At 08:37 AM 10/27/2009, Samudra Haque wrote:
>Yes, I usually take care to divide my correspondence amongst the
>particular groups I am working with, and this is also the basis in
>which I recently proposed moving to (a) moderated forum (such as
>phpBB) or (b) sub-dividing the amsat-bb list into amsat-engineering
If AMSAT goes to a forum, I'm out of here, I can't cope with the
volume of messages on a forum, much easier in email. Email lists can
be moderated too, but the separation might be a good way to simplify
73 de VK3JED / VK3IRL
I read with interest an article on the web "ECHO - America's First
Communications Satellite" By John R. Pierce which is available here:
I know ham radio operators love using their hand helds to communicate
using active transponders or active repeaters in space... no issue
were there any ham radio projects (either through amsat-na or abroad)
that implemented a passive reflector on an orbital vehicle like
I quote from http://www.satmagazine.com/cgi-bin/display_article.cgi?number=490218137
The Echo-1 Balloon Satellite as it sits, fully inflated, at a Navy
hangar in Weeksville, North Carolina. The spacecraft measured 100 feet
across when deployed, and was nicknamed a ‘satelloon’ by those
involved in the project. The mylar film balloon acted as a passive
communications reflector for transcontinental and intercontinental
telephone (voice), radio and television signals. Echo 1 re-entered the
atmosphere May 24, 1968.
What strikes me is the implications of a large large very large
antenna (reflector), if only it could be reflective on one side of the
sphere only .... (any ideas?)
The Echo 2 was a 135-foot rigidized inflatable balloon satellite. The
satellite is shown undergoing tensile stress test in a dirigible
hanger at Weekesville. The satellite, 50 times more rigidized than
Echo I. When folded, the satellite is packed into the 41-inch diameter
canister shown in the foreground.
Did early amsat folks consider duplicating / adding to any of these
projects or launch their own 'satelloon' that did not carry an active
RF payload ? Could we outfit one of our future microsats to provide a
reflector to aid in Earth-LEO DXing like meteor-scatter ?
73 de Samudra, N3RDX
After recently working a number of rare grids activated by our fellow
satellite ops, (again THANK YOU!!) I've been looking over the grid map and
wondered what grids are most needed. I, like most, have grids that others
may dream of working and confirming and vice versa. Then, there are those
grids that are so common, most everybody has worked and confirmed them.
Since there are no HEO's and only the FM birds with a couple of linear
birds, this survey will be focused on the North American area.
I am undertaking a task to get a better reading on what grids are
"outstanding" in need of activation. I am looking at obtaining the top 25
grids from the predominately 10 grid fields covering the U.S., Canada and
Mexico, for the total of 250 grids. Yes, most of these grids will be in the
U.S., however, I'm sure there will be some mention of VE and XE grids as
well. What I would like everybody to do is take some time and look at your
grid map and write down 25 grids from each of the grid fields that cover the
U.S., Canada and Mexico. Those grid fields are: CN, DN, EN, FN, CM, DM, EM,
FM, DL, EL. If you don't need at least 25 grids from a particular grid
field, no problem, just enter those you still need. Example. Let's say you
only need three grids from DM, they are DM74, 75, 76. Just enter those
To make things simple and easy I will give an example of how the data can be
entered and e-mailed to me. Here is an example.
CN 79, 82, 93, 95, 99
DN 02, 03, 07, 13, 15, 17, 19, 22, 24, 25, 34, 37, 38
As you can see, it's relatively easy, and very easy if you've kept up on
your grid map. :)
A couple of notices.
1. Please, do not send any "water grids" since any operation from them is
sporadic and most cases, impracticle to activate for most of us.
2. Please send your data to me via e-mail, attaching it to this e-mail will
be fine. The cutoff date is November 14, 2009. This will give all plenty
of time to look over their maps and data.
Questions, comments or just sending the data, please send an e-mail.
Looking forward to receiving your replies!
