| Page 1 of 2 | 1 | 2 |
|
|
6L6 substitute
After years of avoiding morse code I am finally getting into it. the
ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie |
6L6 substitute
JIMMIE wrote:
After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitute for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie An 807 IS a 6L6 with a top cap anode connection. Any of the TV line output valves will also do the job if you want cheap, the 6DQ6B works well and has an octal base (The sockets for the 807 are rare). 6146 or 2e26 etc work well but will cost you more. Steve H |
6L6 substitute
On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH
StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. 73 de n4jvp |
6L6 substitute
JIMMIE wrote:
After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie I'd go for a PL509 sweep output tube. I've had a kilowatt out of four of them! Bob |
6L6 substitute
Registered User wrote:
On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. 73 de n4jvp I'm in the UK and haven't been able to find any at the local hamfests, where can I get them from? Octal sockets are readily available over here. Steve H |
6L6 substitute
Bob wrote:
JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie I'd go for a PL509 sweep output tube. I've had a kilowatt out of four of them! Bob My first amp had 3 PL519s with a lethal power supply using a voltage tripper direct off the 240V mains, heaters were direct off mains via a 1n5406 diode. It's still up in the parents loft somewhere, must dig it out over the holidays and give it a try.... Steve H |
6L6 substitute
On Thu, 04 Dec 2008 21:24:37 +0000, Stev eH
StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: Registered User wrote: On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. 73 de n4jvp I'm in the UK and haven't been able to find any at the local hamfests, where can I get them from? Octal sockets are readily available over here. Hmm, I'm surprised you haven't come across any at boot sales. I'm of no help when it comes to vendors in the UK. You might try your favorite search engine. The first page of this search links to several vendors including one in AU. http://www.google.com/search?hl=en&q...ocket&aq=f&oq= eBay is another possibility. 73 de n4jvp |
6L6 substitute
On Thu, 4 Dec 2008, JIMMIE wrote:
Date: Thu, 4 Dec 2008 06:23:48 -0800 (PST) From: JIMMIE Newsgroups: rec.radio.amateur.homebrew Subject: 6L6 substitute After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. Maybe you should look at how you bypassed the screen grid to ground with a capacitor. Once I built a 6146 pentode, grounded-cathode amplifier for 160 meters and was disappointed that it went into self-oscillation. After thinking about it, and then the light bulb over my head went off, I looked and realized I did not have the screen grid bypassed to ground (what, 0.01 mfd or so?), and when I soldered one in, all of my self oscilation stopped. You should not have to worry about neutralization if you are anywhere in the HF bands (or, at the worst, maybe on ten meters). I've built several 6AQ5, 6V6, etc., one tube, xtal-controlled CW transmitters. All worked fine. I am considering an 807 as a replacement Suggestions would be appreciated. You might also want to check the connections to the control grid. If for some reason you have a -- for example -- cold solder joint and the control grid is actually floating, then it will oscillate all by itself, too. Jimmie |
6L6 substitute
On Thu, 4 Dec 2008, Registered User wrote: Date: Thu, 04 Dec 2008 19:30:30 -0500 From: Registered User Newsgroups: rec.radio.amateur.homebrew Subject: 6L6 substitute On Thu, 04 Dec 2008 21:24:37 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: Registered User wrote: On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. 73 de n4jvp I'm in the UK and haven't been able to find any at the local hamfests, where can I get them from? Octal sockets are readily available over here. Hmm, I'm surprised you haven't come across any at boot sales. I'm of no help when it comes to vendors in the UK. You might try your favorite search engine. The first page of this search links to several vendors including one in AU. http://www.google.com/search?hl=en&q...ocket&aq=f&oq= eBay is another possibility. 73 de n4jvp Might try Fair Radio Sales, in Lima Ohio (USA). I think www.fairradio.com, and they do (most of the time) answer email. They have stuff that is not in the catalog, too. |
6L6 substitute
"Stev eH"
StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote in message ... My first amp had 3 PL519s with a lethal power supply using a voltage tripp{l}er direct off the 240V mains, heaters were direct off mains via a 1n5406 diode. It's still up in the parents loft somewhere, must dig it out over the holidays and give it a try.... Steve H Do you realize that the RMS value of half-wave rectified AC is not one half of the applied RMS voltage but rather 0.707 of the applied RMS voltage. So your three 40 volt filament PL519s actually saw about 56 volts RMS across each filament. I'll bet you wondered why the filaments were so bright. To properly measure this voltage, you need a true RMS voltmeter. Most inepensive AC voltmeters actually measure the peak voltage and display the result on a scale calibrated for a sine wave input. RMS (root mean square) is the equivalent DC voltage that would produce the same HEATING in a resistance as the applied waveform. Most hams are quite confused by this. Looking over some websites explaining this, one of the better ones is a Google Book Search of "Electric Machinery Fundamentals" by Stephen J. Chapman who presents the mathematics in detail starting on page 163: http://books.google.com/books?id=ltg...m=10&ct=result As an interesting side note, the Philips datasheet on the PL519 is the first I have seen that explicitly discusses Barkhausen interference and how to suppress it. 73, Dr. Barry L. Ornitz WA4VZQ |
