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Sweep tube
Hi, all concerned:
What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. Fella used to sell 'em in some of the mid-west hamfests, but I haven't seen him for a while. Think his name is Don, and that he was also in to Racal receivers. TIA & 73 |
Behold, David J Windisch signalled from keyed 4-1000A filament:
Hi, all concerned: What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. Fella used to sell 'em in some of the mid-west hamfests, but I haven't seen him for a while. Think his name is Don, and that he was also in to Racal receivers. TIA & 73 I know the Sylvania 6LF6 tubes, custom made for Motorola were heavier duty - rated 50 watts Pa continuous........ -- Gregg *It's probably useful, even if it can't be SPICE'd* http://geek.scorpiorising.ca |
Gregg wrote in message news:4XtJc.56662$eO.20724@edtnps89...
Behold, David J Windisch signalled from keyed 4-1000A filament: Hi, all concerned: What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. Fella used to sell 'em in some of the mid-west hamfests, but I haven't seen him for a while. Think his name is Don, and that he was also in to Racal receivers. TIA & 73 I know the Sylvania 6LF6 tubes, custom made for Motorola were heavier duty - rated 50 watts Pa continuous........ 6JS6 is the number that emerges from the cobwebbed long term memory - used a lot in Yaesu stuff as pa tubes, ie 101's. Cheaper than 6146's in those days, now the situation is reversed so the old rigs are being modified to 6146's Unless you have boxes of them stashed away, dont design anything around them, a long obselete technology... 73 de VK3BFA Andrew PS - I have several dozen 807's in the junk box, will use them one day..... |
Andrew VK3BFA wrote:
Gregg wrote in message news:4XtJc.56662$eO.20724@edtnps89... Behold, David J Windisch signalled from keyed 4-1000A filament: Hi, all concerned: What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. Fella used to sell 'em in some of the mid-west hamfests, but I haven't seen him for a while. Think his name is Don, and that he was also in to Racal receivers. TIA & 73 I know the Sylvania 6LF6 tubes, custom made for Motorola were heavier duty - rated 50 watts Pa continuous........ 6JS6 is the number that emerges from the cobwebbed long term memory - used a lot in Yaesu stuff as pa tubes, ie 101's. Cheaper than 6146's in those days, now the situation is reversed so the old rigs are being modified to 6146's Unless you have boxes of them stashed away, dont design anything around them, a long obselete technology... 73 de VK3BFA Andrew PS - I have several dozen 807's in the junk box, will use them one day..... 807's are becoming pricey these days. Still some cheap 1625's available though. There must have been a google of them made during WWII. |
....[snip]....
807's are becoming pricey these days. Still some cheap 1625's available though. There must have been a google of them made during WWII. After reading an article about building an amplifier which used ten 1625's with paralleled RF but with series filaments directly across the 120-volt line, I've been saving them; hope to find the right round tuit someday.... --Myron. -- Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448 NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol) |
That's similar to my ideas, which include doubling the 240V mains to 600V to
put on the plates. an isolation xfmr would be needed for the filaments, tho. 600V at 4-5A would give a ballpark of 50 ohms plate resistance, low enough for no-tune techniques. Still haven't found that tube # tho ;o) 73, Dave, N3HE SNIP After reading an article about building an amplifier which used ten 1625's with paralleled RF but with series filaments directly across the 120-volt line, I've been saving them; hope to find the right round tuit someday.... SNIP |
Behold, David J Windisch signalled from keyed 4-1000A filament:
600V at 4-5A would give a ballpark of 50 ohms plate resistance, low enough for no-tune techniques. Still haven't found that tube # tho ;o) Parallel a few 6080's ;-) -- Gregg t3h g33k "Ratings are for transistors....tubes have guidelines" http://geek.scorpiorising.ca |
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After reading an article about building an amplifier which used ten 1625's with paralleled RF but with series filaments directly across the 120-volt line, I've been saving them; hope to find the right round tuit someday.... ================================= Considering that with so many valves (tubes) in parallel operation the inter-electrode capacitance is multipled accordingly, it would be intriguing to know up to which frequency this set-up could be sensibly used. I have seen a CB amp using as many as 12 of the 1625 tubes. There were 6 in parallel on each side of a push pull circuit. Not sure how clean the output was but they seemed efficiant enough to give about 300 to 500 watts out of carrier power and the modulation sounded good. |
After reading an article about building an amplifier which used ten 1625's with paralleled RF but with series filaments directly across the 120-volt line, I've been saving them; hope to find the right round tuit someday.... ================================= Considering that with so many valves (tubes) in parallel operation the inter-electrode capacitance is multipled accordingly, it would be intriguing to know up to which frequency this set-up could be sensibly used. I have quite a number of 'never used' 807s in the junkbox , pardon me .........NOS box. Frank GM0CSZ / KN6WH |
Low plate resistance swamps the capacity ;o)
73, Dave, N3HE "Highland Ham" wrote in message ... SNIP================================= Considering that with so many valves (tubes) in parallel operation the inter-electrode capacitance is multipled accordingly, it would be intriguing to know up to which frequency this set-up could be sensibly used. I have quite a number of 'never used' 807s in the junkbox , pardon me ........NOS box. SNIP |
"David J Windisch" wrote in message ...
