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#11
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Michael Black wrote:
Perfboard was around long before most hobbyists had heard of wire wrap. Once transistors came along, perfboard tended to be the method of construction, unless you were planning to do it point to point on a chassis like you would with tubes. "Messy" has no relevance since the wiring was under the board. You'd use component leads to connect the parts, and if they weren't long enough, bits of wire. That's right... Maybe it would help to give an example where plain perfboard was the best construction method. I recently built a small power distribution board which involved four 0.1in-pitch connector headers, a voltage regulator IC and a few passive components. Why choose plain perfboard for this project? Mostly because the wiring underneath was going to be fairly complex, so hand-wiring was going to be the easiest way to make the board reasonably small. The advantage of hand-wiring is that you can have as many crossovers as you like, using insulated wire. What other techniques didn't I choose? Even a double-sided PC board would have needed some jumpers, and wouldn't have been worth the effort for a one-off project. A single-sided PC board would have required lots of jumpers, and copper-strip perfboard (Veroboard/Vectorboard) would have been even worse. So bare perfboard it was. The four headers were temporarily superglued onto the board, so they wouldn't fall out when the board was turned over to do the wiring. Under the board, I ran a common ground bus of 18SWG/16AWG tinned copper wire around all the headers. The other small components were pushed through the holes, and anchored by their leads as the various connections were made. Most of the wiring was done point-to-point using the bare component leads. Crossovers were handled using kynar insulated wire - sold for wire-wrapping, but excellent for point-to-point soldered wiring too. By the time all the header pins had been soldered to, the headers were well anchored through the board and are very secure. The whole thing looks quite tidy from the top. If neatness is important (and indeed, why not make a good job of it?) the main consideration is to cut the board cleanly and file off the ragged edges. And the ones with bits of copper at each hole had the advantage, as someone pointed out, that you could solder the components to the board before adding the wires. People were hesitant to make their own etched circuit boards, and even after they became fairly common in hobby circles, many would say "I don't want to bother" and they'd stick with perfboard. Certainly... and as I just said, it's one of the preferred techniques for one-off construction. If perfboard faded from view in recent years, it's likely because etched circuit boards have tended to take over, if not made by the hands of the hobbyist then because people were buying premade circuit boards. Maybe plain perfboard just hasn't had much publicity. As an author, I can see why: if it's a fairly basic 'follow these instructions' project, then at the very least you're expected to design a PC board; but if it's a project for experienced constructors, you don't need to tell them how to build it. In either kind of article, plain perfboard probably doesn't get a mention... but it's still there. As someone pointed out, perfboard is not so great for RF. Better to use a blank piece of copper circuit board, and build on top of that, so you have the copper as a good ground point. Yep. The strengths of plain perfboard are for DC, audio and slow logic circuits, and in the sheer versatility of hand-wiring underneath the board. But that's likely "messier" than using perfboard with the wiring on the bottom. Of course, from time to time I've used copper circuit board as "perfboard", drilling holes where needed and reaming out the copper from around the holes so the components go in without shorting. Wire up on the non-copper side of the board, like perfboard, but all ground connections go to the copper on the top side. If all the grounds are to the common top-side groundplane, it doesn't look messy at all. The top-side looks very neat and the wiring underneath is simplified by the absence of ground wires. Above all, the RF performance will probably be very good. For this kind of project, I very often use PCB design software to work up the layout, but don't always etch a board. Just as often, I cut a piece of single-sided board, tape a 1:1 printout of the PCB design onto the board and use it as a drilling template. Then I hand-wire the underside using the layout as a guide. -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek |
#12
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"Michael Black" wrote in message
... As someone pointed out, perfboard is not so great for RF. Better to use a blank piece of copper circuit board, and build on top of that, so you have the copper as a good ground point. But that's likely "messier" than using perfboard with the wiring on the bottom. But how something looks is irrelevant. You can stick it in a box out of view. Building over circuit board actually works better than perfboard, because it's easier to run wires in a three dimensional space. If you look at the manhattan style work of Jim Kortge (http://www.qsl.net/k8iqy/) or Chuck Adams (http://www.qsl.net/k7qo/) it's hard to call it "messier". Of course, few of us mortals can do the sort of work they can. ... |
