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Older ARRL Handbooks
All right, I'm hoping someone here can clue me into finding the one(s)
I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. I've found a very good used book search engine, but unless I have a better idea of what to look for, It's going to be hit and miss. Any help would be greatly appreciated. Ralph |
Older ARRL Handbooks
julian814 wrote:
All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. ... Just about any year's Handbook from the 60's would have what you're looking for. They really didn't change that much from year to year. |
Older ARRL Handbooks
"julian814" ) writes:
All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. I've found a very good used book search engine, but unless I have a better idea of what to look for, It's going to be hit and miss. Any help would be greatly appreciated. Ralph But if you're just looking for projects, any of the magazines would have had plenty, and it's just a matter of picking them from the right years so they not only use tubes, but of the right vintage tubes. And if you can't find old magazines, you can get QST on CDROM, so a volume of that from the right time period would supply plenty of projects. Of course, most of the projects in the Handbook came from QST to begin with, so it's not like you miss much in the project department. Of course, a lot of TV sets were AC/DC, so the filament voltages are all over the map since you'd put them in series to run directly off the AC line. Unless they start with "6" or "12" the tubes may not be so useful. Michael VE2BVW |
Older ARRL Handbooks
Depending on the vintage of the tubes, you might trouble finding data on
them. In the '60s, TV manufacturers made a lot of extra money by changing the tube lineup every year. This required service shops to buy several sets of new tubes every year as replacements. Typically, the innards of the tubes were virtually identical to older ones, but with different pinouts, filament voltages, and combinations of tubes within the envelopes. If your tubes are from this era, you probably won't find them in the Handbook. You might have to get one of the later RCA tube manuals for tube information, then compare specs with various tube types used in Handbook projects to find projects you can build with the tubes you have. Good luck! Roy Lewallen, W7EL |
Older ARRL Handbooks
Of course, a lot of TV sets were AC/DC, so the filament voltages are all over the map since you'd put them in series to run directly off the AC line. Unless they start with "6" or "12" the tubes may not be so useful. ============================= Being in series means they would all be used with the same filament current which can be easily implemented with a circuit employing a 78xx device in constant current mode (obviously in a DC environment) Frank KN6WH / GM0CSZ |
Older ARRL Handbooks
julian814 wrote:
All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. I've found a very good used book search engine, but unless I have a better idea of what to look for, It's going to be hit and miss. Any help would be greatly appreciated. Ralph I was in Powell's Technical Books the other day, they had several from the '50s and '60s. This link will get you several listings (and I'll get a kickback if you buy one!). I already grabbed the 1944 issue (thank you thank you thank you for making me look!). http://www.powells.com/partner/30696...RRL%20Handbook -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Posting from Google? See http://cfaj.freeshell.org/google/ "Applied Control Theory for Embedded Systems" came out in April. See details at http://www.wescottdesign.com/actfes/actfes.html |
Older ARRL Handbooks
Here is a site with lots of FREE books dealing with tube design. There
are old ARRL and Orr radio handbooks as well. http://www.pmillett.com/tecnical_books_online.htm The files are huge so you better have a high-speed (not dial-up) internet connection. Have fun - Roger |
Older ARRL Handbooks
julian814 wrote:
All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. Not sure whether this is what you're looking for but I found two sites that seem to contain most of the tube data that was in the ARRL Handbook: http://www.nj7p.org/Tube4.php http://tdsl.duncanamps.com/tubesearch.php -- Doug Smith W9WI Pleasant View (Nashville), TN EM66 http://www.w9wi.com |
Older ARRL Handbooks
Highland Ham wrote: Being in series means they would all be used with the same filament current which can be easily implemented with a circuit employing a 78xx device in constant current mode (obviously in a DC environment) Frank KN6WH / GM0CSZ Andy adds: That's true as long as the current requirements were the same. For instance, putting a 12V/1amp filament in series with a 12 V/200ma filament will not do well on 24 volts.... Just like putting a 100 watt and a 7 watt light bulb in series across 220 volts....., (guess which one will be the brightest, and for how long :)))) ?? ) The currents were matched in the 5 tube AC/DC radios, but generally you have to check the filament current rating as well as the filament voltage rating in order to do this...... It ain't rocket surgery, but you can't put tube filaments in series indiscriminately. Andy W4OAH |