Low plate resistance swamps the capacity ;o) 73, Dave, N3HE "Highland Ham" wrote in message ... SNIP================================= Considering that with so many valves (tubes) in parallel operation the inter-electrode capacitance is multipled accordingly, it would be intriguing to know up to which frequency this set-up could be sensibly used. I have quite a number of 'never used' 807s in the junkbox , pardon me ........NOS box. SNIP OK, we are all agreed - EVEYONE has heaps of 807's in the junkbox for the "one day" project....... 73 de VK3BFA Andrew |
This is hilarious. The OP asked a question. And asks it again:
What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. It has an *octal* base. Fella used to sell 'em in some of the mid-west hamfests, but I haven't seen him for a while. Think his name is Don, and that he was also in to Racal receivers. 73, Dave, N3HE "Andrew VK3BFA" wrote in message om... SNIP OK, we are all agreed - EVEYONE has heaps of 807's in the junkbox for the "one day" project....... 73 de VK3BFA Andrew |
"David J Windisch" wrote in message ...
This is hilarious. The OP asked a question. And asks it again: What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. It has an *octal* base. So what kind of base does your mystery tube have? |
"David J Windisch" wrote in message ...
This is hilarious. The OP asked a question. And asks it again: What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. It has an *octal* base. So what kind of base does your mystery tube have? Ah, nevermind. I see now that the "it" in your question is not the 6MJ6, but your mystery tube... |
The point is, that I don't know what the nomenclature is, and asked for help
with it in the OP. "Someone" mentioned this tube in a post "somewhere" several years ago. I've searched archives for faulty-memory-recollections of the nomenclature, to no avail. For latecomer Noeding: I'd like to get enough of them to experiment with no-tune techniques, which might be practical with plate voltage around 600 and plate current of 4 or 5 amps. The "hilarious" comment referred to plain old thread-wander ;o) 73, Dave, N3HE "J M Noeding" wrote in message ... On 19 Jul 2004 15:38:46 -0700, (Mike Silva) wrote: "David J Windisch" wrote in message ... This is hilarious. The OP asked a question. And asks it again: What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. It has an *octal* base. So what kind of base does your mystery tube have? Ah, nevermind. I see now that the "it" in your question is not the 6MJ6, but your mystery tube... perhaps it is just a silly request when he has nothing else to talk about, it might be 6JS6, 6KD6, or perhaps it was 6JM6.... and 6JM6 GE Vacuum Radio Tubes is offered on internet and the Current Price: $0.99 so, when 100 persons have commented, it might be a better idea to read the type number on the glass again and tell us which type the question was about??? http://home.online.no/~la8ak/e81.htm --- J. M. Noeding, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/c.htm |
On Tue, 20 Jul 2004 somebody from "over there" wrote:
"Someone" mentioned this tube in a post "somewhere" several years ago. I've searched archives for faulty-memory-recollections of the nomenclature, to no avail. It might have been a hoax, or perhaps problem with memory - not the eyes...... For latecomer Noeding: I'd like to get enough of them to experiment with no-tune techniques, which might be practical with plate voltage around 600 and plate current of 4 or 5 amps. The "hilarious" comment referred to plain old thread-wander ;o) Well, I'd still endorse the idea of using 807, it is not so many other 6.3V tubes with the same socket, so you are more certain which type goes there, and not at least - it was once mentioned water-cooling (QST 1951??) - probably a good idea for those of you who like to tune for very long periods to get the last microwatt into the antenna 73, jm --- J. M. Noeding, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/c.htm |
David J Windisch wrote:
The point is, that I don't know what the nomenclature is, and asked for help with it in the OP. "Someone" mentioned this tube in a post "somewhere" several years ago. I've searched archives for faulty-memory-recollections of the nomenclature, to no avail. For latecomer Noeding: I'd like to get enough of them to experiment with no-tune techniques, which might be practical with plate voltage around 600 and plate current of 4 or 5 amps. The "hilarious" comment referred to plain old thread-wander ;o) 73, Dave, N3HE "J M Noeding" wrote in message ... On 19 Jul 2004 15:38:46 -0700, (Mike Silva) wrote: "David J Windisch" wrote in message ... This is hilarious. The OP asked a question. And asks it again: What's the nomenclature for that sweep tube, produced just for Admiral TVs years ago, that's heavier-duty than any of the other tubes? I thought it was 6MJ6 -- but, no. It has an *octal* base. So what kind of base does your mystery tube have? Ah, nevermind. I see now that the "it" in your question is not the 6MJ6, but your mystery tube... perhaps it is just a silly request when he has nothing else to talk about, it might be 6JS6, 6KD6, or perhaps it was 6JM6.... and 6JM6 GE Vacuum Radio Tubes is offered on internet and the Current Price: $0.99 so, when 100 persons have commented, it might be a better idea to read the type number on the glass again and tell us which type the question was about??? http://home.online.no/~la8ak/e81.htm --- J. M. Noeding, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/c.htm It may be best to pick the least expensive "big" sweep tube for which you have specs, and parallel enough of them to get the impedance where you want it to be. You should also be able to run the voltage down a bit at the tube's rated current. This will reduce your power output but it'll reduce your impedance at the same time. If you use a 3:1 step-down on your output you'll load the plate with 450 ohms. This will require a 1.3A peak current with a 600V plate supply, and should be good for 300W or more PEP output -- may be easier to start there than at 5A! -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
