Messages

31

Equipment / Re: Using two SDRs with two aerials for steerable array?

« on: November 05, 2012, 1339 UTC »

Here's a ham that has used Softrocks to do it on 160m.  I'm guessing this would work for a small range of frequencies, since changing to a different frequency band would change all the phase relationships, and would have to be re-calculated.   

http://k1lt.com/

Now it's looking like a whole lot of work.  I'll still have to keep mulling this one. . .

32

Equipment / Re: To balun or not to balun?

« on: November 05, 2012, 1338 UTC »

I'm a little cornfused over what state your aerial is currently in.  Is it still a loop, or now is it an end-fed length of 275' wire?

For receive, you can forget the balun altogether.  Really.  If, however, it makes you feel better to use one, go the cheap route and wind 10' of coax into a randomly wound coil 6-8" in diameter right at the aerial feed point.

If it's now a random wire, no balun is needed, as it is not a balanced aerial.  Better to run 50' or so of a ground wire (along the ground) soldered directly to the coax.

In the end, if you don't have one already, save up your shekels and get yourself an "antenna tuner".  MFJ makes some decent ones for cheap, and they can be found on Ebay and Craig's List (or your local ham fest).

Or, you could <gasp!> build your own.

33

Equipment / Re: Using two SDRs with two aerials for steerable array?

« on: November 03, 2012, 1459 UTC »

Anybody thought of doing this?  I see two methods that might be interesting:

A) two identical vertical aerials[1] spaced >0.1 wavelength apart, each connected to a separate SDR.  
Use software to continuously change the phase between the two SDRs, then mix it
Voila!  Electronically steerable array.  Essentially what you get here is a steerable null.

This has been discussed a few times on a few forums.

Comparing the phase of a signal received by both gives you angle of arrival, for very quick RF DF capability.  Adjusting the phase relationship between the two SDRs steers the beam.

Of course, with only two SDRs/antennas you have a bi-directional system, meaning two main lobes/nulls 180 degrees apart, and two possible directions of arrival, also 180 degrees apart.  Adding a third SDR and antenna could reduce that to a single main lobe/null.  A fourth would be better yet.

T!

. . .and doing 4 receivers could be dirt cheap with softrocks or similar.  The piece I would be hung up on is how to execute it in software.

34

North American Shortwave Pirate / Re: Radio Ronin Shortwave 6925AM 3 November 0009 UTC

« on: November 03, 2012, 0029 UTC »

S3 to S5 in STL, but getting better

00:20 Led Zeppelin, Stairway to Heaven
00:24 Will you still call me superman (really don't know the title of  this song)
00:28 Radio Ronin Shortwave ID, with email address and postings to HFU and fRN appreciated
00:28 More music

AM mode.

35

General Radio Discussion / 03 November Undercover Radio Broadcast

« on: November 02, 2012, 2104 UTC »

If you missed it, it was *very* entertaining.  I think the good Dr. should do about every 5th show with this format!  Answer all of life's important questions, reminisce about the old days, talk about the differences in Pirate Radio then and now.

I enjoyed it immensely, after he switched to SSB.

Go the Undercover!

36

Equipment / Using two SDRs with two aerials for steerable array?

« on: November 02, 2012, 2058 UTC »

Anybody thought of doing this?  I see two methods that might be interesting:

A) two identical vertical aerials[1] spaced >0.1 wavelength apart, each connected to a separate SDR. 
Use software to continuously change the phase between the two SDRs, then mix it
Voila!  Electronically steerable array.  Essentially what you get here is a steerable null.

2) One vertical and one horizontal aerial, each connected to an SDR.
Do that phasing thing from above.
Voila!  Diversity reception.

Obviously, I haven't clearly thought this all out.  Once upon a time I thought it might be neat to try something like this with two softrocks (or other cheap SDR), with two sound cards (tied to the same xtal clock).  I'm still thinking about it.  This has got to be easier than running phasing lines, etc., out in the yard for the dogs to "comment" upon.

Was denkst du?

37

North American Shortwave Pirate / Re: Undercover Radio 6925am 0318 UTC 11/2/2012

« on: November 02, 2012, 0344 UTC »

Seem to be broadcasting in AM


03:29  ID
03:30 talking, but I can't make it out
03:31 something about garbage
03:32 Dr. Benway, Undercover radio, broadcasting in the middle of nowhere.

From S3 to in the dirt near St. Louis, MO.

switches modes to SSB at 03:50 & sig goes up to S5 with a shout out to choat.

38

North American Shortwave Pirate / Re: UNID SSTV 6925USB 0256UTC 1Nov12

« on: November 01, 2012, 1453 UTC »

Looks like it's time to make beer.  Hops & grain.

39

Equipment / Re: What Radio Did you start your listening hobby with?

« on: November 01, 2012, 1358 UTC »

They take up a ton of space, they weigh a ton, and honestly, there are better receivers out there.  I thoroughly enjoyed mine (complete with meters), but it was time to move on. 

The small sailboat I bought with the money has better dynamic range, but poorer selectivity.

40

North American Shortwave Pirate / Re: Captain Morgan 6925 am 0130

« on: November 01, 2012, 0315 UTC »

Caught the good Capt. playing


01:47 There coming to take me away!

01:49 Mussorsky's Night on Bald Mountain

01:51  Some other music (or someone coming in on top of you.), signal pretty much down in the mud here

01:53 Captain Morgan ID

01:54 they're coming to take me away (again)

01:55 into some other music

somewhere near STL

41

Equipment / Re: What Radio Did you start your listening hobby with?

« on: October 30, 2012, 2155 UTC »

A transistorized Zenith Transoceanic my grandfather had.  This was the 70's.  We only visited once a year or so, so I would sit and listen to the BBC, foreign broadcasters, and of course WWV.

Graduated to a Sony 2010 right after college (still have and use).  Had an R390/A for 20 or so years, recently parted with it.  I now use my trusty old TR7 mostly, although I'm dabbling in SDR and phasing direct conversion radios. . .

42

Equipment / Re: POLL: What type of antenna do you use?

« on: October 30, 2012, 1327 UTC »

Interesting that you put T2FD as a choice.  I had a T2FD up for years--it's a great aerial.  When I built it I was young and stupid, and built it to withstand The Inquisition (or whatever)--12 ga. solid copper wire, PVC spreaders, etc. etc.

Were I to build another one, it would be much lighter.  It's a nice, quiet, broadband aerial, and worked well with my R390/A.  Ah, those were the days, decoding TASS RTTY in EE out of Cuba. . .

For now, it's the 40m dipole outside at 50' and a 20m magnetic loop in the attic. . .

43

North American Shortwave Pirate / Re: XFM 6970 AM 0055 oct 28

« on: October 28, 2012, 0107 UTC »

Fading up and down between S2 and nothing right now (0105) near STL.

44

North American Shortwave Pirate / Re: Pirate Radio Boston 6925 AM 0200 UTC 10/27

« on: October 27, 2012, 0341 UTC »

Coming up at 0335, music, best copy on USB

0337 "Welcome to 20th anniversary of Pirate Radio Boston."

Someone was a professor in Montreal.  Talk of favorite QSLs, Pirate Yacht club and some red head, "she was gorgeous."  Beavis and Butthead QSL. 

email and snail mail addresses given.  (pirateradioboston@gmail.com)

Signal about S4 to S5 near St. Louis, MO

45

North American Shortwave Pirate / Re: Radio True North, 6935am, 10-27-12, 0315z

« on: October 27, 2012, 0329 UTC »

Just chiming in for a sig report here.  Really in the mud, but audible in MO @ 0329.