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Messages - SW-J

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421
Equipment / Re: UDXF discussion on baluns
« on: July 03, 2010, 1432 UTC »
Yes, but ferrite will "flux out" and permeability fall to zero with oversaturation (usually caused by too small core or DC in the lines somehow causing trouble) far quicker.

Iron powder is less susceptible to ID-10-T errors ;D

I did a test with a 1/2" "T" and "FT" toroid, identical windings and a 12W CB... the "FT" heated up a heckuva lot quicker with a 2:1 mismatch.

Thanks for the linkage, Al!

Peace!

Selection of proper materials for usually the _lowest_ frequency of operation is part of the design process ... the core manufacturers have in their datasheets/catalogs formulas for calculating magnetic flux densities and the maximums for the various ferrite and powdered iron materials ... so, *do the math, select the proper material and all should be well!

(*Been there - done that)

422
I missed it.  Musta been Throbbing elswhere...

J, How you like that Degen 1103?   I picked one up a couple of yrs ago and discovered its a nice radio for very little cash.   Other than the funky volume control mode...

Another thing Throb, I'm finding use for the DE31 active loop antenna I bought with this Degen 1103 radio ... I've got the antenna with suction cup attached to the sliding glass door/windows listening to SW (WBCQ 7415) with a T-storm in progress ...

Will have to try the Active Loop antennas on a car window, since it is known that telescoping rod antennas don't/won't work in side a car (owing to the 'waveguide beyond cutoff effect' and for the same reason 2 Meters doesn't work well from inside a vehicle but 450 MHz and 900 on up do.)


423
Equipment / Re: UDXF discussion on baluns
« on: July 02, 2010, 1541 UTC »
Baluns are typically made on certain ferrite or powdered iron cores with specific turns ratios, various mixes of cores and turns windings nets you the different multiplier values, just as in any other transformer of the electrical variety.

Bzzzzt!

The 'core mix' has very little to do with 'multiplier values' but has to do with increasing the magnetic field flux density and therefore the inductance value and the effective coupling seen between primary and secondary windings ... higher core permeabilities mean fewer turns are required to obtain a particular flux value, but the ratios between a pri winding and sec winding would remain the same - no change in ratio there.

Just thought I would clear up what may be a misconception ...

424
North American Shortwave Pirate / Re: OUTHOUSE RADIO 6930 AM
« on: July 02, 2010, 1435 UTC »
I missed it.  Musta been Throbbing elswhere...

J, How you like that Degen 1103?   I picked one up a couple of yrs ago and discovered its a nice radio for very little cash.   Other than the funky volume control mode...

The Degen - hottest thing since a Texas summer like the one we've been having ...

Have learned to live with the volume control 'thing'. Amazed at the performance on AM and SW bands.

425
North American Shortwave Pirate / Video: OUTHOUSE RADIO 6930 AM
« on: July 02, 2010, 0406 UTC »
A bit of Outhouse Radio picked up on a Degen 1103 receiver:

http://www.youtube.com/v/fsQNeEQLIfI&hl=en_US&fs=1"

426
North American Shortwave Pirate / Re: OUTHOUSE RADIO 6930 AM
« on: July 02, 2010, 0239 UTC »
8930 kHz 0148z / 8:48 PM CDT  <<<<<<   HUH?????

You would not believe how good the signal sounds in FM ( 7 kHz bandwidth setting on an Icom ) during those quieter segments of music ... I kid you not ...

427
North American Shortwave Pirate / Re: OUTHOUSE RADIO 6930 AM
« on: July 02, 2010, 0223 UTC »
0101 tune in, "409" heard here, followed by Beatles (99% sure Strawberry Fields).

measuring 6931.6 am, 24331

Cheers, Terry

There's quite a bit of FM on his carrier (literally: his carrier is 'FMing') to ... switch to FM mode and note demodulated pgm audio ...

I should add, trying to find the 'carrier' with a narrow CW filter ... it is FM'd so it's not a pure CW tone ...

Just an observation; I'm not criticizing ...

Sounds okay in AM tho!

428
North American Shortwave Pirate / Re: OUTHOUSE RADIO 6930 AM
« on: July 02, 2010, 0153 UTC »
Copy in backyard with Degen DE1103 / 1103 portable battery op radio ...

