Anybody who has prized the lid off from their mobile phone recently
cannot have failed to notice the tinplate-like screens shielding the RF
stages, in a similar manner to the lids on TV tuners.

As a ferrous screen is better than just aluminium for magnetic shielding,
I wonder if any have pressed into service the tinplate from cans of
baked beans to provide a similar function?

If so, what was the success in fabricating the springy fingers to ensure
a good seal?

On Tue, 12 Nov 2013, gareth wrote:

Anybody who has prized the lid off from their mobile phone recently
cannot have failed to notice the tinplate-like screens shielding the RF
stages, in a similar manner to the lids on TV tuners.

As a ferrous screen is better than just aluminium for magnetic shielding,
I wonder if any have pressed into service the tinplate from cans of
baked beans to provide a similar function?

If so, what was the success in fabricating the springy fingers to ensure
a good seal?


What you do is find small cans, eat or discard the contents, wash
carefully, and then use those for the separate modules. No need to build
something up, the structure is sound as it is. Use a piece of circuit
board for the cover.

Then when it's all done, you hide it behind a wooden cabinet, safe in the
knowledge that nobody will look inside the fancy wooden box to see the
"ugly" tin cans, and safe in the knowledge that the tin cans will provide
the needed shielding so you can have the fancy wooden cabinet to hide it
all.

There was an early transistorized SSB transceiver in QST, and the author
actually build some of the stages in emptied out IF transformers (the tube
kind, that were so big).

MIchael VE2BVW

"Michael Black" wrote in message
news:alpine.LNX.2.02.1311121238260.16553@darkstar. example.org...
On Tue, 12 Nov 2013, gareth wrote:

Anybody who has prized the lid off from their mobile phone recently
cannot have failed to notice the tinplate-like screens shielding the RF
stages, in a similar manner to the lids on TV tuners.

As a ferrous screen is better than just aluminium for magnetic shielding,
I wonder if any have pressed into service the tinplate from cans of
baked beans to provide a similar function?

If so, what was the success in fabricating the springy fingers to ensure
a good seal?


What you do is find small cans, eat or discard the contents, wash
carefully, and then use those for the separate modules. No need to build
something up, the structure is sound as it is. Use a piece of circuit
board for the cover.

Actually, you have something there, say from a tin of sliced pineapple to,
sit over
an ugly-constructed blank PCB.

Some years ago, to satisfy the need for a wavemeter, I made one up for
144MHz
by soldering together a number of tins, opened at both ends to make the
outer part
of a cavity wavemeter, with a 1/4" stair rod for the plunger. It's about 5'
long
when fully extended, but gives me fundamental plus 3rd harmonic checks.

"Michael Black" wrote in message
news:alpine.LNX.2.02.1311121238260.16553@darkstar. example.org...

There was an early transistorized SSB transceiver in QST, and the author
actually build some of the stages in emptied out IF transformers (the tube
kind, that were so big).

Actually, I've a pile of 2MHz valve IFTs which are earmarked for the IF
strip
in an ongoing (actually a bit too long ongoing :-( ) RX project here.

Emptied "tin" cans have been used by resourceful builders for eons. Some
decades ago, in a "73" magazine was an article about using the original, tin
plated steel beer cans for antenna construction. The tin plate really took
to soldering, and so........ the "beer can vertical" evolved. Mine was a
quarter wave vertical ground plane for the newly opened 15 meter band.
Emptying the required number of beer cans was a formidable task, but someone
had to do it. With my homebrew 2E26 final running almost 20 watts, plate
blushing dull red on long dashes, that old beer can vertical worked all
continents in one hour one afternoon....... while contemplating a 40 meter
version.
Old Chief Lynn, W7LTQ

Emptied "tin" cans have been used by resourceful builders for eons. Some
decades ago, in a "73" magazine was an article about using the original, tin
plated steel beer cans for antenna construction. The tin plate really took
to soldering, and so........ the "beer can vertical" evolved. Mine was a
quarter wave vertical ground plane for the newly opened 15 meter band.
Emptying the required number of beer cans was a formidable task, but someone
had to do it. With my homebrew 2E26 final running almost 20 watts, plate
blushing dull red on long dashes, that old beer can vertical worked all
continents in one hour one afternoon....... while contemplating a 40 meter
version.
Old Chief Lynn, W7LTQ

"gareth" wrote in news:l5tmj6$scp$1@dont-
email.me:

Anybody who has prized the lid off from their mobile phone recently
cannot have failed to notice the tinplate-like screens shielding the RF
stages, in a similar manner to the lids on TV tuners.

As a ferrous screen is better than just aluminium for magnetic shielding,
I wonder if any have pressed into service the tinplate from cans of
baked beans to provide a similar function?

I used to make screened enclosures from old oil cans until they changed
them to plastic. Easy to solder, easy to cut and fold - you could usually
ignore the fold allowance - and reasonably rigid if you folded the top and
bottom edges over fully.


If so, what was the success in fabricating the springy fingers to ensure
a good seal?

I just made the covers slightly oversize and bent the edges in a bit
further. A blob of solder would keep them in place and was relatively easy
to remove if necessary.

On Thu, 14 Nov 2013, 2M0QRO/MM wrote:

gareth wrote:


I wonder if any have pressed into service the tinplate from cans of
baked beans to provide a similar function?


CANTENNA ???

That was a paint can. Probbly the kit Heathkit made the most profit on,
since they just had to buy empty paint cans for the cabinets.

A round "box" like that isn't so useful, hard to arrange on the desk and
where's the front panel? But in the solid state age, most controls could
be remoted, so the paint can could be a very useful chassis. I've seen
them used for things where you need a lot of shielding. There was some
exotic military surplus in the old days that were in round cans, I get for
airplanes, though I don't know why they had round cabinets. But those were
the days when remote ment motors for controls, and clunky relays for
switches. There was a relatively rare SSB transceiver that was in a can
like that, synthesized (but based on crystals), it was really exotic. I
remember the surplus columnist in CQ writing about it, then saying "but I
traded it for something, because I couldn't find the control box for it
and without it, the thing is useless". He knew people in the military, so
he could test the transceiver via a borrowed control box.

Michael VE2BVW

On 14/11/13 19:33, 2M0QRO/MM wrote:
gareth wrote:


I wonder if any have pressed into service the tinplate from cans of
baked beans to provide a similar function?


CANTENNA ???

Ooh, ah, Cantenna, ooh ah Cantenna.
Sorry, ****ed again.
--
;-)
..
73 de Frank Turner-Smith G3VKI - mine's a pint.
..
http://turner-smith.co.uk
..
Ubuntu 12.04
Thunderbirds are go.

Cantina's FOREVER!

"Frank Turner-Smith G3VKI" wrote in message
...
On 14/11/13 19:33, 2M0QRO/MM wrote:
gareth wrote:


I wonder if any have pressed into service the tinplate from cans of
baked beans to provide a similar function?


CANTENNA ???

Ooh, ah, Cantenna, ooh ah Cantenna.
Sorry, ****ed again.
--
;-)
.
73 de Frank Turner-Smith G3VKI - mine's a pint.
.
http://turner-smith.co.uk
.
Ubuntu 12.04
Thunderbirds are go.