Older ARRL Handbooks
Michael Black wrote: But if you're just looking for projects, any of the magazines would have had plenty, and it's just a matter of picking them from the right years so they not only use tubes, but of the right vintage tubes. That's the real trick, isn't it? ;-) And if you can't find old magazines, you can get QST on CDROM, so a volume of that from the right time period would supply plenty of projects. Of course, most of the projects in the Handbook came from QST to begin with, so it's not like you miss much in the project department. Cool, I'll have to look into it. Of course, a lot of TV sets were AC/DC, so the filament voltages are all over the map since you'd put them in series to run directly off the AC line. Unless they start with "6" or "12" the tubes may not be so useful. You're right, the voltages range anywhere from 3 to 33 volts. Two of them are 6V6 tubes, so I have some hope there. Most of them are miniatures, and some of them have the numbers missing, which makes things really interesting. Ralph |
Older ARRL Handbooks
Doug Smith W9WI wrote: julian814 wrote: All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. Not sure whether this is what you're looking for but I found two sites that seem to contain most of the tube data that was in the ARRL Handbook: http://www.nj7p.org/Tube4.php http://tdsl.duncanamps.com/tubesearch.php Well, these should definitely help me identify which tubes are the most useful, especially the first link. It's a start. I could use some schematics, though. Ralph |
Older ARRL Handbooks
6V6 was the quintessential beam power audio output tube of the 1940s through
the 1960s. You can generally "read" the missing numbers if there is anything left of the imprint by gently rubbing the tube on your hair. THe oil from your hair will stick to what is left of the printing and make it readable for a short time. You might take a permanent marker if and when you finally read the number and mark the tube. As has been alluded to in several posts, you are not limited to the exact tube that the original project had in it. For example, the 6U8 was the VHF/UHF RF oscillator/mixer of choice in thousands of designs. However, a 6J6 oscillator with a 6BE6 mixer will work every bit as good if you aren't fussy about VHF reception. There are dozens of tricks you can play with mix & match tube lineups, some better than others. Jim You're right, the voltages range anywhere from 3 to 33 volts. Two of them are 6V6 tubes, so I have some hope there. Most of them are miniatures, and some of them have the numbers missing, which makes things really interesting. |
Older ARRL Handbooks
"julian814" ) writes:
wrote: Here is a site with lots of FREE books dealing with tube design. There are old ARRL and Orr radio handbooks as well. http://www.pmillett.com/tecnical_books_online.htm The files are huge so you better have a high-speed (not dial-up) internet connection. Thanks, but I have two problems - I'm stuck using dialup, and most of these books seem over my head. Interesting, nonetheless. Unless you pay by the hour, it's doable with dialup. Do it late at night so there's no disturbances, and hopefully less traffic. Be selective, figuring out what you might find useful before downloading. I have dialup, and I grabbed some of those books last year, using this same method. It took time, but if you plan it right, it doesn't get in the way. Just don't plan to be able to do much else at the same time as the download. Unfortunately, while I did record the times it took to download those books I did download, I have no idea where I put that list. Of those books, the 15th edition of THe Radio Handbook is likely the best choice, since it's the most recent of the handbooks they have there. Most of the books are more text books, and the 1941 ARRL Handbook is likely going to use older tubes than you have, same with the 1940 Radio Handbook. Michael VE2BVW |
Older ARRL Handbooks
RST Engineering wrote:
6V6 was the quintessential beam power audio output tube of the 1940s through the 1960s. You can generally "read" the missing numbers if there is anything left of the imprint by gently rubbing the tube on your hair. THe oil from your hair will stick to what is left of the printing and make it readable for a short time. You might take a permanent marker if and when you finally read the number and mark the tube. Another thing that has worked for me is to put the tube in the freezer for a few hours. Frost forms in a different pattern around where the number was than on the rest of the envelope. Sometimes. -- Doug Smith W9WI Pleasant View (Nashville), TN EM66 http://www.w9wi.com |
Older ARRL Handbooks
