absorbent pad which helped slightly. I assumed they were all pretty loud not having any previous experience.
Slight correction its not fan noise it appears to be hum from probably the mains transformer?
I think you should make that video a little darker
I have an 811 amp with a foot switch I made from an old straight key. Ive been holding the straight key down to key the amp, and pressing the PTT in RTTY mode to send a carrier while tuning the amp.
Am I doing this right?
The comet cn901 can be opened and calibrated against a bird meter etc. Is the MFJ 891 like that?
From 4:48 to 5:07 you keyed up the Amp for 19 seconds. I agree that tuning should be perhaps in the 7 or 8 second range maximum as it's very hard on the tubes and I always wait at least 10 seconds between each attempt Were you not concerned when you were tuning it for that length of time?
I agree and generally try to keep it to about 5 seconds. Since I was tuning into a dummy load and the amp was already pretty close to being right on I wasn't as concerned. I wouldn't recommend doing it that long on a regular basis by any means.
I have a tube linear. In order to tune mine, I set the band, then adjust the bottom knob lower, while sweeping the top knob for maximum power. I think that you are likely using the wrong procedure.
The procedure I use is the same that is described in the manual from the manufacturer.
You saving on hydro
Why you go back and forth so many times between load and plate is a bit puzzling to me. The primary cause of 811a tube failure is heat caused by over tuning
Because each adjustment has an effect on the other one. Once you know where it needs to be set on each band you can write it down and tune to it right away. Initially though it may take a few adjustments of each capacitor to get it dialed in. As long as you only key up for a few seconds and let them cool down in between they will be fine.
800w output doesn’t seem possible… if you’re pushing it that hard, the 811 tubes will be ruined. maybe with the 572 tubes because the tolerate higher current.
AND the 1000w 🤨
Its all about the duty cycle. the amp will produce more then 800 watts pep but for how long before the anodes glow red is the limiting factor.
With all respect I completely disagree with how your running this amp ....
Agreed. This video should be disregarded as it is incorrect. The proper way is using the Grid current meter to get to max PO without excessive Grid current. What kills triodes operating AB1 in grounded grid, is excessive grid current, so this is what must be used (the right meter). . The correct tune up procedure is best demonstrated by Tom, W8JI, the designer of the AL-811 series amps. He shows how to quickly and properly tune the AL-811H in just a few secs using the Ig meter, which avoids excessive tune up time, risking tube damage, as was done here.
See his video here: th-cam.com/video/ptWD2dTRi0g/w-d-xo.html