I've been a "new" ham since 1990 and just enjoyed your four-part L4B presentation. If I wind up owning/restoring/maintaining one, let it be on your head! I've owned a T4X/R4B/MS4 since the early 1990s and have never had them on the air. They might be my first real "project." 73 de KC6OEI
Jim your knowledge is priceless! I have learned an incredible amount of watching you over the years. Thank you so much for taking the time to share these things with us.
The chain of events you described reminds me of nearly every project I engage in -- especially the ones that I feel should be "straightforward." 🤣 It's a completely natural flow in the troubleshooting process to focus on what changed recently. Problems arise, though, when one gets so locked-in to that thinking that other possibilities are missed. Really enjoyed this series. It's been a while since I worked with a tube amp, but this highlights just how rugged, well designed, and well made the Eimac 3-500Z tubes were. 40+ years of service at full legal power is impressive, to say the least!
Hi Jim, Hope you are feeling better. You look good in the series of videos. I checked the date code on the Eimac tubes for my SB-221 being converted to a 220 and it is 7836. Stay safe. 73 WJ3U
They are amazing tubes. Blood tests today showed some problems. I will be going back to the hospital tomorrow for transfusion 27; I think that is the number. Not good as I cannot keep my RBC up. 73, Jim
Another series of interesting videos Jim. I have a SB-220 with a pair of 3-500Zs. I paid $200 for it about 15 years ago. It worked for about a year & then tripped the internal circuit breaker. I replaced the electrolytic capacitors & the metering board with Harbach replacement kit. Got it working just fine. 73 de K5AVJ
Nice video. Got hit by a TV high voltage once. I’ll never forget it! If you don’t remember those learning times, you shouldn’t be messing where you shouldn’t be messing. Thanks for the great video, Jim 73’s Bob Runge W1LSZ
Thank you for this excellent series of videos about the tubes and the amp! I'm looking forward to a future review of the 811A tubes. Thanks again! ~ 73 ~ AC7WH
@@ham-radio Very nice! I purchased an Ameritron AL-811H two years ago. I use it with my Icom IC-7300 and a small vertical antenna designed for portable use. With SSB I've had QSOs from my home in Sutherlin, Oregon with hams all across the USA, and in Asia, Indonesia, Australia, South America, and more! That amp really helps me "get out there" and I've received multiple comments on my excellent signal and audio quality.
Well I thought this was great to watch and listen to. I didn’t understand much of the electronic references but as a mechanical engineer found the build quality interesting. The “old” stuff always offers more “soul” to me rather than the tech today.73. 💙 G0uvl
It was well built but showing its age. It was designed for long transmit duty cycles with 2kW input power. I need to clean it somehow and soon. It is really dirty. I heated up the RG8X to where it was hot to the touch. 73, Jim W6LG
@@ham-radio you’re amazing 🤩 Can you blow it out with a compressed gas canister… I get them from Costco but I think its butane??? That’s in them… WD40 cleans up dirty fascia and cabinet boxes.73. 💙 G0uvl
Very interesting set of videos Jim. I worked on an L4B last year that I had a similar situation with. I thought it was the tubes also, then I believe it was something I changed on the soft start board that needed replacing. It was a frustrating experience to say the least. I finally got it running and it works perfect. Wish I had the bigger transformer. 73 Mark W0NCL
You did an excellent Job, Elmer Jim! Keep well and tnx for the Video. Happy Weekend into Rocklin / CA & 73 de Your Friend Uncle Günter, the Rhine River Maniac 💯🙋♂
Been there and done that, Jim. Just have to walk away sometimes and let it sit. Possibly a diode reversed in the string - who knows. It is easy to overlook the same thing many times but patience and perseverance on your part got it working again. Stay safe especially around that 2.5 KV in amplifiers like this. I just built another 3-1000Z amplifier maybe we can have a QSO on soon. 73 WA4QGA
Thanks, this video series has been helpful. I picked up an AL80B at a ham fest as my first amplifier. It seems to work pretty good, but I have had to do some work on it. I think it is a good introductory amplifier to tube circuits with only one 3-500Z tube. It still has the Amperex French made tube in it and it consistently puts out 700-850 watts on all bands. I usually run it in the 600-700 range. If I ever find a suitable transformer, I would like to build a 2 tube version similar to your old Drakes. 73, KF0BBU
Hi Jim, my 2 3-500Z amplifier has been relatively trouble free, however annoyingly the transmit/receive relay operating coil went open circuit. nothing clever but it was a little fiddly to remove. On the bench the coil still measured open circuit so I started looking for a replacement in the usual online places. After a few days with nothing about to drop in my lap for cheap or free I revisited the relay. Heated up the tags on the operating coil and it reverted to the correct 5k ohms. That was over a decade ago and it is still working, I fully expected the repair to last maybe a week. As for defective components I tend to chop all of the legs off before they go in the bin, it is too easy to waste time retesting components that you find on the bench...
