Ameritron Amplifier AL-811 Instructions Have MANY MISTAKES About Tuning As Shown By Jim Heath W6LG
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- Опубліковано 21 сер 2024
- In reviewing just one page of an Ameritron Amplifier Instruction Manual for the AL-811HD, there were many mistakes including grammar and how to tune that Jim Heath W6LG found. Jim offers an improved way to correctly tune an Ameritron Amplifier. As an example, Ameritron refers to XMIT, XMT and XTM for the same control that is labelled XMT. You know, it could simple have Transmit! The manual also discusses tuning up your exciter's load and plate controls. Most of us do not have a plate and load control on an exciter (transmitter). We mostly have transceivers that are no tune.
I really like how you correct the grammar in the manual. We need more people like you!
I have written Standard Operating Procedures for pharmaceutical manufacturing and sterile operations for most of my forty-year career. Like you, I am surprised at the obtuse and error-filled instructions for this instrument. Even if English is not one's first language, there are people who write and proofread for a living who could offer help. Thanks!
Thank you for doing this. I'm a new general and don't have an elmer. Without you and the UA-cam crew, I'd be lost.
Glad I could help. I hope to hear you on 20 meters soon. 73, Jim W6LG
I just viewed this video. Thanks for posting. I’ve had an AL811H for a few years, but I rarely use an amp. But, during the times that I did use it, using the supplied tuning instructions, I always ended up hoping it was correct and saw jittery meters. I tuned the amp this evening after viewing, presetting the load and plate, then starting the process at 20 watts and stepped up through the 20 watt steps. All bands tuned smoothly and the process was so smooth. Metering looked great, not sudden jumps or strange readings. These are good amps, just take care of the 811’s. I feel certain that this new tuning procedure will add life to my amp. Thanks! KE8EC.
Excellent. Tubes will become even more expensive. So take care of the ones that you have....as you have discussed. 73, Jim
Thanks Jim!!! You service is invaluable!!😊
Thank you Jim! I have an AL-811 and have never been quite sure how to tune it. Thanks to you the existing tubes should last much longer. 73's de WV6T
a trick: watch series on flixzone. I've been using it for watching lots of of movies these days.
@Jesse Liam Definitely, have been using flixzone for since november myself :)
Very clear, concise, and helpful instructions on tuning an old-style amplifier. That being said, I was watching this and it became so absolutely clear, once again, why so many of us got in line for the Mercury 3s.
73!
I am rebuilding a Gonset 101. I found this to be very helpful. They are all basically the same design and tuning. Thank You, Jim.
Hi Jim, I think the "desired output level" is the level at which you want to operate which may be less than full output. I think what they're saying is to tune for max output then dial down drive until you reach desired output, which in my case is about 200 watts. Not the clearest set of instructions for sure.
I agree. Your method is what I use and have no problems.
the required position of load control depends on drive power to keep grid current as low as possible
if you want 200 watts you tune with minimum drive level which gives 200 watts and NOT at some higher drive
I get 200 watts with 20 watts drive
If you tune with 50 watts and then lower drive to 20 watts you will get less power out than if you tuned with 20 watts drive
you won't hurt anything but you're getting less efficiency your way
I concur. I tuned my 811H for max into an oil can dummy load, then adjusted the transceiver drive to get an output not to exceed 300W because that’s the max my tuner could handle. Fortunately, now I have a Tune-A-Tenna adjustable inverted vee, so I can get 1:1 on any frequency (7MHz & up, due to small lot & mast height)... so now I can go nuts.
My first linear is the 3-tube AL-811, and the manual (version 4!) is as badly written and confusing as this one (almost identically so). I have typed up what you say, Jim, as it applies to my smaller amplifier.
1. Select the amplifier band switch to the appropriate band and turn on but place in Standby. Place the Meter switch to read Plate Current (Ip).
2. Select the default Load and Plate settings per the amplifier manual (page 7).
3. Tune the antenna to the desired frequency with the ATU. (The amplifier should still be in Standby.)
4. Switch the ATU to the dummy load.
5. Put the transceiver in CW
6. Tune the linear for maximum power output by progressively increasing the transceiver output power in 4 steps: 20W, 40W, 60W, 80W then of drive.
•Each step should limit tuning time to 7 seconds maximum and be separated by a 10 second break.