#13
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In article , "Ian White, G3SEK"
writes: Michael Black wrote: Perfboard was around long before most hobbyists had heard of wire wrap. Once transistors came along, perfboard tended to be the method of construction, unless you were planning to do it point to point on a chassis like you would with tubes. "Messy" has no relevance since the wiring was under the board. You'd use component leads to connect the parts, and if they weren't long enough, bits of wire. That's right... Maybe it would help to give an example where plain perfboard was the best construction method. I recently built a small power distribution board which involved four 0.1in-pitch connector headers, a voltage regulator IC and a few passive components. Why choose plain perfboard for this project? Mostly because the wiring underneath was going to be fairly complex, so hand-wiring was going to be the easiest way to make the board reasonably small. The advantage of hand-wiring is that you can have as many crossovers as you like, using insulated wire. What other techniques didn't I choose? Even a double-sided PC board would have needed some jumpers, and wouldn't have been worth the effort for a one-off project. A single-sided PC board would have required lots of jumpers, and copper-strip perfboard (Veroboard/Vectorboard) would have been even worse. So bare perfboard it was. The four headers were temporarily superglued onto the board, so they wouldn't fall out when the board was turned over to do the wiring. Under the board, I ran a common ground bus of 18SWG/16AWG tinned copper wire around all the headers. The other small components were pushed through the holes, and anchored by their leads as the various connections were made. Most of the wiring was done point-to-point using the bare component leads. Crossovers were handled using kynar insulated wire - sold for wire-wrapping, but excellent for point-to-point soldered wiring too. By the time all the header pins had been soldered to, the headers were well anchored through the board and are very secure. The whole thing looks quite tidy from the top. If neatness is important (and indeed, why not make a good job of it?) the main consideration is to cut the board cleanly and file off the ragged edges. Ian, I'm in perfect agreement with what you and Michael Black wrote. I base that on working prototypes made for over three decades. It seems as though perfboard has been around longer...:-) One thing that all should remember: Electrons don't care about "neat" construction. "Neat" gets something past inspectors, appeals to customers, looks mighty fine and "professional" in photographs. Electrons don't care for any of that. Fields and waves only care about placement of conductors and nearby dielectric material. And the ones with bits of copper at each hole had the advantage, as someone pointed out, that you could solder the components to the board before adding the wires. People were hesitant to make their own etched circuit boards, and even after they became fairly common in hobby circles, many would say "I don't want to bother" and they'd stick with perfboard. Perf and hand wiring SAVES TIME. Homebrewing is about making electronic things at home. Few of us have TIME at our disposal. For relatively simple circuit arrangements, it would take me (somewhat experienced) more time to sketch out a PCB foil pattern and check it against a schematic than direct-wiring a perf-board circuit. A PCB still has to be masked and etched and cleaned. Printed circuit boards originally were a tremendous advantage in mass production of electronics. It could physically hold components as well as perfectly reproduce wiring paths...compared to the longer time needed to mount (vacuum tube style) components and then hand-wire all the connections, usually in several stages of wiring by different assemblers. Production costs dropped considerably once all got through the capital equipment expenditure for PCB machinery. SMT got a big following because it was small...but also because it cut down on production even more. Fewer holes to drill (sometimes none) and the "baking" ovens didn't need as much maintenance as the flow soldering machines did with peanut oil, cleaner and degreaser, solder solutions. SMT took the basic PCB construction technique. Certainly... and as I just said, it's one of the preferred techniques for one-off construction. If perfboard faded from view in recent years, it's likely because etched circuit boards have tended to take over, if not made by the hands of the hobbyist then because people were buying premade circuit boards. Maybe plain perfboard just hasn't had much publicity. As an author, I can see why: if it's a fairly basic 'follow these instructions' project, then at the very least you're expected to design a PC board; but if it's a project for experienced constructors, you don't need to tell them how to build it. In either kind of article, plain perfboard probably doesn't get a mention... but it's still there. Perf with hand-wired "solder side" connections doesn't photograph well. Image is important in magazine layout. :-) As someone pointed out, perfboard is not so great for RF. Better to use a blank piece of copper circuit board, and build on top of that, so you have the copper as a good ground