It's in working cond. but hasn't been plugged in b/c electricity may be too strong

[Reece]

Yeah, I knew all that about power line frequency and transformer iron: I was just following the joke line.

[Sandy G]

"Honest, Occifer, me 'n' Beaufort here was goin' to my granmother's house to take her to Wednesday nite Prayer Meetin', when this Deer run out in the road in front of my truck, which caused us to swerve 'n' land upside down in this big pile of Beer Cans..." Same sort of story...

[Jeffhs]

The seller may not know what he or she is talking about. Many if not most ebay sellers know little or nothing about electricity or electronics; most folks outside our hobby know just enough to unplug a piece of equipment that smokes, sparks or blows the house fuses when plugged into an outlet. I think this may have been the case with this seller. The person may not (probably didn't) realize that most radios, TVs and other appliances will operate on today's 120-volt electricity every bit as well as they did when the design center was 117 volts. Three volts (five if we are talking about 115 volts), after all, isn't that much of a difference; most appliances, radios, TVs, again, will operate perfectly well anywhere within a range of 115-120 volts, 60Hz AC. A certain maker of incandescent light bulbs (I forget the name) marketed a line of bulbs, some years ago (perhaps in the '80s), designed to operate on 130 volts AC. The claim was that these bulbs would last much longer on 120-volt circuits. I believe it, as I had one of these in a desk lamp. The bulb lasted some five or six years; when I finally had to replace it, the lamp base had somehow welded itself to the socket. I had the dickens of a time removing the bulb, having to literally wreck the socket to do so.

BTW, speaking of light bulbs, what (if anything) is there to prevent any electric light bulb from operating on DC power as well as AC? I have a desk lamp with a sticker on the inside of the shade that reads, "CAUTION: To reduce the risk of fire, use only a 60-watt Type A or smaller lamp. . . . 120V 60Hz AC only." I'm puzzled as to why there is a warning against using this lamp on DC power. Seems to me it should work just as well on DC as well as AC; after all, a lamp filament should light on either, as long as the voltage is correct.

[Robert Grant]

Two thoughts why:

The "AC ONLY" warning is on so many things, that manufacturers (who, these days, usually do not speak any English) apply it generically to all plug-in products shipped to North America.

It may also be because of compact fluorescent bulbs, I strongly suspect they won't work with DC, though I have not tried it. Traditional fluorescent systems absolutely will not work with 120 V DC.

You are correct about incandescent bulbs, they work fine on DC, were first used with DC, and (smaller bulbs) are used extensively with DC.

As a sidenote, I thought it quite amusing when I lit a 40W incandescent using the AAx60 alkaline "B" battery I rigged for my Trans-Oceanics.

[bgadow]

I ran an AA5 off of my "B" pack (mine is made of 9volters) for just a minute, out of curiousity. Eliminated a lot of noise...would also eliminate those batteries right quick, I suppose!

[Reece]

Originally Posted by bgadow

I ran an AA5 off of my "B" pack (mine is made of 9volters) for just a minute, out of curiousity. Eliminated a lot of noise...would also eliminate those batteries right quick, I suppose!

LOL, right, that would suck the juice out of those batteries faster than Dracula! I did that "back in the day" off a Burgess 90-volt B battery and it quickly left the Burgess just a quivering mass....

Re: running old sets on modern juice, some older radios from the '30's and '40's have anemic power transformers that work and test OK but get uncomfortably hot run at 117-122 volts that a lot of people have. My line voltage this morning is running around 122.5. I've seen reports of others having voltages in the upper one-twenties. Some folks hook up a bucking transformer to drop the voltage usually either 6 or 12 volts. The set operates fine and the transfomer just gets a little warm.

[YamahaFreak]

Originally Posted by Robert Grant

The "AC ONLY" warning is on so many things, that manufacturers (who, these days, usually do not speak any English) apply it generically to all plug-in products shipped to North America.

The six-volt battery rechargeable air pump that came with my inflatable airbed has a label on it that suggests that I could be killed by electrocution if I drop it into the bathtub while bathing. It goes on to say that leaving the power switch 'ON' while charging may cause the pump to violently explode.

[Jeffhs]

Originally Posted by Robert Grant

Two thoughts why:

The "AC ONLY" warning is on so many things, that manufacturers (who, these days, usually do not speak any English) apply it generically to all plug-in products shipped to North America.

It may also be because of compact fluorescent bulbs, I strongly suspect they won't work with DC, though I have not tried it. Traditional fluorescent systems absolutely will not work with 120 V DC.

You are correct about incandescent bulbs, they work fine on DC, were first used with DC, and (smaller bulbs) are used extensively with DC.

As a sidenote, I thought it quite amusing when I lit a 40W incandescent using the AAx60 alkaline "B" battery I rigged for my Trans-Oceanics.

Interesting. I did not realize until now that standard, tubular fluorescent bulbs (I think this may also apply to GE's 37-watt "Circline" circular fluorescent tubes of the '60s, which were used in overhead kitchen lighting fixtures of that era) will not, under any circumstances, work on direct current. The same reasoning may well apply to today's compact fluorescents, which have circuitry in their bases that could be damaged or destroyed if the bulb were to be operated on anything other than AC power.

I bet that "B" battery pack didn't last long when you did your experiment with trying to operate a 40-watt incandescent with it. The battery probably wouldn't have lasted five minutes if you had tried this with, for example, a 75-watt bulb; as for a 100-watt or larger one(!)--well, the thing would light for perhaps ten seconds, then the battery would be totally exhausted.

I didn't realize, either, that incandescent light bulbs were first used on direct-current circuits, although it makes sense since many major US cities had DC electric service in their downtown areas until well into the 1950s, with some buildings having DC for elevator motors, et al. as late as the late '80s. I cannot speak for other cities, but think Cleveland had DC power downtown for years; I'm not sure about the residential areas of the city or the suburbs.

Come to think of it, DC power must have been in use even in some residential areas as late as the 1960s; witness the AC-DC All-American Five table radios, most of which were designed to operate on 115 volts AC or DC. (Most such radios, except those with clocks, were designed to operate on either power source; if you were willing to do without the clock, even clock radios would work on AC or DC.) However, when television arrived, the sets were designed for use on alternating current only, the series-string filament circuits and AC-line-derived B+ supplies in these receivers notwithstanding. I once read in an old TV repair manual (circa 1950s) that the term "AC/DC" does not apply to such TV sets as it does to radios. Series-string TV sets were known as "transformerless" sets, as they were not designed for operation on DC power circuits.