•Ensure Grid Current meter never exceeds 100mA (half scale deflection).
•Ensure Plate Current meter (bottom scale) never exceeds 450mA (two thirds scale deflection).
a. Adjust the Load control to peak the output power, then pause CW
b. Adjust the Plate control to peak the output power, then pause CW
c. Adjust the Load control to peak the output power, then pause CW
d. Adjust the Plate control to peak the output power, then pause CW
Repeat step 6 for the next power level.
Ensure Grid and Plate current are under the aforementioned limits before finishing.
7. Adjust the Load control 1/2 a scale position clockwise (upwards) to protect from 100W of drive.
Thanks
Thanks Jim! I have had an 811 (used) for 3 yrs and never used it because I didn't completely understand the instructions and was afraid of damaging the tubes. This helps! Hard to believe the instructions are so poorly written, and they're not even made in China! 🤣
Tubes are actually pretty rugged, as long as you don't consistently abuse them.
Earlier this evening, I saw a series of videos showing how to connect and tune up your amplifier. Tune-up really isn't all that complicated.
"Hooking up your Ameritron Amplifier" ua-cam.com/video/gt0k0FY1ipk/v-deo.html
"Tuning your Ameritron Amplifier - Part 1 of 2" ua-cam.com/video/OT1UaCrVvd4/v-deo.html
"Tuning your Ameritron Amplifier - Part 2 of 2" ua-cam.com/video/zPcfRfn_No0/v-deo.html
ua-cam.com/video/ke2nbwqBywc/v-deo.html Several more out there that actually show you how to tune. Cheers.
Not written in China, that’s the dumbing down of America! JohnBoyUtah KJ7TBR 🇺🇸😎📡🎙
Thank you for this OM. The SB 230 quit before I did. I picked up an AL-811H AND a Commander 2500 new in the box. The 811H is in line thanks to THIS video Jim. 73 N7ECV
Thanks Jim. this information helps me a great deal. I'm a new ham and confess I'm struggling to learn. I'm always nervous about damaging my equipment as there are many ways to do it. This information might just prevent me from making mistakes while using the amp.
Thank you very much for this very informative video. Just acquired an AL-811, and will be eager to get it set up. I've been a ham for about 5 years, previously had a solid state Ameritron, which I was never able to get properly adjusted. Looking forward to getting this one in line and working. Nice to have the extra power when it may be needed.
Thanks Jim, I have had a 811 and now I have a 811H , I agree with you the manual is poorly written. I spent hours trying to make sure I was turning it right.
The 811H is sitting idle while I'm using a Dentron 160-10.
Thanks again.
73
Excellent video! When the vendor produces inferior/substandard/just plain wrong documentation, it needs to be pointed out to protect buyers.
Hi Jim, I bought a AL-811XCE at the start of lockdown here. We are limited to 400W. I too was slightly confused with the terrible user manual, so took my time to research its use, (I've never had a amp). Using your earlier amp video and W8JI's website for info, I tune as you describe. I was worried about causing damage by incorrect use initially to a £1200 piece of gear. My antennas are as close to resonant as I can get but I also bought a 600W auto-tuner to touch up just in case, if that doesn't tune, no power used until issue found. Take care, have a great New Year. 73 MM1SYD
Hey Jim we talked earlier about tuning my amp so I thought I would review this video. It all makes sense and I followed along with my 811H. Thanks again for advice. Ken W0KRD
Shouldn't the Grid Current meter (Load Control) be to the LEFT of the Plate Current meter (Plate Control)
to match up with the recommended initial Chart settings and the Load and Plate Knobs?
I think it would be more understandable if the protocol stayed consistent. W7WOW
As you point out, there are many mistakes and they have not been fixed. Just tune the amp as discussed and it will last for many years. 73, Jim
to sum it up .tune for max output and then increase load to the point where power starts to drop a bit...ok you do that in small steps (say 20, 40, 60w of drive)...but in fact that is what to do..tune for max power without overdriving and without going over 180mA on the grids...well explained how to do it safely (in 3 or 4 steps of power setting) ...
increasing load lowers grid current (and output if loaded too high)... so there is a sweet spot (and that is what we are looking for ... not?!?)
