Thinking Small

Been Playing with Micro powered radios as of late. I’m sending MP3’s from my PC to a portable radio via a low powered AM band transmitter. I based my setup from the “Mighty Mite” QRP type transmitter. And it works like a charm. I knew it would. Those CW machines tend to do well on AM.
I suspect that it will do well for AM phone as well, after I get my ticket. ( with distance limitations).
Last time I wrote about the “Mite” or the “Pixie”, I got slammed by the Hams. I was gonna cause the apocalypse or something If I didn’t use high dollar high powered radios. I was gonna cause all kind of over modulation and harmonics all around. Well, BITE MY BIG HAIRY PARTS MR. MOFO.
I am impressed with both the “MITE” and The “Talking Pixie”Mod.
On the Mite I used a 386 for a buffer amplifier  fed in to the base of the transistor on the audio end and a lowpass filter at the RF out end.
Other Mite Mods: are 2n2222a Transistor and lower power for the bat pack. It’s running on 3-5 vdc. The  variable cap is from a old radio scrap project. About a 365 pf. which tunes a crystal in the AM range. On a 1.5 inch form L=1 is 45 turns, tapped at 15 — L=2 is 6 turns or
L=1 is 60 turns, tapped at 20 —L=1 is 8 turns. Depending on the crystal used and How far you bend it.
 It covers my area about a 1 block radius. Note. For AM transmission the code key can be used as PTT. Close key to transmit.
It’s fairly stable and clean sounding, But I ain’t done with it yet. I want to make the final design modular so I can experiment with it some more.

Is it legal?  

 http://www.hobbybroadcaster.net/        

http://en.wikipedia.org/wiki/Title_47_CFR_Part_15#Unlicensed_broadcasting

Now I want to do a pair of AM “Talking Pixie”Mods.


Factoid:

530 to 1600 kHz: This is the Medium wave Broadcast band (also known as the “AM” broadcasting band). The channel separation is 9 kHz in Europe, Africa and Asia, and 10 kHz in the Americas. In the United States, the frequencies of 1230, 1240, 1340 1400, 1450, and 1490 kHz are allocated only for local stations (low power) and you may simply hear a ‘rumble’ on those frequencies, esp. at night due to the heavy congestion. Many powerful stations in South America use a non-standard frequency step in this band.
1600 to 1710 kHz: In USA the Medium wave Broadcast band now ends at 1700 kHz, with 1610 to 1700 kHz being the new “X” or “extended” band. New stations began appearing here in late 1997, and this new “X band” is providing excellent DX listening opportunities. In Europe you can hear medium wave pirate radio stations in this band.

There have been some old timer radio operators whom have offered encouragement. In the same breath I can state the main reason I don’t have my ticket yet is due to a few attitudes that I have encountered, plus the fact that I have to go to another county for the testing. It is not available here.

There is something satisfying hearing my play list coming from one of my old radios, Something better than hearing the same list from an MP3 player. Now, I need pictures and some sample recordings to post.
Before I leave Ya’ll this AM, I would encourage Ya’ll to experiment, or build something, or restore something, as it feels good. Later, Dragon

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About theelderdragon15601

Bleh.
This entry was posted in Homebrew, Microcasting, QRP, Rado. Bookmark the permalink.

4 Responses to Thinking Small

  1. Craig Cavanaugh says:
  2. Elder Dragon says:
  3. Sunnybrook Farm says:
  4. Elder Dragon says:

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