Messages

346

The RF Workbench / Re: TDA2003 has been obsoleted

« on: September 03, 2013, 2355 UTC »

Try the LM1875.  Still in full production from TI (Who acquired National recently).  Its also a 20W part, vs. 10W for the TDA2003, and shares the same pinout.

+-RH

Hi Redhat - I'm not sure how well the 1875 behaves on a 12 volt supply.  Maybe I'll play with one and see, if can I find some time for it.  I was using 1875s a while back when I was playing around with a 24 volt Heising modulation scheme.  It was definitely a good performer at the higher voltage level.

347

SDR - Software Defined Radio / Re: $100 SDR

« on: September 03, 2013, 0214 UTC »

Well Labview, I've been looking for an affordable way to dip my toe into the SDR waters.  Thanks for the heads up.  I will pre-order one of these also.  That way, if I likee, I will spendee more later on.  Who knows.  Mebbe even Mr. Fansome will be tempted by this...

348

The RF Workbench / Re: A simple shortwave pirate transmitter build

« on: September 03, 2013, 0153 UTC »

A few weeks ago I thought of getting back into it, to change
The Guerrilla tx to be a little more simple and reliable to make,
and easier to get parts

Hey RA - It's great to hear that you're pitching back in to the Guerilla project again!  Your present design is, hands down, the easiest way to get on the air and I'm juiced to see what changes you'll be making.  The Guerilla is definitely where any budding transmitter builder should start, and if it could use 100% E-Z-2-find and Rad Shack parts, well, that's about as good as it gets...

349

The RF Workbench / TDA2003 has been obsoleted

« on: September 03, 2013, 0138 UTC »

Another VERY useful part (for 12V audio amps and modulators) bites the dust and I am sorry to see these go.  I just received this notification from Digi-Key:

Dear Valued Digi-Key Customer,
You have purchased the following part number from Digi-Key within the last two years. The manufacturer has announced an update to the part status.

Manufacturer STMICROELECTRONICS
Description IC 10W CAR AUDIO AMP PENTAWATT
Manufacturer Part Number TDA2003AV
Digi-Key Part Number 497-11263-5-ND
Status Obsolete 
Last Time Buy Date Undefined By Supplier
Substitutes Please click here

I'm sure we'll be able to buy these for a couple more years but they will be drying up more and more, starting now.  So if you've been waiting...

350

The RF Workbench / Re: A simple shortwave pirate transmitter build

« on: August 29, 2013, 2014 UTC »

  Turns out I was using torrids that I thought would work, but had completely different inductance values (whoops!).  I swapped out the inductors with the correct values, and had 10 watts into a dummy load.  Live and learn.

I feel your pain.  I once used what LOOKED like T50-2s from a hamfest table in a build and the same thing happened to me.  After checking with an inductance meter and working backward from the calculations, they turned out to have an AL value of 175 rather than 49, indicating #3 material.  These toroids were red just like #2s, but should have been gray.  "Somehow" these fails from the factory found their way onto that table.  I wonder how many other people ended up with non working projects.  I'll always love hamfests, but I now pass on buying my toroids there.

351

The RF Workbench / Re: Components to have on hand ?

« on: August 20, 2013, 0245 UTC »

Great thread idea!  I wholeheartedly agree with keeping parts on hand.  With minimum orders, shipping costs, and difficulty finding some things, it just makes good sense to me.  Things I "stockpile" that I consider necessary to keep on hand:

Toroids (T50-2, T80-2, T50-6, T80-6) and some ferrite beads-CWS Bytemark, Toroid King
Caps and resistors - all common values - All, Jameco, Dan's Small Parts & Kits
Transistors - 2N3904, 2N3906, 2N2222, 2N3053, 2N3055 - Jameco, Dan's Small Parts & Kits
FETs and JFETs - 2N3819, MPF102, 2N7000, IRF510 - Jameco, Dan's Small Parts & Kits
Op Amps and Linear - TL074, LM555, LM3900, LM741, LM311 - Jameco, Mouser
Linear Audio Chips - TDA2002 (or 2003), LM386 - Mouser
Regulators - LM7812, LM7806, LM7805, LM7905, LM317, 78L05, 78L06, 78L12 - Jameco, Dan's Small Parts & Kits
MISC: T1.75 LEDs (various colors), 22 ga hookup wire, 20 ga magnet wire, many sizes of heat shrink tubing, RCA connectors, SO239s, 3.5" connectors, 2 and 3 pole terminal blocks, several sizes of potentiometers and trimmers... pant pant pant... whew!

And I'm sure I missed some stuff...

I would imagine everyone has a different list, depending on their main interests...

