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Re: Halicrafters SX17 transformer

 

Well, he says sheepishly, this is true for the Thordarson, 50-60 cycles.? The PAECO frequency range is from 50 to 1000 cycles.??I still think the PAECO is the all around winner, if this is a contest.

Rechecking the?Stancor, it does say 60 cycles but the bigger mistake is in the B+ current rating.? I should have said the Stancor P-6013.? The difference is 90 vs 120 mA.? This may be a problem when the cost is driving the spec.? Less copper, less iron, lower price.

Regards,
Jim


Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Thursday, May 30, 2024 at 07:36:07 PM CDT, Jim Whartenby <old_radio@...> wrote:


Yes. according to the catalog, 50-60 cycle

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Thursday, May 30, 2024 at 12:08:20 PM CDT, don Root <drootofallevil@...> wrote:


Jim, are these 50 cycle ?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Thursday, May 30, 2024 11:18 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

John

There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.

?

STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:

2 1/2 inch by 2 9/16 mounting hole spacing

325 - 0 - 325 volts @ 150mA

5 volts @ 3 amps

6.3 volts @ 5 amps

?

THORDARSON? model 22R05

2 1/2 inch by 3 1/8 inch mounting hole spacing

300 - 0 - 300 volts @ 120 mA

5 volts @ 3 amps

6,3 volts @ 5 amps

?

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.

PAECO model 910-94

2,5 inch by 2.34 inch mounting hole spacing

315 - 0 - 315 volts @ 125 mA

5 volts @ 2 amps

6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.

This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

?

Regards,

Jim

?

?

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

?

?

On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:

?

?

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?
Re: Halicrafters SX17 transformer

 

¿ªÔÆÌåÓý

Lee ¨C You have that completely backward. ¨C 73 ¨C Mike

?

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell NJ 07731

908-902-3831

?

From: [email protected] <[email protected]> On Behalf Of Lee Bahr
Sent: Thursday, May 30, 2024 5:28 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

You can run 60 cycle transformers on 50 cycles but you can't run 50 cycle transformers on 60 cycles.? A 60 cycle transformer has more iron in it then one for 50 cycles.

Lee, w0vt

On 5/30/2024 3:24 PM, Richard Knoppow wrote:

It seems to me that most 60Hz power transformers will perform OK on
50Hz although they may run hot.

On 5/30/2024 12:34 PM, John via groups.io wrote:

Since the radio is in the UK, it would need to operate on 50Hz mains.
Looking at the data, the Stancor appears to be for operation on 60Hz,
whereas the Thordarson catalog states that the 22R05 operates on both 50
and 60Hz.

I am also going to post on a vintage radio forum which is predominantly
UK based so see whether there is a UK based outlet or whether anyone
here in the UK might have a suitable salvaged spare, and now that I know
what I m looking for, also check eBay. I am happy to ship from the USA
if need be and options are limited, but obviously shipping to the UK is
not cheap so I do appreciate Jim¡¯s kind offer.

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Halicrafters SX17 transformer

 

Yes. according to the catalog, 50-60 cycle

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Thursday, May 30, 2024 at 12:08:20 PM CDT, don Root <drootofallevil@...> wrote:


Jim, are these 50 cycle ?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Thursday, May 30, 2024 11:18 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

John

There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.

?

STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:

2 1/2 inch by 2 9/16 mounting hole spacing

325 - 0 - 325 volts @ 150mA

5 volts @ 3 amps

6.3 volts @ 5 amps

?

THORDARSON? model 22R05

2 1/2 inch by 3 1/8 inch mounting hole spacing

300 - 0 - 300 volts @ 120 mA

5 volts @ 3 amps

6,3 volts @ 5 amps

?

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.

PAECO model 910-94

2,5 inch by 2.34 inch mounting hole spacing

315 - 0 - 315 volts @ 125 mA

5 volts @ 2 amps

6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.

This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

?

Regards,

Jim

?

?

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

?

?

On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:

?

?