point. Yep. The strengths of plain perfboard are for DC, audio and slow logic circuits, and in the sheer versatility of hand-wiring underneath the board. Right on! But...if one is familiar with RF layout through experience and a "feel" for lead placement and lengths, perf can be used on up to 70 MHz. That is NOT recommended for beginners who have just memorized Ohm's Law. At RCA EASD in the 1970s we regularly used Douglas Electronics 11-DE-1 boards for prototyping digital logic at equivalent clock rates up to 10 MHz. Those held 12 DIPs had three-hole pads and #24 or #26 insulated wire did the interconnects on the component side. A 44-pin edge contact allowed plug-in assembly and extenders. That was most excellent for churning out 1- to 3-of-a-kind prototypes at up to 150 cards per system. Techs could just follow a schematic and hand-wire the cards...sort of "connect the dots" kind of operation. Was very good with few errors done by anyone. Douglas is still in business and the 11-DE-1 prototype board is still available in the USA at about $12 each. A comparable Vector Electronics prototype board is about the same price. I prefer the Douglas since it is gold-flashed and a variant is available with a ground plane on the component side. But that's likely "messier" than using perfboard with the wiring on the bottom. Of course, from time to time I've used copper circuit board as "perfboard", drilling holes where needed and reaming out the copper from around the holes so the components go in without shorting. Wire up on the non-copper side of the board, like perfboard, but all ground connections go to the copper on the top side. If all the grounds are to the common top-side groundplane, it doesn't look messy at all. The top-side looks very neat and the wiring underneath is simplified by the absence of ground wires. Above all, the RF performance will probably be very good. For this kind of project, I very often use PCB design software to work up the layout, but don't always etch a board. Just as often, I cut a piece of single-sided board, tape a 1:1 printout of the PCB design onto the board and use it as a drilling template. Then I hand-wire the underside using the layout as a guide. I cheat a bit. Originally an illustrator, I sketch out the foil paths on vellum 1:1, mark the drill holes and use the vellum as a small center-punch guide. The paths are then painted in with lacquer, free-hand, using the vellum as a guide. Lacquer can be peeled off after etching with a sharp graphics knife (an X-Acto modeller's knife to olde-tymers) and dissolved in acetone to be reused later. Lacquer works fine with ferric chloride etchant. Enamel does NOT. Enamels, now common in aircraft model shops can be undercut in the etching. One has to really hunt for low-enough-price lacquer now but it once was standard "dope" for modelers. I'm still using a half-pint bottle of Testor's model airplane Dope obtained in 1947 (Testor's wisely changed the name slightly after that). Acetone in pint can sizes is available in U.S. do-it-yourself stores. :-) Len Anderson retired (from regular hours) electronic engineer person |
#14
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In article , "Ian White, G3SEK"
writes: Michael Black wrote: Perfboard was around long before most hobbyists had heard of wire wrap. Once transistors came along, perfboard tended to be the method of construction, unless you were planning to do it point to point on a chassis like you would with tubes. "Messy" has no relevance since the wiring was under the board. You'd use component leads to connect the parts, and if they weren't long enough, bits of wire. That's right... Maybe it would help to give an example where plain perfboard was the best construction method. I recently built a small power distribution board which involved four 0.1in-pitch connector headers, a voltage regulator IC and a few passive components. Why choose plain perfboard for this project? Mostly because the wiring underneath was going to be fairly complex, so hand-wiring was going to be the easiest way to make the board reasonably small. The advantage of hand-wiring is that you can have as many crossovers as you like, using insulated wire. What other techniques didn't I choose? Even a double-sided PC board would have needed some jumpers, and wouldn't have been worth the effort for a one-off project. A single-sided PC board would have required lots of jumpers, and copper-strip perfboard (Veroboard/Vectorboard) would have been even worse. So bare perfboard it was. The four headers were temporarily superglued onto the board, so they wouldn't fall out when the board was turned over to do the wiring. Under the board, I ran a common ground bus of 18SWG/16AWG tinned copper wire around all the headers. The other small components were pushed through the holes, and anchored by their leads as the various connections were made. Most of the wiring was done point-to-point using the bare component leads. Crossovers were handled using kynar insulated wire - sold for wire-wrapping, but excellent for point-to-point soldered wiring too. By the time all the header pins had been soldered to, the headers were well anchored through the board and are very secure. The whole thing looks quite tidy from the top. If neatness is important (and indeed, why not make a good job of it?) the main consideration is to cut the board cleanly and file off the ragged