6L6 substitute
"NoSPAM" wrote in
: snips "Electric Machinery Fundamentals" by Stephen J. Chapman who presents the mathematics in detail starting on page 163: snips Howdy, Coincidence! That book is on my kitchen table at the moment. It's ok, but this is probably more suited to the purpose; http://www.tpub.com/neets/book7/27a.htm 73,Grumpy |
6L6 substitute
On Thu, 04 Dec 2008 21:24:37 +0000, Stev eH wrote:
Registered User wrote: On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. 73 de n4jvp I'm in the UK and haven't been able to find any at the local hamfests, where can I get them from? Octal sockets are readily available over here. Steve H I have some. How many you need? Cheers, Gregg |
6L6 substitute
On Dec 4, 1:20*pm, Registered User wrote:
On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsd*gfgsfghgjsghgsljhglhdjfg hfufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbl wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. Chinese Ceramic 5- and 7-pin sockets for 807's and 1625's are readily available. e.g. P-ST5-216 and P-ST7-311 from Antique Electronic Supply, or the same thing from ESRC on Ebay, items 130273824548 and 130273500741, or similar thigns from at least a dozen other web suppliers. (Antique Electronic Supply and ESRC I've been doing business with for many years). Vintage ceramic sockets from the 40's and 50's made by EF Johnson etc. turn up at hamfests pretty regularly too. Tim N3QE |
6L6 substitute
On Thu, 04 Dec 2008 06:23:48 -0800, JIMMIE wrote:
After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie Dunno if it's been mentioned yet -- 2E26. The 807 is _not_ a 6L6 in a different envelope -- it's quit arguably the 6L6's big brother, but it's got different ratings; it could probably be shoe-horned into a circuit designed for the 6L6, but you'd be missing out on about 6dB of final output power. Antique Electronics Supply has 2E26's for $6.00 each, so it's not a bad buy -- and the 2E26 goes into an octal socket. -- Tim Wescott Control systems and communications consulting http://www.wescottdesign.com Need to learn how to apply control theory in your embedded system? "Applied Control Theory for Embedded Systems" by Tim Wescott Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html |
6L6 substitute
On Thu, 04 Dec 2008 06:23:48 -0800, JIMMIE wrote:
After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie Have you considered a 6L6 with careful shielding at the socket? IIRC the pins that neighbor the plate pin would be at RF potential; you could put a big, flat, high-value ceramic right between those socket pins to shield the grid, and possible even extend the shield out if you were willing to hand-make a cap from copper strip and Kapton tape. It's kinda heroic measures to take on a tube that's more expensive now than it's "high-tech" RF brethren, but if you just gotta have that metal- tube look it may do the trick. -- Tim Wescott Control systems and communications consulting http://www.wescottdesign.com Need to learn how to apply control theory in your embedded system? "Applied Control Theory for Embedded Systems" by Tim Wescott Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html |
6L6 substitute
On Dec 5, 11:28*am, Tim Wescott wrote:
On Thu, 04 Dec 2008 06:23:48 -0800, JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie Have you considered a 6L6 with careful shielding at the socket? *IIRC the pins that neighbor the plate pin would be at RF potential; you could put a big, flat, high-value ceramic right between those socket pins to shield the grid, and possible even extend the shield out if you were willing to hand-make a cap from copper strip and Kapton tape. It's kinda heroic measures to take on a tube that's more expensive now than it's "high-tech" RF brethren, but if you just gotta have that metal- tube look it may do the trick. -- Tim Wescott Control systems and communications consultinghttp://www.wescottdesign.com Need to learn how to apply control theory in your embedded system? "Applied Control Theory for Embedded Systems" by Tim Wescott Elsevier/Newnes,http://www.wescottdesign.com/actfes/actfes.html I have a NOS 6DQ6 I can use in place of the 6L6s. I think they will work. the biggest problem will be relocating the plate circuit. I will have to add a front panel to my "fool killer" to hold the tuning caps. Jimmie |
6L6 substitute
geek wrote:
On Thu, 04 Dec 2008 21:24:37 +0000, Stev eH wrote: Registered User wrote: On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. 73 de n4jvp I'm in the UK and haven't been able to find any at the local hamfests, where can I get them from? Octal sockets are readily available over here. Steve H I have some. How many you need? Cheers, Gregg I could do with a pair, I have several 807 in the junk box and the look far better to me than the "Modern" style of valve. The email address is valid BTW. Steve H |
6L6 substitute
On Dec 5, 12:27*pm, Stev eH
I could do with a pair, I have several 807 in the junk box and the look far better to me than the "Modern" style of valve. Even modern Chinese-made 807's have the ST glass shape. The one that is not sexy is the 807W. My favorite book of tube pr0n is "RCA Air-Cooled Transmitting Tubes", TT3. Great big full-page engravings of the best tubes. Worth all 25 cents. Tim. |
6L6 substitute
On Fri, 05 Dec 2008 17:27:27 +0000, Stev eH wrote:
geek wrote: On Thu, 04 Dec 2008 21:24:37 +0000, Stev eH wrote: Registered User wrote: On Thu, 04 Dec 2008 17:56:27 +0000, Stev eH StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdgfgsfghgjsghgsljhglhdjfgh fufgfhzysgfhczgugfvzlvufzvllgfzlyfyvlgbylvdfghvbly wrote: The sockets for the 807 are rare The 807 uses a readily available 5 contact socket. The 1625 (12V equivalent) uses a 7 contact socket which can be difficult to locate. 73 de n4jvp I'm in the UK and haven't been able to find any at the local hamfests, where can I get them from? Octal sockets are readily available over here. Steve H I have some. How many you need? Cheers, Gregg I could do with a pair, I have several 807 in the junk box and the look far better to me than the "Modern" style of valve. The email address is valid BTW. Steve H Hi Steve, Sent you an email :-) Mine is geek at scorpiorising dot ca if you don't get it. Cheers, Gregg |
6L6 substitute
Stev eH wrote:
JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitute for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie An 807 IS a 6L6 with a top cap anode connection. Any of the TV line output valves will also do the job if you want cheap, the 6DQ6B works well and has an octal base (The sockets for the 807 are rare). 6146 or 2e26 etc work well but will cost you more. Steve H The 6BG6G / GA sweep tube is identical to the 6L6G but with a top plate cap. |
6L6 substitute
Tim Wescott wrote:
On Thu, 04 Dec 2008 06:23:48 -0800, JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie Dunno if it's been mentioned yet -- 2E26. The 807 is _not_ a 6L6 in a different envelope -- it's quit arguably the 6L6's big brother, but it's got different ratings; it could probably be shoe-horned into a circuit designed for the 6L6, but you'd be missing out on about 6dB of final output power. The 807 IS a 6L6G with a 5 pin base and the plate connected to the top. The published ratings of the 6L6G look different than the 807 because of their intended use. ICAS ratings for the 6L6G were never published. Also the 807 has additional shielding and insulation over the 6L6G that make it usable at higher frequencies and voltages than the 6L6G. Most 807's have ceramic spaces to support the plate which are lacking in the 6L6G. But make no mistake about it, the two tubes share the IDENTICAL cathode, grids, and plate structures. The 6BG6G tv sweep tube IS an 807 with an octal base. It has the same ceramic plate supports, but lacks the extra rf shielding. The 1625 is an 807 with a 12.6 volt heater and a large (same as type '59) 7 pin base. The type 1614 is a metal tube based on the 6L6. It is a transmitting version, and probably has additional shielding. Otherwise its internal structure is the same as the 6L6 metal type. The type 1619 is sorta kinda a 6L6 with a directly heated 2.5v cathode. Same metal bulb as the 6L6. Specs' are different due to the different element spacing thanks to the filament cathode. This tube is often triode connected to replace 45's and 2A3's in old radios with a socket adapter. As a result the of the construction differences regarding shielding, the 807 often would NOT need neutralization while 6L6G's and 6BG6G tubes used as rf power amps do. The 6L6GA was identical to the 6L6G except that the bulb shrunk from an ST16 to an ST14 size. The 6L6GB was identical except for the bulb changing again to a T14. The 6L6GC is a totally different bottle with higher plate and screen dissipation and plate voltage ratings. The 6L6GC was said to be a plug in replacement for the older 6L6 tubes, but RCA kept the 6L6GB around for a while anyway. In fact a bias re-adjustment was a good idea when replacing an older 6L6 with the 'GC version if a cathode bias resistor wasn't used. Antique Electronics Supply has 2E26's for $6.00 each, so it's not a bad buy -- and the 2E26 goes into an octal socket. |
6L6 substitute
In article
, JIMMIE wrote: I am considering an 807 as a replacement Jimmie- Just how simple will this transmitter be? My first novice transmitter was built from an ARRL publication back in the 50s. The specification was for a single 6V6, used as a crystal oscillator with output coupled to the antenna. I found I could get more power with a 6L6 plugged into the same socket. Along the way to getting more power, I found that crystal current would increase to the point where the crystal would fracture! If you use a 807 or 1625, I hope you will have a lower power oscillator driving it. Something like a 6AG7 would make a nice crystal oscillator, and should have sufficient output to drive an 807. 73, Fred K4DII |
