All:
I send this separate note to advise you of some major developments with
Eagle. Many of you are already aware of them, but in case I missed
someone, I send this separate update.
Two nights ago, I authorized expenditure of funds for purchase of
components and construction of four prototypes of the UHF receiver
designed by John Stephenson, KD6OZH.
The boards will be distributed as follows:
one to Juan Rivera, WA6HTP, for Acceptance Testing followed by
limited vacuum and thermal testing
one to be demonstrated at Dayton
one to the SDX folks for their development
one to be put through the ATP either here by me, or wherever anyone
else wants to evaluate. This will then become available as needed for
demonstrations or SDX development
Events leading to this decision:
Design by John and Peer review
Development of ATP by Juan and peer review
Assembly of a procurement, construction, and test team of Project
Oscar members under Juan's leadership
PCBoard layout by John. Peer review of schematic to board
correlation in progress
Development of costed Bill of Materials (BOM) by the Project Oscar
team. This was a LOT of work, and actually resulted in some tweaks to
design and component selection
Peer review of the BOM in progress
I have authorized $4100 for this effort. A small fraction of this cost
includes consumables for surface mount construction and some assembly
tools which will become AMSAT property and will be used again. AMSAT
costs were reduced by a significant amount of "scrounging."
I submitted some of this information for publication in ANS, but don't
yet know if I was ahead of the deadline or not.. If I was late, I hope
it will appear next week.
This seems to me a huge step. We have completed one design cycle on one
component and are now about to transition, for that one component, from
the concept exploration/definition phase into construction of hardware.
Prototype hardware, yes, but we will soon have some real test results
and something real to show. The short list above belies a whole lot of
work by a whole lot of folks, alll of whom I thank. Many of you
participated in the earlier reviews of John's design and Juan's ATP.
The near-frantic effort over the last few weeks by John and the Project
Oscar folks (many of whom I'm just getting to know through various
emails and echolink conferences) has been intense.
As we progress with procurement and construction, I will receive and
share progress updates as major milestones are met.
The documents mentioned above are not all on EaglePedia yet, but will
be. In particular, one unexpected fallout of the recent efforts is a
BOM which may be a good template for other teams to use. It certainly
made it easy for me to see and understand, "how many, how much?"
Thank you all.
Very 73,
Jim
wb4gcs(a)amsat.org
All:
For your information, I provide some information regarding my status and
forthcoming availability.
My day job is getting busier. As a result of a bunch of things, I'm now
the manager of what we'll call "shipboard automation." This means I
have tentacles in all hardware, OS infrastructure, and custom
applications being developed for the shipboard areas I care about.
There are many things going on, but not necessarily well. Part of my
mission is to herd the cats, set some priorities, and get some stuff
done -- enough churn.
I'll be attending "targeted selection" training for the next 2 days. TS
is an interviewing technique, and there is a need for my assistance in
interviewing candidates. Yeah, I know, there are millions, and it's not
different from what I've done before, but training is training. I will
be out of pocket the next two days, but briefly available in the
evenings. (Obvious conclusion: I would welcome resumes from engineers
seeking employment in the Pittsburgh area.)
Starting Sunday (1 Apr), I'll be at Bechtel Project Management training
for a week. I'm very excited about this -- Bechtel routinely does
things that very few organizations in the world can do, on time, in
budget, and without getting anybody hurt. This tremendou educational
opportunity has been in the works for over a year. I'll have the laptop
with me and access to email, but it will be after long days and several
hours of homework each night. So, I'll be reachable, but in a
limited/delayed way. This is a good thing, I'm SURE I'll get things out
of this which will help me help Eagle.
Bottom line: Don't stop sending me anything, just recognize that my
responses may be delayed. We are within hours of authorizing
construction of UHF receiver prototypes -- that work will be my highest
AMSAT priority.
Thanks & 73,
Jim
wb4gcs(a)amsat.org
MIMIX has just announced some 2 stage moderate power (+20dBM 1dB
compression, 23 dB gain, 4-21 GHz) Intermediate Power Amps that look
interesting. They talk in terms of small 3x3 QFN SMT footprints. See
http://www.mimixbroadband.com/PR/PR_022607.html for press release info.
Anyone know anything about these parts?
73, Tom
My current understanding of the DC power bus is that it is driven by banls
of 4 Lithium-ion cells. These normally provide 2.7-3.6 V per cell but have
4.2V across them during charging at the end of the charging cycle. This
would mean that the DC power bus in Eagle is 10.8-16.8 VDC. I don't see this
documented in EagePedia. Is this correct?
73,
John
KD6OZH
Team:
Our next TS conference will be Tuesday night at 2100 EST, 1800 PST, 0200
ZULU.
The agenda is posted on the TeamSpeak conferences page of EaglePedia.
Please add to it and join us Tuesday night.
Note: I'll be travelling to VA and the weather is looking ugly (to be
kind), so I might be a few minutes late. If I don't show up, please
press on and take good notes.
Thanks & 73,
Jim
wb4gcs(a)amsat.org
A message sent to the SoftRock40 news group led to an interesting
discovery. There is an interesting 4-part series in the journal "High
Frequency Electronics" that is a tutorial on various techniques to
achieve high efficiency power amplifiers. The article mentions the
Doherty technique from the 1930's which was the progenitor of Meinzer's
HELAPS. To fetch the series, surf to
http://www.rfcafe.com/references/magazine_articles/magazine_articles_2003.h…
which leads to the 4-part article "RF & Microwave Power Amplifier &
Transmitter Technologies".
73, Tom
I am working on a theme about Eagle for Dayton.
What I have now is "The Eagle Build Begins".
I am looking for other suggestions, so bring them on. This will go on a banner at the center of the booth and in the Eagle area.
Let me know by Thursday evening, EDT.
Thanks,
Gould
Team:
I think I remember someone on here saying that they had access to the
IEEE library.
I'm seeking an article, W. C. Williams, "Reliability: Lessons from
NASA,": IEEE Spectrum Vol 18 No 10, Oct 1981, pp 79-84. This is
referrenced in the Davidoff book.
As a member, I'm supposed to be able to get a free 30 day trial, for
which I've signed up, but it will be some number of working days. If
any of you already have access & could get me this article, I'd
appreciate it.
Thanks & 73,
Jim
wb4gcs(a)amsat.org
