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#41
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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 |
#42
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The "dead bug" way? I'm not sure what this means - please forgive me I'm
new to this :-) ========= This is a method of construction where components are soldered to unetched printed circuit board islands (made with a special rotary bit which only removes a thin ring from the copper surface ) or to insulated PCB patches glued onto the unetched PCB ,with ICs glued to the PCB with the legs up (hence dead bug) and connected to other components . If permissible ,additional 'connecting points' are achieved by soldering high value resistors (a number of MegaOhms) perpendicularly onto the PCB with the other end serving as the connecting point. It is also called ugly construction . Extensive info on these methods is given in an excellent book for homebrewers : "Experimental Methods in RF Design" Chapter 1. ; published by ARRL. Frank GM0CSZ / KN6WH |
#43
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The "dead bug" way? I'm not sure what this means - please forgive me I'm
new to this :-) ========= This is a method of construction where components are soldered to unetched printed circuit board islands (made with a special rotary bit which only removes a thin ring from the copper surface ) or to insulated PCB patches glued onto the unetched PCB ,with ICs glued to the PCB with the legs up (hence dead bug) and connected to other components . If permissible ,additional 'connecting points' are achieved by soldering high value resistors (a number of MegaOhms) perpendicularly onto the PCB with the other end serving as the connecting point. It is also called ugly construction . Extensive info on these methods is given in an excellent book for homebrewers : "Experimental Methods in RF Design" Chapter 1. ; published by ARRL. Frank GM0CSZ / KN6WH |
#44
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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: ============= These surface mount sockets have substantial screwed connections and are made of PVC which as suggested might not be the optimum for VHF applications ,but also might not be able to cope with the heat produced by the relevant valve (tube), especially when the valve is of the medium to high power variety. Frank GM0CSZ / KN6WH |
#45
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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: ============= These surface mount sockets have substantial screwed connections and are made of PVC which as suggested might not be the optimum for VHF applications ,but also might not be able to cope with the heat produced by the relevant valve (tube), especially when the valve is of the medium to high power variety. Frank GM0CSZ / KN6WH |
#46
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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. =============== Talking about nails ,some time ago in the dutch amateur radio mag. 'Electron' , there was an article describing a kid's radio. ,dubbed 'Nail Radio' . Its construction was on a piece of timber into which copperclad nails had been hammered in circuit diagramme configuration .. The components (for this medium wave receiver) were subsequently soldered to the nail heads. A superb way to introduce newcomers to electronics and radio home-brewing. Frank GM0CSZ / KN6WH |
#47
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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. =============== Talking about nails ,some time ago in the dutch amateur radio mag. 'Electron' , there was an article describing a kid's radio. ,dubbed 'Nail Radio' . Its construction was on a piece of timber into which copperclad nails had been hammered in circuit diagramme configuration .. The components (for this medium wave receiver) were subsequently soldered to the nail heads. A superb way to introduce newcomers to electronics and radio home-brewing. Frank GM0CSZ / KN6WH |
#48
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Frank Dinger wrote:
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. =============== Talking about nails ,some time ago in the dutch amateur radio mag. 'Electron' , there was an article describing a kid's radio. ,dubbed 'Nail Radio' . Its construction was on a piece of timber into which copperclad nails had been hammered in circuit diagramme configuration . The components (for this medium wave receiver) were subsequently soldered to the nail heads. A superb way to introduce newcomers to electronics and radio home-brewing. Frank GM0CSZ / KN6WH hehehe...as a kid I built a crystal radio like that. No soldering though. -Bill |
#49
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Frank Dinger wrote:
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. =============== Talking about nails ,some time ago in the dutch amateur radio mag. 'Electron' , there was an article describing a kid's radio. ,dubbed 'Nail Radio' . Its construction was on a piece of timber into which copperclad nails had been hammered in circuit diagramme configuration . The components (for this medium wave receiver) were subsequently soldered to the nail heads. A superb way to introduce newcomers to electronics and radio home-brewing. Frank GM0CSZ / KN6WH hehehe...as a kid I built a crystal radio like that. No soldering though. -Bill |
#50
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On Mon, 20 Oct 2003 16:43:06 +0100, "Frank Dinger"
wrote: Talking about nails ,some time ago in the dutch amateur radio mag. 'Electron' , there was an article describing a kid's radio. ,dubbed 'Nail Radio' . Its construction was on a piece of timber into which copperclad nails had been hammered in circuit diagramme configuration . The components (for this medium wave receiver) were subsequently soldered to the nail heads. A superb way to introduce newcomers to electronics and radio home-brewing. A real circuit "board". Any technique that works, is good technique. Happy trails, Gary (net.yogi.bear) ------------------------------------------------ at the 51st percentile of ursine intelligence Gary D. Schwartz, Needham, MA, USA Please reply to: garyDOTschwartzATpoboxDOTcom |
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