I guess easiest is to SHOW it to your friend in real...
in a 4 tubes amp the "dip" is not that easy to see but the max power on an external power meter shows you that sweet spot ...main thing is to watch max grid current (not to trip that safety circuit) ....and do not overdrive it
hey Jim, they’re from Mississippi... it’s just written in southern.
I’ve been using RTTY and stepping up input power from 20 watts, then 40, 55 and finally 65-70 but I do not tune to the maximum of 80 watts. I stay below peak so I’m not over driving the amp. I’m going to start following your tuning recommendations! I like using good habits when operating and being able to protect my equipment.
Thank you for sharing your experience & wisdom!
Richard: An experienced technical writer is an experienced technical writer. It doesn't matter where they came from. This writer wasn't experienced plus he didn't do the necessary research to get it right. I get it that your comment was tongue in cheek.
It was not written in Mississippi! It was written in the middle of the US. 73, Jim
I have found the manual for the 811 to be terrible at best. I'm glad I stumbled across your video.
Hi Jim. Kd9rek here. Great video. Definitely of benefit to me. Thanks again my friend. -73
Thanks Jim. I'm so glad you made this video. It helps so much.
Hi Jim. I agree with your comments about the lack of proof reading. Those instructions are certainly confusing. I came from the old school of building my own high power transmitters and always tuned the plate for max RF output first on a power meter pretty much the same as you described (with one eye on the plate current).
Along came my AL-82 and did the same as with your instructions about the steps of input power to the amp. So, it appears I did the Plate / Load order the opposite way but in my defence, I always was conscious of excessive plate current from the beginning of the tuning procedure.
I shall reverse the order and see how things come out. At the end of my tuning, My IMD products have been
Great video as always, Jim de AC3LZ
Thank you Sir for valuable info. . I have the AL 811 H& I will tune it again as per your directions. In the past it has given some trouble & I sent it to Ameritron during warranty period to set it right again, Unfortunately again some gone wrong n & one of my amateur radio friend made some modifications & now is working well.
DATTA
VU2DSIU
Great video instruction. Thanks so much. I’ve been totally frustrated in getting my amp to tune up.
Great video. Always enjoy your lessons.
Man I can't wait to get an amp! Still trying to get a ham shack together and working on getting my antenna game solid first.
Antenna game??? Don't buy and amplifier. You are dangerous and will hurt or kill someone. Probably yourself.
Hi (again) Jim. I commended you in your other video about the exceptionally poorly written manual re: the AL-811. My only concern with what you've shared in this video, is that you say to key the rig and then tune the Plate, then Unkey and key again and adjust the Load (repeatedly for 20w / 40w / 60w ). The concern I have, is that I understand that you should wait perhaps 15 seconds (that may be a bit of overkill) between keydowns, as this gives the tubes a chance to recover. If you key the rig and do a Plate adjustment for say 7 seconds, then Unkey and then immediately key down again for another 7 seconds (without any delay between keydowns), isn't this potential to abuse the tubes somewhat? That's my ONLY concern with what you've suggested. Everything else looks and sounds bang on to me. Thanks and stay safe.
I am a fairly new ham (a little over 2 years) and dove in head first into HF on 10 meters, and I have the 811A. I had NO problems picking up the tuning routine for the amp OR the Kenwood 830-S for that matter. Love running the tube gear. Did not get the 2 meter radios until earlier this year! But, I am sorry that there are so many mispellings in this manual. I do not believe my manual had these errors. Anyway, let it be known, that the H model (which you have there) is NOT rated for AM, while the A (3 tube) model will handle a full HALF HOUR keydown in AM mode which is why I bought it. I have also had NO trouble with any number of MFJ or Ameritron products in my short time on the air. Thanks for the video. de KC1JZR (PS. the 811-A has a very convenient ALC circuit).
I am a new Bee also General & Tech in one day !! I love the tube amps from my chicken radio days on CB in the late sixties early seventies! What MFJ has done to just the 811 amps is appalling , low QC what a crying shame! I have a three tube and I modified the sh@&): out of it and all I want from it is 500 Watts. And it’s good now! You-Tube is full of corrective mods for these amps. And they point out all of MFJ’s mistakes ! Court adjourned! JohnBoyUtah KJ7TBR 😎🇺🇸📡🎙
Very interesting and useful video! Merry Christmas, Jim!