edges. Ian, I'm in perfect agreement with what you and Michael Black wrote. I base that on working prototypes made for over three decades. It seems as though perfboard has been around longer...:-) One thing that all should remember: Electrons don't care about "neat" construction. "Neat" gets something past inspectors, appeals to customers, looks mighty fine and "professional" in photographs. Electrons don't care for any of that. Fields and waves only care about placement of conductors and nearby dielectric material. And the ones with bits of copper at each hole had the advantage, as someone pointed out, that you could solder the components to the board before adding the wires. People were hesitant to make their own etched circuit boards, and even after they became fairly common in hobby circles, many would say "I don't want to bother" and they'd stick with perfboard. Perf and hand wiring SAVES TIME. Homebrewing is about making electronic things at home. Few of us have TIME at our disposal. For relatively simple circuit arrangements, it would take me (somewhat experienced) more time to sketch out a PCB foil pattern and check it against a schematic than direct-wiring a perf-board circuit. A PCB still has to be masked and etched and cleaned. Printed circuit boards originally were a tremendous advantage in mass production of electronics. It could physically hold components as well as perfectly reproduce wiring paths...compared to the longer time needed to mount (vacuum tube style) components and then hand-wire all the connections, usually in several stages of wiring by different assemblers. Production costs dropped considerably once all got through the capital equipment expenditure for PCB machinery. SMT got a big following because it was small...but also because it cut down on production even more. Fewer holes to drill (sometimes none) and the "baking" ovens didn't need as much maintenance as the flow soldering machines did with peanut oil, cleaner and degreaser, solder solutions. SMT took the basic PCB construction technique. Certainly... and as I just said, it's one of the preferred techniques for one-off construction. If perfboard faded from view in recent years, it's likely because etched circuit boards have tended to take over, if not made by the hands of the hobbyist then because people were buying premade circuit boards. Maybe plain perfboard just hasn't had much publicity. As an author, I can see why: if it's a fairly basic 'follow these instructions' project, then at the very least you're expected to design a PC board; but if it's a project for experienced constructors, you don't need to tell them how to build it. In either kind of article, plain perfboard probably doesn't get a mention... but it's still there. Perf with hand-wired "solder side" connections doesn't photograph well. Image is important in magazine layout. :-) As someone pointed out, perfboard is not so great for RF. Better to use a blank piece of copper circuit board, and build on top of that, so you have the copper as a good ground point. Yep. The strengths of plain perfboard are for DC, audio and slow logic circuits, and in the sheer versatility of hand-wiring underneath the board. Right on! But...if one is familiar with RF layout through experience and a "feel" for lead placement and lengths, perf can be used on up to 70 MHz. That is NOT recommended for beginners who have just memorized Ohm's Law. At RCA EASD in the 1970s we regularly used Douglas Electronics 11-DE-1 boards for prototyping digital logic at equivalent clock rates up to 10 MHz. Those held 12 DIPs had three-hole pads and #24 or #26 insulated wire did the interconnects on the component side. A 44-pin edge contact allowed plug-in assembly and extenders. That was most excellent for churning out 1- to 3-of-a-kind prototypes at up to 150 cards per system. Techs could just follow a schematic and hand-wire the cards...sort of "connect the dots" kind of operation. Was very good with few errors done by anyone. Douglas is still in business and the 11-DE-1 prototype board is still available in the USA at about $12 each. A comparable Vector Electronics prototype board is about the same price. I prefer the Douglas since it is gold-flashed and a variant is available with a ground plane on the component side. But that's likely "messier" than using perfboard with the wiring on the bottom. Of course, from time to time I've used copper circuit board as "perfboard", drilling holes where needed and reaming out the copper from around the holes so the components go in without shorting. Wire up on the non-copper side of the board, like perfboard, but all ground connections go to the copper on the top side. If all the grounds are to the common top-side groundplane, it doesn't look messy at all. The top-side looks very neat and the wiring underneath is simplified by the absence of ground wires. Above all, the RF performance will probably be very good. For this kind of project, I very often use PCB design software to work up the layout, but don't always etch a board. Just as often, I cut a piece of single-sided board, tape a 1:1 printout of the PCB design onto the board and use it as a drilling template. Then I hand-wire the underside using the layout as a guide. I cheat a bit. Originally an illustrator, I sketch out the foil paths on vellum 1:1, mark the drill holes and use the vellum as a small center-punch guide. The paths are then painted in with lacquer, free-hand, using the vellum as a guide. Lacquer can be peeled off after etching with a sharp graphics knife (an X-Acto modeller's knife to olde-tymers) and dissolved in acetone to be reused later. Lacquer works fine with ferric chloride etchant. Enamel does NOT. Enamels, now common in aircraft model shops can be undercut in the etching. One has to really hunt for low-enough-price lacquer now but it once was standard "dope" for modelers. I'm still using a half-pint bottle of Testor's model airplane Dope obtained in 1947 (Testor's wisely changed the name slightly after that). Acetone in pint can sizes is available in U.S. do-it-yourself stores. :-) Len Anderson retired (from regular hours) electronic engineer person |