Las Vegas, NV
The PCR-1000 and the UT-10 L-band module have been sold.
The Arrow antenna is still available! Keep in mind the current new/retail price for this antenna is $139 (plus shipping). That makes this one "better than new" ;-)
1) Arrow II Antenna 146/437-10WBP Satellite version with built-in
diplexer and split boom. Condition: nearly new, only assembled about
5 times. Elements/boom neatly numbered via label-maker tape. $100 +
>>Date: Mon, 26 Oct 2009 15:51:50 -0400
>>Subject: FS items (Arrow, PCR-1000, 1.2 GHz module for TS-790).
>>From: "Mark L. Hammond" <marklhammond(a)gmail.com>
>>I need to pursue a tower/rotor/antenna project. Therefore, I am
>>selling some items in the shack to help fund the project. The prices
>>are "fair" and therefore "firm". I'm giving the BB a shot before I
>>take these to a local hamfest or eBay. Prices do not include
>>SOLD 2) Icom PCR-1000 receiver. Includes receiver, serial cable, and
>>power supply. Condition: few minor scuffs/scratches, perfect working
>>condition. (The variable bandwidth permits reception of 38k4 packet
>>signals!) $250 + shipping/insurance.
>>SOLD 3) UT-10 1.2 GHz L-band module for Kenwood TS-790. This is a
>>plug-n-play module, about a 5-10 min. no-tuning install. Includes
>>screws. Condition: Perfect working order, low transmit time, full
>>10W output. Price: $475 + shipping/insurance.
>>Please contact me directly offlist at: marklhammond AT gmail DOT com
Mark L. Hammond [N8MH]
Talk to Neal, W6FOG on the 2225z pass of AO-27, and he advised me he will be leaving San Francisco Bay on Friday, Oct 30th, hoping for 4 good days for a sail to La Paz, Mexico. So, starting that date, be on the lookout for him out in the water.
JoAnne Maenpaa, K9JKM, wrote:
>I guess you're observing that AMSAT's GEO proposal has to fit into the GEO
satellite commodity market.
Should Amsat be working with NetHope to design a better terminal? How do we
work with these guys to convince them that they should be using a ham
satellite instead of a commercial service? One big advantage of the commercial
service is that it exists now. How do we get the money from funding agencies,
either government, corporate, or non-profit? Where does Amsat fit in to this
world? Have they even heard of us, our history and our capabilities?
>I've maintained that a GEO satellite is best suited to link widely deployed
sectors of the Incident Command System.
I think most government-based emergency authorities are not going to be
interested in building or funding a system that they do not design and
control. They consider amateur radio to be a last-ditch thing that they would
rather not count on, they would rather have an in-house system that fits in to
their chain of command and shows their funding authorities that they are fully
on top of emergency communications and don't need to rely on amateur
volunteers coming forward in time of need. A non-governmental organization
like NetHope might be more receptive to our proposals. We need to think hard
and come up with new ideas.
Dan Schultz N8FGV
Cute Re-entry Competition
It seems that when a satellites, reache an altitude as low as about 170km they will be down very quickly. According to Space Track elements, and InstanTrak tracking software Cute was still orbiting when the perigee was below 150 Km.
My theory is that cubesats stay in orbit longer because they have a large mass relative to their very small cross section and so experience far drag than bulkier objects.
Using that idea I ran the last element set for several orbits and made an arbitrary decision that re-entry probably took place at a perigee of 130Km or so thus putting re-entry pretty much dead centre between two competition entries.
I therefore declare Ib OZ1MY and David G0MRF as joint winners !!!
On receipt of current postal addresses I will mail out a patch kit to each of the lucky winners.
Thanks to Ib, David and everyone else who took part, it was fun to plot the curves and I learned a bit about atmospheric density and solar flux.
73 John G7HIA
IPS Radio and Space Services, have a useful paper on satellite orbital decay calculations.
Thanks to Ken GW1FKY for sending me a copy.