crap radio

On May 4, 7:33=A0pm, RichD wrote: > I bought an armband radio last week, for > wear when jogging. =A0It's a digital scanning > model; you cannot select a particular station, > it just scans until it finds a signal strong > enough to lock. >

Hopefully not the guys here but it _is_ annoying that it is designed so poorly at all. I have lists of stupid designs from many manufacturers including Sony, Toyota, Magnavox, Samsung, Panasonic, VW and numerous others. Oh well.

G=B2

You didn't pay more than $5 for that radio though, did you? Hopefully not more than $2.99? :-)

I don't own any of those "one button" radios -- I agree the design is stupid!

more than $2.99? :-)

Its a free-running VCO with AFC and simple ramp for station search.

I doubt it can hold a station for long or re-lock with AFC, if the signal drops out. Maybe that is why it looks for the next station.

In every case you get what you pay for.

On a sunny day (Mon, 4 May 2009 19:33:52 -0700 (PDT)) it happened RichD wrote in :

Consider carrying a small oscillator with you, set it to the wanted station's frequency, but a bit weaker in strength. Then when the watch loses the station, it should still lock on your oscillator. Not simple, but it could work. Alas for all that design you could buy a real radio.

Why didn't you return it to the store as soon as you discovered that it's crap?

Thanks, Rich

I got one about the size and shape of an ear, for about three bucks, BATTERIES INCLUDED! I.e., the radio with batteries was cheaper than the batteries themselves! Ironically, it's got an edgwise pot with a switch for volume a la 1960's transistor radios, but only one button for tuning; fortunately, it stays in one place so stays locked onto whatever station it stops on. But I really don't like having to scan through two dozen crap stations before I find somehthing I like.

But, mainly, it's for when The Big One hits.

Cheers! Rich

Too expensive for such a "radio".

Huh? An AA cell costs me about 20c, or so.

I would most certainly not rely on that thing for the big one. The best radios were the ones made in the 60's and 70's. Most of what came afterwards in the consumer markets is junk.

These are button cells, about 3X as thick as an actual button.

And I could have been using hyperbole - I'd have to check. ;-)

Cheers! Rich

That is a dollar store item, and they never seem to be out of stock around here. Some even have a built in flashlight.

I have seen this several times - purcahase a product which is unusable, and clearly no one at the manufacturer has ever tried. They build and peddle it, but don't use it.

VW?

-- Rich

$12

-- Rich

I did.

Then what? The retailer will notify the supplier, or return it, but they might think it's a defective unit, rather than recognize it's hopeless junk.

What should happen, the retailer should drop it entirely. I guess they need a lot returns, or zero sales, before that...

-- Rich

Ouch!

For $12 you should definitely expect something much better. I'm glad you returned it...

What'll likely happen is this:

$12, instant mfg rebate -$5 Then: $12, instant mfg rebate -$10 Then: Free, if you buy 3 pounds of pears

I don't think so.

It has a digital readout of the station (I use FM band only), which means a PLL and frequency generator. So it has logic and memory. It should be trivial to fix the register of the freq. generator, whenever it locks. But instead, it does that assole scan...

Otherwise, it's a nice packahge. It's a cylinder, the size of a large cigar, with 2 buttons: Reset, and Scan; and digital display.

It's worth less than what I paid.

-- Rich

Actually, it doesn't -- there are some FM radios today that are of the regular old varactor-tuned superheterodyne architecture that have a digital frequency readout that's really just a frequency counter. I would guess they needed a clock for some bits of digital logic anyway, and someone said, "aha!"

I have seen one where the "digital frequency readout" was in essence a glorified digital voltmeter. It's amazing what some folks try to peddle these days and it seems that purchasing agents for major store chains occasionally fall for them.

Other times you can find true gems. Like an electric screwdriver at Costco. LiIon, enourmous torque, I've probably drilled 100 holes with it in rapid order even though it's not meant to be a drill. But it didn't sell, probably didn't look "manly" enough. They almost gave away the last ones for well under $10 to clear the shelf space.

Hmm... do you know if they try to then build a very linear (or at least well-known) transfer function between frequency and voltage and then use, e.g., a bandgap as the reference voltage? (Varactor tuning vs. voltage is seldom at all close to linear...) Or do they just use a lookup table that can be programmed at test to relate tuning voltage to frequency? I suppose one could even use an op-amp and a handful of diode-resistor feedback arms to make a relatively arbitrarily-shaped inverse transfer function and the resistors could be laser trimmed to do the "programming."

IIRC they linearized it inside one of those "uC under a tar blob". Probably a 10c four-bitter where the datasheet and assembler command file only comes in Chinese. I could stall out the oscillator and it still read 101.5MHz :-)

I bet they didn't even care if the linearity wasn't there or the frequency was off (it was, big time). Probably the tooth pick broke when the production folks adjusted mine. Then again it was one of those freebies handed out in a gift bag. The sad part was that the company who bought these gift bags probably overpaid for those things. The good news was that there also was Godiva chocolate and truffles in the gift bag.

Such technical gimmickry can go farther, to the point where things become dangerous. One engineer in Europe was measuring rechargeables, don't remember but could have been LiIon. A NTC was used to determine excessive heat during the charge process. Turned out that one brand had a "thermistor" that always read 10K, regardless of temperature. Hmm ...