@@ham-radio Hi Jim, you have plenty on your plate, but at the best of times dealing with defective parts is frustrating. FWIW my amplifier uses a zener for the bias and I always planned to put a diode string in, but on the basis that I will wait for the zener to fail first. 73
Something crazy is going on with my L7. I bought it used. The first time I used it the output was a little lower than what I thought it should be. About 900 watts out on 40 and 80 and a little over 1500 on 20. now I can only get 200 or 300 0n 40 and 80 and 1000 on 20. Ive connected it to a dummy load to see if it might be something else in my station. Now Im starting to jump to conclusions.
Hi Jim, the capacitors attached to the gang tune or the choke may have a dry joint? the L/C circuit could be causing the extra load on the input circuit causing the resistor to go in the transformer trying to deliver more load than its rated for? { i have no idea actually} just a thought
As an electronic technician many years ago, there is usually a “looped” circuit and the component that went bad was the weakest part in the loop. Those diodes were probably compromised and you replaced them. What other components are in the loop that is also compromised? Great visual on your repairs! Glad you broke it down to four short videos, as most techs would fall asleep after 15-20 minutes. 73 de KD6UYK (Tim).
I think I was at 43 minutes. I had too much to say. Those diodes had me frustrated for sure. I've ordered new diodes and will trash the old ones. I had no idea how old they are. Thanks, Jim W6LG
Hey Jim, I have Drake L7B and am planning to change the tubes. Is there anything to measure and adjust inside the amp? Or do I need just to replace them with a new ones? Is there any checklist to follow? Thanks for the video, 73!
It is better to have tubes that are close in terms of efficiency, bias, filament current and voltage. So, I needed two new tubes that are somewhat matched. Having two very different tubes would lead to problems. 73, Jim W6LG
How much less output does your L4B produce on 10 meters compared to 20 ? Mine seems to be about 300 watts less , do you consider that normal Jim ? Thanks for another video Jeff VE7GMX 73
I think it is a few hundred watts less. I will test that after I solve some cabling issues. I got the RG8X that I was using much too hot with just tuning up. I need to cable with 213 or LMR400. RG8X was just for the video in a big hurry. 73, Jim W6LG
@@ham-radio First it is a natural occurence so it cannot be evaluated in the same sense as man made electric currents. It is also transient which creates a problem studying its nature. It has charecteristics of DC current in that electrons flow in one direction however it changes potential during travel giving it charecteristics of AC current. My theory is it is a unique natural current with many charecteristics common to both AC and DC. Therefore it is uniquelly lightning current.
also it is probably the by product or conversion of another energy source. A discharge from a point of high energy to low energy much like a waterfall from gravity. The base being electron in place of water and the source being a tranfer of energy from several souces much like gravity to move the water from a high energy state to a lower state. Entropy. Afterall everything in the physical world follow the same path.
Thanks Jim! Great journey.
I've been a "new" ham since 1990 and just enjoyed your four-part L4B presentation. If I wind up owning/restoring/maintaining one, let it be on your head! I've owned a T4X/R4B/MS4 since the early 1990s and have never had them on the air. They might be my first real "project." 73 de KC6OEI
Jim your knowledge is priceless! I have learned an incredible amount of watching you over the years. Thank you so much for taking the time to share these things with us.
Hey Jim, and its working very well, great signal and maybe the best audio anywhere 🙂
The chain of events you described reminds me of nearly every project I engage in -- especially the ones that I feel should be "straightforward." 🤣
It's a completely natural flow in the troubleshooting process to focus on what changed recently. Problems arise, though, when one gets so locked-in to that thinking that other possibilities are missed.
Really enjoyed this series. It's been a while since I worked with a tube amp, but this highlights just how rugged, well designed, and well made the Eimac 3-500Z tubes were. 40+ years of service at full legal power is impressive, to say the least!
