20% off on SolderSmoke -- The Book

Today only. Use coupon code LUCKY and take 20% off.

For more info on the SolderSmoke book see http://soldersmoke.com/book.htm

Sinclair 1000 Computer For Sale

Take a walk down (low) memory lane...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320699873588&ssPageName=STRK:MESELX:IT

SolderSmoke Podcast #134

http://soldersmoke.com/soldersmoke134.mp3

May 15, 2011
New "Ikea" microphone
NOVA QRP Club
WSPR T/Rouble resolved
Finishing up Rome WSPR rig
Easy-Peasy on Asus eee-PC
Space Station Packet Beacon
Boatanchor News: DX-100, HT-37, "CQR" anchors, 75 meter antenna Drake 2-B history interview by W8SX
Lew McCoy and Ernest Hemingway
Ade Weiss, QRPoetry and Ade's new book
Regen theory
MAILBAG (with a focus on New Zealand)

Landing on Titan to the Sounds of Saturn

These are real images from the Huygens probe. And the sound is apparently from the radio signals generated by Saturn. I agree -- it sounds nicer than Jupiter!

Euro Zone: SolderSmoke Kindle-book Now Available

SolderSmoke -- Global Adventures in Wireless Electronics is now available on the Amazon.de (German) web site. Payment in Euros.
https://www.amazon.de/dp/B004V9FIVW

WONDERMARK! (Comics with the Knack)

As part of our occasional series on Knack-related comic strips, today we present Wondermark. This link will take you to the first page: http://wondermark.com/tink1/ From there, look for the little "NEXT" hand on the right of the comic. There are eight. All of them are gems. Also, be sure to check out the author's bio:
http://wondermark.com/about/

WSPR -- THE MOVIE!

VK2TPM made some nice videos of the Weak Signal Propagation Reporting System (WSPR) maps over time. Its kind of fun to watch the propagation shift from trans-Atlantic to trans-Pacific.

More: http://www.youtube.com/user/vk2tpm#p/u/4/U1sBGZzNv8s

T/R Success with WSPR

Thanks to everyone who sent in advice on my WSPR t/r troubles. I now have it all sorted out. In the image above you can see the cable from the serial port that carries the RTS T/R signal from the computer. It goes to a switching transistor that controls a relay that in turn switches the three relays that actually do T/R for the rig. One question: On the Linux computer the RTS signal seems to switch between +5 and -5 volts, but on the Windows machine it was +10 and -10. Why?
I'm really pleased to have the computer interface working. It is kind of neat to bring together the complex technology of the computer and the simple technology of a DSB/Direct Conversion rig.

Five Planets Visible in the Morning

The good folks over at spaceweather.com have once again alerted us to an important astronomical event: During May, early risers will be treated to a conjunction of Mars, Jupiter, Venus, and Mercury. (The fifth visible planet would be the one you are standing on!) The Moon is thrown in as a bonus. The photo above was taken by Liz Gleeson on Magnetic Island (Australia) -- what a great location!

More T/Rouble

I get the RTS signal when using a Windows PC, but when I try to switch over to a Linux computer, I don't get the T/R signal from pin 7. Is there some code or setting in Linux that I need to change to make this happen?

Working on T/R circuit for HB WSPR rig --need help!

I'm finally working on the PTT T/R circuit for my homebrew DSB /Direct conversion 30 meter transceiver. I hope to use the simple one transistor circuit from W3PM's FB HB WSPR rig.

But I need info on the PTT signal that will come from the computer serial port. Which pins on the 9 pin serial port connector? What kind of signal comes out? Is it 5 volts on transmit? What settings should I use in WSPR? RTS? Any other setting changes needed?

I hope to be transmitting AND receiving soon.

AMSAT OSCAR 7 -- No Batteries, Running Directly From Solar Panels

From the AMSAT site:

AMSAT-OSCAR 7 was launched November 15, 1974 by a Delta 2310 launcher from Vandenberg Air Force Base, Lompoc, California. AO-7 was launched piggyback with ITOS-G (NOAA 4) and the Spanish INTASAT. Built by a multi-national (German, Canadian, United States, and Australian) team of radio amateurs under the direction of AMSAT-NA. It carried Mode A (145.850-950 MHz uplink and 29.400-500 MHz downlink) and Mode B (432.180-120 MHz uplink and 145.920-980 MHz downlink (inverted)) linear transponders and 29.500 and 145.700 MHz beacons. The 2304.1 MHz was never turned on because of international treaty constraints.

In mid 1981 AO-7 ceased operation due to battery failures. It was thought at that time that the batteries had shorted. However on June 21, 2002, at least one of the shorted batteries went open-circuit, allowing the satellite to waken whenever it is in sunlight, and randomly begin operation in one of 4 modes.

According to the log at planetemily.com/ao7/ao7log.php, this old warrior is still supporting transponder action in mode A and mode B as recently as 9/10/09, and on a regular basis, whenever it is in sunlight.

When the satellite is in sunlight for extended periods of time, the 24-hour timer still switches the bird between modes A and B. Listen for the corresponding beacon to determine which mode the satellite is currently operating in, or refer to the above mentioned web page to see what mode has recently supported QSO\'s as the best estimate of what is the current mode of operation.

Please remember, there are no (functional) batteries, so the satellite\'s power input is limited to whatever output can be generated by the ancient solar panels. Use the least uplink power possible to minimize your downlink power usage, and maximize the number of simultaneous QSO\'s supported in the passband. There are other operating tips at:http://www.planetemily.com/ao7/usage.php
Linear transponder birds are a scarce commodity these days, so please use AO-7 responsibly, but please DO enjoy her!