6L6 substitute
Fred McKenzie wrote:
In article , JIMMIE wrote: I am considering an 807 as a replacement Jimmie- Just how simple will this transmitter be? My first novice transmitter was built from an ARRL publication back in the 50s. The specification was for a single 6V6, used as a crystal oscillator with output coupled to the antenna. I found I could get more power with a 6L6 plugged into the same socket. Along the way to getting more power, I found that crystal current would increase to the point where the crystal would fracture! If you use a 807 or 1625, I hope you will have a lower power oscillator driving it. Something like a 6AG7 would make a nice crystal oscillator, and should have sufficient output to drive an 807. 73, Fred K4DII The 6AG7 - 807 combo is a classic. E. F. Johnson sold a 50 Watt Novice transmitter in the '50's with this tube line up (also a 5R4GY rectifier IIRC). Other tubes that have been used as the oscillator/driver were the 6CL6, 12BY7, 6GK6, and 5763. |
6L6 substitute
"Stev eH" StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdg fgsfghgjsghgsljhglhdjfghfufgfhzysgfhczgugfvzlvufzv llgfzlyfyvlgbylvdfghvblyry wrote in message ... JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitute for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie An 807 IS a 6L6 with a top cap anode connection. Any of the TV line output valves will also do the job if you want cheap, the 6DQ6B works well and has an octal base (The sockets for the 807 are rare). 6146 or 2e26 etc work well but will cost you more. Steve H No way! Back in the old days I've used both 6L6 and 807's and they are not the same tube at all. You could probably use a 6L6 to drive an 807 though IIRC, the usual driver for an 807 was often a 6AG7 but I'd sure a 6L6 would be fine |
6L6 substitute
philo wrote:
"Stev eH" StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdg fgsfghgjsghgsljhglhdjfghfufgfhzysgfhczgugfvzlvufzv llgfzlyfyvlgbylvdfghvblyry wrote in message ... JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitute for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie An 807 IS a 6L6 with a top cap anode connection. Any of the TV line output valves will also do the job if you want cheap, the 6DQ6B works well and has an octal base (The sockets for the 807 are rare). 6146 or 2e26 etc work well but will cost you more. Steve H No way! Back in the old days I've used both 6L6 and 807's and they are not the same tube at all. You could probably use a 6L6 to drive an 807 though IIRC, the usual driver for an 807 was often a 6AG7 but I'd sure a 6L6 would be fine Just for grins I got out the RCA tube handbook and compared the plate curves for the 807 and the 6L6. Up to the limits for the 6L6, they are IDENTICAL. The 807 curves go to higher plate voltage and current. The 807 and the 6L6 have the SAME cathode, grid and plate structures. The differences are in the shielding added to the 807 to reduce grid-plate and grid-cathode capacitance, and in the plate support spacers which are ceramic in the 807 to increase the operating voltage rating of the tube (which is also helped by the plate top connection). You can see the added shielding just above and below the plate supports. The 807 is a MUCH better performer at RF than the 6L6, it usually does NOT require neutralization and would have more power gain than the 6L6. At Audio frequencies the two tubes will perform IDENTICALLY within their maximum ratings. |
6L6 substitute
"ken scharf" wrote in message ... philo wrote: "Stev eH" StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdg fgsfghgjsghgsljhglhdjfghfufgfhzysgfhczgugfvzlvufzv llgfzlyfyvlgbylvdfghvblyry wrote in message ... JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitute for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie An 807 IS a 6L6 with a top cap anode connection. Any of the TV line output valves will also do the job if you want cheap, the 6DQ6B works well and has an octal base (The sockets for the 807 are rare). 6146 or 2e26 etc work well but will cost you more. Steve H No way! Back in the old days I've used both 6L6 and 807's and they are not the same tube at all. You could probably use a 6L6 to drive an 807 though IIRC, the usual driver for an 807 was often a 6AG7 but I'd sure a 6L6 would be fine Just for grins I got out the RCA tube handbook and compared the plate curves for the 807 and the 6L6. Up to the limits for the 6L6, they are IDENTICAL. The 807 curves go to higher plate voltage and current. The 807 and the 6L6 have the SAME cathode, grid and plate structures. The differences are in the shielding added to the 807 to reduce grid-plate and grid-cathode capacitance, and in the plate support spacers which are ceramic in the 807 to increase the operating voltage rating of the tube (which is also helped by the plate top connection). You can see the added shielding just above and below the plate supports. The 807 is a MUCH better performer at RF than the 6L6, it usually does NOT require neutralization and would have more power gain than the 6L6. At Audio frequencies the two tubes will perform IDENTICALLY within their maximum ratings. Wow...thanks for the info. They are considerably closer in specs than I realized. Of course, you could run an 807 quite a bit past their official ratings and never burn one out. I recall tuning my transmitter for absolute maximum output...and that occurred right around 50watts input. (probably on 40 meters. I'm sure that on ten meters it would have been a lot less) Ran my 807 rig for years like that. Don't really know what my 6L6 transmitter would have done... just ran it on 40 meters at about 25 watts input...we always just considered them to be audio tubes. If I were going to build a tube transmitter today, I'd probably use a 6146B. |
