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?)



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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?)



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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