On Tue, 20 Jul 2004 08:56:15 -0700, Tim Wescott
wrote: It may be best to pick the least expensive "big" sweep tube for which you have specs, and parallel enough of them to get the impedance where you want it to be. You should also be able to run the voltage down a bit at the tube's rated current. This will reduce your power output but it'll reduce your impedance at the same time. If you use a 3:1 step-down on your output you'll load the plate with 450 ohms. This will require a 1.3A peak current with a 600V plate supply, and should be good for 300W or more PEP output -- may be easier to start there than at 5A! of course, but still the impedance from each tube is high, and it does not see 50 ohm or whatever load, and still you may need an antenna tuner. But I was pulling the leg, since it is not a problem for any moderate intelligent ham to tune a transmitter. Since I am electronic engineer and have been working with transmitters it amuses me to see that colleagues don't understand about PLATE and LOAD, and have really difficulties to tune a transmitter, other radio amateurs have commented about the same. It is odd that you need to be an amateur to understand how to tune a transmitter, and I have never seen it as a problem, even when I started with a Starflite TX 38 years ago 73, jm --- J. M. Noeding, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/c.htm |
J M Noeding wrote:
On Tue, 20 Jul 2004 08:56:15 -0700, Tim Wescott wrote: It may be best to pick the least expensive "big" sweep tube for which you have specs, and parallel enough of them to get the impedance where you want it to be. You should also be able to run the voltage down a bit at the tube's rated current. This will reduce your power output but it'll reduce your impedance at the same time. If you use a 3:1 step-down on your output you'll load the plate with 450 ohms. This will require a 1.3A peak current with a 600V plate supply, and should be good for 300W or more PEP output -- may be easier to start there than at 5A! of course, but still the impedance from each tube is high, and it does not see 50 ohm or whatever load, and still you may need an antenna tuner. But I was pulling the leg, since it is not a problem for any moderate intelligent ham to tune a transmitter. Since I am electronic engineer and have been working with transmitters it amuses me to see that colleagues don't understand about PLATE and LOAD, and have really difficulties to tune a transmitter, other radio amateurs have commented about the same. It is odd that you need to be an amateur to understand how to tune a transmitter, and I have never seen it as a problem, even when I started with a Starflite TX 38 years ago 73, jm --- J. M. Noeding, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/c.htm Perhaps if the knobs were relabeled "TX" and "Antenna", and the plate current meter was relabeled "reflected power"? I see nothing wrong in principal with wanting to build a no-tune tube transmitter, although it may be more work than building a microprocessor-controlled transmitter tuner, and you may run into insurmountable output-capacitance problems. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
On Tue, 20 Jul 2004 12:08:34 -0700, Tim Wescott
wrote: Perhaps if the knobs were relabeled "TX" and "Antenna", and the plate current meter was relabeled "reflected power"? Can't really remember. Last time I had to assist it was Rohde&Schwartz 10kW 88.8MHz FM broadcast transmitter, and the colleague could hardly achieve 1kW output, hi. Another ham worked at another medium wave broadcast station in the summer 1960, and mentioned on an occasion that "they had no idea how to tune a transmitter", they had some different transmitters, incl. an old Marconi 10kW TX from 1933. I see nothing wrong in principal with wanting to build a no-tune tube transmitter, although it may be more work than building a microprocessor-controlled transmitter tuner, and you may run into insurmountable output-capacitance problems. Well, I see 100pF output capacitance to cause some troubles on 450 ohm Another problem is that all plate connections to a common point must be measured to the same length. I am told this is really a problem, even for a longwave transmitter, the reference transmitter operated on 360kHz as a console radio station, see my page http://home.online.no/~la8ak/k56.htm 73, Jan-Martin --- J. M. Noeding, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/c.htm |
"David J Windisch" wrote in message ...
The point is, that I don't know what the nomenclature is, and asked for help with it in the OP. A quick google on admiral "sweep tube" turned it up: 6LW6. The post was by Tom, W8JI in 2000. 73, Mike, KK6GM |
impedance for 100pf on 14MHz is -j114, perhaps not so good in a 450ohm
circuit see http://www.noding.com/la8ak/12345/n12.htm for broadband techniques with ferrite transformers, and you could always read W2FMI's book "Transmission Line transformers", but I wouldn't use transmission line transformers myself 73 jm --- J. M. Noeding, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/c.htm |
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Tks, OM. 73, Dave, N3HE
"Mike Silva" wrote in message om... "David J Windisch" wrote in message ... The point is, that I don't know what the nomenclature is, and asked for help with it in the OP. A quick google on admiral "sweep tube" turned it up: 6LW6. The post was by Tom, W8JI in 2000. 73, Mike, KK6GM |
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