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Break in tubes
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I have put them in and sit on stand by,get a cup of coffee...and 5 to 10 min later nuteralize them...make sure all voltages and current are proper...73s de n0zna
Let them heat up for 20 minutes tune them and talk on them if their is no gas issue and no arcing then you should not need any elaborate break in. Unlike capacitors if nothing is wrong with them their is no need to babby them or to torture them. Just use them and in time they will settle in just fine.
Some parts do wear in nicely......Like in audio circuits cap's sound best as they get some age on them or if electrically flogged for a few months before you put them in the circuits. I have never though heard or seen any real evidence of RF circuits behaving better with used or broken in parts.
If their is data on this I would love to read it. In audio circuits you can see and hear the difference with something as simple as a cap replacement. I doubt the fidelity of amateur gear is high enough to even matter. In fact I have never heard a radio that actually sounded good all of them suck from a fidelity stand point.
Some parts do wear in nicely......Like in audio circuits cap's sound best as they get some age on them or if electrically flogged for a few months before you put them in the circuits. I have never though heard or seen any real evidence of RF circuits behaving better with used or broken in parts.
If their is data on this I would love to read it. In audio circuits you can see and hear the difference with something as simple as a cap replacement. I doubt the fidelity of amateur gear is high enough to even matter. In fact I have never heard a radio that actually sounded good all of them suck from a fidelity stand point.
What where you hoping for??? A tube is a more complex version of a light bulb!!! You do not break in a light bulb do you! You have metal wire with coatings on it that take a given amount of power. They radiate electrons that get picked up and carried into the circuit in a given manner that produces gain or limits the direction power can flow. They radiate radiant heat from various spectrums of light given off. From the time you fire up a tube it is dieng a slow death from day one as it use's up the coating on the filament and the plate get's loaded with non-essential debris. The wear that is happening is physical wear and tear but it is related to the molecular action of the flow of sub atomic particles mostly electron emissions in this case. It is not like the wear you get from mechanical parts that are rubbing like a camshaft in an engine their is no amount of heat treating, heat cycling, burnishing or deposition of ZDDP, Molly,Sulfur or phosphates on the surfaces that is going to mid agate or reduce wear should the hydrodynamic boundary layer of oil fail to separate the parts.
In the case of a tube it is just like a light bulb in that no amount of "break in" will change the wear function or how the wear occurs or the rate at which it occurs assuming you are providing it with an environment equal to what it was designed for!
I love the Harry Potter books but magic has no place in science and tubes are governed by science not magic, not faith not religion, not politics.
So no one can give you what does not exist and when it comes to tubes their is no way to magically break them in short of using them with in the guidelines set forth by the OEM that designed and made the tube!Their isno manner of operation today that will affect how they operate tomorrow. Long tube life comes from always operating them with int heir performance envelope and the lower side of the envelope you go generally the long the life!
I can make up something if you like that will make you feel insanely involved and will keep your mind busy as a mad hatter but in the end it would be total non-sense.
The best you can do is operate the tubes slightly under their peak voltages so if the heater takes from 12.3-13.6Volts often you might find it works just fine at say 11.9 volts......That would provide slightly longer life. How much life??? Well that is a question no one can answer. On the other hand some people would tell you the opposite that more voltage and less current is the way to go for longer tube life. Both schools of thought make great arguments for their belief but as far as I know neither has any real science to back up their claim!
If you want to see what I think is best practice for engine break in and Chrysler is much in line with this method too as are every single pro race team go to Motune USA for excellent reading that is the best I can do for break in and it has nothing to do with tubes!!! LOL
In the case of a tube it is just like a light bulb in that no amount of "break in" will change the wear function or how the wear occurs or the rate at which it occurs assuming you are providing it with an environment equal to what it was designed for!
I love the Harry Potter books but magic has no place in science and tubes are governed by science not magic, not faith not religion, not politics.
So no one can give you what does not exist and when it comes to tubes their is no way to magically break them in short of using them with in the guidelines set forth by the OEM that designed and made the tube!Their isno manner of operation today that will affect how they operate tomorrow. Long tube life comes from always operating them with int heir performance envelope and the lower side of the envelope you go generally the long the life!
I can make up something if you like that will make you feel insanely involved and will keep your mind busy as a mad hatter but in the end it would be total non-sense.
The best you can do is operate the tubes slightly under their peak voltages so if the heater takes from 12.3-13.6Volts often you might find it works just fine at say 11.9 volts......That would provide slightly longer life. How much life??? Well that is a question no one can answer. On the other hand some people would tell you the opposite that more voltage and less current is the way to go for longer tube life. Both schools of thought make great arguments for their belief but as far as I know neither has any real science to back up their claim!
If you want to see what I think is best practice for engine break in and Chrysler is much in line with this method too as are every single pro race team go to Motune USA for excellent reading that is the best I can do for break in and it has nothing to do with tubes!!! LOL
The light bulb does not have a anode. It does not have to hold back high voltage by preventing leakage. Tubes do. Most new tubes will require no break in procedure other then slight adjustments to the filament voltage on larger broadcast tubes. The problem is new old stock tubes that were never used but manufactured decades ago.
They can become gassy while sitting on the shelf due to slight loss of the vacuum through the seals. This is especially true of older Russian tubes like the GI-7B and GS-35B but is also common on old sweep tubes that are pushed to their maximum plate voltage in RF service.
They can arc internally when put under load the first time. Then there is nothing you can do to save the tube in most cases. However, if you take the time to apply only filament voltage for 12 hours, you can burn off any residual gas inside the tube through the getter element. It takes this long because there is literally no circulation inside the tube.
For many years RF Parts has recommended doing this with NOS sweep tubes. There are much more elaborate processes that involve using variacs to slowly bring the filament voltage up and then the same for the plate over the course of many hours. This is usually required only on those Russian surplus radar tubes.
