Re: Hallicrafters SX17 modifier noise limiter
Hi gang, The 6H6 dual diode was used in many Hallicrafter rx's, as noise tube. Check Bama for: S85, S40, and other series rx's schematics. I have an S85, that is wired as an late S40B, for the noise limiter ckt., and not as shown for S85 schematic. The factory did many wonderful running changes,( my sarcasm) and using?up of?parts. They are a good receiver. Good Luck, Dale, N2DM.??
Someone pointed me to a link here:
?
?
This version of the manual does have the circuit which contains the 6H6 along with modified BOM list, so clearly a factory design at some point in the history of manufacture of this receiver.
?
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Re: Hallicrafters SX17 modifier noise limiter
Someone pointed me to a link here:
?
?
This version of the manual does have the circuit which contains the 6H6 along with modified BOM list, so clearly a factory design at some point in the history of manufacture of this receiver.
?
|
Re: S-38B Tuning Shaft Query
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
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
|
Re: S-38B Tuning Shaft Query
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 ?
toggle quoted message
Show quoted text
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 -- don??? va3drl
|
Re: Hallicrafters SX17 modifier noise limiter
PS, I am aware that the 6H6 was used as a modification in the SX28 and I have found and downloaded a circuit diagram for that modification as a reference. Possibly the SX17 circuit might be be similar but it would be interesting to hear whether anyone else has encountered this valve in the SX17?
|
Hallicrafters SX17 modifier noise limiter
I have been working on a hallicrafters SX17 receiver and so far work is progressing (audio and detector circuit restored and interstage transformer replaced) although a bit slowly and cautiously. Yesterday, when I removed it for the first time, I discovered that in the position of the 6J5 'silencer' triode, was actually a 6H6 double diode. This puzzled me initially until I Google and looked at the datasheets and discovered that the 6H6 can be used for the noise limiter function. Both the early and late versions of the circuit diagrams I have so far found both show the 6J5 in that position. It is no wonder that the voltages don't match the table in the manual! However, was this modded by someone, or was it a factory design? I couldn't see any obvious indication of changes to the wiring, only that some components were different. However, someone gave me a hint to have a look at the valve base, which I did this morning and it is stamped 6H6! This does suggest that the modification was added at the factory.
?
I wonder, does anyone have or come across a circuit diagram showing this modification, i.e. a 6H6 rather than a 6J5 in the noise limiter circuit?
Has anyone already reverse engineered it perhaps? I am minded to reverse engineer it anyway, but it might help if there is already an updated circuit in existence somewhere.
?
|
Re: 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.
toggle quoted message
Show quoted text
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
|
Re: S-38B Tuning Shaft Query
Jim, I just wanted to pinpoint that any AC power transmission system made of wires is ruled by transmission line theory. As such, some effects that are more easily seen in the RF domain, like SWR, can also happen on power lines. A line of a quarter wavelength is a funny case because it behave as an impedance inverter. Put a short at one end, and what you “see” at the other end is an open circuit, and vice-versa. A quarter wavelength at 60Hz is 1250km, assuming that the energy moves at the speed of light. But if the real velocity is 90% of the speed of light, a quarter wavelength is 1125km. The Manitoba DC line from Nelson River to Winnipeg is 895km long: not a full quarter wavelength at 60 Hz, but… I am sure that one of the reasons that motivated the use of a DC power transmission system there was the potential difficulties to “match” the line against load variations events. Hydro-Quebec engineers here had a lot job to conceive the 735kV James Bay to Montreal power line (~1000km in length) compensation system. And also to keep the James Bay alternators in sync with the rest of the province power grid, 24/7 ! ? 73, Jacques, VE2JFE in Montreal ? If it is a matched lossless transmission line then there is no reflected power so the load receives 100% of the power!? Or at least that is the theory.? <grin>
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Re: S-38B Tuning Shaft Query
Richard ??RE:?? When my family visited the Canadian side of Niagara Falls when I was a kid they had 25Hz power. Way back Toronto wanted Niagara power to run street cars, and 25 cycles is more stable 60 for longer distances, so that was used, ?but that is only part of the story about 25 cycles at Niagara. 130 years ago there were all kinds of rotary converters/ motor generator sets to allow all kinds of connections.. especially around Niagara Falls and buffalo where a lot of power battles were fought ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Wednesday, July 31, 2024 5:33 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] S-38B Tuning Shaft Query? DC is still used for specific long distance transmission lines. For
instance the Pacific Intertie which runs at near a million bolts DC from
The Dales in Oregon to Los Angeles. I have been at the Sylmar receiving
station where it is converted to AC for distribution. Its like something
from a high budget sci-fi movie. When I visited, quite a long time ago
some of the conversion equipment was covered with tarps because there
was secret technology involved. I think now other gear is used but don't
know. The Sylmar plant is owned jointly by the Los Angeles Department of
Water and Power and the Southern California Edison company but run by
the DWP. It can supply the entire demand of the city but normally
supplies about half, the other half coming from the four corners plant
and a mix of other sources such as Boulder Dam and some local generating
stations.
