Yes, there were many AC/DC sets previous to the AA5. The AA5 uses a
set of tubes designed for series heater use one 115V circuits without
the need for an additional dropping resistor. Some earlier sets used
balast tubes or series resistors mounted in metal cans or "curtain
burner" resistive line cords. More complex radios used different
combinations of tubes but the idea was to have the filaments run
directly off the line.
BTW, the Germans had a set of tubes after WW-2 also made for AC/DC
specials but for 240 volt lines. The notorious tube used in the
Telefunken (Neumann) U-47 microphone was a high voltage heater tube,
designed for that use. Its purpose in the U-47 was to run the heater off
the same supply as the bias for the microphone element. The more
expensive, variable pattern mic, the M-49, had a conventional power
supply since it had to have variable bias to change the directional
pattern.
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On 8/1/2024 2:21 AM, Jim Whartenby via groups.io wrote:
First town to be electrified using overhead wires, Roselle, NJ, 19
January 1883, See:
. <>
To answer the question on what prompted the development of? AC/DC radios
was the elimination of the most expensive single component in an AC
powered radio, the power transformer.? It seems that the AC/DC radio
design predates the AA5, see:
<>? This shows the Stewart Warner Model R-108 circa 1933.
Regards,
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.
Murphy
On Thursday, August 1, 2024 at 03:11:25 AM CDT, don Root
<drootofallevil@...> wrote:
I saw another article or two indicating DC to an area of mostly textiles
, and elevators in ?apartments. My guess would be that houses, apt
units, would want the new gadgets that mostly ran on AC, but the
elevators would be a costly upgrade. Here in southern Ontario in the
1950¡¯s 25 cycles was replaced with 60 cycle, and the hydro co/govt did
conversions or bought you a new washing machine etc.
Sorry to everyone for my part in hijacking 110 AC/DC and twisting it up
to HVDC etc
*From:*[email protected]
[mailto:[email protected]] *On Behalf Of *Richard Knoppow
*Sent:* Thursday, August 1, 2024 3:39 AM
*To:* [email protected]
*Subject:* Re: [HallicraftersRadios] S-38B Tuning Shaft Query
I don't know. The articles I found don't make it clear. I can't even
find a list of cities that had DC power. Evidently New York, or at least
Manhattan did and parts of Boston. Power was distributed to buildings
and factories but I can't find specific references to homes.
There is a pretty extensive article on the "war of the currents" at
<
<>
Which has some information on early power distribution, but you link
this so have already read it.
Now, comes the question of why Hallicrafters and virtually all other
radio manufacturers made AC/DC radios and phonographs. Was there a big
market or was it due to the economy of not having to use transformers?
Since transformerless sets could operate inherently on both AC and DC
the DC might just have come with the territory. DC was also used on many
ships and boats so radios made to work on them would have to run on DC.
But, Hallicrafters made an AC/DC version of the S-40 receiver as the
S-52 and later the S-77. These were advertised as marine receives but
don't have the MF marine band, they are essentially the same as the S-40
series with some changes in tubes to allow series heaters. So, perhaps
the marine market was large enough to justify manufacturing them.
You have piqued my curiosity so I will do some more searching.
On 7/31/2024 4:40 PM, don Root wrote:
Richard, just for the record, did they distribute DC to homes? Exactly where
<>
<
<> ??talks about it,
and just says ¡°customers¡±, with no mention about houses or special
businesses.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
