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Steel no good for chassis? (Which metal is best for old regen designs?)
Hi all,
I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. They don't make mention of the reasons for this, however. I was wondering if ease of machinability for the amatuer working with simple hand tools, and perhaps also weight savings, were main factors, or was it mainly for lack of magnetic interation with the coils? We also have sheets of aluminum, brass, and stainless that I can use but I'm not sure if they can be resistance welded, so I would have to bolt the face onto the main chassis box. Anyone have any further ideas or insights? thanks in advance, Dave |
David Forsyth wrote:
Hi all, I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. They don't make mention of the reasons for this, however. I was wondering if ease of machinability for the amatuer working with simple hand tools, and perhaps also weight savings, were main factors, or was it mainly for lack of magnetic interation with the coils? We also have sheets of aluminum, brass, and stainless that I can use but I'm not sure if they can be resistance welded, so I would have to bolt the face onto the main chassis box. Anyone have any further ideas or insights? thanks in advance, Dave Steel will be fine. Your suspicions about workability are correct but there is also plating/painting to consider. -Bill |
David Forsyth wrote:
Hi all, I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. They don't make mention of the reasons for this, however. I was wondering if ease of machinability for the amatuer working with simple hand tools, and perhaps also weight savings, were main factors, or was it mainly for lack of magnetic interation with the coils? We also have sheets of aluminum, brass, and stainless that I can use but I'm not sure if they can be resistance welded, so I would have to bolt the face onto the main chassis box. Anyone have any further ideas or insights? thanks in advance, Dave Steel will be fine. Your suspicions about workability are correct but there is also plating/painting to consider. -Bill |
I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. They don't make mention of the reasons for this, however. I was wondering if ease of machinability for the amatuer working with simple hand tools, and 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. |
I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. They don't make mention of the reasons for this, however. I was wondering if ease of machinability for the amatuer working with simple hand tools, and 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. |
Yes, I have found when building regenerative receivers wood is the best
chassi. However a metal front panel is a must. However I only use battery tubes with low voltage. Never more than 45 volts. But when building solid-state regeneratives. A good ground plane helps. Build it the dead bug way. |
Yes, I have found when building regenerative receivers wood is the best
chassi. However a metal front panel is a must. However I only use battery tubes with low voltage. Never more than 45 volts. But when building solid-state regeneratives. A good ground plane helps. Build it the dead bug way. |
The "dead bug" way? I'm not sure what this means - please forgive me I'm
new to this :-) Dave "Bill Hennessy" wrote in message . .. Yes, I have found when building regenerative receivers wood is the best chassi. However a metal front panel is a must. However I only use battery tubes with low voltage. Never more than 45 volts. But when building solid-state regeneratives. A good ground plane helps. Build it the dead bug way. |
The "dead bug" way? I'm not sure what this means - please forgive me I'm
new to this :-) Dave "Bill Hennessy" wrote in message . .. Yes, I have found when building regenerative receivers wood is the best chassi. However a metal front panel is a must. However I only use battery tubes with low voltage. Never more than 45 volts. But when building solid-state regeneratives. A good ground plane helps. Build it the dead bug way. |
David Forsyth wrote: Hi all, I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. Nothing wrong with steel. Altoid mint tin-plated steel boxes are very popular for QRP projects, and tin-plated boxes are often used for screening on commercial RF PCBs. 73, Leon |
David Forsyth wrote: Hi all, I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. Nothing wrong with steel. Altoid mint tin-plated steel boxes are very popular for QRP projects, and tin-plated boxes are often used for screening on commercial RF PCBs. 73, Leon |
"Dead bug" construction means components mounted with legs up. I have not
seen this done with vacuum tube projects. More important than the chassis material is that ground connections come to a common point rather than scattered about the chassis. Ray |
"Dead bug" construction means components mounted with legs up. I have not
seen this done with vacuum tube projects. More important than the chassis material is that ground connections come to a common point rather than scattered about the chassis. Ray |
My first Heathkit radio used copper-clad steel. I think this is a great
combination for electro-magnetic shielding from low frequencies where you need the ferrous material to high frequencies where you need the highly conductive copper skin. Galvanised steel isn't a bad choice either. Steel is needed if you use the radio in the vicinity of CRT's, computers, etc. Good luck, Tom |
My first Heathkit radio used copper-clad steel. I think this is a great
combination for electro-magnetic shielding from low frequencies where you need the ferrous material to high frequencies where you need the highly conductive copper skin. Galvanised steel isn't a bad choice either. Steel is needed if you use the radio in the vicinity of CRT's, computers, etc. Good luck, Tom |
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 -- 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! =----- |
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 -- 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! =----- |
"David Forsyth" wrote in message ... I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. Your articles aren't old enough. After real wooden breadboards went out of style, metal chassis were cadmium-plated steel. Aluminum chassis didn't appear in wide ham use until a few years after WW2. Nowadays I prefer using PC board for mounting components. The Al chassis being upside-down used as a shielded base. In many cases the smaller components can be just soldered together in "basket weave" construction supported by the ones that need to be soldered to the PC-board ground plane. Decades ago Pete Sulzer did his prototypes in full basket-weave style without a ground plane - but few people can visualize ground loops well enough to build RF circuits that way. When you visited his company you'd see his prototypes hanging from nails on the wall. For air-dielectric capacitors: two plates one centimeter on a side, separated by one centimeter equals one picofarad. That's forgetting fringing and other edge effects. Bob C w3otc |