Yes and yes it is remarkable. 73, Jim
Hi Jim,
Hope you are feeling better. You look good in the series of videos. I checked the date code on the Eimac tubes for my SB-221 being converted to a 220 and it is 7836. Stay safe. 73 WJ3U
They are amazing tubes. Blood tests today showed some problems. I will be going back to the hospital tomorrow for transfusion 27; I think that is the number. Not good as I cannot keep my RBC up. 73, Jim
Hey Uncle Don, how are you doing? Have a great Weekend & 73 de Uncle Günter the Rhine River Maniac 💯🙋♂
Just okay nephew. Trying to stay active. Thanks for asking. I hope you are okay. 73, Jim
Another series of interesting videos Jim. I have a SB-220 with a pair of 3-500Zs. I paid $200 for it about 15 years ago. It worked for about a year & then tripped the internal circuit breaker. I replaced the electrolytic capacitors & the metering board with Harbach replacement kit. Got it working just fine. 73 de K5AVJ
That was a good choice. 73, Jim
Nice video. Got hit by a TV high voltage once. I’ll never forget it! If you don’t remember those learning times, you shouldn’t be messing where you shouldn’t be messing. Thanks for the great video, Jim 73’s
Bob Runge
W1LSZ
Thanks Bob. I worked too hard and got sick. So I will take it easy for a few days. 73, Jim
This was quite the educational experience!
Thanks, 73, Jim
Thank you for this excellent series of videos about the tubes and the amp! I'm looking forward to a future review of the 811A tubes. Thanks again! ~ 73 ~ AC7WH
Thanks, I am now looking for an 811H Ameritron. 73, Jim
@@ham-radio Very nice! I purchased an Ameritron AL-811H two years ago. I use it with my Icom IC-7300 and a small vertical antenna designed for portable use. With SSB I've had QSOs from my home in Sutherlin, Oregon with hams all across the USA, and in Asia, Indonesia, Australia, South America, and more! That amp really helps me "get out there" and I've received multiple comments on my excellent signal and audio quality.
Well I thought this was great to watch and listen to. I didn’t understand much of the electronic references but as a mechanical engineer found the build quality interesting. The “old” stuff always offers more “soul” to me rather than the tech today.73. 💙 G0uvl
It was well built but showing its age. It was designed for long transmit duty cycles with 2kW input power. I need to clean it somehow and soon. It is really dirty. I heated up the RG8X to where it was hot to the touch. 73, Jim W6LG
@@ham-radio you’re amazing 🤩 Can you blow it out with a compressed gas canister… I get them from Costco but I think its butane??? That’s in them… WD40 cleans up dirty fascia and cabinet boxes.73. 💙 G0uvl
Very interesting set of videos Jim. I worked on an L4B last year that I had a similar situation with. I thought it was the tubes also, then I believe it was something I changed on the soft start board that needed replacing. It was a frustrating experience to say the least. I finally got it running and it works perfect. Wish I had the bigger transformer. 73 Mark W0NCL
Thanks for sharing! 73 Jim
Jim, thanks for sharing.
You are very welcome
You did an excellent Job, Elmer Jim! Keep well and tnx for the Video. Happy Weekend into Rocklin / CA & 73 de Your Friend Uncle Günter, the Rhine River Maniac 💯🙋♂
Been there and done that, Jim. Just have to walk away sometimes and let it sit. Possibly a diode reversed in the string - who knows. It is easy to overlook the same thing many times but patience and perseverance on your part got it working again. Stay safe especially around that 2.5 KV in amplifiers like this. I just built another
3-1000Z amplifier maybe we can have a QSO on soon. 73 WA4QGA
Nice! That's such a good tube. Could be more like a 3-1500Z or bigger. It has breat performance. Sound like fun. 73, Jim
Thanks, this video series has been helpful. I picked up an AL80B at a ham fest as my first amplifier. It seems to work pretty good, but I have had to do some work on it. I think it is a good introductory amplifier to tube circuits with only one 3-500Z tube. It still has the Amperex French made tube in it and it consistently puts out 700-850 watts on all bands. I usually run it in the 600-700 range. If I ever find a suitable transformer, I would like to build a 2 tube version similar to your old Drakes. 73, KF0BBU
Ya, you are probably at the max output. Just watch the grid current. Don't push it too hard. 73, Jim
Hi Jim, my 2 3-500Z amplifier has been relatively trouble free, however annoyingly the transmit/receive relay operating coil went open circuit. nothing clever but it was a little fiddly to remove. On the bench the coil still measured open circuit so I started looking for a replacement in the usual online places. After a few days with nothing about to drop in my lap for cheap or free I revisited the relay. Heated up the tags on the operating coil and it reverted to the correct 5k ohms. That was over a decade ago and it is still working, I fully expected the repair to last maybe a week. As for defective components I tend to chop all of the legs off before they go in the bin, it is too easy to waste time retesting components that you find on the bench...