Hi Jim, thanks again for another informative video. I'm curious as to why you suggest tuning load first and then plate since all the instructive videos I've watched including my own years of experience say to tune plate first for maximum output then the load. I look forward to your take on this. Again, thank you for all your knowledge and video production. Otto Altobell K2BY.
his way may help prevent overdriving the grids momentarily if not watching the grid meter otherwise it doesn't matter
This amp will not stop transmitting if the swr rises above 2:1. The solid state Ameritrons will but the tank circuit in the tube amps can handle an swr of 3:1 and have no protection circuit to shut it down. Don't know why they even have that in the manual.
Hello Jim. The AL-811 is a bestseller of all Ameritron Amps. It's an effordable amp working fine and durable if you treat it well. Buying the Version with the 572B Tubes is to recommend cuz the 811's really suck. It's not the loudest Amp of Ameritron's Production Line but it will do the Trick to get you through the Pileup and QRM. Nice video again ,Jim. 73's de DK5ONV
AMEN !
@@garysmith8455 AWOMAN !
I was really looking into getting one of these but the poor attention to detail makes me seriously second guess that. I hope they up their game it would go a long way. First impressions are always the most important
Don't you worry, these amps are built like tanks right here in the USA! All component assemblies have a sticker on them marked by the employee that inspected it.
@@garysmith8455 that part I know and I like -a lot! Let’s get them to make the product people are proud to own! Think apple products
Thanks John. It would have been nice to see your video when i first got my 811 3 tube amp. It is a older amp i bought used with RCA finned tubes in it. I must admit i have not done the load plate loade plate sequence as you teach somehow the instructions werent clear about that. I have been setting the load where the factory suggested and starting just under 20 watts and i usually peak the plate quickly rest and do the load. I have been doing it backwards for at least 5 years. Oops! I guess it's tougher than me! I always make sure the PLATE current is less than max, like the three tube amp max is 150 ma instead of 2oo ma on the H model with four tubes i'm usually at about 140 ma on the plate and can't remember grid current but it is lower than it can be by a fair ammount. I am usually running around 450-500 watts with about 38 percent drive on the IC 7300. I will have to experiment and see what happens. When i get it peaked and tweaked, I do rotate the load till the output drops just a little. I guess i am lucky. Mine is old enough not to have the limiter although I believe if can be added.
I am very dyslexic and get lots of stuff wrong. When I would testify, the Bailiff would say: Mr. Heath raise your right hand and ..... I had to stop and think. Right/left....hmm. 73, Jim
Jim wondering if MFJ would let you proofread the manuals, and make some coinage. A friend of mine has one that was made in Brooksville, Florida
Ameritron needs to be changed to Chinacon
I used to have AL811 with three 811 tube. it put out 400 watts comfortably with CW. I let it go, because , I mostly do slow speed cw, and they can hear me , but I could not hear them anymore. I think amplifier for fine for SSB / voice. AG6JU
I understand, You may change your posiion on that over time. 73, Jim W6LG
Hi Jim, fwiw I just checked the user/service manual I have for the 811H, it is different but included the "typo" XTM and also the interconnection diagram shows transmitter/transceiver. The references in the manual refer to "exciter" a common description but may be confusing to someone new to this. My manual also shows 4 811s.... undoubtedly a bit of a mess and surprising since the product has been around for many years. As you correctly said your manual conflicts regarding grid trip etc. 73
Hi Jim, belated Merry Christmas and wishing you all the best in 2021. Personally I'm glad to see the backside of 2020 for a number of reasons. I own an 811 and your comments re tuning are very helpful. I have one question and that is this, if I wanted to operate at say 200 watts, do I go through the full tuning procedure to max output (600 w) and then dial down the drive till I achieve 200 watts output without readjusting Load and Plate controls? Alternatively do I tune amp without taking it to max power and simply increase drive till I achieve approx 200 watts output on amp and then adjust load and plate to achieve full output at that level of drive? Hope that's clear.
Norbert: your initial suggested procedure is correct. That is, tune for max recommended power as per manual and then dial the drive power down to *your* desired power level.
@@alanbrown4766 Hi Alan. Thanks for reply and that's technique I've been using. I'm finding ti takes slighty higher drive, about 27 watts to get 200 out vs 20 watts when using other technique, but probably a lot kinder to the tubes. Happy holidays to you and yours and try and stay safe.