352

The RF Workbench / Re: 73 Magazine Index and archive

« on: August 12, 2013, 0316 UTC »

Great find, LabView!  I was a devoted 73 subscriber for several years.  With QST always seemingly filled with construction projects written by PHDs, 73 consistently featured down to earth projects for real people.  And Wayne Green's often irreverent editorials were a great counterweight to the stodgy ARRL hardliners.  Always a hoot to read.  Thanks for the heads up!

353

Equipment / Re: A Sloped Folded Dipole Antenna for 43 Meter Band

« on: August 11, 2013, 0026 UTC »

Really good piece Chris.  I have a similar problem here and your article gives me food for thought concerning a fall antenna project.  I realize that its difficult to tell, but have you noticed any "shading effects" in the direction of the mast tree trunk?  My "mast tree" here is in an unfortunate place... natch.  Thanks for the idea.

354

General Radio Discussion / Re: Sun Will Flip Its Magnetic Field Soon

« on: August 11, 2013, 0002 UTC »

there have been fewer observed sunspots this year than in the maximums of previous cycles

Damn global warming!

355

General Radio Discussion / Re: Poll: Favorite albums

« on: August 09, 2013, 2143 UTC »

Wow Redhat -great question, tough choice.  Hand me the sickle please...  I winnowed mine by tossing out compilations (sorry Ronnie Montrose!), albums where to my ears there's not a dog in the bunch, albums where the artist stretched a bit but it still worked musically, and albums that I still listen to at least once a year all the way through.  I still ended up with way too many... in no particular order:

John Hiatt-Slow Turning
The Who-Who's Next
Jethro Tull-Minstrel In The Gallery, Thick As A Brick
Tom Petty and the Heartbreakers-Full Moon Fever
Kinks- Lola Vs Powerman and the Moneygoround (I love "Word Of Mouth" too, Lance!)
Steve Earle-Exit 0
Monster Magnet-Powertrip
Slade-Keep Your Hands Off My Power Supply (US release)
Pure Prairie League-Bustin' Out
Big Sugar- Heated (US release)
Mojo Nixon-The Real Sock Ray Blue
Brian Setzer-Live Nude Guitars
Zappa -Joe's Garage, Overnite Sensation
Southern Culture On The Skids-Liquored Up and Laquered Down
Sass Jordan-Rats
King's X- Faith Hope Love
Eddie Money-No Control
Foghat-Energized
BTO-Head On

And I'm sure there are MANY more...

356

QSLs Received / Re: Radio Totse eQSL

« on: August 06, 2013, 2307 UTC »

Congratulations guys - that one is a real catch!

357

The RF Workbench / Feel like building something?

« on: August 06, 2013, 1639 UTC »

If your soldering iron keeps giving you wistful looks when you walk by, I'd like to suggest an easy transmitter project.  I have posted build plans for the RF section of the LULU transmitter on the 30 Below blog.  I'll be following up with another post discussing techniques to AM modulate it.  I hope you try it. 

358

The RF Workbench / Re: 2N1711

« on: August 03, 2013, 0042 UTC »

I can still dead bug simple prototypes with SMD, but like you say, with lots of magnification!  And teeny tiny tools.

I quess I am old...I remember shedding tears when the CK722 went obsolete.  It was the device of choice in so many of the projects in Lou Garner's Transistor Topics column!

I feel your pain Joe.  I mourn for several myself - 40673s, VN66s, et al.  My eyes have gone far enough around the bend that I now steer clear of SMDs.  Not just the eyesight, but for that shaky, iron-gripping hand of mine.  Too much alcohol, I guess.   Redhat - enjoy it while you can Brother.  It really doesn't last forever...

359

The RF Workbench / Re: 2N1711

« on: August 01, 2013, 2358 UTC »

Boy! Another discrete bites the dust.  I'll miss them.  I used the 1711 to good effect in the Corsairs for the driver transistor.  The gain is lower than others commonly used, but the audio quality blew the others away handily.  The missing gain would then be made up for in the final, by running two MOSFETs in parallel.  I guess I'll have to spring for some... thanks Chris!

360

The RF Workbench / Welcome to the Dark Side

« on: July 30, 2013, 2355 UTC »

Hi all,
Chris has graciously made space available here for discussions about building gear, operating gear, antennas, portable operation, care and feeding of battery packs, and, so, much, more.  This is the sort of thing the homebrewpirateradio group has been doing for nearly ten years.  And now the doors have been thrown wide open.  Hopefully some open discussions from the operators side will bring more cooperation and experimentation, AND entice some new voices onto the airwaves.  Have fun...