iShartMedia quality

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iShartRadio quality:
[Booby Trap commercial]
“This is a test of the Emergency Alert System.”
[Tootsie’s Cabaret commercial]

Heard on WBGG-FM about 1:18 AM. No data bursts were sent. Not even a period of silence.

Let’s not even think too deeply here about what a sin it is to put spots for two rival businesses of the same type in the same stop set. It’s very disrespectful to your advertisers. Then again if they had any respect they wouldn’t be cutting spots in a studio where the equipment has a distinctly audible whining hiss.

Amateur Radio Testing Sessions in Miami-Dade

This is an unofficial listing and you may want to confirm with the club before going for a testing session!

For any amateur radio exam session, please be sure to bring photo ID, the exam fee (unless you’re going to a Laurel VEC session which has none) and a calculator. Calculator apps on a smartphone don’t cut it here. What kind of silly borks do you take us volunteer examiners for? Ha!

 

For whatever odd reason, the testing sessions in Miami-Dade County have sometimes disappeared from the master database on the ARRL website.

 

These are the clubs I’m aware of that regularly host exam sessions:

Dade Radio Club of MiamiTesting sessions monthly in Doral.

Contact: Mike Jasinski, KE4DP@arrl.net

Second Monday of the month, starting 7:00 PM at the Miami-Dade County Emergency Operations Center / Fire Rescue headquarters, 9300 N.W. 41 Street, Doral FL.
Upon arriving, drive up to the front of the building and go left to the gate. If this is closed, ring the intercom and tell the guard you’re there for the Dade Radio Club meeting.

Everglades Amateur Radio Club – Testing sessions monthly in Homestead.

Second Friday of the month, starting 7:30 PM at the South Dade Agricultural Center, 18710 SW 288th St., Homestead, FL.

Contact: Ryan W4NTR, ryan@bbnx.net

Special Events with testing:

South Florida Tropical Hamboree – Originally a Miami event, now held in Fort Lauderdale, but I’ll include it anyway.

The beautiful music of CIALYN

I was looking around at the Boards Of Canada Subreddit and found a link to CIALYN’s “A Night Of A Short Wave Listener”.

 

I’m very glad I did, because this is just wonderful. The style is very much like that of Boards of Canada, with really mysterious sounding synthesizers and samples that sound like they were off some wonderful but long forgotten tape.

The SoundCloud page has some wonderful tracks too.

[soundcloud url=”https://api.soundcloud.com/playlists/224681377″ params=”auto_play=false&hide_related=false&show_comments=true&show_user=true&show_reposts=false&visual=true” width=”100%” height=”450″ iframe=”true” /]

 

Definitely worth looking at if you like BoC. Just saying.

Misspent youth – the Yihua YH-305D

Boy, was I ever young and stupid. It was the summer of 2004 or so, and various Chinese electronics vendors were just starting to flood the US market with some really cool looking toys, and the quality hadn’t faded to zero on them yet either! Mostly….?

At the time I’d just gone through a big mess with most of my workshop having been left out in the rain for several days in my absence, so I didn’t have a power supply. I bought this Yihua YH-305D on eBay and thought it was pretty great for the price, even after it arrived with the instruction manual calling it a “DC POWRE SUPPY” and the plastic nuts on the front panel binding posts don’t actually… work. (I got around this using banana plug leads.)

Years later it finally occurred to me to be suspicious of the fact that the constant current regulation is sloppy as hell, and the cooling fan starts to run if you draw more than one amp off it continuously. At five amps steady draw, the Powre Suppy doesn’t get noticeably warm, but the fan continues to howl forever.

I opened it and realized just how misspent my youth truly was.

wp-1483573643309.jpgThis… beautiful… board greeted me right away. There are places where traces kinda got half etched over there on the side then subsequently, but incompletely, covered with solder to fix it. Ummmmmmmm yeeeeeaaaaah D-

wp-1483573603318.jpgThe underside of the regulator pass transistor assembly. That’s three *supposed* 2N3055 transistors, paralleled. Why would you need three 2N3055’s for five amps?? You can run 15 amps through ONE real 2N3055 if it’s heatsinked properly. Oh wait, I forgot the key word… real. Genuine. Official. Not Pure Unadulterated Chineseium. I couldn’t get a picture of the labels on these “2N3055” transistors that were SO GOOD that they had to put three in parallel to pass 5 amps, but I was able to get a peek at it and they were printed in a gray looking ink with a nonsense logo– it looked like the Marvell Semiconductors logo??!! Either way, this video details what I’m probably actually looking at and why they are… very… very… derated.