6L6 substitute
philo wrote:
"ken scharf" wrote in message ... philo wrote: "Stev eH" StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdg fgsfghgjsghgsljhglhdjfghfufgfhzysgfhczgugfvzlvufzv llgfzlyfyvlgbylvdfghvblyry wrote in message ... JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitute for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie An 807 IS a 6L6 with a top cap anode connection. Any of the TV line output valves will also do the job if you want cheap, the 6DQ6B works well and has an octal base (The sockets for the 807 are rare). 6146 or 2e26 etc work well but will cost you more. Steve H No way! Back in the old days I've used both 6L6 and 807's and they are not the same tube at all. You could probably use a 6L6 to drive an 807 though IIRC, the usual driver for an 807 was often a 6AG7 but I'd sure a 6L6 would be fine Just for grins I got out the RCA tube handbook and compared the plate curves for the 807 and the 6L6. Up to the limits for the 6L6, they are IDENTICAL. The 807 curves go to higher plate voltage and current. The 807 and the 6L6 have the SAME cathode, grid and plate structures. The differences are in the shielding added to the 807 to reduce grid-plate and grid-cathode capacitance, and in the plate support spacers which are ceramic in the 807 to increase the operating voltage rating of the tube (which is also helped by the plate top connection). You can see the added shielding just above and below the plate supports. The 807 is a MUCH better performer at RF than the 6L6, it usually does NOT require neutralization and would have more power gain than the 6L6. At Audio frequencies the two tubes will perform IDENTICALLY within their maximum ratings. Wow...thanks for the info. They are considerably closer in specs than I realized. Of course, you could run an 807 quite a bit past their official ratings and never burn one out. I recall tuning my transmitter for absolute maximum output...and that occurred right around 50watts input. (probably on 40 meters. I'm sure that on ten meters it would have been a lot less) Ran my 807 rig for years like that. Don't really know what my 6L6 transmitter would have done... just ran it on 40 meters at about 25 watts input...we always just considered them to be audio tubes. If I were going to build a tube transmitter today, I'd probably use a 6146B. Well the 6L6 has changed over the years, while the 807 never did (except for the 'W' version). Later 6L6 versions might have changed the outward appearance of the plate in response to cost cutting and automated assembly lines, but the internal spacing of the elements remained the same. If you look on the QST archives (are you an ARRL member?) on line for those old 'QSL 40' series of articles on home brew transmitters using the 6L6G tube you can see in the pictures how the plate structure is the same for the original 6L6G tube as the 807. And if the claims for this tube in those home brew articles is true, the 6L6 was JUST as rugged as the 807 in being pushed past it's ratings. Only the 6L6 would probably arc over at the socket before the plate voltage reached what the 807 would handle (I've heard of 807's taking over 1000 volts on the plate just fine!). The official ICAS ratings for the 807 allow up to 750 volts at 100ma plate current, and there is a typical operation shown at 75 watts input, so at 50w your transmitter wasn't even breaking a sweat yet! A pair of 807's in AB2 (SSB linear) will put out 120w PEP, just about the same as a pair of 6146's. The 6146B officially will do about 135-140w in the same service. Note that ICAS ratings for the 6L6 were never published, but you can assume that the 6L6 is identical to the 807 EXCEPT for the plate voltage rating, which I would guess is good to 500v or so. |
6L6 substitute
