John – Phil
Thanks, back to the drawing board! Seemed
like a good idea, but with these limitations, I doubt that we would want to do
it this way.
Eric
From:
xylo-sdr-bounces@lists.ae5k.us [mailto:xylo-sdr-bounces@lists.ae5k.us] On Behalf Of John Kolb
Sent: Wednesday, January 04, 2006
2:54 AM
To: Xylo-SDR
Discussion
Subject: Re: [Xylo-SDR] Some
design thoughts requested
It's thinner than a standard 0.062" thick PCB - don't remember if it's
0.031 or 0.050,
but being thinner limits the number of layers that are practical.
We were using SODIMM format cards in a similar fashion at my previous employer
and found that the PCB's/sockets were good for only a limited number of
insertions.
OK if you pick out a set of modules and assemble a unit once, but not a good
connector choice for experimenters.
John KK6IL
At 04:11 PM 1/3/2006, you wrote:
One advantage of the DDR size card is that if you don't need a large
card it could be the size of a DDR module which is pretty small. You could fit
a SR5 and the bandpass module in one stick and still have a little room.
There is a board thickness that you need to maintain in order to get good
contact to the socket, I don't have calipers at home to measure the thickness
of a DDR card, and see if that is a standard thickness.
At 05:50 PM 1/3/2006, you wrote:
Guys
Done!
Lets go DDR DIMM sockets… with a MB of our design. Now (or first)
we need an extruded aluminum (or other) project case with slides, in the size
we are talking about so we can define the board real-estate as default to slide
in the enclosure. Space on every few rails for a faraday shield between boards.
The PCI bus gave us cheap L-Brackets on a third side for connectors, however in
this design everything must come out the ‘front’ of the box. It
would be nice if we could design a ‘front’ panel based on a PCB
which could be drilled for common connector sizes and be reproduced for
different projects. Heck, even a blank buss structured, motherboard, power
distribution, project case of this sort could be a product with all the
experimenters around!
Sell this and fund our xylo boards! (smile)
Comments?
Eric
From:
xylo-sdr-bounces@lists.ae5k.us [ mailto:xylo-sdr-bounces@lists.ae5k.us] On Behalf Of KD5NWA
Sent: Tuesday, January 03, 2006
2:44 PM
To: Xylo-SDR
Discussion
Subject: Re: [Xylo-SDR] Some design
thoughts requested
That is workable for small boards, with .05" (1.27mm) pin spacing it's
very doable even with homemade PCB boards.
Boards 5.5"x3.5" would be a reasonable board size, and with todays
components you can put a whole lot of circuitry in a board that large.
I've seen someone build a little jig to use a router to route the connector and
a belt sander to bevel the edge connector at home.
I have not been able to find ready-made prototype boards.
I've found an interesting source of IC header boards, reasonable when you
consider the quantities you get.
P516 and P507 look interesting.
< http://www.beldynsys.com/singledual.htm
>
At 12:11 PM 1/3/2006, you wrote:
Hello all,
I considered using DDR SIMM sockets for a project. You get 184
contacts and they give you a card width of 5.25". The height of the
card is not restricted (within reason).
http://www.molex.com/pdm_docs/sd/876362002_sd.pdf
It is kind of like the SIMMStick idea, but with more contacts (184 vs
30). 30 pin SIMM sockets are very hard to get these days and I see
that Molex has scheduled the 72 pin SIMM sockets for obsolescence.
The DDR DIMM sockets should be around for a while yet. They are
relatively cheap ($1.92 ea Digikey).
73 de Phil N8VB
On 1/2/06, Eric Ellison <ecellison@comcast.net>
wrote:
>
>
>
> Cecil
>
>
>
> Yes, I'll go back and look at Eurocard standard. This looks great. GUD
> HUNTING! Thanks for all the links. One way or tother I think we need a
buss
> for our end product. Your point about size of the boards we might want to
> manufacture is well taken. They should be able to go on a little more than
a
> postage stamp, and be VERY inexpensive to produce - external connectors
> being the limiting size factor! One reason I was looking at Memory Chip
> risers.
>
>
>
> I moused around a little today, and really can't see where I can justify
> Eagle Software in any serious production version. So I'll probably monkey
> around with Kicad, which is a really nice GPL product. I mentioned earlier
> that there was some problem with the Drill files, which they have
corrected.
> Only benefit of Eagle IS the plethora of template files available. I don't
> mind eating on my lunchtime and creating new parts! Good exercise and I am
> getting fatter! (No Testosterone!)
>
>
>
> Sparkfun has a pretty good batch deal for prototype boards and also a lot
of
> interesting new products. I like their little 3 buck power supplies. Also
> have a some 28 pin SOIC to DIP experimenter stuff for about the same
price.
>
>
>
> http://www.sparkfun.com/shop/index.php?shop=1&cart=525299&cat=1&PHPSESSID=abce58b426cb8d0d0c3cf4b1495f0312
>
>
>
> Other prototype boards can be had at:
>
>
>
> http://protoboards.theshoppe.com/index.html
>
>
>
> Will return!