@@norbertstepien9185 there is no need whatsoever to tune at higher drive
just tune for max out at the drive power level you want to use
that gets you the most EFFICIENCY
otherwise you're producing 7 watts more heat that is dissipated in the grids
Great video. Whoever wrote this needs a swift backhand. 73's k2ufh
in joy video learning lot from you Rob Qld
learning lot from you Rob Qld Aussie land
Like Roger below I have an amplifier, not a Ameritron, I fear to use and your instructions have set me on the correct track for tuning. I have a late 70s Sigma 3000 D (2 3-500 tubes). Question: If I do not choose to run at 2000 Watts (because it will kill my tuner), can I stop at any point along the way, slightly increase the load and proceed to operate say at 900 watts. WS7T
I do the latter and by doing that, don't damage equipment. Thanks Jerry and 73, Jim
Thanks Jim, you just saved me from buying one of these. If the manual is full of errors, what can I expect in using it? I'll continue to look for something else.
I have this exact unit, & had exact same complaints about the instructions. I’m very critical of poor English. I have to keep reminding myself that not everybody is good in all subjects at school. The very best electronics engineer might suck at spelling, much less typing. The actual amp has a very long track record of success... proven quality. I would still encourage you to buy one if you find a good deal.
I have an AL 811 and I did the 10 meter mod this morning. It will not key up on any band. I bought it used a year ago and this is the first time I connected it and according to Ameritron, the 10 m mod is the same as the 811H. So today I am scanning You tube and asking questions. Any help would be appreciated.
Thank you Jim!
Great technical writing. Reminds me of service manuals I have used that were a direct translation from Italian to English.
Try direct translation from Japanese to English. I used to work in a Sony service center.
Hope things are good up the hill from here. Ciao! Jim
@@ham-radio Yep, things are as good as can be expected, I miss Thursday morning coffee.
I own an AL811H. I watch ONLY the power output meter as I peak the plate control. I watch ONLY the plate current meter as I adjust the power input. I watch ONLY the grid current meter as I adjust the load control. And if the grid current ever goes above 200, IMMEDIATELY turn off the input from your transceiver because you probably forgot to switch to the correct band or connect the correct antenna. 73--Tom NC3Y
What’s your opinion on doing most of the tuning into a dummy load, then just the final tweak into the antenna?
@@kelvin0mql
Sure. That's a good idea. Just watch the grid current when you switch to the antenna and adjust the load to put the grid current to 150-170 ma.
Real fine, but, likewise as you stated, (why didn’t they just use a picture of the amp instead of a drawing) maybe you could have just aquired an Ameritron amp and tuned it on video, it would have been much better😮 but thanks
Jim, thanks for putting up this video! I have a used AL-811H sitting in my shack waiting to be installed. I know this video will be of great help. I do have a question though. In the section SSB Tune Up it references "between 20 and 50 percent of the CW carrier readings". What does that actually mean? I hate to guess.
Lloyd - W1LBM
perhaps add an actual quote of what you're referring to but it sounds like it talks about the difference in ssb peak vs carrier or average power as indicated by 'not-peak-reading' or average reading meters. Those meters will often show 20 to 50 percent deflection of actual ssb peak power.
Thanks Jim 73
Merry Christmas to you and the Family Jim.
IS THAT A THUNDER BOLT 305 IN THE BACKGROUND ?
I was shopping for an amp and this one was recommended by my radio shop. Since I have zero experience with ham radio amps I pulled up the manual, read it like your friend did and passed on it because I wouldn’t have been able to set it up using their instructions. Disappointing. Still looking.
Hi Jim, I have an unrelated question about SWR. My SWR changes when it rains. I'm using a Cushcraft AR-10 Ringo Ranger on 10 meter. Could you give me some insight of what may be happening? Thank you! I didn't see any other formum that I could use to ask you a question so forgive me if I goofed up.
the antenna get wet when rain on ten meter
Felt like working with dad on a piece of equipment
N4LAK. When you tune this amp, or any tube amp, what theoretically are you trying to do? I read the instructions carefully and I study tube theory, but I don’t “get it”.
You tune the amplifier to the frequency of transmission. Giving a clean and effective amplified signal. Careful not to overdrive will make it last for years.
