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#21
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"Ralph Mowery" ) writes:
Aluminum is usually easier for most to work with with simple hand tools. Steel is fine but it might rust and look bad after a while. Make the chassie out of whatever kind of metel that you think is the best for you to work with . Electrically there will be little if any differance. And of course, everyone did use steel (once things progressed beyond wood and bakelite chassis) right up until aluminum because readily available and/or cheap enough, at which point I doubt anyone used steel except if what they were building was really really heavy, ie a kilowatt modulator or final. Michael VE2BVW |
#22
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John Bartley ) writes:
I'm not sure how to do the tubes in a DB format, but everything else should be straightforward. I'm not sure it completely translates to tubes, since "dead bug" seems to suggest everything mounted on one side of the circuit board. But people did take advantage of copper circuit board in tube circuits. Invert the chassis, and use it merely to protect the circuitry. Sometimes the tubes were mounted with a bracket (made of more circuit board, and even soldered to the main board) on the copper side of the board, the most obvious times were when the tubes were Nuvistors, but the scheme was used sometimes when compact construction was desired. But usually, the tube sockets were mounted in holes in the circuit board, and if aluminum is easier than steel to work with, copper circuit board is even easier. Once the tube sockets were in place, then everything would be wired up as usual, with the difference being that it was really easy to drill a hole for a coil, and every time a ground point was needed, it was a simple matter of soldering the lead to the copper circuit board. No high wattage iron or gun is needed, since the copper isn't really thick. If you need to change things, it's relatively easy to disconnect that ground point, and unlike with old methods, you don't have an extra hole if you do change it. Leads could be short, because you could make ground connections where they were needed rather than where there was a ground lug. Because of the tube sockets, this tended to be a bit more formal than with solid state devices, but it was still a neat way to build, and some of the most busy builders used it because they were always trying to improve things. Frank Jones did a lot of this sort of thing, at least after Nuvistors came along. Even before that, many of his converter projects were built on an inverted chassis, with a piece of aluminum for mounting the parts rather than circuit board. Bill Hoisington K1CLL wrote tons of articles in the sixties ane early seventies, and pretty much everything was build on circuit board. He was not concerned with looks, and the few times there were photographs, they did look very "dead bug" like. He even built an amplifier with a 4CX250 or such on copper circuit board. Michael VE2BVW |
#23
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John Bartley ) writes:
I'm not sure how to do the tubes in a DB format, but everything else should be straightforward. I'm not sure it completely translates to tubes, since "dead bug" seems to suggest everything mounted on one side of the circuit board. But people did take advantage of copper circuit board in tube circuits. Invert the chassis, and use it merely to protect the circuitry. Sometimes the tubes were mounted with a bracket (made of more circuit board, and even soldered to the main board) on the copper side of the board, the most obvious times were when the tubes were Nuvistors, but the scheme was used sometimes when compact construction was desired. But usually, the tube sockets were mounted in holes in the circuit board, and if aluminum is easier than steel to work with, copper circuit board is even easier. Once the tube sockets were in place, then everything would be wired up as usual, with the difference being that it was really easy to drill a hole for a coil, and every time a ground point was needed, it was a simple matter of soldering the lead to the copper circuit board. No high wattage iron or gun is needed, since the copper isn't really thick. If you need to change things, it's relatively easy to disconnect that ground point, and unlike with old methods, you don't have an extra hole if you do change it. Leads could be short, because you could make ground connections where they were needed rather than where there was a ground lug. Because of the tube sockets, this tended to be a bit more formal than with solid state devices, but it was still a neat way to build, and some of the most busy builders used it because they were always trying to improve things. Frank Jones did a lot of this sort of thing, at least after Nuvistors came along. Even before that, many of his converter projects were built on an inverted chassis, with a piece of aluminum for mounting the parts rather than circuit board. Bill Hoisington K1CLL wrote tons of articles in the sixties ane early seventies, and pretty much everything was build on circuit board. He was not concerned with looks, and the few times there were photographs, they did look very "dead bug" like. He even built an amplifier with a 4CX250 or such on copper circuit board. Michael VE2BVW |
#24
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Wow this is some really great info! Thanks Jim and to all others who took