The Dales is hydroelectric, Four Corners is coal/gas far from the
city because it produces pollution, so its hidden way out in the stix.
If anyone ever figures out how to produce cheap electricty without
pollution it will be a revolution in the world.
25hz power was evidently a result of General Electric pushing it
for industrial and railroad use. When my family visited the Canadian
side of Niagara Falls when I was a kid they had 25Hz power. The
flickering of the room lights was very obvious. The Pennsylvania
Railroad ran on 25Hz current, not sure if it still does. They wanted to
convert to 60Hz several years ago so that they could buy power from
independent sources but found it was too expensive. Another General
Electric installation.
At one time Los Angeles was partly on 50Hz power and partly on 60Hz.
I think the 50Hz was continued until the end of WW-2. I don't remember
all the history but think LADWP was 60Hz and SCE was 50Hz plus there
were a lot of independent power companies in smaller cities like
Burbank. Lots of this history is on the web. ? --
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998 -- don??? va3drl
|
Locked
Re: Hallicrafters group storage space
"Back in the early years of these groups, computer memory and dial-up connections limited discussions.? Now these issues are trivial, digital memory is cheap and internet connections are quite fast.? It just seems easier for me to leave past comments in the post then to go back and research what was discussed in the past.? "
I was beginning to feel the hand of Jack Hill in this post...? (if you know you know).? :-)
The amount of storage used by text is insignificant.??
The transformer discussion was interesting!
John K5MO
|
Locked
Re: Hallicrafters group storage space
All the samples appear okay to me. ? 73, Gary – W6GVS ? Sent from for Windows ?
toggle quoted message
Show quoted text
From: don Root via groups.ioSent: Wednesday, July 31, 2024 7:55 PM To: [email protected]Subject: Re: [HallicraftersRadios] Hallicrafters group storage space ? TEST image formats GIG ,TIF, PNG, JPG?? I WILL DELETE POSTING IN 1,2 DAYS, UNLESS SOMEBODY WANTS IT LONGER ? 骋滨贵………………….. ? ?? ? 笔狈骋………………  ?
? TIF……………… ? 
? JPG?? ------------------ ? 
………… ALL COPIED OUT OF MS “PAINT” ? ?
--
don??? va3drl
|
Re: Very Nice 8R-40 Incoming!
The 8R-40 information on the Web indicates that its chassis is laid out
essentially the same as my S-40B with the exception that the 5Y3 is
replaced by a solid state rectifier so the 8R-40 has only seven tubes.
It does have a BFO. I haven't compared the schematics other than that.
73,
Maynard
W6PAP
toggle quoted message
Show quoted text
On 7/31/24 06:18, John Meade W2XS wrote: It looks to be in nice shape. Good luck with it. It looks like an S40B
with a 5R10 dial on it, minus the BFO.
|
Re: S-38B Tuning Shaft Query
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. ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Wednesday, July 31, 2024 1:46 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] S-38B Tuning Shaft Query? Turns out the last DC in the US was Con Edison in NYC, discontinued
in 2007. However converters were installed in some buildings to operate
devices requiring DC.
On 7/31/2024 10:22 AM, Richard Knoppow wrote: If the neutral side of the line is really neutral. The rule in the
old days, as detailed in most handbooks, was to put the plug in to get
minimum hum. Of course on DC the set would not work if the plug was in
the wrong way. Is there anyplace now with DC current? Was once common on
ships. Must be pretty rare. I think NYC still had some DC until fairly
recently due to elevators and other machinery requiring it. --
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998 -- don??? va3drl
|
Re: S-38B Tuning Shaft Query
If it is a matched lossless transmission line then there is no reflected power so the load receives 100% of the power!? Or at least that is the theory.? <grin> Jim Re: [HallicraftersRadios] S-38B Tuning Shaft Query 
Wed, Jul 31 at 4:14 PM
There is another reason to use DC on very long power transmission lines, and this one is not necessary obvious…
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
There is another reason to use DC on very long power transmission lines, and this one is not necessary obvious… On certain installations, and I believe that the Manitoba line is one, the length of the line approach a quarter wavelength at 60 Hz. What the transmission line theory then tells you ?? ? 73, Jacques, VE2JFE in Montreal ? Yes – because DC has no “crest factor,” it makes greater efficient use of transmission.? The peak, average, and RMS values for DC are all the same, reducing insulation requirements and eliminating the periods of the AC wave where the instantaneous RMS current is more than the time-averaged RMS current. As we remember I squared R is the formula for loss, so less loss, less heat, smaller conductors, and cheaper insulators!