It would be better to show tuning up a tube amp in a video and maybe a review on how the tuning section works looking at a simple single tube schematic. I have always used a tube amp on HF. As you add power your tune can change so for a clean signal I always tune up to the power I will run. I see in the background you have a tube amplifier, since they all work about the same it would be a good visual tool. Last time I looked at a manual on how to tune a tube output section was when I had my first radio, it was a Kenwood 830S. Even I was confused just listening to you read that trash manual.
I have done that and you can see me with a Drake L4b. 73, Jim
Hope the quality of the product exceeds that of the instructions. Based on this, I Would never buy one.
My friend AE4MQ had one. He had no issues with it at all. I'd love to go QRO, but I need a DX Cammander antenna first. de KI5CWY
I have one. Great amp for the price point. Just terrible operating instructions.
Ameritron is a MFJ brand since quite a while ago - go figure :)
MFJ Mighty Fine Junk LOL
@@mikemcdonald5147 low hanging fruit but so true...MFJ's quality control or lack of is very poor
How do you set the ALC on an 811H Amp? This presentation helped me a lot. Thank you.
I do not use ALC because it can lead to distortion. I tune the amp for max out and then increase the load control watching the grid current decrease. In other words, I load the amp for more output than the transceiver can supply. 73, Jim
I like Jim’s approach here, because the voltage on the ALC line from the 811H amp is way too high for most modern solid state transceivers, anyway.
Thanks for some clarification. Jim. I have an 811 and want to only run approx 300 w. Do I still tune for max output then reduce drive , or is it ok to tune to 300 and stop?
you should find the minimum drive power on each band that will give you the desired output and tune at that drive power
@Southeastern777 Correct. You are not.
Case in point, I built a 10W tube AM transmitter. With it, no way to tune up with 80W of drive. Similar story with folks who happen to use any other sort of lower-power transceiver.
Gotta swing with the bat you’ve got.
You tune for Max power then turn the power down on your radio.
That’s how they write in Sparks!
Perhaps. I offered to fix the manual and even drafted a few pages. They declined my offer. Take care. We are going to have some nasty weathers in the next 10 days. 73, Jim W6LG
Well - did you really expect a high quality manual from Ameritron (now quite some time an MFJ brand)?
I did. And, I do. 73, Jim
Nice video, Jim. I notice you have MSNBC on the tv in the background. For effect?
Hi Tim, Great to hear from you. I watch the three news channels. The TV is often running when I am doing things. Thanks Tim! 73, Jim
orange man bad
@@andhanwer not anymore lol
@@lizzyfan1986 Still very bad. Just not as relevant anymore.
Pretty sure they’re talking average power and not plate current when mentioning the 20 to 50% in SSB.
What about tuning the input of the amp so the transceiver sees a low swr?
That's what you should do. The input, often called a tuned input, can be a pi network or less. Careful tuning is important. Some argue that a high Q gives better results. 73, JIm
I've been running an AL-811H for over five years, and I can guaran-durn-tee you that the initial load setting is nowhere near 3 1/2 for the upper end of 40 meters. 7 1/2 is more like it.
Tune for max out by stepping up the drive in small increments. Then at max out look at the grid current again and advance the load control even further. 73, Jim
@@ham-radio Yes, and when I do that, the load control is at 7 1/2.
hello Jim what do you think about AQLS 600s or AL 811 73 Paul
Nicely built, good design, a lot of value for the money. 73, Jim
I think I see why your friend is confused.
Unbelievable Jim!
Jim, I've never seen one of these amps, but I could tune one now following your instructions. I'm from Mississippi (notice I said from) and those instructions are NOT written in southern. It's just bad grammar, bad punctuation, bad sentence structure, and bad writing.
Hi Jim I seen you came back you made a new video and I hope you are doing well make a difference in the videos for the year 2021 and and also and how is your nice happy New year Jim hope this year 201 will be good for you and me and I wish you the good the best and and good health
This has been tremendously helpful. A lot of us are wondering how to tune the amp for running lower power levels. Is it best to tune the amp for max power as you explained, and then turn the transceivers power down to reach desired total power output? Or do you tune the amp for max power at the power level desired and be done with it? 73. - KN4IQE
I always tune for max out and then dial down the drive. It will be clean, slightly less efficient with low IMD. Thanks Steve. 73, Jim
@@ham-radio Thanks again Jim!
