Been awake now over 4 days.....I suffer from terrible insomnia and cannot afford the only pills that work well for me which are Lunesta. Insurance only covers Ambien and those do really bad things to me!!! SO I appology if I get odd with my post structure. I hope to sleep soon took some anti-hystimines lots of them to get a head start on sleeping.
Now on topic. I was thinking that when my son pass's his test and I do as well neither of us has a 100watt radio. On top of that I do not have anything currently that will operate on Amateur bands. I could modify a type rated CB easy enought for use on 10meter but I am not going to do that. I was thinking a 2950DX would be perfect because I can afford to get him one and they are rock stead on SSB,FM,AM and CW. I owned one of the original 2950's pre-dx model and no I never operated outside of allowed freq. I used it to mostly listen.
So I was thinking that if I simply copy a tube amp design from one of the many Amateur Home Brew Sites that will not help me much.
ALso I was looking at older Heathkit 6M,2M, 80, 4o and 20 and most of the old Novice class stuff was very weak in output by today's standards. Especialy true is the "Lunch-box" series.
So I was wondering if anyone had a good idea on the best tube to use based on bang for the buck and cheap enough to pick up 2-3 extra so I have spares should the market dry up.
I could use low power sweep tubes but to me that would be a step in the wrong direction since they are more expensive then they should be and the supply available is always questionable. In this case I would actually by from a large retailer so I know the tubes are tested and that they will replace anything that arrives DOA.
I am thinking that 40-60 watt's would be all the drive I need so a one tube preamp/driver is easy to do. If it was going to be just me operating I would not be afraid to use some old but NOS swep tubes I have on hand because I am not hard on tubes. Add a 13 year old to the mix and 2 9 year olds and I suddenly get worried about useing sweep tubes even int he driver section.
Since I am building from scratch voltages and curent isnot a big deal but it would be nice to stay with a tube that operates nicely at or bellow the 2500 volts the drive tubes will see and it would be ideal to keep the heater voltage in multiples of 6.3, 12.6, 24-ish etc.....I know 24 is less then a clean multiple of 6.3 just making a point of what would be ideal. Alos it does not have to be grounded grid like the main tubes are going to be run but that would prob. be a good idea too come to think of it.
So the tuning input will be tuned to these not the final and these will drive the tube finals. I am guessing that smaller, less powerful tubes will be esier to match a transitorized RF output amp from the radio to then the big output tubes. Just a guess mind you......I am also thinking that the tube drivers will match the ouput tubes better as well.
I am leaning towards the 811A because it is 100 watt of output, easier if what I have read is accurate to keep running clean and free of oscillation and parasitic issues then the 4186B/W etc........ I thought about other tubes but this one seems to make a good candidate.
In real life does the 811 tube work well at 12 meter, 6 meter, and all modes of operation? All I saw was Class C amp info for it.
So I was thinking about adding a switched in pre-amp section with a glass envelope RF tube. The 811A and 4196W/B model of tubes came to mind.
I know I am not going to use some monster like an 813 because if I was going to go that route I would just build the entire amp from 813's.
The output tubes will be Russian Military Surplus. Definitely going to build it so they can be switched out so once he has a more powerful rig he can take those driver's out of the system with just a flip of a switch.
Is their a better higher gain glass tube that I should be looking at?
I thought about Russian 509's but have heard they do
not work well about 30Mhz?
If I read the data sheet correctly 1.65 watt's of drive will give the 811A full output of 100 watt's so we could turn the RCI 2950 DX's power way down.
If I get the time tomorrow I am going to rough out the RF deck plate for the main output tubes. I have 3 thick aluminium shield plates for Full Sive GM 4X4's. Each one of the three is about the size of two laptops.
I have not found the chassis yet for the amp or the power supply.
Now on topic. I was thinking that when my son pass's his test and I do as well neither of us has a 100watt radio. On top of that I do not have anything currently that will operate on Amateur bands. I could modify a type rated CB easy enought for use on 10meter but I am not going to do that. I was thinking a 2950DX would be perfect because I can afford to get him one and they are rock stead on SSB,FM,AM and CW. I owned one of the original 2950's pre-dx model and no I never operated outside of allowed freq. I used it to mostly listen.
So I was thinking that if I simply copy a tube amp design from one of the many Amateur Home Brew Sites that will not help me much.
ALso I was looking at older Heathkit 6M,2M, 80, 4o and 20 and most of the old Novice class stuff was very weak in output by today's standards. Especialy true is the "Lunch-box" series.
So I was wondering if anyone had a good idea on the best tube to use based on bang for the buck and cheap enough to pick up 2-3 extra so I have spares should the market dry up.
I could use low power sweep tubes but to me that would be a step in the wrong direction since they are more expensive then they should be and the supply available is always questionable. In this case I would actually by from a large retailer so I know the tubes are tested and that they will replace anything that arrives DOA.
I am thinking that 40-60 watt's would be all the drive I need so a one tube preamp/driver is easy to do. If it was going to be just me operating I would not be afraid to use some old but NOS swep tubes I have on hand because I am not hard on tubes. Add a 13 year old to the mix and 2 9 year olds and I suddenly get worried about useing sweep tubes even int he driver section.
Since I am building from scratch voltages and curent isnot a big deal but it would be nice to stay with a tube that operates nicely at or bellow the 2500 volts the drive tubes will see and it would be ideal to keep the heater voltage in multiples of 6.3, 12.6, 24-ish etc.....I know 24 is less then a clean multiple of 6.3 just making a point of what would be ideal. Alos it does not have to be grounded grid like the main tubes are going to be run but that would prob. be a good idea too come to think of it.
So the tuning input will be tuned to these not the final and these will drive the tube finals. I am guessing that smaller, less powerful tubes will be esier to match a transitorized RF output amp from the radio to then the big output tubes. Just a guess mind you......I am also thinking that the tube drivers will match the ouput tubes better as well.
I am leaning towards the 811A because it is 100 watt of output, easier if what I have read is accurate to keep running clean and free of oscillation and parasitic issues then the 4186B/W etc........ I thought about other tubes but this one seems to make a good candidate.
In real life does the 811 tube work well at 12 meter, 6 meter, and all modes of operation? All I saw was Class C amp info for it.
So I was thinking about adding a switched in pre-amp section with a glass envelope RF tube. The 811A and 4196W/B model of tubes came to mind.
I know I am not going to use some monster like an 813 because if I was going to go that route I would just build the entire amp from 813's.
The output tubes will be Russian Military Surplus. Definitely going to build it so they can be switched out so once he has a more powerful rig he can take those driver's out of the system with just a flip of a switch.
Is their a better higher gain glass tube that I should be looking at?
I thought about Russian 509's but have heard they do
not work well about 30Mhz?
If I read the data sheet correctly 1.65 watt's of drive will give the 811A full output of 100 watt's so we could turn the RCI 2950 DX's power way down.
If I get the time tomorrow I am going to rough out the RF deck plate for the main output tubes. I have 3 thick aluminium shield plates for Full Sive GM 4X4's. Each one of the three is about the size of two laptops.
I have not found the chassis yet for the amp or the power supply.