Michael Black wrote: "julian814" ) writes: wrote: Here is a site with lots of FREE books dealing with tube design. There are old ARRL and Orr radio handbooks as well. http://www.pmillett.com/tecnical_books_online.htm The files are huge so you better have a high-speed (not dial-up) internet connection. Thanks, but I have two problems - I'm stuck using dialup, and most of these books seem over my head. Interesting, nonetheless. Unless you pay by the hour, it's doable with dialup. Do it late at night so there's no disturbances, and hopefully less traffic. Be selective, figuring out what you might find useful before downloading. I have dialup, and I grabbed some of those books last year, using this same method. It took time, but if you plan it right, it doesn't get in the way. Just don't plan to be able to do much else at the same time as the download. Unfortunately, while I did record the times it took to download those books I did download, I have no idea where I put that list. Of those books, the 15th edition of THe Radio Handbook is likely the best choice, since it's the most recent of the handbooks they have there. Most of the books are more text books, and the 1941 ARRL Handbook is likely going to use older tubes than you have, same with the 1940 Radio Handbook. Thanks, I'll give it a go. I work from 4 pm to midnight weekdays, so I think I'll try this again tonight after work. Ralph |
Older ARRL Handbooks
RST Engineering wrote: 6V6 was the quintessential beam power audio output tube of the 1940s through the 1960s. You can generally "read" the missing numbers if there is anything left of the imprint by gently rubbing the tube on your hair. THe oil from your hair will stick to what is left of the printing and make it readable for a short time. You might take a permanent marker if and when you finally read the number and mark the tube. Thanks, I'll give it a try. As has been alluded to in several posts, you are not limited to the exact tube that the original project had in it. For example, the 6U8 was the VHF/UHF RF oscillator/mixer of choice in thousands of designs. However, a 6J6 oscillator with a 6BE6 mixer will work every bit as good if you aren't fussy about VHF reception. There are dozens of tricks you can play with mix & match tube lineups, some better than others. TJ Linday says as much in the Impoverished Radio Experimenter. Thing is, he was scant on details. I wrote them about my project, and I'm hoping they'll have some ideas. Ralph |
Older ARRL Handbooks
Another thing that has worked for me is to put the tube in the freezer
for a few hours. Frost forms in a different pattern around where the number was than on the rest of the envelope. Sometimes. And after you take it out of the cooler, "huff" on it once or twice (just as people "huff" on their eyeglasses before wiping them with a cloth) and the moisture from your breath may outline the tube identification. -- --Myron A. Calhoun. Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge NRA Life Member and Rifle, Pistol, & Home Firearm Safety Certified Instructor Certified Instructor for the Kansas Concealed-Carry Handgun license |
Older ARRL Handbooks
julian814 wrote:
All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. How complex of a receiver are you looking to build? There are a PILE of simple tube circuits on http://www.intio.or.jp/jf10zl/index.html . Most of them use Japanese tubes (the site is in Japan, after allg) but I would suggest in many cases you can figure out what U.S. tubes are similar. -- Doug Smith W9WI Pleasant View (Nashville), TN EM66 http://www.w9wi.com |
Older ARRL Handbooks
You can download free a long list of archaic technical books, including
a number of ARRL Handbooks, at the following URL: http://www.pmillett.com/tecnical_books_online.htm julian814 wrote: All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. I've found a very good used book search engine, but unless I have a better idea of what to look for, It's going to be hit and miss. Any help would be greatly appreciated. Ralph |
Older ARRL Handbooks
|
Older ARRL Handbooks
Well, after much hair pulling and gnashing of teeth, I managed to
download the 15th edition of Radio Handbook last night. No straight receivers that use tubes, though. Going to have to look at the math section to see if there's some way I can work up a schematic of my own. Thing is, math isn't my strong suit. Also going to have a look at some of the older books. If worse comes to worst, I know of a few places online where I can buy the tube that are in the schematics I do have. Ralph |
Older ARRL Handbooks