Sounds like someone in charge at Ameritron needs to watch this video and fix their instructions lol
This is sad for sure. I work on a lot of equiptment from China. There manuals are the same. Its often a word for word translation. Whis means it often doesn't make any sense at all. You're left scratching your head.
I am not sure about it being a translation. But it sure needs an overhaul. At least the one that Iooked at needed work. 73, Jim
Tuning instructions are poorly structured/written. This was written based on the AL-811 manual (using three 811A Tubes, accepts up to about 70W drive, 50-0453-1 Schematic (relay drivers)).
Setup - Install an external antenna tuner and antenna switch between the amplifier and antenna. (Ant/Load >> Switch > Tuner > Amp). The switch selects either the antenna or load.
Step 0.1 - Set up the amplifier to HV, STBY, OFF (all switches down). Set the band to the desired band. Set the LOAD and PLATE controls to their preset positions for the desired band/frequency.
If the external tuner has preset positions, set them now. If the Ext tuner has a bypass, select BYPASS.
Step 0.2 - Tune the transceiver using its internal tuner into the dummy load. (CW mode, low power.) Unkey.
Step 0.3 - Switch from the load to the antenna. Tune the external tuner for best match. (CW mode, low power.) Unkey.
Step 0.4 - Turn on the amplifier. Meters should be lit. Check Plate voltage (about 1700V). Select Ip (plate current). Check Plate current (should be 0mA). Check Grid current (should be 0mA).
Step 0.5 - Switch the amplifier to OPR.
Step 0.6 - Key the transceiver (CW, minimum/no power). Check XMT LED is lit, PLATE current should be about 110mA.
Step 0.7 - Raise transceiver power for GRID current about 60mA, or PLATE current about 200mA (whichever occurs first).
Adjust the transceiver internal tuner for best match into the amplifier.
Slightly adjust PLATE and GRID controls for max antenna power.
Reduce transceiver power if GRID current exceeds 120mA, or PLATE current exceeds 400mA.
Step 0.8 - Raise transceiver power for desired Antenna operating power.
Reduce transceiver power if GRID current exceeds 120mA, or PLATE current exceeds 400mA.
Record Band, Frequency, LOAD and PLATE settings for future set-up.
If band/frequency are changed, set the amp to STBY and return to step 0.1 (PWR remains on, PLATE current remains selected).
In all modes, clipping (flat topping) can be detected using a monitor scope. If clipping occurs, reduce transceiver power.
The amplifier will require reducing transceiver power if overheating is a problem (overheating is not defined). The manual suggests 400W output, 100% duty cycle in CW mode is the design limit for maximum safe heating, and is likely a good limit for constant power modes such as SSTV, FM, RTTY, PACKET, AMTOR.
Brett KA7CGB
Thanks.
So, idle current is 110ma. Correct?
Why the need to use the transceiver internal tuner?
Why the need to "retune" the antenna tuner in the transceiver when increasing drive power?
How much drive does it take to get to 60ma grid current?
What is "desired Antenna operating power"?
So first step is 60ma of grid current and then final step is 120ma of grid current and 400ma of plate current. Is that correct?
You said, "In all modes, clipping (flat topping) can be detected using a monitor scope." You said in "all modes". Is that correct?
For those who do not have a monitor scope, what should they do?
You said, "The manual suggests 400W output, 100% duty cycle in CW mode is the design limit for maximum safe heating, and is likely a good limit for constant power modes such as SSTV, FM, RTTY, PACKET, AMTOR." Okay, 400 watts output at 60% efficiency would be about 90 watts of plate dissipation per tube. At 63% efficiency would be about 80 watts per tube. So you are recommending drive the tubes to where the plate dissipation is somewhere between 80 and 90 watts per tube. Doesn't that tube have a rated maximum plate dissipation of 60 watts?
You say to have a max grid current of 120ma. I thought that they recommended no more than 100ma. Is your 120ma correct?
Okay, that was a lot to read and digest. Thanks for your input. I cannot recommend your procedure but many may find your step by step the way to go. Thanks again for you detailed and thoughtful approach. I do appreciate the time and effort it took. Thank you! 73, Jim
@@ham-radio > Why the need to use the transceiver internal tuner?: I looked t the schematic for one of the amplifiers. The exciter drives a tuned Pi circuit in the amplifier, and I had read elsewhere that sometimes these may be mis-tuned. Adjusting the transceiver tuner ensures best match until you understand how the transceiver and amplifier match each other when you switch bands.