"David Forsyth" wrote in message ... I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. Your articles aren't old enough. After real wooden breadboards went out of style, metal chassis were cadmium-plated steel. Aluminum chassis didn't appear in wide ham use until a few years after WW2. Nowadays I prefer using PC board for mounting components. The Al chassis being upside-down used as a shielded base. In many cases the smaller components can be just soldered together in "basket weave" construction supported by the ones that need to be soldered to the PC-board ground plane. Decades ago Pete Sulzer did his prototypes in full basket-weave style without a ground plane - but few people can visualize ground loops well enough to build RF circuits that way. When you visited his company you'd see his prototypes hanging from nails on the wall. For air-dielectric capacitors: two plates one centimeter on a side, separated by one centimeter equals one picofarad. That's forgetting fringing and other edge effects. Bob C w3otc |
"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 |
"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 |
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 |
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 |
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 ================================================== |
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 ================================================== |
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 :). |
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 :). |
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. |
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. |
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! =----- |
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! =----- |
Michael Black wrote:
"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 I have seen a few nice layouts on Brass chassis, as well. Easier to work than steel, and you can still solder to it. I built some tube RF decks on 1/16" brass sheet stock, and mounted them into a steel cabinet years ago. -- Michael A. Terrell Central Florida |
Michael Black wrote:
"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 I have seen a few nice layouts on Brass chassis, as well. Easier to work than steel, and you can still solder to it. I built some tube RF decks on 1/16" brass sheet stock, and mounted them into a steel cabinet years ago. -- Michael A. Terrell Central Florida |
John Bartley wrote:
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! =----- One thing to watch out for. Relay sockets are not made to run at high temperatures, so you have to make sure they don't melt or burn. -- Michael A. Terrell Central Florida |
John Bartley wrote:
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! =----- One thing to watch out for. Relay sockets are not made to run at high temperatures, so you have to make sure they don't melt or burn. -- Michael A. Terrell Central Florida |
"Michael A. Terrell" wrote in message ... One thing to watch out for. Relay sockets are not made to run at high temperatures, so you have to make sure they don't melt or burn. Yikes!!!!!!!!! Wherever are you going to find temperatures in a receiver that would melt any plastic? Polystyrene miniature tube sockets were used in "UHF" radio receiving projects. Soldering to their contacts took some skill to avoid melting the plastic, but there was no problem during operation. I'll grant you that transmitting firebottles might bother a polystyrene socket. |
"Michael A. Terrell" wrote in message ... One thing to watch out for. Relay sockets are not made to run at high temperatures, so you have to make sure they don't melt or burn. Yikes!!!!!!!!! Wherever are you going to find temperatures in a receiver that would melt any plastic? Polystyrene miniature tube sockets were used in "UHF" radio receiving projects. Soldering to their contacts took some skill to avoid melting the plastic, but there was no problem during operation. I'll grant you that transmitting firebottles might bother a polystyrene socket. |
R J Carpenter wrote:
"Michael A. Terrell" wrote in message ... One thing to watch out for. Relay sockets are not made to run at high temperatures, so you have to make sure they don't melt or burn. Yikes!!!!!!!!! Wherever are you going to find temperatures in a receiver that would melt any plastic? Polystyrene miniature tube sockets were used in "UHF" radio receiving projects. Soldering to their contacts took some skill to avoid melting the plastic, but there was no problem during operation. I'll grant you that transmitting firebottles might bother a polystyrene socket. That was what I was thinking. Someone trying to use a sweep tube to build a small transmitter, and having heat problems with the socket. -- Michael A. Terrell Central Florida |
R J Carpenter wrote:
"Michael A. Terrell" wrote in message ... One thing to watch out for. Relay sockets are not made to run at high temperatures, so you have to make sure they don't melt or burn. Yikes!!!!!!!!! Wherever are you going to find temperatures in a receiver that would melt any plastic? Polystyrene miniature tube sockets were used in "UHF" radio receiving projects. Soldering to their contacts took some skill to avoid melting the plastic, but there was no problem during operation. I'll grant you that transmitting firebottles might bother a polystyrene socket. That was what I was thinking. Someone trying to use a sweep tube to build a small transmitter, and having heat problems with the socket. -- Michael A. Terrell Central Florida |
Aluminum= nice to work with+very light+dose not rust+not really that
expensive -- http://www.qsl.net/sv1hao "David Forsyth" wrote in message ... Hi all, I recently became interested in trying to build a small two-tube regen type receiver for broadcast and/or shortwave reception. I designed a simple chassis based on some vintage articles on the subject. This is the classic 'metal box with attched front faceplate' design. I was going to use cold-rolled steel since we have this at work and spot weld the face to the main chassis, but then I got to thinking that perhaps the steel might interfere with the coils. I noticed also after this that every old article that I've come across usually suggested aluminum for the chassis. They don't make mention of the reasons for this, however. I was wondering if ease of machinability for the amatuer working with simple hand tools, and perhaps also weight savings, were main factors, or was it mainly for lack of magnetic interation with the coils? We also have sheets of aluminum, brass, and stainless that I can use but I'm not sure if they can be resistance welded, so I would have to bolt the face onto the main chassis box. Anyone have any further ideas or insights? thanks in advance, Dave |
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