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?
Re: Halicrafters SX17 transformer

 

Other way around, the low frequency transformer must have more
iron. There may be additional losses in a tranformer at higher
frequencies but generally 50Hz will run fine at 60Hz. Where transformers
must run at very high frequencies, like 400Hz, they must be specially
designed for it. Same at 25Hz, those will run fine at 60Hz but might get
hot. They are usually very heavy compared to a 50 or 60Hz transformers.
One of the power supplies for the BC-779 Super-Pro runs at 25 to 60 Hz
and must weigh about three times what a 60Hz supply does. Of course it
also needs larger chokes and capacitors.
Of course, high frequency supplies, generally used in aircraft, also
need different chokes and filter caps.


On 5/30/2024 2:28 PM, Lee Bahr wrote:
You can run 60 cycle transformers on 50 cycles but you can't run 50
cycle transformers on 60 cycles.? A 60 cycle transformer has more iron
in it then one for 50 cycles.

Lee, w0vt

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
Re: Halicrafters SX17 transformer

 

¿ªÔÆÌåÓý

Jacques, you must have your good binoculars in-use. I was reading? the tests box. Yes it says 50/60 ?under the core diagram and it says 50/60 ,127va on top of the 3D drawing of the transformer too.

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jacques_VE2JFE
Sent: Thursday, May 30, 2024 3:39 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer
Importance: High

?

Don, please read the .pdf more attentively.

Just at the right of the GRY ¨C ELECTROSTATIC SHIELD, what do you see ??

?

73, Jacques, VE2JFE in Montreal

?

De?: [email protected] <[email protected]> De la part de don Root
·¡²Ô±¹´Ç²â¨¦?: 30 mai 2024 14:39
??: [email protected]
Objet?: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Jacques, as I read it this is a 60 Hz , nota ?50 Hz ?unit

Don

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jacques_VE2JFE
Sent: Thursday, May 30, 2024 1:59 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Another possible replacement is a Hammond 372DX.

See attached.

?

73, Jacques, VE2JFE in Montreal

?

De?: [email protected] <[email protected]> De la part de don Root
·¡²Ô±¹´Ç²â¨¦?: 30 mai 2024 13:08
??: [email protected]
Objet?: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Jim, are these 50 cycle ?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Thursday, May 30, 2024 11:18 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

John

There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.

?

STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:

2 1/2 inch by 2 9/16 mounting hole spacing

325 - 0 - 325 volts @ 150mA

5 volts @ 3 amps

6.3 volts @ 5 amps

?

THORDARSON? model 22R05

2 1/2 inch by 3 1/8 inch mounting hole spacing

300 - 0 - 300 volts @ 120 mA

5 volts @ 3 amps

6,3 volts @ 5 amps

?

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.

PAECO model 910-94

2,5 inch by 2.34 inch mounting hole spacing

315 - 0 - 315 volts @ 125 mA

5 volts @ 2 amps

6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.

This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

?

Regards,

Jim

?

?

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

?

?

On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:

?

?

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?

?


--
don??? va3drl

_._,_._,_


--
don??? va3drl
Re: Halicrafters SX17 transformer

 

¿ªÔÆÌåÓý

You can run 60 cycle transformers on 50 cycles but you can't run 50 cycle transformers on 60 cycles.? A 60 cycle transformer has more iron in it then one for 50 cycles.

Lee, w0vt

On 5/30/2024 3:24 PM, Richard Knoppow wrote:

It seems to me that most 60Hz power transformers will perform OK on
50Hz although they may run hot.

On 5/30/2024 12:34 PM, John via groups.io wrote:
Since the radio is in the UK, it would need to operate on 50Hz mains.
Looking at the data, the Stancor appears to be for operation on 60Hz,
whereas the Thordarson catalog states that the 22R05 operates on both 50
and 60Hz.

I am also going to post on a vintage radio forum which is predominantly
UK based so see whether there is a UK based outlet or whether anyone
here in the UK might have a suitable salvaged spare, and now that I know
what I m looking for, also check eBay. I am happy to ship from the USA
if need be and options are limited, but obviously shipping to the UK is
not cheap so I do appreciate Jim¡¯s kind offer.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Halicrafters SX17 transformer

 

It seems to me that most 60Hz power transformers will perform OK on
50Hz although they may run hot.


On 5/30/2024 12:34 PM, John via groups.io wrote:
Since the radio is in the UK, it would need to operate on 50Hz mains.
Looking at the data, the Stancor appears to be for operation on 60Hz,
whereas the Thordarson catalog states that the 22R05 operates on both 50
and 60Hz.