For the other questions, I don't know about you, but I wouldn't want to be driving maximum power into the amp before tuning with the possibility that when tuned, the amp would be operating beyond specified power. During tune-up, I'd want to be somewhat conservative, and sneak up to maximum power. Your milage may vary.
> Doesn't that tube have a rated maximum plate dissipation of 60 watts?: Perhaps - I didn't look at the tube specs. I was going by what I read in the manual, which suggested overheating could occur... eventually (max power, keyed 100%). Cooling depends on many things not addressed by the tube specs.
As you get experience with your set-up, you'll figure out there are a few steps you can probably skip. But for the novice, they're just trying to figure out what "normal" looks like.
Brett KA7CGB
@@ham-radio >For those who do not have a monitor scope, what should they do?: The monitor scope (or any scope with X/Y display function and something to sample the amplifier output ) positively indicates when clipping begins. The next best option would be to use a peak-reading wattmeter, and be conservative (refrain from striving for max specified power). If you don't have either of those... Tune another radio to a 2nd and third harmonic of your transmit frequency and listen for splatter (or have a nearby friend help with this. A friend with a pan-adapter or spectrum analyzer can also help.) If all you have is a basic wattmeter - your advice to reduce SSB power so average output power is about 20% of maximum makes sense to me.
Hi Brett,Thanks for getting back to me.I built my first amplifier in 1967+/-.
The amp tuned input, as you know, is low Q. Another stage of tuning (transceiver's tuner) in between might be good in reducing harmonics.I believe that tuning for max out and then increasing loading is a requirement. Increasing the load control until the output drops ensures linearity.
Watching grid current is a must. Excessive grid current will damage a tube(s) very quickly.Some data sheets are very conservative. Others are not.
I have talked with guys that helped design the 3-500z and 4-1000. They confirmed the conservative ratings. The 811A does not, as far as I can tell, have much additional plate and grid dissipation.
At this time I have a pair of 3-500z and a GS35B amp.Thanks very much, Jim W6LG
yeah, the AL-811 tuning instrux are horrible. hardly anyone i know understands "page 7" of this manual. the best way to tune this amp is by peaking the grid current and then dialing up the load to achieve the proper mA for the tubes. Tom W8JI, the designer of this amp, has a great YT video on tuning it. 'Tom W8JI' is his username.
That instructions are more than a bit confusing!
THOSE instructions are more than a bit confusing too LOL :)
I other words not only poor soldering QC , but bad directions an all for $1000.00 WOW welcome to ham radio new bee’s! JohnBoyUtah KJ7TBR 🇺🇸😎📡🎙
Yes. So, as you point out, examining the amp before applying power is a good idea. I have seen tubes out of the socket, loose wires and other poor connections. The design is good and the amp overal is good for the money. The owner just needs to be very careful in doing a review prior to plugging it in. And, never open the box without extreme caution to make certain that nothing inside has a charge on it. Thanks for writinig. 73, Jim
CTR Engineering, mods are all good
Very pedantic video. Sheesh. Only thing missing was the red pen.
Actually, I would have used a red pencil. Please watch the next video where I discuss why I was very critical of that page in the instructions and how I offered a detailed step by step way to tune up that amplifier that will help the tubes. Thanks, Jim W6LG
The manuals from MFJ are all adapted from the originals and have been cut and pasted to the max . They need to hire someone that can proofread and explain in simplified terms
how to accomplish the task at hand. The antenna manuals are just as bad.
Harry, that explains it. You must be right. Thanks Harry. Now I get it. 73, Jim
Nice explaination....I cannot tune my 811 they way they explain it. I also have 572b tubes but running from 20 watts then trying to tune up to 80 watts pegs my grid in the corner. I found w8ji.com who I gather is a creator of the amp has a good explaination of tuning it along with troubleshooting, amplifier history and design. But I was finally able to tune it and getting just about 700 watts on ssb
MFJ all you need to say
BUSH & Trump Inauguration speech in slow motion. "BACKWARDS talk", ALMOST LIKE SHADE, says what they HAVE done to us and what they WILL do to us.Myron C Fagan explains well.