Topics

1

Equipment / 5 w IRF510 tx kit from QRP club.

« on: February 24, 2014, 2154 UTC »

.

I was reading about this 5 wattt  IRF510 transmitter kit the other day
in an AM Amateur Radio website.    32 dollars.   
Just add your modulator, and crystal.

http://www.4sqrp.com/NS40.php

.

2

The RF Workbench / another Guerrilla transmitter is born.

« on: September 13, 2013, 0346 UTC »

I got e-mails about low power out from this circuit.
Only about a  watt or so...

http://www.angelfire.com/de/RadioAnarchy/

I went to Radio Shack and got the capacitors there...
and at work today figured out a circuit board plan to cut
out with the Dremel tool on some double sided copper board
.. .did not take long...

at first power up, I got about 5 watts of power... then I added another turn to L3 and
go a little more power.... about 7 watts.....   no problems..
for C5 I have two .001 MFD caps in series, for 500 pico-Farad.

so for L3 we should start with 6 to 7 turns,, then unwind..
also the value of these caps at C6 are not that accurate..

if you have a variable capacitor  around 1200 pico-F  for C6, that would be good.

but we are trying to keep it simple and easy, and low cost.. . .

so I built 2 just like this and have no problem getting several watts out of carrier power.
The picture of the O-scope is showing 10 volts per division...across my MFJ 50 ohm dummy load.

I have the IRF510 heatsinked to the copper board.

I will make a diagram with my layout and all...

check it out...
http://www.angelfire.com/de/RadioAnarchy/

3

The RF Workbench / what power source and modulator used ? ?

« on: September 07, 2013, 1546 UTC »

.

so what power source is being used out there for your homebrew transmitters? ?

there was all this talk about keeping them run on 12 Volts so that a battery
can be used, and bcsting from out in the woods (or desert).....
and also most have an Astron 12 V supply, actually putting
out 13.8 V, so these can be used at home.

also, what is being used for a modulator out there ?  guitars amps ?
car stereo amp?  or homebrew ?  The TDA2003 circuit ?
winding your own modulation transformer.. ? ?

also you can use your laptop computer power supply.
they are usually at 18 volts, and can deliver a few amps.
and just about everybody out there has one of these.

I am asking, since I have a few series modulator circuits,
that needs some tweaking.  But it is basically a linear
power supply, that changes output voltage along
with the audio input, as well as regulated power for the
tx oscillator and modulator audio section.  So this is
the power source for the whole system.

So is there any interest in  this out there ?

.

4

SDR - Software Defined Radio / SDR - NBFM, or DSB, AM synchronous demodulation ? ?

« on: September 04, 2013, 2125 UTC »

hey Y'all...

I never messed with any SDR.

But have seen all this "waterfall" stuff.

So do these SDR's receive, in the MW/SW bands:  FM ? 
can  go narrow band FM ?
 have AM synchronous detection?   SSB ? DSB ? ? .

I have some things to try here soon...    I have a DSB modulator circuit
in my head, that can be applied to any of these little transmitters.
yes that is Double sideband, both upper and lower, no carrier,
or a low level carrier can be inserted, for synchronous demodulation.
The sound quality should be good, since there is no bandpass
filter involved.   

also may try narrow band FM....  1 Khz deviation or so..

years ago on 7415 kHz FM mode (the usual 5 kHz deviation)
I received on my Yaesu 757
the long version of "Inna Gadda Da Vida"     

funny, on the amateur radio bands you can not experiment like this.
It is too much work, or way too technical for most of them guys.
And they complain.    "oooh, to much bandwith"  etc. etc. etc.
Remember, on the HAM bands, when you hear them old guys with their
old vacuum tube radios in AM mode, it does not mean they know anything!!

5

General Radio Discussion / "The surveillance state" - any good safe web based e-mail sites.

« on: August 18, 2013, 1510 UTC »

I got an e-mail to my radioanarchy@yahoo.com  from Yahoo Inc.

It was real, not a webpage forgery / SPAM.

It said they went through my contacts and deleted the invalid
e-mail address for me.   

I checked, and they did delete accounts..

How nice of them to do what is best for me ! ! !

so what web based e-mail services are out there that are
kinda secure ? ? ? 

any that hide your IP address ?

and won't get into who I e-mail to, or who are my contacts

(P.S. - yes, I understand this was done by a computer most likely.. but still...)

     

6

North American Shortwave Pirate / Channel Z 11428 kHz

« on: January 15, 2012, 2350 UTC »

Jan. 15,  23:25 to 23:45 zulu    11428 kHz  a.m. mode.

Channel Z Radio coming in and out.

sometimes a nice strong signal.

heard some Deep Purple, The Doors, U2.

ID's with e-mail address.    "CZ" in Morse Code

7

North American Shortwave Pirate / Channel Z Shortwave 11428 kHz

« on: January 14, 2012, 1127 UTC »

set the alarm, woke up, turned the radio on, and heard a beat note with the BFO on at 11:00 zulu.

signal coming in and out on  11428 kHz a.m. mode.

heard "Rebel Rebel" by David Bowie.

other various songs heard, throughout the bcst.

"Frankenstein"   "Woman from Tokyo"

at 11:20 zulu  an ID for  Channel Z

11:20    "CZ" in Morse Code

just after 12:00 zulu heard a stong Morse Code ID of "CZ"  then sounds like
transmitter was turned off.

down here near New Orleans.

 

8

North American Shortwave Pirate / Captain Morgan Shortwave - 6951 kHz a.m.

« on: December 03, 2011, 0319 UTC »

was receiving Captain Morgan Shortwave on 6951 kHz
Dec. 03   0228 zulu   with a strong signal for a while.

9

Equipment / simple shortwave transmitter you can build.

« on: February 20, 2011, 1842 UTC »

Here is the new version of a simple transmitter you can build.

changed it again (July 3, 2011)

just got the breadboard version going now.

about 7 watts output.

http://www.angelfire.com/de/RadioAnarchy/

nnnn