I am also going to post on a vintage radio forum which is predominantly
UK based so see whether there is a UK based outlet or whether anyone
here in the UK might have a suitable salvaged spare, and now that I know
what I m looking for, also check eBay. I am happy to ship from the USA
if need be and options are limited, but obviously shipping to the UK is
not cheap so I do appreciate Jim¡¯s kind offer.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
Re: Halicrafters SX17 transformer

 

¿ªÔÆÌåÓý

Don, please read the .pdf more attentively.

Just at the right of the GRY ¨C ELECTROSTATIC SHIELD, what do you see ??

?

73, Jacques, VE2JFE in Montreal

?

De?: [email protected] <[email protected]> De la part de don Root
·¡²Ô±¹´Ç²â¨¦?: 30 mai 2024 14:39
??: [email protected]
Objet?: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Jacques, as I read it this is a 60 Hz , nota ?50 Hz ?unit

Don

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jacques_VE2JFE
Sent: Thursday, May 30, 2024 1:59 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Another possible replacement is a Hammond 372DX.

See attached.

?

73, Jacques, VE2JFE in Montreal

?

De?: [email protected] <[email protected]> De la part de don Root
·¡²Ô±¹´Ç²â¨¦?: 30 mai 2024 13:08
??: [email protected]
Objet?: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Jim, are these 50 cycle ?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Thursday, May 30, 2024 11:18 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

John

There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.

?

STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:

2 1/2 inch by 2 9/16 mounting hole spacing

325 - 0 - 325 volts @ 150mA

5 volts @ 3 amps

6.3 volts @ 5 amps

?

THORDARSON? model 22R05

2 1/2 inch by 3 1/8 inch mounting hole spacing

300 - 0 - 300 volts @ 120 mA

5 volts @ 3 amps

6,3 volts @ 5 amps

?

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.

PAECO model 910-94

2,5 inch by 2.34 inch mounting hole spacing

315 - 0 - 315 volts @ 125 mA

5 volts @ 2 amps

6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.

This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

?

Regards,

Jim

?

?

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

?

?

On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:

?

?

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?

?


--
don??? va3drl

Re: Halicrafters SX17 transformer

 

Since the radio is in the UK, it would need to operate on 50Hz mains. Looking at the data, the Stancor appears to be for operation on 60Hz, whereas the Thordarson catalog states that the 22R05 operates on both 50 and 60Hz.

I am also going to post on a vintage radio forum which is predominantly UK based so see whether there is a UK based outlet or whether anyone here in the UK might have a suitable salvaged spare, and now that I know what I m looking for, also check eBay. I am happy to ship from the USA if need be and options are limited, but obviously shipping to the UK is not cheap so I do appreciate Jim¡¯s kind offer.
Re: Halicrafters SX17 transformer

 

¿ªÔÆÌåÓý

Jacques, as I read it this is a 60 Hz , nota ?50 Hz ?unit

Don

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jacques_VE2JFE
Sent: Thursday, May 30, 2024 1:59 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Another possible replacement is a Hammond 372DX.

See attached.

?

73, Jacques, VE2JFE in Montreal

?

De?: [email protected] <[email protected]> De la part de don Root
·¡²Ô±¹´Ç²â¨¦?: 30 mai 2024 13:08
??: [email protected]
Objet?: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Jim, are these 50 cycle ?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Thursday, May 30, 2024 11:18 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

John

There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.

?

STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:

2 1/2 inch by 2 9/16 mounting hole spacing

325 - 0 - 325 volts @ 150mA

5 volts @ 3 amps

6.3 volts @ 5 amps

?

THORDARSON? model 22R05

2 1/2 inch by 3 1/8 inch mounting hole spacing

300 - 0 - 300 volts @ 120 mA

5 volts @ 3 amps

6,3 volts @ 5 amps

?

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.

PAECO model 910-94

2,5 inch by 2.34 inch mounting hole spacing

315 - 0 - 315 volts @ 125 mA

5 volts @ 2 amps

6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.

This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

?

Regards,

Jim

?

?

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

?

?

On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:

?

?

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?


--
don??? va3drl
Re: Halicrafters SX17 transformer

 

¿ªÔÆÌåÓý

Another possible replacement is a Hammond 372DX.

See attached.

?

73, Jacques, VE2JFE in Montreal

?