I know. I was maybe a little angry. Replacements are very inexpensive. 73, Jim
@@ham-radio Hi Jim, you have plenty on your plate, but at the best of times dealing with defective parts is frustrating. FWIW my amplifier uses a zener for the bias and I always planned to put a diode string in, but on the basis that I will wait for the zener to fail first. 73
Something crazy is going on with my L7. I bought it used. The first time I used it the output was a little lower than what I thought it should be. About 900 watts out on 40 and 80 and a little over 1500 on 20. now I can only get 200 or 300 0n 40 and 80 and 1000 on 20. Ive connected it to a dummy load to see if it might be something else in my station. Now Im starting to jump to conclusions.
Hi Jim, the capacitors attached to the gang tune or the choke may have a dry joint? the L/C circuit could be causing the extra load on the input circuit causing the resistor to go in the transformer trying to deliver more load than its rated for? { i have no idea actually} just a thought
If so that could bee dangerous. I do have spares from Russia that are big and in new condition. Thanks! 73, Jim
As an electronic technician many years ago, there is usually a “looped” circuit and the component that went bad was the weakest part in the loop. Those diodes were probably compromised and you replaced them. What other components are in the loop that is also compromised? Great visual on your repairs! Glad you broke it down to four short videos, as most techs would fall asleep after 15-20 minutes. 73 de KD6UYK (Tim).
I think I was at 43 minutes. I had too much to say. Those diodes had me frustrated for sure. I've ordered new diodes and will trash the old ones. I had no idea how old they are. Thanks, Jim W6LG
Hey Jim, I have Drake L7B and am planning to change the tubes. Is there anything to measure and adjust inside the amp? Or do I need just to replace them with a new ones? Is there any checklist to follow? Thanks for the video, 73!
With the advent of Ameritron / MFJ going out of business, I wonder how much longer companies will continue to make tubes for the amateur market?
I think they will provided that there is a commercial market first and foremost. Make sense? 73, Jim
Jim, is this all stuff you could have gone down to MarVac to get, back in the day?
Yes you could back then. 73, Jim
Jim ... since only one tube was bad, how would you feel about only replacing one tube? Any comments about foreign made tubes? ... de K5AVJ
It is better to have tubes that are close in terms of efficiency, bias, filament current and voltage. So, I needed two new tubes that are somewhat matched. Having two very different tubes would lead to problems. 73, Jim W6LG
How much less output does your L4B produce on 10 meters compared to 20 ?
Mine seems to be about 300 watts less , do you consider that normal Jim ?
Thanks for another video
Jeff VE7GMX
73
I think it is a few hundred watts less. I will test that after I solve some cabling issues. I got the RG8X that I was using much too hot with just tuning up. I need to cable with 213 or LMR400. RG8X was just for the video in a big hurry. 73, Jim W6LG
Jim. Is lightning AC or DC current? Be careful how you answer, it may be shocking.
My guess, since I don't know, would be DC. Sounds like you are going to say it ia AC. Educate us in a "brief" response. 73, Jim
@@ham-radio First it is a natural occurence so it cannot be evaluated in the same sense as man made electric currents. It is also transient which creates a problem studying its nature. It has charecteristics of DC current in that electrons flow in one direction however it changes potential during travel giving it charecteristics of AC current. My theory is it is a unique natural current with many charecteristics common to both AC and DC. Therefore it is uniquelly lightning current.
also it is probably the by product or conversion of another energy source. A discharge from a point of high energy to low energy much like a waterfall from gravity. The base being electron in place of water and the source being a tranfer of energy from several souces much like gravity to move the water from a high energy state to a lower state. Entropy. Afterall everything in the physical world follow the same path.
Problems always come in 3s 😂
I could not get ahead on that one for a few days. Wait a pain in the a... it became. Thanks Jay, 73, Jim
More complicated is better. Old classic amps not enough to go around.