"ken scharf" wrote in message ... philo wrote: "ken scharf" wrote in message ... philo wrote: "Stev eH" StevehkhhSDJvhvbjjxbvvbhnvbhzjdnxzvzhzdshbvnjzvnb vnvjbvbcjbvvvvnmxvzjhjzsdg fgsfghgjsghgsljhglhdjfghfufgfhzysgfhczgugfvzlvufzv llgfzlyfyvlgbylvdfghvblyry wrote in message ... JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitute for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie An 807 IS a 6L6 with a top cap anode connection. Any of the TV line output valves will also do the job if you want cheap, the 6DQ6B works well and has an octal base (The sockets for the 807 are rare). 6146 or 2e26 etc work well but will cost you more. Steve H No way! Back in the old days I've used both 6L6 and 807's and they are not the same tube at all. You could probably use a 6L6 to drive an 807 though IIRC, the usual driver for an 807 was often a 6AG7 but I'd sure a 6L6 would be fine Just for grins I got out the RCA tube handbook and compared the plate curves for the 807 and the 6L6. Up to the limits for the 6L6, they are IDENTICAL. The 807 curves go to higher plate voltage and current. The 807 and the 6L6 have the SAME cathode, grid and plate structures. The differences are in the shielding added to the 807 to reduce grid-plate and grid-cathode capacitance, and in the plate support spacers which are ceramic in the 807 to increase the operating voltage rating of the tube (which is also helped by the plate top connection). You can see the added shielding just above and below the plate supports. The 807 is a MUCH better performer at RF than the 6L6, it usually does NOT require neutralization and would have more power gain than the 6L6. At Audio frequencies the two tubes will perform IDENTICALLY within their maximum ratings. Wow...thanks for the info. They are considerably closer in specs than I realized. Of course, you could run an 807 quite a bit past their official ratings and never burn one out. I recall tuning my transmitter for absolute maximum output...and that occurred right around 50watts input. (probably on 40 meters. I'm sure that on ten meters it would have been a lot less) Ran my 807 rig for years like that. Don't really know what my 6L6 transmitter would have done... just ran it on 40 meters at about 25 watts input...we always just considered them to be audio tubes. If I were going to build a tube transmitter today, I'd probably use a 6146B. Well the 6L6 has changed over the years, while the 807 never did (except for the 'W' version). Later 6L6 versions might have changed the outward appearance of the plate in response to cost cutting and automated assembly lines, but the internal spacing of the elements remained the same. If you look on the QST archives (are you an ARRL member?) on line for those old 'QSL 40' series of articles on home brew transmitters using the 6L6G tube you can see in the pictures how the plate structure is the same for the original 6L6G tube as the 807. And if the claims for this tube in those home brew articles is true, the 6L6 was JUST as rugged as the 807 in being pushed past it's ratings. Only the 6L6 would probably arc over at the socket before the plate voltage reached what the 807 would handle (I've heard of 807's taking over 1000 volts on the plate just fine!). The official ICAS ratings for the 807 allow up to 750 volts at 100ma plate current, and there is a typical operation shown at 75 watts input, so at 50w your transmitter wasn't even breaking a sweat yet! A pair of 807's in AB2 (SSB linear) will put out 120w PEP, just about the same as a pair of 6146's. The 6146B officially will do about 135-140w in the same service. Note that ICAS ratings for the 6L6 were never published, but you can assume that the 6L6 is identical to the 807 EXCEPT for the plate voltage rating, which I would guess is good to 500v or so. Been a long time...but I am sure the plate voltage on my 807 was at least 600 volts or so. One thing I also recall, when I had a filter cap short out on a different set... is seeing the rectifier tube arc over. Of course, once the faulty cap. was replaced...the tube worked fine! |
6L6 substitute
ken scharf wrote:
snip (I've heard of 807's taking over 1000 volts on the plate just fine!). The official ICAS ratings for the 807 allow up to 750 volts at 100ma plate current, and there is a typical operation shown at 75 watts input, so at 50w your transmitter wasn't even breaking a sweat yet! A pair of 807's in AB2 (SSB linear) will put out 120w PEP, just about the same as a pair of 6146's. The 6146B officially will do about 135-140w in the same service. snip FWIW, here is a homebrew quad 837/807 linear that does 2kw PEP with 2KV on the plates (I have it but did not homebrew this one): http://www.cybertheque.org/homebrew/837_linear I took the photos some years ago using a digital camera with focus and image burn issues; this summer I intend to reshoot these with a better camera. Michael |
6L6 substitute
"msg" wrote in message ernet... ken scharf wrote: snip (I've heard of 807's taking over 1000 volts on the plate just fine!). The official ICAS ratings for the 807 allow up to 750 volts at 100ma plate current, and there is a typical operation shown at 75 watts input, so at 50w your transmitter wasn't even breaking a sweat yet! A pair of 807's in AB2 (SSB linear) will put out 120w PEP, just about the same as a pair of 6146's. The 6146B officially will do about 135-140w in the same service. snip FWIW, here is a homebrew quad 837/807 linear that does 2kw PEP with 2KV on the plates (I have it but did not homebrew this one): http://www.cybertheque.org/homebrew/837_linear I took the photos some years ago using a digital camera with focus and image burn issues; this summer I intend to reshoot these with a better camera. Michael Looks good! For "on-line" viewing the photos you took look fine on this end. |
6L6 substitute
On Sun, 07 Dec 2008 13:08:00 -0600, msg wrote:
ken scharf wrote: snip (I've heard of 807's taking over 1000 volts on the plate just fine!). The official ICAS ratings for the 807 allow up to 750 volts at 100ma plate current, and there is a typical operation shown at 75 watts input, so at 50w your transmitter wasn't even breaking a sweat yet! A pair of 807's in AB2 (SSB linear) will put out 120w PEP, just about the same as a pair of 6146's. The 6146B officially will do about 135-140w in the same service. snip FWIW, here is a homebrew quad 837/807 linear that does 2kw PEP with 2KV on the plates (I have it but did not homebrew this one): http://www.cybertheque.org/homebrew/837_linear I took the photos some years ago using a digital camera with focus and image burn issues; this summer I intend to reshoot these with a better camera. Michael I built a 837 "linear" back around 1958. I used mercury vapor rectifier tubes - love that blue glow. It worked pretty well at about 1200V. I used it mostly for CW and some AM. The 837s were cheap and pretty rugged. Damn near killed my self on the high voltage so I got rid of it. Bruce W0BF |
6L6 substitute
On Sat, 06 Dec 2008 16:41:00 -0500, ken scharf
wrote: Fred McKenzie wrote: In article , JIMMIE wrote: I am considering an 807 as a replacement Jimmie- Just how simple will this transmitter be? My first novice transmitter was built from an ARRL publication back in the 50s. The specification was for a single 6V6, used as a crystal oscillator with output coupled to the antenna. I found I could get more power with a 6L6 plugged into the same socket. Along the way to getting more power, I found that crystal current would increase to the point where the crystal would fracture! If you use a 807 or 1625, I hope you will have a lower power oscillator driving it. Something like a 6AG7 would make a nice crystal oscillator, and should have sufficient output to drive an 807. 73, Fred K4DII The 6AG7 - 807 combo is a classic. E. F. Johnson sold a 50 Watt Novice transmitter in the '50's with this tube line up (also a 5R4GY rectifier IIRC). Other tubes that have been used as the oscillator/driver were the 6CL6, 12BY7, 6GK6, and 5763. That would be the Johnson Viking Adventurer. I built one in 1955 from a kit. I later replaced the 807 with a 6146 - didn't make much difference, actually. Bruce W0BF |
6L6 substitute
"Bruce W. Ellis" wrote in message ... On Sat, 06 Dec 2008 16:41:00 -0500, ken scharf wrote: Fred McKenzie wrote: In article , JIMMIE wrote: I am considering an 807 as a replacement Jimmie- Just how simple will this transmitter be? My first novice transmitter was built from an ARRL publication back in the 50s. The specification was for a single 6V6, used as a crystal oscillator with output coupled to the antenna. I found I could get more power with a 6L6 plugged into the same socket. Along the way to getting more power, I found that crystal current would increase to the point where the crystal would fracture! If you use a 807 or 1625, I hope you will have a lower power oscillator driving it. Something like a 6AG7 would make a nice crystal oscillator, and should have sufficient output to drive an 807. 73, Fred K4DII The 6AG7 - 807 combo is a classic. E. F. Johnson sold a 50 Watt Novice transmitter in the '50's with this tube line up (also a 5R4GY rectifier IIRC). Other tubes that have been used as the oscillator/driver were the 6CL6, 12BY7, 6GK6, and 5763. That would be the Johnson Viking Adventurer. I built one in 1955 from a kit. I later replaced the 807 with a 6146 - didn't make much difference, actually. Bruce W0BF Yep, that's what I started out with. Bought my Adventurer used back in 1964 along with an HQ-110c. When I got my General ticket I got a nice drifty Knight Kit VFO. My antenna relay was taken from an old pinball machine! My best contact was Ascension Island . Africa on a 40 meter CW.. I used a wire vertical... that was not terribly vertical G |
6L6 substitute
On Dec 5, 11:28*am, Tim Wescott wrote:
On Thu, 04 Dec 2008 06:23:48 -0800, JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie Have you considered a 6L6 with careful shielding at the socket? *IIRC the pins that neighbor the plate pin would be at RF potential; you could put a big, flat, high-value ceramic right between those socket pins to shield the grid, and possible even extend the shield out if you were willing to hand-make a cap from copper strip and Kapton tape. It's kinda heroic measures to take on a tube that's more expensive now than it's "high-tech" RF brethren, but if you just gotta have that metal- tube look it may do the trick. -- Tim Wescott Control systems and communications consultinghttp://www.wescottdesign.com Need to learn how to apply control theory in your embedded system? "Applied Control Theory for Embedded Systems" by Tim Wescott Elsevier/Newnes,http://www.wescottdesign.com/actfes/actfes.html Thanks Tim, I rplaced the 6L6 with a 6DQ6 and all is right with the world on this end. Im putting out about 40 watts on 80M. My next project may be building a little super rengerative receiver. Im trying to see just how little I can get by with and still have a productive station. Jimmie |
6L6 substitute
You could try the 5B/254M which is a smaller and slimmer version of the 807.