De?: [email protected] <[email protected]> De la part de don Root
·¡²Ô±¹´Ç²â¨¦?: 30 mai 2024 13:08
??: [email protected]
Objet?: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

Jim, are these 50 cycle ?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Thursday, May 30, 2024 11:18 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

John

There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.

?

STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:

2 1/2 inch by 2 9/16 mounting hole spacing

325 - 0 - 325 volts @ 150mA

5 volts @ 3 amps

6.3 volts @ 5 amps

?

THORDARSON? model 22R05

2 1/2 inch by 3 1/8 inch mounting hole spacing

300 - 0 - 300 volts @ 120 mA

5 volts @ 3 amps

6,3 volts @ 5 amps

?

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.

PAECO model 910-94

2,5 inch by 2.34 inch mounting hole spacing

315 - 0 - 315 volts @ 125 mA

5 volts @ 2 amps

6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.

This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

?

Regards,

Jim

?

?

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

?

?

On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:

?

?

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?

372DX.pdf
372DX.pdf

Re: Halicrafters SX17 transformer

 

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Jim, are these 50 cycle ?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Thursday, May 30, 2024 11:18 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Halicrafters SX17 transformer

?

John

There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.

?

STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:

2 1/2 inch by 2 9/16 mounting hole spacing

325 - 0 - 325 volts @ 150mA

5 volts @ 3 amps

6.3 volts @ 5 amps

?

THORDARSON? model 22R05

2 1/2 inch by 3 1/8 inch mounting hole spacing

300 - 0 - 300 volts @ 120 mA

5 volts @ 3 amps

6,3 volts @ 5 amps

?

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.

PAECO model 910-94

2,5 inch by 2.34 inch mounting hole spacing

315 - 0 - 315 volts @ 125 mA

5 volts @ 2 amps

6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.

This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

?

Regards,

Jim

?

?

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

?

?

On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:

?

?

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?

_._,_._,_


--
don??? va3drl
Re: Halicrafters SX17 transformer

 

John
There are various catalogs from replacement transformer manufacturers, I looked at STANCOR and THORDARSON, for example.? There are others.? I have not looked at my junque box so there are still other possibilities.
?
STANCOR? model PC8420 / PM8420 (same transformer, different mounting) has the following specs:
2 1/2 inch by 2 9/16 mounting hole spacing
325 - 0 - 325 volts @ 150mA
5 volts @ 3 amps
6.3 volts @ 5 amps

THORDARSON? model 22R05
2 1/2 inch by 3 1/8 inch mounting hole spacing
300 - 0 - 300 volts @ 120 mA
5 volts @ 3 amps
6,3 volts @ 5 amps

Another transformer of interest is the one found in the Hewlett-Packard 200CD audio oscillator.? This might be available either locally to you or on eBay?? It has 115 - 230 volt split primary windings which is a plus.
PAECO model 910-94
2,5 inch by 2.34 inch mounting hole spacing
315 - 0 - 315 volts @ 125 mA
5 volts @ 2 amps
6.3 volts @ 3.55 amps.? It should do 4 amps with no trouble.
This is an over designed power transformer with very conservative ratings so it should fit the bill but it's mounting is upright not horizontal like that in the SX-17.? It also contains a 8H @ 125 mA filter choke.? The manual is available on-line, with photos.? I have a history with this transformer.

Regards,
Jim


Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Thursday, May 30, 2024 at 05:28:29 AM CDT, John via groups.io <siloam@...> wrote:


I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?
Re: Halicrafters SX17 transformer

 

I completely forgot about noting the current on the low voltage windings! I added up the heater currents and arrived at the same 3.9A that you did. In addition to this, according to the data-sheet, the heater for the rectifier on the 5V winding takes 3A.

For the exercise, I also tried calculating the valve currents according to the cathode voltage and the cathode resistor. I did struggle to understand how to apply that for the 6R7 and the 6J5, but was able to do calculations for some of the other valves. The meter amplifier valve also puzzled me since the 95ohm resistor and 10V cathode voltage would suggest 100mA or thereabouts, but the data-sheet states that the maximum running current for the 6J7G is 2mA, so that didn¡¯t make sense. For those that I was unsure of, I just used the value from data-sheet and arrived at somewhere around 150mA which is in a similar ball-park, although in all probability there are errors in my calculations. The values for first two 6K7¡¯s were also curious as they come to approximately 12mA (8/700) which is more than the 10mA shown on the data-sheet. There is, of course, R1, the RF gain control in series, but one would presumably have to assume the highest case at minimum setting? It would seem that the valves can be pushed pretty hard at that setting.