the time to respond! On a side note - I was trying to join the "Glowbugs" mailing list that I've seen mentioned on a number of web sites, but I havent gotten any responses to my to "subscribe" emails. Is this a dead list? If so, are there any similar current alternatives? On a second side note - does anyone happen to know what the formula would be to calculate the capacitance between two metal plates of a given area and given spacing, having an air dielectric? thanks again to all! Dave "jim rozen" wrote in message ... In article , David Forsyth says... Anyone have any further ideas or insights? Steel is cheap. This is one reason that one of the most famous two-tube (+ 1 audio) regenerative receivers - the national SW3 - was manufactured with a steel chassis, and a steel enclosure. Aluminum is easier to work with obviously. As a practical matter, I would try to keep your coils at least one coil diameter away from the metal chassis, steel or aluminum. In the SW3 they did this by putting the coils right in the center of the shield compartmets, and by standing the coil sockets up on standoffs. Jim ================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ================================================== |
#25
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Wow this is some really great info! Thanks Jim and to all others who took
the time to respond! On a side note - I was trying to join the "Glowbugs" mailing list that I've seen mentioned on a number of web sites, but I havent gotten any responses to my to "subscribe" emails. Is this a dead list? If so, are there any similar current alternatives? On a second side note - does anyone happen to know what the formula would be to calculate the capacitance between two metal plates of a given area and given spacing, having an air dielectric? thanks again to all! Dave "jim rozen" wrote in message ... In article , David Forsyth says... Anyone have any further ideas or insights? Steel is cheap. This is one reason that one of the most famous two-tube (+ 1 audio) regenerative receivers - the national SW3 - was manufactured with a steel chassis, and a steel enclosure. Aluminum is easier to work with obviously. As a practical matter, I would try to keep your coils at least one coil diameter away from the metal chassis, steel or aluminum. In the SW3 they did this by putting the coils right in the center of the shield compartmets, and by standing the coil sockets up on standoffs. Jim ================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ================================================== |
#26
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On Sun, 19 Oct 2003 11:59:57 -0400, John Bartley wrote:
David Forsyth wrote: The "dead bug" way? I'm not sure what this means - please forgive me I'm new to this :-) Hehe, don't feel too bad. I have zero experience with solid state stuff, so when I was told to build my trial projects in DBSF format, I was left scratching my head. I laughed out loud when I was shown a "Dead Bug Squashed Flat" project. This is your components laid out flat on a perfboard and the wires run straight, point to point. It really does look like a DBSF!! I'm not sure how to do the tubes in a DB format, but everything else should be straightforward. "General Radio" used to sell tube sockets which were surface mount with side terminals. I've looked high and low for some of these, but haven't had any luck. They'd be ideal for breadboard tube projects. cheers Omron has surface mount sockets for thier line of relays, can't remember if they're 8 or 11 pin though. Check it out, you might get lucky . |
#27
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On Sun, 19 Oct 2003 11:59:57 -0400, John Bartley wrote:
David Forsyth wrote: The "dead bug" way? I'm not sure what this means - please forgive me I'm new to this :-) Hehe, don't feel too bad. I have zero experience with solid state stuff, so when I was told to build my trial projects in DBSF format, I was left scratching my head. I laughed out loud when I was shown a "Dead Bug Squashed Flat" project. This is your components laid out flat on a perfboard and the wires run straight, point to point. It really does look like a DBSF!! I'm not sure how to do the tubes in a DB format, but everything else should be straightforward. "General Radio" used to sell tube sockets which were surface mount with side terminals. I've looked high and low for some of these, but haven't had any luck. They'd be ideal for breadboard tube projects. cheers Omron has surface mount sockets for thier line of relays, can't remember if they're 8 or 11 pin though. Check it out, you might get lucky . |
#28
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Only one problem I ever had with a steel chassis was a project that
used a rather sizable power transformer. The transformer induced currents into the steel chassis that caused metering problems. It was corrected by using a single-point ground to the chassis. Steel chassis were the norm for much of the tube years, commercial and amateur. |
#29
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Only one problem I ever had with a steel chassis was a project that
used a rather sizable power transformer. The transformer induced currents into the steel chassis that caused metering problems. It was corrected by using a single-point ground to the chassis. Steel chassis were the norm for much of the tube years, commercial and amateur. |
#30
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W7TI wrote:
If you're using octal type tubes, there are sockets made for industrial relays which fit the tubes perfectly. They are as you describe; surface mount with side terminals. They no doubt add a small amount of inductance and capacitance which could affect VHF operation, something to keep in mind. McMaster-Carr has them on page 819 of their online catalog: http://www.mcmaster.com/ Very nicely done!!! Thank you. These are the ideal thing for an experimenter. -- regards from :: John Bartley 43 Norway Spruce Street Stittsville, Ontario Canada, K2S1P5 ( If you slow down it takes longer - does that apply to life also?) -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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