Doug Smith W9WI wrote: julian814 wrote: All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. How complex of a receiver are you looking to build? Nothing too complex, two tubes or so. What I want to build is something that looks like it's from a 1950's Cold War era post apocalyptic story. I definitely want to use tubes, and I have some headphones from that era as well. The receiver has to be able to drive the headphones. They are NOT crystal headphones. There are a PILE of simple tube circuits on http://www.intio.or.jp/jf10zl/index.html . Most of them use Japanese tubes (the site is in Japan, after allg) but I would suggest in many cases you can figure out what U.S. tubes are similar. Fascinating, but I didn't see anything close to what I'm looking for. Thanks anyway. Ralph |
Older ARRL Handbooks
julian814 wrote:
Doug Smith W9WI wrote: julian814 wrote: All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. How complex of a receiver are you looking to build? Nothing too complex, two tubes or so. What I want to build is something that looks like it's from a 1950's Cold War era post apocalyptic story. I definitely want to use tubes, and I have some headphones from that era as well. The receiver has to be able to drive the headphones. They are NOT crystal headphones. There are a PILE of simple tube circuits on http://www.intio.or.jp/jf10zl/index.html . Most of them use Japanese tubes (the site is in Japan, after allg) but I would suggest in many cases you can figure out what U.S. tubes are similar. Fascinating, but I didn't see anything close to what I'm looking for. Thanks anyway. Ralph I don't recall the url but I remember a 2-3 tube receiver from the 40's that might be what you want. It was a simple superhet with a regenerative detector. Used a 6k8 as the converter and a 6c8g as the detector / audio. It drove a pair of magnetic phones. The set used two plugin coils, one for the antenna circuit and one for the oscillator. Each antenna coil served double duty as the oscillator coil on the next higher band (moved the antenna coil from the antenna coil socket to the oscillator coil socket and put a new coil in the antenna coil socket to change bands). There is a variation that added a 6sj7 as the detector and the other half of the 6c8 became a bfo. This first appeared in Feb 1941 QST. The details are on the web someplace, google for it. |
Older ARRL Handbooks
julian814 wrote:
How complex of a receiver are you looking to build? Nothing too complex, two tubes or so. What I want to build is something that looks like it's from a 1950's Cold War era post apocalyptic story. I definitely want to use tubes, and I have some headphones from that era as well. The receiver has to be able to drive the headphones. They are NOT crystal headphones. There are a PILE of simple tube circuits on http://www.intio.or.jp/jf10zl/index.html . Most of them use Japanese tubes (the site is in Japan, after allg) but I would suggest in many cases you can figure out what U.S. tubes are similar. Fascinating, but I didn't see anything close to what I'm looking for. Thanks anyway. I would suggest this one ( http://www.intio.or.jp/jf10zl/17ew8.htm ) would be a good starting point. It should work with most standard double-triodes (12AX7, 12AT7, 12AU7, 12SN7, etc.) or two single triodes. (6C4, 6J5, etc.). This one ( http://www.intio.or.jp/jf10zl/12au70v1.htm ) could also be adapted - use more than 12 volts on the plates and put a ~5k:8-ohm transformer in the plate of the second tube (instead of the R-C network) and it should do what you're trying to do. -- Doug Smith W9WI Pleasant View (Nashville), TN EM66 http://www.w9wi.com |
Older ARRL Handbooks
ken scharf ) writes:
julian814 wrote: Doug Smith W9WI wrote: julian814 wrote: All right, I'm hoping someone here can clue me into finding the one(s) I want. What I need is a handbook that has schematics for tube equipment circa the 1960's. I have a boxful of tubes from television sets from that era, and I was hoping I could put together a receiver from some of them. I do have the first volume of Impoverished Radio Experimenter, which talks about using "newer" tubes in older schematics, but the scant few Lindsay talks about aren't among the tubes in my box. How complex of a receiver are you looking to build? Nothing too complex, two tubes or so. What I want to build is something that looks like it's from a 1950's Cold War era post apocalyptic story. I definitely want to use tubes, and I have some headphones from that era as well. The receiver has to be able to drive the headphones. They are NOT crystal headphones. There are a PILE of simple tube circuits on http://www.intio.or.jp/jf10zl/index.html . Most of them use Japanese tubes (the site is in Japan, after allg) but I would suggest in many cases you can figure out what U.S. tubes are similar. Fascinating, but I didn't see anything close to what I'm looking for. Thanks anyway. Ralph I don't recall the url but I remember a 2-3 tube receiver from the 40's that might be what you want. It was a simple superhet with a regenerative detector. Used a 6k8 as the converter and a 6c8g as the detector / audio. They were called "supergainers" and apparently Frank Jones, of later VHF fame, was a big proponent of them in the thirties. The earlier Radio Handbook on that webpage someone posted about would have them, the 1936 version or whatever. I didn't suggest downloading that one since I had the impression the tubes available to the original poster were miniature, and the book predates those. Michael VE2BVW k |
