I never run the Palomar 350Z in the high position. The reason being is that with 2 Watts DK and 13 pep I get 125 DK and 500 pep (in the low position.)
The only thing the 350z does differently in the high position is gives me a dead key of approximately 300+ Watts with the same 500 pep.
I just wanted to run it in the high position for a few minutes. Unfortunately I forgot that it was indeed in the high position for the two hours I spent on the air that day. On one key down I got long-winded. And I guess you could say I popped my cherry. For the first time in my life I actually heard a noise startling pop. It wasn't an explosion. There was no smoke nor smell. But there's certainly was a pop. And a pop loud enough to stop my heartbeat for a second. Okay I'm going to be honest. The pop almost made me shit my pants. This is what happened and in my opinion the person who repaired it did a wonderful job. He not only repaired the pop issue but did several other things as I did give him carte blanche to do whatever he needed to get the 350Z not only in working order but if possible better working order then it came from the factory. I never thought to ask him to get the preamp working as I never use amplifier preamps anyway. Although I must say after trying it two days ago while some slight skip was rolling in from Florida the 350Z and it's cheesy preamplifier actually helped pulling in a station that I made contact with. I most likely would not have made that contact had I not been for the option to use the preamplifier. There was several other things he did to the amplifier that made it a better working amplifier. I'll just stick to the original post at hand. This is what the loud pop was.
Three capacitors burned up. I don't know which one of them went pop. But the one that did go pop obviously caused to others to melt down.
This is the repair photo
As you can see he didn't just replace the blown and burnt diodes he added a component that I can only assume made an improvement on the original design in that area of the amplifier.
I run the 350Z in the low stage and even though I believe he said there would be no issue running it in the high position he also suggested what I believed from the beginning was that there's absolutely no reason to run it anywhere but in the low side. The only difference is the 200 what dead key while running it in the high position as opposed to the low. Most of us know that is not going to make a difference on the other end. The only thing it could do is put unnecessary stress on 40 year old tubes. Tubes that cost between 50 and $70 each if you can find them. Then you have to hope that the seller is honest. I think many people purchase tubes that are probably no better or worse than the ones they're replacing. The six tubes in this 350Z are still showing full output with excellent audio reports from the transceiver I'm currently driving it with. 2 watts DK and 13 pep seems to be keeping the amplifier happy. This amplifier had the b+ relay modification added to it many years ago and runs nice. It doesn't get any hotter than 6 sweep tubes should. The cover is slightly warm to the touch and as long as I keep the key Downs under a minute (ideally 30 to 45 seconds) the temperature will not rise that much. I tend to be long-winded but I'm trying to teach myself that you just can't be long-winded when using these old sweep tube amplifiers. I would venture to Guess that being long-winded even with a newer amplifier that doesn't use sweep tubes one should be careful at how long they actually key down and modulate. Anyway. I just wanted to share my first capacitor explosion/pop story with you guys. And show the before and after pictures in hopes that those in the know will tell me if they think this was a good repair. He also repaired the mfj 828. It finally works the way it should. I sent it to him without even letting him know I was sending it. I had some extra room inside the shipping box for the 350Z so bubble wrapped the 828 and sent it along. I'm not sure what he did but he did not charge me. I'm going to send him both my wm1's as they're both showing different readings and either one or both most likely need an alignment. God bless. 73's
The only thing the 350z does differently in the high position is gives me a dead key of approximately 300+ Watts with the same 500 pep.
I just wanted to run it in the high position for a few minutes. Unfortunately I forgot that it was indeed in the high position for the two hours I spent on the air that day. On one key down I got long-winded. And I guess you could say I popped my cherry. For the first time in my life I actually heard a noise startling pop. It wasn't an explosion. There was no smoke nor smell. But there's certainly was a pop. And a pop loud enough to stop my heartbeat for a second. Okay I'm going to be honest. The pop almost made me shit my pants. This is what happened and in my opinion the person who repaired it did a wonderful job. He not only repaired the pop issue but did several other things as I did give him carte blanche to do whatever he needed to get the 350Z not only in working order but if possible better working order then it came from the factory. I never thought to ask him to get the preamp working as I never use amplifier preamps anyway. Although I must say after trying it two days ago while some slight skip was rolling in from Florida the 350Z and it's cheesy preamplifier actually helped pulling in a station that I made contact with. I most likely would not have made that contact had I not been for the option to use the preamplifier. There was several other things he did to the amplifier that made it a better working amplifier. I'll just stick to the original post at hand. This is what the loud pop was.
Three capacitors burned up. I don't know which one of them went pop. But the one that did go pop obviously caused to others to melt down.
This is the repair photo
As you can see he didn't just replace the blown and burnt diodes he added a component that I can only assume made an improvement on the original design in that area of the amplifier.
I run the 350Z in the low stage and even though I believe he said there would be no issue running it in the high position he also suggested what I believed from the beginning was that there's absolutely no reason to run it anywhere but in the low side. The only difference is the 200 what dead key while running it in the high position as opposed to the low. Most of us know that is not going to make a difference on the other end. The only thing it could do is put unnecessary stress on 40 year old tubes. Tubes that cost between 50 and $70 each if you can find them. Then you have to hope that the seller is honest. I think many people purchase tubes that are probably no better or worse than the ones they're replacing. The six tubes in this 350Z are still showing full output with excellent audio reports from the transceiver I'm currently driving it with. 2 watts DK and 13 pep seems to be keeping the amplifier happy. This amplifier had the b+ relay modification added to it many years ago and runs nice. It doesn't get any hotter than 6 sweep tubes should. The cover is slightly warm to the touch and as long as I keep the key Downs under a minute (ideally 30 to 45 seconds) the temperature will not rise that much. I tend to be long-winded but I'm trying to teach myself that you just can't be long-winded when using these old sweep tube amplifiers. I would venture to Guess that being long-winded even with a newer amplifier that doesn't use sweep tubes one should be careful at how long they actually key down and modulate. Anyway. I just wanted to share my first capacitor explosion/pop story with you guys. And show the before and after pictures in hopes that those in the know will tell me if they think this was a good repair. He also repaired the mfj 828. It finally works the way it should. I sent it to him without even letting him know I was sending it. I had some extra room inside the shipping box for the 350Z so bubble wrapped the 828 and sent it along. I'm not sure what he did but he did not charge me. I'm going to send him both my wm1's as they're both showing different readings and either one or both most likely need an alignment. God bless. 73's