With respect to filament voltage, you have to know what type of tube you're using before you play with this voltage. Directly heated cathodes (those that require no warm up time) as found in a 3-500Z for example, can be run at reduced voltage so long as enough electrons are being boiled off it's thorium to support the peak emissions. In other words, until power output begins to drop. This typically lengthens the tube life.
If you try this on an oxide coated cathode (those that require warm up time) including all sweep tubes you will quickly reduce the life of the tube. This oxide coating is very fragile and can be striped right off the cathode if operated before fully heated. Once the cathode on this type of tube is heated, a protective barrier is formed around the cathode to prevent this damage. Operation before full warm up time or at reduced filament voltage will kill these tubes prematurely by allowing electron flow before the cathode is protected.
They can become gassy while sitting on the shelf due to slight loss of the vacuum through the seals. This is especially true of older Russian tubes like the GI-7B and GS-35B but is also common on old sweep tubes that are pushed to their maximum plate voltage in RF service.
They can arc internally when put under load the first time. Then there is nothing you can do to save the tube in most cases. However, if you take the time to apply only filament voltage for 12 hours, you can burn off any residual gas inside the tube through the getter element. It takes this long because there is literally no circulation inside the tube.
For many years RF Parts has recommended doing this with NOS sweep tubes. There are much more elaborate processes that involve using variacs to slowly bring the filament voltage up and then the same for the plate over the course of many hours. This is usually required only on those Russian surplus radar tubes.
With respect to filament voltage, you have to know what type of tube you're using before you play with this voltage. Directly heated cathodes (those that require no warm up time) as found in a 3-500Z for example, can be run at reduced voltage so long as enough electrons are being boiled off it's thorium to support the peak emissions. In other words, until power output begins to drop. This typically lengthens the tube life.
If you try this on an oxide coated cathode (those that require warm up time) including all sweep tubes you will quickly reduce the life of the tube. This oxide coating is very fragile and can be striped right off the cathode if operated before fully heated. Once the cathode on this type of tube is heated, a protective barrier is formed around the cathode to prevent this damage. Operation before full warm up time or at reduced filament voltage will kill these tubes prematurely by allowing electron flow before the cathode is protected.
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The 6LF6 tubes are classed as receiving tubes and are aged and ready to go out of the box.
They were uses in TV as a horizontal sweep power tube.
During the TV days they never required any aging to be used during a service call or repair because the original design and use was not for transmitting... they had to be ready to use.
Where this aging comes from is a myth.
I have been in the tube manufacturing line of work many years ago and know this is how they were made, tested and boxed for shipment..
Good luck.
They were uses in TV as a horizontal sweep power tube.
During the TV days they never required any aging to be used during a service call or repair because the original design and use was not for transmitting... they had to be ready to use.
Where this aging comes from is a myth.
I have been in the tube manufacturing line of work many years ago and know this is how they were made, tested and boxed for shipment..
Good luck.
During the tube TV days, these tubes were $3.40 each, fresh stock, and operated at 15 KHz. Today they can reach $100, have been sitting on a shelf for at least 30 years for any air to migrate into the vacuum through leaky seals and are being asked to operate at more then 1000 times the frequency. Not to mention almost as much plate dissipation in some cases....lol. It's not a bad idea to run those filaments for hours prior to use on old tubes that have not been lit in decades. No myth here. Need proof? Google GS-35B tube conditioning. There are examples where many were pulled right off the shelf and tested on a Hi-Pot tester.
Some were found to have an internal breakdown voltage as low as 1800 volts before they began to leak. This is a sure sign the tube would arc internally at its full 3500 volt anode rating and destroy the tube without current limiting during the breakdown. The same tube after conditioning could hold back several KV more then its rated anode voltage before any leakage current was detected on the Hi-Pot tester. That's proof enough for me. For sweep tubes specifically, RF Parts posted a service bulletin on conditioning NOS prior to use.
Since we are classifying these tubes as receiving or transmitting, it is interesting to note that several tube manufacturers had internal company arguments over the same topic. After RCA saw many of its receiving tubes like the 6L6GC get developed into the 6146A transmitting tube, corporate sent down orders that no more receiving tubes would evolve into transmitting tubes on their production lines. They saw it as undesirable competition to their existing line of transmitting tubes.
GE on the other hand would do anything to make a buck. Come to think of it they still do by not paying any income tax. Nevertheless, they could turn a sweep tube into a transmitting tube quicker then you could blink your eye. Take the 8950 for example. All they did was take a 6LF6, swap out the filament for a 12 volt version to make it attractive for mobile TX use and used an extra pin in the base to double connect the cathode.
The best was when Maco the CB linear company contacted GE back in the 1970's about manufacturing a sweep tube just for them. Maco talked GE into taking their 8950 and adding additional plate material in the form of fins that were folded back to dissipate more heat and stuffed into a larger glass envelope! Hard to believe but that's where the M-2057 came from. The sweep tube made by GE for CB not TV.
GE on the other hand would do anything to make a buck. Come to think of it they still do by not paying any income tax. Nevertheless, they could turn a sweep tube into a transmitting tube quicker then you could blink your eye. Take the 8950 for example. All they did was take a 6LF6, swap out the filament for a 12 volt version to make it attractive for mobile TX use and used an extra pin in the base to double connect the cathode.
The best was when Maco the CB linear company contacted GE back in the 1970's about manufacturing a sweep tube just for them. Maco talked GE into taking their 8950 and adding additional plate material in the form of fins that were folded back to dissipate more heat and stuffed into a larger glass envelope! Hard to believe but that's where the M-2057 came from. The sweep tube made by GE for CB not TV.
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