The heatsink they are bolted to also explains the fan behavior. It’s nothing more than a flat plate with very little mass and surface area.

wp-1483574274591.jpgThe fan sucks up air from right above it and exhausts it out the back when the thermal switch seen in the background snaps on. I’m not sure how hot it has to get to trigger that, but it sure gets there in no time.

wp-1483573638001.jpgThe main filter capacitor looks underwhelming and I have my doubts it’s actually a Rubycon as its clothing would suggest.

 

This is paired to, uhhh, the death capacitor, as I lovingly call it. If you are using a power supply like this as a limited current source and you lose connection to the load momentarily, and the voltage limit is significantly higher than the voltage the load pulls it down to, any capacitor on the output will be charged up to that level. Once connection is reestablished to the load, it is presented with very high available current at this higher voltage. I detonated some high efficiency white LEDs under test with a power supply like this years ago while trying to develop a boost converter based driver for solar lighting applications and was royally pissed. So, without further ado, the death cap…

wp-1483573631845.jpgand…. the… rubber cement disaster of the century. The entire front of the supply is just…… bespooged with this cement…. Another red cement is found splattered all over the place as well. At left in the above picture is the digital meter board which I am not even going to touch let alone try to calibrate the screwed up zero point on, FORGET THIS

 

wp-1483573620558.jpgThe board is supported only by one small bracket from the rear; if I drop this power supply it will experience the sweet release of death it so sorely longs for.

 

Yeah. I was young and stupid and I bought this.

 

There’s a great thread on EEVBlog’s forum about these, including the wonderful thing that happens when you switch one on and it goes wham, overshoot, boing, boing, boing, and either stops bouncing or… not…

 

Amateur Radio Testing January 8 in Palm Beach

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Picture entirely unrelated

Are you around Palm Beach and want to take the exam to become an amateur radio operator or upgrade to a higher license class? See below.

Still need to study or take a practice exam to see if you’re ready? Check out HamStudy.org.

Bring photo ID and a calculator to the exam session. Since this is a Laurel VEC session, don’t bring the exam fee, as there is none. 😉

Dear Amateur,

This Sunday the Palms West Amateur Radio Club Laurel VEC team will be giving exams for all classes of Amateur Radio licenses.

Come and test with us on Sunday, January 8 at 10:00 AM at Fire Station #28, 1040 Royal Palm Beach Blvd, Royal Palm Beach 1 block south of Okeechobee Blvd.  There is no charge, and you do not have to register.

If you are coming to upgrade, please bring a copy of your license and a photo ID card, like your driver’s license.  There is no charge for testing!

If you know of someone who has been studying to become a ham, bring them along, even if they feel they need to do more studying.

And if you are a VE, please let me know if you can come and help.

73, John, K2CIB
RadioWhiz at gmail dot com

American Dream… I’m so done

I’m so very very DONE and so are your chances of ever getting anywhere on the roads in northwest Miami-Dade in 2020. I had heard nothing but radio silence on this project for over a year, and this is probably why– they were trying hard to apply decorative wallpaper to an elephant in the room to conceal it.

“It is unlikely that all needed interchange improvements will be approved and constructed by 2020, the build out year for ADM,” Lisa Colmenares, a state transportation planner for South Florida, wrote in a Nov. 23 letter to Miami-Dade. “If any of the interchange improvements fail to be approved … by 2020, the base transportation network that is the foundation of [the county’s] traffic analysis will be invalid.”

They don’t even know—–

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Here’s its likeness in cable nightmare form.

Measure up: a beautiful vintage meter.

So a meter is a meter is a meter, right?

Bzzzzzzzzzz.

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This monster is nearly eight and a half inches wide.

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Neat scale.

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Spade tipped needle.

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The passive scale illumination: a ground glass band on top allows ambient light to light the dial.

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Connection post. This isn’t exactly a blazing sensitive meter– putting a digital multimeter set to ohms across it yields no visible deflection. (Some meters peg!) Setting the DMM to diode check, which usually applies 5mA or so, gave me about a 61. Please admire that rough carpentry. I love finding things like this!

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Better view of that nicely made wooden base. Unlike the edges of the connection post holes, the outside is immaculate.

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Dwarfing a Gossen Lunasix.

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Hand written serial number.

What was this made for? Judging by the lack of any visible brand name, wood tabletop base, and unusual scale with no units, I’m suspecting it was a classroom/lab piece. You’d calibrate with a known voltage reference and do the math yourself. You know, old school nonsense. 😉

The low sensitivity is curious too. I’ll have to test later and see just what scales out to a 100.

I did open the meter briefly because there was some loose material rattling around that I didn’t want damaging the movement. An old wire wound spool resistor is mounted inside in parallel with the movement, likely for damping. It looked similar to the spools in my Weston but covered in cloth tape instead of wax.