#15
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On Wed, 04 Feb 2004 06:31:08 -0800, James W
wrote: When working with simple perfboard (just holes, no 'traces' connecting the holes) how does one connect the components together? I'm guessing by using jumper wires for point-to-point wiring on the backside, but that seems a bit ugly. - jim I don't have a catalog anymore, but Vector used to make a variety of pins, for both wire wrap and solder, that fit in their perfboards. Punch in the pins, mount the components on them, run the connections on the bottom and solder. They also had a wiring pencil that could be used to run the connections. The wire had an insulation that would melt when hit with solder. I wired up a couple of simple IC based digital designs with one. I just used normal DIP sockets for the IC's. Bob McConnell N2SPP |
#16
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On Wed, 04 Feb 2004 06:31:08 -0800, James W
wrote: When working with simple perfboard (just holes, no 'traces' connecting the holes) how does one connect the components together? I'm guessing by using jumper wires for point-to-point wiring on the backside, but that seems a bit ugly. - jim I don't have a catalog anymore, but Vector used to make a variety of pins, for both wire wrap and solder, that fit in their perfboards. Punch in the pins, mount the components on them, run the connections on the bottom and solder. They also had a wiring pencil that could be used to run the connections. The wire had an insulation that would melt when hit with solder. I wired up a couple of simple IC based digital designs with one. I just used normal DIP sockets for the IC's. Bob McConnell N2SPP |
#17
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I'm using a very elegant "in-between" technique which combines the
flexibility of perfboard wire with the shielding and relative precision advantages of copper-clad. It's also very cheap! I buy rolls of adhesive copper tape of various widths from a stained-glass supplies store. I'll use the wide tape for covering one side of the PCB with the ground plane. Then, on the other side, I'll construct traces of the size and placement that I want with small pieces of copper tape. If I need to make a correction, I can usually add or cut away more foil. If I need to join pieces of tape electrically, a small dab of solder along the edge works nicely. Copper tape allows me to do double sided work at will without the need for chemicals or the danger of using an electric drill to rout away copper. I've been able to bang out one small circuit per weekend and usually get it right the first time, if not the second. Try it! You'll be pleasantly surprised. The Eternal Squire Roy Lewallen wrote in message ... A good way to connect the components is to simply bend the component leads over. Often, they're long enough to reach between connected components. If not, short bare wires can be added. It can be done quite neatly, and the result is very durable. But if beauty is important to you, you should probably go to the trouble of making a PCB. This method shares a problem with conventional one- or two-sided non-ground plane PCBs in that proper bypassing and "grounding" requires some skill and knowledge. It's easy to end up with "ground" currents from multiple circuits sharing a common conductor, which can often lead to crosstalk and oscillation. This becomes more of a problem with increasing frequency, but because virtually all modern semiconductors have substantial gain at very high frequencies, it can still be a problem even when the operating frequency is low. I personally favor "ugly" construction, in which components are mounted over a solid ground plane. This reduces the impedance of inter-circuit ground connections so is considerably more forgiving of less-than-optimum layout. Roy Lewallen, W7EL James W wrote: When working with simple perfboard (just holes, no 'traces' connecting the holes) how does one connect the components together? I'm guessing by using jumper wires for point-to-point wiring on the backside, but that seems a bit ugly. - jim --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.564 / Virus Database: 356 - Release Date: 1/19/04 |
#18
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I'm using a very elegant "in-between" technique which combines the
