[hpsdr] ATLAS TDR & VNA Test Results

[Eric Ellison]

Ray

 

Thanks! Great work! Will be interested in the plots! GREAT WORK everyone who
is contributing.

 

Here is my proposal on production.

 

First, anyone out there who has had boards made, including lurkers, perhaps
you can get a quote on 100 quantity boards using the files posted by Phil_C.
I do have 2 quotes so far, thanks to Lyle and Phil_C. The lowest 100
quantity quote puts the board cost at about $11 - 12 dollars. (more details
to follow). If we go with Lyle's distributor the quantity 200 discount is
pretty deep, and I might consider going 200 for inventory.

 

We currently stand at 72 board orders.

 

Perhaps everyone can push the Atlas on any and every forum which might have
an interest between now and next Thursday.

 

On Thursday we'll will freeze orders on this round. If still under 100 I
will order 100 and inventory the remainder (possibly 200).

 

On Next Friday the order will be placed with the mfgr, to be delivered (to
me?) in 10 days. I will ship the boards within 2 business days of receipt,
USPS..( unless Dayton intervenes.)

 

Comments: ?

 

Eric - AA4SW

 

 

 

 

 

 

 

 

  _____  

From: hpsdr-bounces at hpsdr.org [mailto:hpsdr-bounces at hpsdr.org] On Behalf Of
Ray Anderson
Sent: Thursday, April 27, 2006 12:09 PM
To: hpsdr at hpsdr.org
Subject: [hpsdr] ATLAS TDR & VNA Test Results

 

 

We had an all day network outage here yesterday so I was incommunicado for
the most part, however I did manage to go hide out in the lab for an hour or
so and do some VNA and TDR tests on the ATLAS board.

 

No problems detected. Everything looked about how I was expecting it to look
except my earlier impedance predictions by way of field solver were off a
bit from the measured impedance values apparently due to some wrong
assumptions that were made in setting up the extractor problem.

 

 

I plan on posting some plots to the web site later today or tomorrow,
however here is the bottom line:

 

 

I performed TDR and VNA measurements on all [0:24]  lines in both the X and
Y busses. All buss lines in each buss looked similar.

 

 

TDR Measurements:

 

X buss:

            Measured impedance : 40 ohms average (predicted 78.5)

 

Y buss

Measured impedance : 46.2 ohms average  (predicted 58)

 

The above measured impedances should be just fine for most applications and
probably workable for LVDS signal if the need should arise.

 

 

 

VNA Measurements:

 

X buss:

 

Measured from DIN connector 1 to 6

Ripple 6 dB p-p from DC to 1.5 GHz

Major Resonances begin occurring at 1.5 GHz (-50dB @ 2.1 GHz)

 

Y buss:

 

Measured from DIN connector 1 to 6

Monotonic rolloff down to about -8db DC to 1GHz

Ripple 6dB p-p 1GHz to 1.5 GHz

Major Resonances begin occurring at 1.5 GHz (-47dB at 2.1 GHz)

 

 

 

So based on:

Lack of assembly issues  (Phil, Chris Ray)

Lack of PS issues (Chris)

Lack of significant SI issues (Ray)

 

 

I'd say we are go for a production build.

 

Thanks to Chris for the assembly instructions and BOM and to Horst for the
refined assembly instructions and the EU BOM!

 

 

73,        Ray   WB6TPU

 

 

 

 

 

 

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