>
>
>
> Viva the Project
>
>
>
> Eric
>
>
>
> ________________________________
>
>
> From: xylo-sdr-bounces@lists.ae5k.us [ mailto:xylo-sdr-bounces@lists.ae5k.us]
> On Behalf Of KD5NWA
> Sent: Monday, January 02, 2006 2:06 PM
> To: Xylo-SDR Discussion
> Subject: Re: [Xylo-SDR] Some design thoughts requested
>
>
>
>
> I'll second the DIN connectors,they are very reliable, and come in
different
> sizes, single, and dual connector cards. I have used them in an industrial
> environment and they worked flawlessly for years. But I'll go one more
step
> forward.
>
> The Eurocard standard allows for mix of one 96 pin connector,
two
> connectors or even three connectors (not needed). Prototype boards are
> cheap, most PCB houses have specials on Eurocard size boards. Card cages
are
> available for low prices for the Eurocard format
>
> Like Leon
said the connectors are expensive but they are self aligning, and
> I've seen then for under $3 on the Internet.
>
> Although the PCI is tempting and cheap for the backplane, it's a bus
that
> is designed for digital logic, all pins are tied to the same pins in all
> cards. Prototype cards tend to be large and expensive.
>
> A brief blurb on Eurocards;
>
> < http://www.yotor.org/wiki/en/eu/Eurocard.htm >
>
> Cheap prototype boards are available for $10 or less, a very
important
> point, $50 to $60 for a PCI card is very expensive, maybe I'm too cheap,
but
> the blank board should not cost more than the components.
> < http://www.sbszoo.com/ve6sbs/sale/cct-brds.htm >
>
> Here are some available at Mouse;
> <
> http://www.mouser.com/index.cfm?handler=data.getPcodes&pcode=BPS%2BPrototype%2BBoards&pcodenumber=85400
> >
>
> Sample enclosure, can be home made from aluminum extrusions.
> < http://www.busboard.net/bps-enc.htm
>
>
>
>
> At 03:34 AM 1/2/2006, Leon Heller wrote:
>
> ----- Original Message -----
>
> From: Eric Ellison
>
> To: 'Xylo-SDR Discussion'
>
> Sent: Monday, January 02, 2006 5:17 AM
>
> Subject: [Xylo-SDR] Some design thoughts requested
>
> Folks
>
>
>
> Even since the PIC 4550 days I have been thinking on how we might conduct
> experiments as well as have a reasonable environment for addingon to the
> project. The obvious answer is a buss of some sort. I have looked at
> everything from Simm riser boards to ISA buss stuff. PCI risers might be
the
> way to go since they are inexpensive ($15) for 3 slot extenders. Also in
an
> end product they fit into the L-brackets of a computer case, or 2U mounts.
> They have assignedpower busswe can use, fairly inexpensive prototyping
> boards. ($50 - $60), are four layer and designed to minimize intra trace
> noise. The buss wouldnt be used for PCI, however it would allow power, (on
> designated standards based lines), intra board connections, and FPGA,
> I2C,signals etc.
>
>
>
> PCI seems to be a little largefor what we are proposing, and the product
> boards would cost more to produce, however, with an established buss we
> could put a radio on one card, FPGA on another Audio on another etc.
>
>
>
> $15 Board amongst others:
>
>
>
>
>
> http://www.plinkusa.net/riser.htm
>
>
>
>
>
>
>
>
>
> Am I off the wall here?
>
>
>
> That's the sort of thing I was thinking of doing. I used to work for Racal
> and they used to build their military radios from separate screened
plug-in
> modules on a backplane.
>
>
>
> I favour DIN41612 connectors for this sort of thing. They are expensive,
> but very reliable, and have pins on 0.1" centres. They can even
accomodate
> co-axial connectors. They are more commonly used in Europe than the USA, but
> you can get them over there without any problems.
>
>
>
> 73, Leon
>
> --
> Leon Heller, G1HSM
> leon.heller@bulldoghome.com
> http://www.geocities.com/leon_heller
> _______________________________________________
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>
>
> Cecil Bayona
> KD5NWA
> www.qrpradio.com
>
> "I fail to see why doing the same thing over and over and
getting the same
> results every time is insanity: I've almost proved it isn't; only a few
more
> tests now and I'm sure results will differ this time ... "
> _______________________________________________
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>
>
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Cecil Bayona
KD5NWA
www.qrpradio.com
I fail to see why doing the same thing over and over and getting the same
results every time is insanity: I've almost proved it isn't; only a few more
tests now and I'm sure results will differ this time ...
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Forum pages: http://www.hamsdr.com/hamsdrforum/
Cecil Bayona
KD5NWA
www.qrpradio.com
"I fail to see why doing the same thing over and over and getting the same
results every time is insanity: I've almost proved it isn't; only a few more
tests now and I'm sure results will differ this time ... "
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