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Author Topic: Where do you go for schematics?  (Read 3028 times)

Offline moof

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Where do you go for schematics?
« on: March 23, 2014, 0154 UTC »
For anything other than 40m AM rigs?  I was thinking a hifer beacon that would let off a pip every couple seconds would be a fun experiment.  Or something for AM in the 15mhz range?
Thanks

Offline ff

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Re: Where do you go for schematics?
« Reply #1 on: March 23, 2014, 1434 UTC »
Hi moof - if you're a member of the Yahoo group homebrewpirateradio you can search through the group files.  There are several beacon transmitters in there.  Bow Vudu's file has some, Channel Z has played with them, and there are others in there also.  The 40 meter ham rigs are all around for obvious reasons.  The switch mode type of circuits that lend themselves well to portable operation and low battery drain are very hard to pull off above 8 MHz or so.  Cheap IRF devices just won't switch fast enough to be efficient at say, 15 MHz.  Some of us in the group are starting to play with topologies like Current Mode Class D amps which get around that problem but these aren't easy circuits to tame. My suggestion would be to look for high band CW circuits that use a bipolar device in its power stage (as opposed to a MOSFET), and then use a 555 timer circuit to make it "pip" at your chosen interval.  Your battery will drain faster with a bipolar in Class C mode but you will be able to get much higher in frequency without using hard to build circuits.  I realize that's a long-winded and indirect answer to your Q but I'm not aware of any high band beaconers so I don't know where to point you.  And I agree, it WOULD be fun to get one going.  Good luck with your Googling.
Hailing from the upstate boondocks region of the progressive paradise which once was New York State

Offline FFZ

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Re: Where do you go for schematics?
« Reply #2 on: April 23, 2014, 1724 UTC »
Google schematics for HiFER beacons using the Epson programmable oscillator.  Very simple circuit and, apparently, very effective.

Here's an example (scroll down a bit):
http://part15.us/files.p15/Transmitters13kHz.html

Offline Reverend Bow Voodoo

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Re: Where do you go for schematics?
« Reply #3 on: April 30, 2014, 1742 UTC »
Hi moof - if you're a member of the Yahoo group homebrewpirateradio you can search through the group files.  There are several beacon transmitters in there.  Bow Vudu's file has some, Channel Z has played with them, and there are others in there also. 

There goes my witness protection program....  :o
Reverend Bow Voodoo
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Bastard Modulation Engineering

Can I Get An Amen?

Offline Pigmeat

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Re: Where do you go for schematics?
« Reply #4 on: May 02, 2014, 1411 UTC »
Where in the Hell have you been, Rev?

Offline Fansome

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Re: Where do you go for schematics?
« Reply #5 on: May 04, 2014, 0411 UTC »
I was thinking the same thing.

Where in the Hell have you been, Rev?