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!

50th Birthday of the Silicon Integrated Circuit

Robert Noyce got his IC patent on April 25, 1961.

Of course, wave soldering would be something to come out of California.

Free Kindle Reader for your PC

This link will take you to the download site. The software will allow you to use your PC as a Kindle reader.
http://www.amazon.com/gp/feature.html/ref=kcp_pc_mkt_lnd?docId=1000426311

Then be sure to get a copy of SolderSmoke -- The Book
http://www.amazon.com/dp/B004V9FIVW

SolderSMOKE APRS symbol

I've been setting up my satellite APRS station. This weekend I finally got the UI-view software running. I had to pick an icon -- this would be the symbol that would show up on the mapping software. In the Azores I had a nice little island with a palm tree. Here in Virginia, well, as I scrolled through the options, suddenly I saw something that seemed appropriate. The coordinates are a bit off, but that, my friends, is a smoke stack emitting 60/40 fumes.

How to Join G-QRP (and get SPRAT) in the USA

From the G-QRP web site:

Formed in 1974, the GQRP Club is a non profit organisation run entirely by volunteers to promote Low Power Radio. Whether you have a ham licence or not - everyone is welcome. Our quarterly magazine SPRAT provides a fascinating read containing articles of varying complexity, from simple test equipment, to fully functioning radio transmitters and receivers. Membership fees are about as low as you will find anywhere and our club sales service to members is second to none.

Indeed. Joining G-QRP and getting SPRAT is something all QRPers and homebrewers should do!

Some SolderSmoke listeners have asked me how they can join G-QRP from the U.S. Bill Kelsey is the club's man in America:

Bill Kelsey - N8ET 3521 Spring Lake Dr., Findlay, OH 45840 U.S.A.

$18 paid in USA.

Bill's e-mail and more info here: http://www.gqrp.com/memb_usa.htm

OR... You can pay directly via PAYPAL:

http://www.gqrp.com/paypaldx.htm

Messages (for me!) from space station

Mark KB1GVR

When I started receiving packets via the International Space Station earlier this month, I noticed a familiar call: KB1GVR. He was one of the few North American stations who could pick up my packet beacons via PCSAT -- he would then relay them to the internet. This month, when I sent my sigs through the ISS, OM GVR spotted them, and sent reply messages to me via the packet system. I didn't get them via the satellite -- they came to me via the "Stations Heard Via ISS" web site. But still, it was fun to run into an old friend via the space station.

The Novice License: Two Years on PROBATION!

Somehow I remembered it as being one year, non-renewable, but Neil, WA4CHQ, wrote to tell me that he remembered a two year term. I think Neil is right. The excellent web page of the Novice Historical Society provides the details and many really nice stories from our days as novices. http://www.novicehistory.org/

555 Contest Finale

Jeri Ellsworth's 555 contest is in the home stretch, and I've got my acceptance speech all ready. "I'd like to thank the members of the Academy... and above all the people of the Azores, who were put at risk by the large kite that carried my 555 timer circuit and 35 mm camera over their unprotected heads..."

Here's my entry: http://www.gadgeteer.us/KAP.HTM

Forrest Mims is one of the judges. Here is what he had to say:

[The participants] displayed an absolutely remarkable range of engineering skills, creativity and dedication to meet the deadline. Also impressive was the use of video and photography to illustrate many of the entries.

This contest helps restore my confidence in analog designers, who have become a very small minority in electronics these days. Some of these projects do with great simplicity and efficiency what exclusively digital designers would have great difficulty emulating. Moreover, a number of these projects have potential commercial merit. Hopefully the developers will be able to pursue this.

The winners will be announced tonight at 9 pm Eastern Time:
http://www.555contest.com/news/

(Oh no! There must be some sort of mistake! I checked the list of finalists and my kite entry is not there!)