Plus – no synchronization problems!!
Interesting return to Edison’s original idea – but without the DC generators he had hoped to see every few blocks in cities, and to homes in rural areas!
Mike/
K5MGR
____________________________________________ ? Mike Langner
929 Alameda Road NW
Albuquerque, NM 87114-1901
(505) 898-3212 home/home office
(505) 238-8810 cell
Richard,? no doubt there is still DC and maybe 25 cycle AC, but all this is limited to specific plants, maybe dedicated electric transportation, large mining and such. I have not seen? any consumer item in North America intended for connection to ?“DC mains” . There are still many DC motors in use , but rotary or static converters get power from AC “mains” at 120V, 460V, 600V, 2300V, 4160V, 13,000V and much much higher for HVDC transmission , and I just now ?bumped into this at ?
And I started all this Nelson River planning as a student at Manitoba hydro Planning department.. all those hydro stations, and just maybe connect those very long lines using HVDC at something like 700,000 volts. Also see here is the line on a map.
? So DC is not dead, but I doubt there is a 110 DC outlet in any North American house, but I’m ready for backlash and getting re-educated. ? Oh sorry , I’m on double time now!
|
Re: S-38B Tuning Shaft Query
Good luck with the S-38B. My original one was accidently included in
a bunch of stuff I had in storage and sold. It was in pretty bad shape
(my fault). I have an S-38 in the queue for restoring.
I got mine by nagging my parents. A neighbor had a B and I decided
I wanted one. I suspect we could have gotten an S-20R for the same
price, would have been a step up but I was very naive and my dad was
too. Oh, well. At nine years old I would not have appreciated the
difference.
toggle quoted message
Show quoted text
On 7/31/2024 3:55 PM, Ron Sharp via groups.io wrote: My original post was about the materials use for the S-38B tuning
extension shafts. Having now pulled the chassis out of the radio, it
turns out that the shafts, which were made of plastic, had been snapped
off just inside the case. What made me think they were extension shafts
were some spacers that had been added between the metal case and the
tuning shaft support brackets. I will make up two new shafts from plastic.
Sorry to give mis-information at the start of the post, but the ensuing
conversation has been most enlightening.
Cheers
Ron Sharp
VK2IRS
Burrill Lake NSW
Australia
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: S-38B Tuning Shaft Query
Post up a couple of pics.
Justin B. - KI5GKD
On 7/31/2024 5:55 PM, Ron Sharp via
groups.io wrote:
toggle quoted message
Show quoted text
My original post was about the materials use for the S-38B
tuning extension shafts. Having now pulled the chassis out of
the radio, it turns out that the shafts, which were made of
plastic, had been snapped off just inside the case. What made me
think they were extension shafts were some spacers that had been
added between the metal case and the tuning shaft support
brackets. I will make up two new shafts from plastic.
?
Sorry to give mis-information at the start of the post, but
the ensuing conversation has been most enlightening.
?
Cheers
Ron Sharp
VK2IRS
Burrill Lake NSW
Australia
--
Justin B.
KI5GKD
|
Re: S-38B Tuning Shaft Query
My original post was about the materials use for the S-38B tuning extension shafts. Having now pulled the chassis out of the radio, it turns out that the shafts, which were made of plastic, had been snapped off just inside the case. What made me think they were extension shafts were some spacers that had been added between the metal case and the tuning shaft support brackets. I will make up two new shafts from plastic.
?
Sorry to give mis-information at the start of the post, but the ensuing conversation has been most enlightening.
?
Cheers
Ron Sharp
VK2IRS
Burrill Lake NSW
Australia
|
Re: Very Nice 8R-40 Incoming!
It has a BFO pitch control, last knob on the right! :-)
?
73,
--
Justin B.
