Showing posts with label digital modes. Show all posts

Electro-mechanical Heaven.... with Hell (Hellschreiber)


Bob LeDoux sent us a link to a really amazing site about the Hellschreiber system.  The site is filled with great videos, pictures, and animations like the one above.  Lots of radio history too.  Check it out: 

http://www.nonstopsystems.com/radio/hellschreiber-function-operation.htm 
This is all the work of F. Dorenberg, N4SPP.  Thanks OM! 

Bob writes:   I'm working on a microcontroller based reader for
this mode.  For old fossils, like us, this mode looks perfect.  It can
be sent using simple CW equipment and it appears to be a great
replacement for those who are tiring of Morse code.
Its perfect for Knack victims. We can even build mechanical printers. Thanks Bob!


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Arduino Hell!



Hi Bill,
 
I am a long time listener of SolderSmoke and a big fan! Since your last podcast was on the use of Arduino’s for ham radio, my Arduino Hellschrieber project may be of interest to you and your listeners. I am using the $15 dollar RadioShack color display they are closing out and a simple circuit with our favorite transistor!
 
I have a video in my second blogpost and all the details with code below.
 
 
 
Keep up the great work, I have your book both in print and Kindle!
 
73, Dan WA6PZB

 Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
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Thoughts on DSB PSK-31



To QRP-L: 

I have a JUMA TRX-1 cw and dsb transceiver. It seems to me that if I transmit an psk signal there would be two signals generated, one on usb and another on lsb. Is this correct? It does not seem like a good thing to do to me.
Thoughts?
73 Larry WB4HLX
-----------------------------

Larry: 

I've been experimenting with DSB PSK for the last few weeks.  Sure, you are using twice the needed bandwidth,  but in this mode that means you are using only an additional 31 HERTZ! That's not a lot.  Also, if (as I am) you are using a Direct Conversion receiver, in your waterfall you will also be looking at two sets of frequencies -- those going about 2 kHz above center AND 2kHz below.  This helps you avoid causing interference:  If the frequency looks clear on your screen, you can be reasonably sure you won't be bothering anyone with your extra sideband.

This is similar to the AM question: there too you are using additional spectrum.  But it is allowed.

Doug DeMaw and other esteemed technical gurus have promoted DSB as a useful mode that -- through its relative circuit simplicity -- encourages the building of homebrew gear.  DeMaw wisely advised against using high power when running DSB.

I've been having fun with PSK DSB.  I've had many contacts.  I'm running less than one watt to a dipole.   One curious thing that I've noticed:  PSK seems to be sideband independent:  When I tune in a PSK signal on my FLDIGI waterfall, the software will decode it even if I have the FLDIGI set for LSB or USB. 

You might also want to try JT-65.

Good luck. 

Glad to hear that I'm not alone.           Center             Glad to hear that I'm not alone.

73   Bill N2CQRhttp://soldersmoke.blogspot.com

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
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DSB Digital Success!



It's ugly but it gets you there.  I finally got the little 30 meter DSB/Direct Conversion transceiver that I built in Rome working on PSK-31 and JT-65.  It features a VXO circuit from George Dobbs, an AF amplifier designed by Roger Hayward, and an RF amp chain designed by Peter Parker.  It produces about 1 watt of RF.  At first I was manually switching the rig from transmit to receive, but this got old real fast, so I built a little VOX circuit -- the AF from the sound card does the switching.  Last night I fired it up on PSK-31 and stations were calling me (including one fellow in Cuba).   Then I went to JT-65 and had a complete QSO with KT1B. Another this morning with K0ASK.  It is kind of fun to combine the simple (this rig) with the complex (the computer and these digi modes).   I find that I can work both JT65 and PSK 31 while keeping the VXO at 10.139 MHz.   

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20
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