Older ARRL Handbooks
Michael Black wrote: ken scharf ) writes: I don't recall the url but I remember a 2-3 tube receiver from the 40's that might be what you want. It was a simple superhet with a regenerative detector. Used a 6k8 as the converter and a 6c8g as the detector / audio. They were called "supergainers" and apparently Frank Jones, of later VHF fame, was a big proponent of them in the thirties. The earlier Radio Handbook on that webpage someone posted about would have them, the 1936 version or whatever. I didn't suggest downloading that one since I had the impression the tubes available to the original poster were miniature, and the book predates those. Thanks, Mike, Ken. I'll have to take a look. I did manage to download some of the files on designing circuits with tubes, and with the online tube manuals I might be able to figure out something on my own. Still, if anyone can think of where I can find something already made up that I can use, I'd appreciate it. Ralph |
Older ARRL Handbooks
julian814 wrote:
Michael Black wrote: ken scharf ) writes: I don't recall the url but I remember a 2-3 tube receiver from the 40's that might be what you want. It was a simple superhet with a regenerative detector. Used a 6k8 as the converter and a 6c8g as the detector / audio. They were called "supergainers" and apparently Frank Jones, of later VHF fame, was a big proponent of them in the thirties. The earlier Radio Handbook on that webpage someone posted about would have them, the 1936 version or whatever. I didn't suggest downloading that one since I had the impression the tubes available to the original poster were miniature, and the book predates those. Thanks, Mike, Ken. I'll have to take a look. I did manage to download some of the files on designing circuits with tubes, and with the online tube manuals I might be able to figure out something on my own. Still, if anyone can think of where I can find something already made up that I can use, I'd appreciate it. Ralph HERE'S the link http://www.io.com/~nielw/3tubrcvr/3tubrcvr.htm |
Older ARRL Handbooks
ken scharf wrote:
julian814 wrote: Michael Black wrote: ken scharf ) writes: I don't recall the url but I remember a 2-3 tube receiver from the 40's that might be what you want. It was a simple superhet with a regenerative detector. Used a 6k8 as the converter and a 6c8g as the detector / audio. They were called "supergainers" and apparently Frank Jones, of later VHF fame, was a big proponent of them in the thirties. The earlier Radio Handbook on that webpage someone posted about would have them, the 1936 version or whatever. I didn't suggest downloading that one since I had the impression the tubes available to the original poster were miniature, and the book predates those. Thanks, Mike, Ken. I'll have to take a look. I did manage to download some of the files on designing circuits with tubes, and with the online tube manuals I might be able to figure out something on my own. Still, if anyone can think of where I can find something already made up that I can use, I'd appreciate it. Ralph HERE'S the link http://www.io.com/~nielw/3tubrcvr/3tubrcvr.htm Oh, nearly forgot.... With a little head scratching, you can replace the 6K8 with a 6u8, 6ea8, 6x8 (etc) triode/pentode. Use the pentode as the mixer and the triode as the oscillator. In many cases the inter-electrode capacitance inside the tube will provide enough coupling from the oscillator to the mixer, but you might need to use a gimick capacitor (twisted wires) from the pentode grid to the oscillator plate. Other tricks are to connect the pentode screen to the oscillator plate, or in the case of the 6x8, the pentode grid 3 to the oscillator grid. The 6c8 may be replaced by ANY dual triode (such as 12au7, 12at7, 12ax7, 6sn7,6sl7, etc....) |
Older ARRL Handbooks
ken scharf wrote:
julian814 wrote: Michael Black wrote: ken scharf ) writes: I don't recall the url but I remember a 2-3 tube receiver from the 40's that might be what you want. It was a simple superhet with a regenerative detector. Used a 6k8 as the converter and a 6c8g as the detector / audio. They were called "supergainers" and apparently Frank Jones, of later VHF fame, was a big proponent of them in the thirties. The earlier Radio Handbook on that webpage someone posted about would have them, the 1936 version or whatever. I didn't suggest downloading that one since I had the impression the tubes available to the original poster were miniature, and the book predates those. Thanks, Mike, Ken. I'll have to take a look. I did manage to download some of the files on designing circuits with tubes, and with the online tube manuals I might be able to figure out something on my own. Still, if anyone can think of where I can find something already made up that I can use, I'd appreciate it. Ralph HERE'S the link http://www.io.com/~nielw/3tubrcvr/3tubrcvr.htm Link to follow up... http://www.io.com/~nielw/3tube_xtal/3tube_xtal.htm |