I struggled a bit with the transformer screw positions but they seem to be placed 100mm (4 inches) apart on the long side and 77mm (3 inches) apart on the short side. Removing the transformer would allow me to make more precise measurements, but that will have to wait for another day or two until I am feeling well enough. I came down with some kind of bug a coulple of days ago.

Anyway, thank you for your help and for taking the time and trouble to confirm the calculations.

As a matter of curiosity, what catalog are you looking at please?
Re: Halicrafters SX17 transformer

 

John
Cathode current flows through the cathode resistor developing the cathode voltage.? Knowing any two one can calculate the third using Ohm's Law.

Using the maximum plate / screen grid currents from the tube manual I find the same 120mA that you report.

Using the cathode voltage and cathode resistor combinations I calculate about 100mA.? This might be a bit high since I substituted tube manual plate current for those tubes that have a grounded cathode.? So the actual plate current is most likely between these two limits.

Summing all of the heater currents, I calculate 3.9 amps.? Need a 4 amp rating or better for the heater winding.

Using 300 volts @ 120 mA for the plate winding, I found three power transformers in the various catalogs.? Using the lower plate current should allow a few more candidates.??

Still need to know the hole spacing for mounting the power transformer to the chassis.
Regards,
Jim



Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Wednesday, May 29, 2024 at 01:25:02 PM CDT, John via groups.io <siloam@...> wrote:


Thank you for sharing the images.?

I have been looking at the table in the manual and diagram as well as valve data sheets to determine the spec of the transformer. The rectifier is connected to its own heater winding and its heater operates at 5vac. The remaining heaters operate at 6.3vac. Finally, the anode voltage at the 6V6 is stated as 300Vdc. Most of the remaining valve anodes are driven via limiting resistors at 260V which is curious given that the datasheet states the maximum operating voltage is 250V, although there is a 10% leeway. In any case.

The three secondaries must therefore be rated at 5Vac, 6.3Vac and 300Vac RMS.

I also looked at the maximum permitted anode current of each valve and added them all up together. It comes to 144mA. The rectifier is rated at 225mA, so that would seem to be well within its capability, assuming all valves were driven at their full current potential, which I dare say, they are probably not.

Rounding up a little for simplicity, 300V x 0.150A = 45W. One also has to allow a bit for lamps etc.

I am not sure how the cathode voltage factors into the calculation of the current each valve is drawing, and have been looking at some valve reference books to understand, but so far have failed to understand. perhaps someone could kindly enlighten me, then I might be a able to arrive at a more accurate calculation.

Thank you for all the feedback and comments so far. They have been very helpful.
Re: Halicrafters SX17 transformer

 

Thank you for sharing the images.?

I have been looking at the table in the manual and diagram as well as valve data sheets to determine the spec of the transformer. The rectifier is connected to its own heater winding and its heater operates at 5vac. The remaining heaters operate at 6.3vac. Finally, the anode voltage at the 6V6 is stated as 300Vdc. Most of the remaining valve anodes are driven via limiting resistors at 260V which is curious given that the datasheet states the maximum operating voltage is 250V, although there is a 10% leeway. In any case.

The three secondaries must therefore be rated at 5Vac, 6.3Vac and 300Vac RMS.

I also looked at the maximum permitted anode current of each valve and added them all up together. It comes to 144mA. The rectifier is rated at 225mA, so that would seem to be well within its capability, assuming all valves were driven at their full current potential, which I dare say, they are probably not.

Rounding up a little for simplicity, 300V x 0.150A = 45W. One also has to allow a bit for lamps etc.

I am not sure how the cathode voltage factors into the calculation of the current each valve is drawing, and have been looking at some valve reference books to understand, but so far have failed to understand. perhaps someone could kindly enlighten me, then I might be a able to arrive at a more accurate calculation.

Thank you for all the feedback and comments so far. They have been very helpful.
Re: Radiotron Designer's Handbook that is searchable using keywords

 

Here is the history of all printings of the RDH, the 1st edition is listed as being published in 1934.