6930 kHz 0148z / 8:48 PM CDT

(sixty-nine thirty - didja really think it was eighty-nine thirty - ever heard of typos ... I've got a lot going on over here!)

429
North American Shortwave Pirate / Re: Wolverine Radio 6925u
« on: July 01, 2010, 2006 UTC »
Quote
Lex, what program do you use to copy SSTV off the air?

MMSSTV, one of the world's great freebie programs.  Should be available from several sites.


Thanks Lex, I'm going to give that a try ...

.

430
General Radio Discussion / Re: Apple Hires Antenna Engineers.
« on: July 01, 2010, 1531 UTC »
You know, this may not be related to 'antenna' deficiencies at all, it may be a multi-path/co-channel interference induced problem ...

Not having not researched the complaint, the 'induced drop call effect' could be being induced by weakening the intended signal from  the presently serving cell site ... and any operating co-channel (same channel) cell sites could be received as a stronger signal ... the result eventually being: a dropped call!

SNR (Signal/Noise ratio) drops below a certain level and - the switch (or the phone) 'releases' (Ericsson term) the call.

All this could be media hoopla based on the published results a classical 'case sample of 1 (one)'  experiment ...

We see this 'muti-path' phenom every day on HF - especially in the situation of 'selective fading' where the fade 'takes out' the carrier say and the broadcast sounds like DSB-supressed carrier ... that's mutli-path distortion as created by two (or more) paths in the ionosphere (or maybe the combo of groundwave and skywave interference in the case of AM radio where the two 'meet' and is referred to as the 'fading wall')

Quote
Groundwave, unless the earth/soil conductivity is changing, would not cause fading. More likely that
a weak skywave is 'phasing' against the groundwave and you end up with fading.
 
The D layer in the ionosphere is not completely absorptive during the day, and so will allow some
signal to reflect. At night the D layer goes away, so at night, it stops absorbing AM broadcast
wavelength radio waves.

When the sun comes back out, the D layer is recreated.

One can experience a "fading wall" at night driving to or away from an AM station at 150 to 200 miles
or so, depending on conditions. I have experienced this several times driving into Dallas and observing
WBAP 820.

Get close enough and no fading; out further and the fading starts as the ground wave is at times
canceled and then alternately reinforced by the skywave signal.


431
North American Shortwave Pirate / Re: Wolverine Radio 6925u
« on: July 01, 2010, 1357 UTC »
...

0337z: SSTV of some nifty looking radio gear

Sure is '70s in here.  Well, mebbe not... can't figure out tonight's theme.



Lex, what program do you use to copy SSTV off the air?
.

432
North American Shortwave Pirate / Re: Wolverine Radio 6925u
« on: July 01, 2010, 0338 UTC »
Wow ... really good signal into NC Texas tonight from "Wolverine Radio".

Time 0335z / 10:35 PM CDT

Listening on Degen DE1103 / 1103 portable battery-powered radio inside the house.

Just copied (audibly) a FAX/Slow-scan transmission.

And, they are off the air now.


Edit: Corrected time.

433
North American Shortwave Pirate / Re: BIG AZZ WEAK SIGNAL
« on: June 30, 2010, 0134 UTC »

0133z / 8:33 PM CDT I can copy them in NC Texas using a Degen DE1103 / 1103 with the built-in whip antenna!

434
General Radio Discussion / Re: Photo of red-head spy
« on: June 29, 2010, 2008 UTC »

Wow ... one of those spies was quite a looker - a fiery redhead with 'a masters in economics' per the story :

http://www.nypost.com/p/news/local/spy_ring_qzWW8bImf9yEDTbtXcQnUL

  I want to know where the rest of the pictures are   ONLY 1 PICTURE of her in lingerie   COME ON NOW STOP TEASING US  ;) ;)

Count on The Smoking Gun to come through:

http://www.thesmokinggun.com/archive/years/2010/0629101chapman1.html

435
General Radio Discussion / Photo of red-head spy
« on: June 29, 2010, 1355 UTC »

Wow ... one of those spies was quite a looker - a fiery redhead with 'a masters in economics' per the story :

http://www.nypost.com/p/news/local/spy_ring_qzWW8bImf9yEDTbtXcQnUL

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