Older ARRL Handbooks
ken scharf wrote: HERE'S the link http://www.io.com/~nielw/3tubrcvr/3tubrcvr.htm Oh, nearly forgot.... With a little head scratching, you can replace the 6K8 with a 6u8, 6ea8, 6x8 (etc) triode/pentode. Use the pentode as the mixer and the triode as the oscillator. In many cases the inter-electrode capacitance inside the tube will provide enough coupling from the oscillator to the mixer, but you might need to use a gimick capacitor (twisted wires) from the pentode grid to the oscillator plate. Other tricks are to connect the pentode screen to the oscillator plate, or in the case of the 6x8, the pentode grid 3 to the oscillator grid. The 6c8 may be replaced by ANY dual triode (such as 12au7, 12at7, 12ax7, 6sn7,6sl7, etc....) I think we may be in business, here. Went through my selection of tubes, and there's a 6X8 and a 12AX7A among them. Three other tubes looked like they had promise - two 12AV6 and a 6BU6. After I'm done with this post, I'm going to Google Images to see if I do indeed have 2000 ohm headphones. I want to make sure, because elsewhere I found a crystal shortwave radio that uses them as well. That might serve my needs better, although it won't have those cool glow in the dark tubes. Ralph |
Older ARRL Handbooks
After using Google images to track down pictures of 2000 ohm
headphones, I am satisfied that those are what I have. (Eight sets, in fact.) Found out the one tube is a 6BJ6, not a 6BU6, but it does still seem usable. Going to ask if I can make some trades with tubesandmore, so I can find a good home for some of the headphones and possibly get the tube sockets and transformers I need for my project. Thanks again to everyone who has helped. Time for me to go do some math. (Ugh!) Ralph |
Older ARRL Handbooks
Today, I am reminded that Google is my friend. After much digging and
prodding, I found what I was looking for. It seems the National SW-54 receiver is as close to what I want as possible without me having to do math. It dates back to the 50's, uses tubes, (in fact, I already have three of the five in it) covers a good amount of the SW band, and will drive either my 2000 ohm headphones or a 4" speaker. BAMA had the manual, but it wouldn't give it up, so I had to go to the mirror site to get it. Everything I need is in it - schematics, parts list, pictures of the assembled receiver. Not exactly the ideal radio for a first try, but nothing good ever came easy, did it? ;-) Thanks again to everyone who offered advice and suggestions. I'll be sure to post when I have it together and let everyone know how I made out. Time to scrounge for parts. Ralph |
Older ARRL Handbooks
julian814 wrote:
After using Google images to track down pictures of 2000 ohm headphones, I am satisfied that those are what I have. (Eight sets, in fact.) Found out the one tube is a 6BJ6, not a 6BU6, but it does still seem usable. Going to ask if I can make some trades with tubesandmore, so I can find a good home for some of the headphones and possibly get the tube sockets and transformers I need for my project. Thanks again to everyone who has helped. Time for me to go do some math. (Ugh!) Ralph You can just measure the resistance of the phones with an ohm meter. The result will be close enough to the impedance (I think in the era they were made they didn't even measure impedance, just the resistance). Also, I have a lot's used 12au7's. If you need a few you can have some for the cost of postage. |
Older ARRL Handbooks
julian814 wrote:
Today, I am reminded that Google is my friend. After much digging and prodding, I found what I was looking for. It seems the National SW-54 receiver is as close to what I want as possible without me having to do math. It dates back to the 50's, uses tubes, (in fact, I already have three of the five in it) covers a good amount of the SW band, and will drive either my 2000 ohm headphones or a 4" speaker. BAMA had the manual, but it wouldn't give it up, so I had to go to the mirror site to get it. Everything I need is in it - schematics, parts list, pictures of the assembled receiver. Not exactly the ideal radio for a first try, but nothing good ever came easy, did it? ;-) Thanks again to everyone who offered advice and suggestions. I'll be sure to post when I have it together and let everyone know how I made out. Time to scrounge for parts. Ralph Ocean State electronics has EXACT replacement coil forms for the beast. (sockets are another story!) They have NORMAL socket type plug in coil forms too. (the national coil forms have different pin spacing than standard tube socket type coils). |
Older ARRL Handbooks
julian814 wrote:
Today, I am reminded that Google is my friend. After much digging and prodding, I found what I was looking for. It seems the National SW-54 receiver is as close to what I want as possible without me having to do math. It dates back to the 50's, uses tubes, (in fact, I already have three of the five in it) covers a good amount of the SW band, and will drive either my 2000 ohm headphones or a 4" speaker. BAMA had the manual, but it wouldn't give it up, so I had to go to the mirror site to get it. Everything I need is in it - schematics, parts list, pictures of the assembled receiver. Not exactly the ideal radio for a first try, but nothing good ever came easy, did it? ;-) Thanks again to everyone who offered advice and suggestions. I'll be sure to post when I have it together and let everyone know how I made out. Time to scrounge for parts. Ralph OPPS, I confused the sw-54 with the sw3-5 series. This one is a "modern" superhet. Do you have the IF transformers, band switch and coils? I have a complete band switch and coil assembly from an old Lafayette short wave receiver. It is a 4 band assembly with rf, osc, and mixer coils intended for use with a 3 gang 365pf/section tuning capacitor. I was thinking of using this in some project (that never happened), but it sounds like just what you want. The coils have slug tuned tracking adjustments, and the oscillator and mixer coils also have trimmer capacitor tracking too. If you can use this let me know. |
Older ARRL Handbooks
ken scharf wrote:
julian814 wrote: Today, I am reminded that Google is my friend. After much digging and prodding, I found what I was looking for. It seems the National SW-54 receiver is as close to what I want as possible without me having to do math. It dates back to the 50's, uses tubes, (in fact, I already have three of the five in it) covers a good amount of the SW band, and will drive either my 2000 ohm headphones or a 4" speaker. BAMA had the manual, but it wouldn't give it up, so I had to go to the mirror site to get it. Everything I need is in it - schematics, parts list, pictures of the assembled receiver. Not exactly the ideal radio for a first try, but nothing good ever came easy, did it? ;-) Thanks again to everyone who offered advice and suggestions. I'll be sure to post when I have it together and let everyone know how I made out. Time to scrounge for parts. Ralph OPPS, I confused the sw-54 with the sw3-5 series. This one is a "modern" superhet. Do you have the IF transformers, band switch and coils? I have a complete band switch and coil assembly from an old Lafayette short wave receiver. It is a 4 band assembly with rf, osc, and mixer coils intended for use with a 3 gang 365pf/section tuning capacitor. I was thinking of using this in some project (that never happened), but it sounds like just what you want. The coils have slug tuned tracking adjustments, and the oscillator and mixer coils also have trimmer capacitor tracking too. If you can use this let me know. PS, if you use this you'll have to change the tube lineup to take full advantage of all the coils. Replace the 50c5 with a 35c5 and add another 12ba6 for an rf amplifier. Actually you should use all 6v tubes and a power transformer. Those AC/DC sets are "undertakers labs" approved shock hazards. An "isolation transformer will fix that of course." The schematic of the receiver the coil switch assembly came from is here http://bama.edebris.com/manuals/lafayett/ha700/ |
Older ARRL Handbooks
I'm starting to think I should just settle for that crystal shortwave
set I found on the Antique Radio website. Less headaches. No idea where to get the coils for the SW-54, so I guess that's out. Besides, since this is my first real attempt at making a radio, I should probably go for something simpler. Going back to Google to see if I can find more on some of the tubes I have. I keep thinking I should be able to make a regenerative receiver with some amplification with the two 12AV6 tubes I have. Ralph |
Older ARRL Handbooks
Managed to find a regenerative receiver based on the 12AT7 tube. I've
been told I can substitute one of my 12AV6 tubes without a problem, so that looks promising. I have some twin triode tubes, as well. (6FQ7, 6BZ7 and 4BC8) I've been wondering if I couldn't make some one tube receivers with them. (Use one triode for regeneration, the other an amplifier.) As for the rest of the tubes I have, I'd be willing to sell or swap for parts I'll need. Ralph |
Older ARRL Handbooks
julian814 wrote:
Managed to find a regenerative receiver based on the 12AT7 tube. I've been told I can substitute one of my 12AV6 tubes without a problem, so that looks promising. I have some twin triode tubes, as well. (6FQ7, 6BZ7 and 4BC8) I've been wondering if I couldn't make some one tube receivers with them. (Use one triode for regeneration, the other an amplifier.) As for the rest of the tubes I have, I'd be willing to sell or swap for parts I'll need. Ralph http://www.lindsaybks.com/bks/twin/index.html |
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