KI5GKD
|
Re: S-38B Tuning Shaft Query
DC is still used for specific long distance transmission lines. For
instance the Pacific Intertie which runs at near a million bolts DC from
The Dales in Oregon to Los Angeles. I have been at the Sylmar receiving
station where it is converted to AC for distribution. Its like something
from a high budget sci-fi movie. When I visited, quite a long time ago
some of the conversion equipment was covered with tarps because there
was secret technology involved. I think now other gear is used but don't
know. The Sylmar plant is owned jointly by the Los Angeles Department of
Water and Power and the Southern California Edison company but run by
the DWP. It can supply the entire demand of the city but normally
supplies about half, the other half coming from the four corners plant
and a mix of other sources such as Boulder Dam and some local generating
stations.
The Dales is hydroelectric, Four Corners is coal/gas far from the
city because it produces pollution, so its hidden way out in the stix.
If anyone ever figures out how to produce cheap electricty without
pollution it will be a revolution in the world.
25hz power was evidently a result of General Electric pushing it
for industrial and railroad use. When my family visited the Canadian
side of Niagara Falls when I was a kid they had 25Hz power. The
flickering of the room lights was very obvious. The Pennsylvania
Railroad ran on 25Hz current, not sure if it still does. They wanted to
convert to 60Hz several years ago so that they could buy power from
independent sources but found it was too expensive. Another General
Electric installation.
At one time Los Angeles was partly on 50Hz power and partly on 60Hz.
I think the 50Hz was continued until the end of WW-2. I don't remember
all the history but think LADWP was 60Hz and SCE was 50Hz plus there
were a lot of independent power companies in smaller cities like
Burbank. Lots of this history is on the web.
toggle quoted message
Show quoted text
On 7/31/2024 1:03 PM, don Root wrote: Richard,? no doubt there is still DC and maybe 25 cycle AC, but all this
is limited to specific plants, maybe dedicated electric transportation,
large mining and such.
I have not seen? any consumer item in North America intended for
connection to ?“DC mains” .
There are still many DC motors in use , but rotary or static converters
get power from AC “mains” at 120V, 460V, 600V, 2300V, 4160V, 13,000V and
much much higher for HVDC transmission , and I just now ?bumped into
this at
<>
And I started all this Nelson River planning as a student at Manitoba
hydro Planning department.. all those hydro stations, and just maybe
connect those very long lines using HVDC at something like 700,000 volts.
Also see
<>
here is the line on a map.
So DC is not dead, but I doubt there is a 110 DC outlet in any North
American house, but I’m ready for backlash and getting re-educated.
Oh sorry , I’m on double time now!
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: S-38B Tuning Shaft Query
There is another reason to use DC on very long power transmission lines, and this one is not necessary obvious… On certain installations, and I believe that the Manitoba line is one, the length of the line approach a quarter wavelength at 60 Hz. What the transmission line theory then tells you ?? ? 73, Jacques, VE2JFE in Montreal ? Yes – because DC has no “crest factor,” it makes greater efficient use of transmission.? The peak, average, and RMS values for DC are all the same, reducing insulation requirements and eliminating the periods of the AC wave where the instantaneous RMS current is more than the time-averaged RMS current. As we remember I squared R is the formula for loss, so less loss, less heat, smaller conductors, and cheaper insulators!
Plus – no synchronization problems!!
Interesting return to Edison’s original idea – but without the DC generators he had hoped to see every few blocks in cities, and to homes in rural areas!
Mike/
K5MGR
____________________________________________ ? Mike Langner
929 Alameda Road NW
Albuquerque, NM 87114-1901
(505) 898-3212 home/home office
(505) 238-8810 cell
Richard,? no doubt there is still DC and maybe 25 cycle AC, but all this is limited to specific plants, maybe dedicated electric transportation, large mining and such. I have not seen? any consumer item in North America intended for connection to ?“DC mains” . There are still many DC motors in use , but rotary or static converters get power from AC “mains” at 120V, 460V, 600V, 2300V, 4160V, 13,000V and much much higher for HVDC transmission , and I just now ?bumped into this at ?
And I started all this Nelson River planning as a student at Manitoba hydro Planning department.. all those hydro stations, and just maybe connect those very long lines using HVDC at something like 700,000 volts. Also see here is the line on a map.
? So DC is not dead, but I doubt there is a 110 DC outlet in any North American house, but I’m ready for backlash and getting re-educated. ? Oh sorry , I’m on double time now!
|
Jim Whartenby
don Root
Jacques_VE2JFE