Clicking on the "HOME" button takes one to a slew of vintage Australian radio and radar equipment.
Regards,
Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Wednesday, May 29, 2024 at 12:24:47 AM CDT, Jim Whartenby <old_radio@...> wrote:


Richard
You are most welcome.
Now for your viewing pleasure is a PDF copy of RDH 1st Edition, circa 1932, all 47 pages!

Regards,
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Tuesday, May 28, 2024 at 10:51:22 PM CDT, Richard Knoppow <1oldlens1@...> wrote:


Thank you for the link. This is an absolutely phenomenal book,
there will never be another like it. I am not sure how many editions it
went to, the later ones with supplements.
I bought one when they first came out and used it until it fell
apart. Of course, I have another hard copy and also a copy of the
Australian original. FWIW, there is nothing in the original that is not
in the American edition and the printing is no better, RCA did a very
good job on the U.S. edition. For those who wonder there was never a
dust jacket, the book came with a plain brown butcher paper wrapper.
Worldradiohistory.com is also a phenomenal site, easy to get lost in.


On 5/28/2024 6:09 PM, Jim Whartenby via groups.io wrote:
The following link will get you a searchable PDF copy that is "only"
36MB and includes the supplement, after the index.
<>
The big problem with this book is that there is just so much information
packed between the covers, it is hard to find helpful information in a
timely manner.? Like any good book, it turns into a time machine!? Now
searching for a keyword returns lots of hits which should make searching
for specific information so much easier.
Enjoy,
Jim
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Radiotron Designer's Handbook that is searchable using keywords

 

Richard
You are most welcome.
Now for your viewing pleasure is a PDF copy of RDH 1st Edition, circa 1932, all 47 pages!

Regards,
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy


On Tuesday, May 28, 2024 at 10:51:22 PM CDT, Richard Knoppow <1oldlens1@...> wrote:


Thank you for the link. This is an absolutely phenomenal book,
there will never be another like it. I am not sure how many editions it
went to, the later ones with supplements.
I bought one when they first came out and used it until it fell
apart. Of course, I have another hard copy and also a copy of the
Australian original. FWIW, there is nothing in the original that is not
in the American edition and the printing is no better, RCA did a very
good job on the U.S. edition. For those who wonder there was never a
dust jacket, the book came with a plain brown butcher paper wrapper.
Worldradiohistory.com is also a phenomenal site, easy to get lost in.


On 5/28/2024 6:09 PM, Jim Whartenby via groups.io wrote:
The following link will get you a searchable PDF copy that is "only"
36MB and includes the supplement, after the index.
<>
The big problem with this book is that there is just so much information
packed between the covers, it is hard to find helpful information in a
timely manner.? Like any good book, it turns into a time machine!? Now
searching for a keyword returns lots of hits which should make searching
for specific information so much easier.
Enjoy,
Jim
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Radiotron Designer's Handbook that is searchable using keywords

 

Thank you for the link. This is an absolutely phenomenal book,
there will never be another like it. I am not sure how many editions it
went to, the later ones with supplements.
I bought one when they first came out and used it until it fell
apart. Of course, I have another hard copy and also a copy of the
Australian original. FWIW, there is nothing in the original that is not
in the American edition and the printing is no better, RCA did a very
good job on the U.S. edition. For those who wonder there was never a
dust jacket, the book came with a plain brown butcher paper wrapper.
Worldradiohistory.com is also a phenomenal site, easy to get lost in.


On 5/28/2024 6:09 PM, Jim Whartenby via groups.io wrote:
The following link will get you a searchable PDF copy that is "only"
36MB and includes the supplement, after the index.
<>
The big problem with this book is that there is just so much information
packed between the covers, it is hard to find helpful information in a
timely manner.? Like any good book, it turns into a time machine!? Now
searching for a keyword returns lots of hits which should make searching
for specific information so much easier.
Enjoy,
Jim
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
Radiotron Designer's Handbook that is searchable using keywords

 

The following link will get you a searchable PDF copy that is "only" 36MB and includes the supplement, after the index.

The big problem with this book is that there is just so much information packed between the covers, it is hard to find helpful information in a timely manner.? Like any good book, it turns into a time machine!? Now searching for a keyword returns lots of hits which should make searching for specific information so much easier.
Enjoy,
Jim
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