flexibility of perfboard wire with the shielding and relative precision advantages of copper-clad. It's also very cheap! I buy rolls of adhesive copper tape of various widths from a stained-glass supplies store. I'll use the wide tape for covering one side of the PCB with the ground plane. Then, on the other side, I'll construct traces of the size and placement that I want with small pieces of copper tape. If I need to make a correction, I can usually add or cut away more foil. If I need to join pieces of tape electrically, a small dab of solder along the edge works nicely. Copper tape allows me to do double sided work at will without the need for chemicals or the danger of using an electric drill to rout away copper. I've been able to bang out one small circuit per weekend and usually get it right the first time, if not the second. Try it! You'll be pleasantly surprised. The Eternal Squire Roy Lewallen wrote in message ... A good way to connect the components is to simply bend the component leads over. Often, they're long enough to reach between connected components. If not, short bare wires can be added. It can be done quite neatly, and the result is very durable. But if beauty is important to you, you should probably go to the trouble of making a PCB. This method shares a problem with conventional one- or two-sided non-ground plane PCBs in that proper bypassing and "grounding" requires some skill and knowledge. It's easy to end up with "ground" currents from multiple circuits sharing a common conductor, which can often lead to crosstalk and oscillation. This becomes more of a problem with increasing frequency, but because virtually all modern semiconductors have substantial gain at very high frequencies, it can still be a problem even when the operating frequency is low. I personally favor "ugly" construction, in which components are mounted over a solid ground plane. This reduces the impedance of inter-circuit ground connections so is considerably more forgiving of less-than-optimum layout. Roy Lewallen, W7EL James W wrote: When working with simple perfboard (just holes, no 'traces' connecting the holes) how does one connect the components together? I'm guessing by using jumper wires for point-to-point wiring on the backside, but that seems a bit ugly. - jim --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.564 / Virus Database: 356 - Release Date: 1/19/04 |
#19
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Of course, from time to time I've used copper circuit board
as "perfboard", drilling holes where needed and reaming out the copper from around the holes so the components go in without shorting. Wire up on the non-copper side of the board, like perfboard, but all ground connections go to the copper on the top side. ============================= Double sided copperclad board is a universal base for anything electronics including RF circuits. I prefer the already mentioned 'dead bug' or 'ugly construction ' method where ICs are involved (legs up ), with the legs to be earthed bent down and directly soldered to the board. Earthed components serve as connection posts for other non-earthed circuit components. For connecting points free from earth I use a special 'island drill' ,a cylindric rotary bit covered with 'diamond grit' leaving a insulated 5mm diameter island to which up to 4 components can be joined. Instead of the islands I also use small 0.25 Watt , 10 MOhm resistors with one end connected to ground ,the other end serving as post ,since many circuits have impedences 2 orders of magnitude lower than 10 MOhm. All earthed components are soldered to other side of board via drilled holes ,hence are perpendicular to board face. The 2 copper clad sides are joined either by multiple connections through drilled holes ,or all-around board edge copper wire/strip connection, the latter especially for vhf circuits. I have no experience in UHF/microwave home brewing , but understand that single sided copper clad teflon board (thin) is normally used. Frank GM0CSZ / KN6WH |
#20
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Of course, from time to time I've used copper circuit board
as "perfboard", drilling holes where needed and reaming out the copper from around the holes so the components go in without shorting. Wire up on the non-copper side of the board, like perfboard, but all ground connections go to the copper on the top side. ============================= Double sided copperclad board is a universal base for anything electronics including RF circuits. I prefer the already mentioned 'dead bug' or 'ugly construction ' method where ICs are involved (legs up ), with the legs to be earthed bent down and directly soldered to the board. Earthed components serve as connection posts for other non-earthed circuit components. For connecting points free from earth I use a special 'island drill' ,a cylindric rotary bit covered with 'diamond grit' leaving a insulated 5mm diameter island to which up to 4 components can be joined. Instead of the islands I also use small 0.25 Watt , 10 MOhm resistors with one end connected to ground ,the other end serving as post ,since many circuits have impedences 2 orders of magnitude lower than 10 MOhm. All earthed components are soldered to other side of board via drilled holes ,hence are perpendicular to board face. The 2 copper clad sides are joined either by multiple connections through drilled holes ,or all-around board edge copper wire/strip connection, the latter especially for vhf circuits. I have no experience in UHF/microwave home brewing , but understand that single sided copper clad teflon board (thin) is normally used. Frank GM0CSZ / KN6WH |
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