SolderSmoke Podcast #133

http://soldersmoke.com/soldersmoke133.mp3

April 19, 2011

-- KindleSmoke
-- Amazon's Whispernet (not to be confused with WSPRnet)
-- April 1 and the Perils of Plausibility
-- The difference (significant!) between Cream of Tartar and Tartar Sauce
-- A short Italian lesson
-- Polyakov QRSS
-- Snort Rosin's Mighty Mite (NOTE: NO FILTER!)
-- Fly Fishing in Space: 2 Meter Packet Beacons and the International Space Station
-- Upside-down Amplifier
-- Rock and Roll and Ham Radio: The Bob Heil Story
-- The Shuttle Discovery Lands in Northern Virginia
-- MAILBAG

Check out the new Ikea Microphone!

New HamStack Project Boards from Sierra Radio Systems

From Sierra Radio Systems (our sponsor):

We just got a batch of new boards that are a very handy companion to the HamStack CPU board. We call it a "Project Board". If you are embedding a CPU board into your own project, that works fine. However, if you want to build a stand-alone application, like a keyer, sequencer, DTMF decoder, reset timer, tone generator, whatever, you will need a power supply, connectors and some sub-circuits. That is what the project board includes. You plug the CPU board on top of the project board and you can program it to do all kinds of things.

The board includes the following sub-circuits...
Features
- 2 digital inputs with 10 pullup resistors to +5v DC
- 4 analog inputs with a selectable voltage range of 0-5 or 0-22 volts DC
- 3 high speed, quiet, SPST reed relays capable of switching up to 500 ma.
- 1 opto isolated digital output
- 1 RS-232 serial port
- 1 analog signal output that can generate a sine wave 0-5kHz at 0-5v DC
- 8870 DTMF decoder chip
- 1 Temperature probe input
- 3 additional general purpose CPU IO connections
- 5v DC power supply (supply rail for logic and analog chips)
- 2.5v DC power supply (bias supply for op amps)
- 3.3v DC power supply (supply rail for 3.3v parts)
- 5 pole low pass filter to condition the analog signal generators output

Ideas...
For repeater builders, you can use the DTMF decoder and relays to make a master site reset controller that sits outside the repeater controller.
You can use the tone generation function to make a portable or bench top test tone generator.
You can use the reed relays to do timer based computer resetting.
Make a CW IDer or beacon transmitter controller.
Battery voltage monitor. Read the voltage, when low, one of the reed relays keys the repeater transmitter and the tone generator send a beep or CW message.
Plus...
We are writing a really cool keyer app that will do iambic mode A/B, record and send programmable macros, with an LCD to show the speed and use a digital rotary encoder to set the speed.
The keyer will be open source and you can hack it to your hearts content.

Anyway, its the perfect platform to build a HamStack based ham radio project. The HamStack (and project board) supports programming in C or Basic.

Check it out on the web site www.hamstack.com

George
KJ6VU

Don Norgaard, W2KUJ -- SSB Pioneer

In SolderSmoke -- Global Adventures in Wireless Electronics I tell of how I struggled to understand the inner workings of my Hallicraters HT-37 single sideband transmitter. This rig used the phasing method of sideband generation, and as a kid I just couldn't understand how it really worked. And this really bothered me. As I recount in the book, through a QST article that was reprinted in the ARRL book SSB for the Radio Amateur, Don Norgaard came to my rescue and allowed me to understand the phasing method.

It was only recently that -- through reading the August 1998 issue of an Electric Radio Magazine article by Jim Hanlon, W8KGI -- that I came to realize that Don was one of the true pioneers of SSB. I think this blog post may be one of the first presentations online of a picture of OM Norgaard. The 1951 QST article notes that "the face may be unfamiliar."

In addition to writing very clear QST articles, Don was the creator of a rig that "revolutionized amateur use of SSB." It was a three tube 75 meter SSB transmitter called the "SSB, Jr." From Jim Hanlon's article: "It used nothing more complicated than simple coils, condensers, resistors, one carrier frequency oscillator crystal, four germanium diodes and three tubes in the classic phasing circuit to put out 5 watts PEP."

Three cheers for Don Norgaard! Three cheers for the phasing method!