|
6L6 substitute
"JIMMIE" wrote in message ... .. My next project may be building a little super rengerative receiver. You mean a regenerative receiver, surely? |
6L6 substitute
On Dec 8, 5:15*am, "Theo" wrote:
"JIMMIE" wrote in message ... . My next project may be building a little super rengerative receiver. You mean a regenerative receiver, surely? Yes one should not type and carry on a conversation with thier wife at the same time. Jimmie |
6L6 substitute
On Mon, 8 Dec 2008 10:07:11 -0000, "Theo"
wrote: You could try the 5B/254M which is a smaller and slimmer version of the 807. Somewhat OT.. Oldtimers refer to a bottle of beer as an 807. Never heard of a 6L6GT referred to that way. I suppose a whiskey bottle could be called an 813. Time for a couple of 807's. Bruce W0BF |
6L6 substitute
ken scharf wrote:
Tim Wescott wrote: On Thu, 04 Dec 2008 06:23:48 -0800, JIMMIE wrote: After years of avoiding morse code I am finally getting into it. the ideal of operating a very simple transmitter appeals to my junkbox/ trashcan construction mentality. I am looking for a substitue for a 6L6 that has the plate brought out the top. I was trying to build a little Glowbug transmitter but was having all kinds of problems neutralizing the the thing. I think I would have better luck if I can separate the grid and plate circuits from each other. I am considering an 807 as a replacement Suggestions would be appreciated. Jimmie Dunno if it's been mentioned yet -- 2E26. The 807 is _not_ a 6L6 in a different envelope -- it's quit arguably the 6L6's big brother, but it's got different ratings; it could probably be shoe-horned into a circuit designed for the 6L6, but you'd be missing out on about 6dB of final output power. The 807 IS a 6L6G with a 5 pin base and the plate connected to the top. The published ratings of the 6L6G look different than the 807 because of their intended use. ICAS ratings for the 6L6G were never published. Also the 807 has additional shielding and insulation over the 6L6G that make it usable at higher frequencies and voltages than the 6L6G. Most 807's have ceramic spaces to support the plate which are lacking in the 6L6G. But make no mistake about it, the two tubes share the IDENTICAL cathode, grids, and plate structures. The 6BG6G tv sweep tube IS an 807 with an octal base. It has the same ceramic plate supports, but lacks the extra rf shielding. The 1625 is an 807 with a 12.6 volt heater and a large (same as type '59) 7 pin base. The type 1614 is a metal tube based on the 6L6. It is a transmitting version, and probably has additional shielding. Otherwise its internal structure is the same as the 6L6 metal type. The type 1619 is sorta kinda a 6L6 with a directly heated 2.5v cathode. Same metal bulb as the 6L6. Specs' are different due to the different element spacing thanks to the filament cathode. This tube is often triode connected to replace 45's and 2A3's in old radios with a socket adapter. As a result the of the construction differences regarding shielding, the 807 often would NOT need neutralization while 6L6G's and 6BG6G tubes used as rf power amps do. The 6L6GA was identical to the 6L6G except that the bulb shrunk from an ST16 to an ST14 size. The 6L6GB was identical except for the bulb changing again to a T14. The 6L6GC is a totally different bottle with higher plate and screen dissipation and plate voltage ratings. The 6L6GC was said to be a plug in replacement for the older 6L6 tubes, but RCA kept the 6L6GB around for a while anyway. In fact a bias re-adjustment was a good idea when replacing an older 6L6 with the 'GC version if a cathode bias resistor wasn't used. I bow to your superior knowledge. How do you know? Time spent busting tubes and looking inside? Old-time service and/or circuit design experience? Experience building tubes? I'd love to see a detailed family tree for some of the more popular tube types. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html |
| All times are GMT +1. The time now is 01:55 AM. |
|
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
RadioBanter.com