I have the radio mentioned above. I would like to begin working on this unit, since it is non working.
could someone please lead me in the right direction?
Jesse

If it's a four tube portable, it might be a Motorola 5A9B. See the schematic on this site:
http://www.electronix.com/catalog/advanced_search_result.php?keywords=11-75
Good luck

:I have the radio mentioned above. I would like to begin working on this unit, since it is non working.
:could someone please lead me in the right direction?
: Jesse

Below are links to the schematic and replacing capacitors. Richard

http://www.nostalgiaair.org/Resources/114/M0012114.htm
http://antiqueradio.org/recap.htm

:Below are links to the schematic and replacing capacitors. Richard
:
:http://www.nostalgiaair.org/Resources/114/M0012114.htm
:http://antiqueradio.org/recap.htm

The Schematic looks nothing like the circuit board I pulled from the plastic cabinet. Mine is a five tube,
but has no wiring underneath. All is is on a printed circuit board. The tubes are identified underneath the board. Numbers are: 50C5 12BA6 12BE6 12AV6 35W4.

Jesse, I sent you the schematic according to SAMS, Set 492 folder 13.

Bill VA

::Below are links to the schematic and replacing capacitors. Richard
::
::http://www.nostalgiaair.org/Resources/114/M0012114.htm
::http://antiqueradio.org/recap.htm
:
:The Schematic looks nothing like the circuit board I pulled from the plastic cabinet. Mine is a five tube,
:but has no wiring underneath. All is is on a printed circuit board. The tubes are identified underneath the board. Numbers are: 50C5 12BA6 12BE6 12AV6 35W4.

:Jesse, I sent you the schematic according to SAMS, Set 492 folder 13.
:
:Bill VA
:
:
Bill,
Thanks, I guess you can see Im a little green at this so far. But like I said the set up of the schematic is nothing like my radio. Im wondering why I cannot find a schematic on my radio. Mine looks totally different. But can someone clear another issue up? I went to radiodaze.com and found what someone told me I need to work on this unit with, a isolation transformer, which I hope I ordered the correct one, where you plug the radio into it, and plug the transformer in the wall? I was told my radio was a all american 5 tube with a hot chassis, can someone please clear this up?

Jesse, I'm sure radiodaze is selling you an isolation transformer if they said so. As I told you in my email SAMS 492-13 is "similiar", sufficient to work on a Model A9B. If the set you have is not almost entirely like the schematic then it's not for you to use. I really don't understand what you mean by different. You had some symptom of problem before you removed the tubes and board? I would think at the least the filter cap needs replacement. Don't you do any work on this radio with it turn on. Until you get a better understanding of the purpose of isolation transformers don't attempt to use it. Most of the time these types of radios can be fixed with replacement of parts. The radio does not need to be on. And if it needs alignment...well to me they aren't worth the trouble.
Bill VA

::Jesse, I sent you the schematic according to SAMS, Set 492 folder 13.
::
::Bill VA
::
::
:Bill,
: Thanks, I guess you can see Im a little green at this so far. But like I said the set up of the schematic is nothing like my radio. Im wondering why I cannot find a schematic on my radio. Mine looks totally different. But can someone clear another issue up? I went to radiodaze.com and found what someone told me I need to work on this unit with, a isolation transformer, which I hope I ordered the correct one, where you plug the radio into it, and plug the transformer in the wall? I was told my radio was a all american 5 tube with a hot chassis, can someone please clear this up?

Jessie, to answer your question about the "hot chassis" you were told about. Earlier (OLD) radios were made to play on AC/DC as thats what was available in the early days of electrification in this country. If you wanted to sell radios, you made them AC/DC so anywhere in the US they could be pluged in. As a short aside, this is why you will find that the filament voltages add up to approximately 110V (50XX4, 35BB2, and 3 6YY7s). The power cord had one side grounded to the chassis and the other side to the circuit wiring. Plugs were not polarized so depending on how it was plugged in the chassis could be your hot wire relative to ground. If you touched the chssis and, say, your steam radiator you lit up! Under Writers Lab was in it's infancy and since the sets were in wood cases usually with closures to prevent the user from getting at the chassis all was we. How about the hapless repairman? He's got this out of the wood case and on his work bench and if he's not careful he gets hit with 110 Volts. If you use an Isolation transformer regardless of what wire goes to the chassis there is no reference to ground (outlet grd, radiator, water pipe, even earth) The flow of electricity only occures between the two wires of the secondary winding of the transformer. What Bill was saying is if your not knowledgable of the above dangers, you could kill yourself playing around with the radio. Even experienced servicemen and electricians make mistakes that can be fatal. While there are other methods to minimize or even totally remove it, the use of the isolation transformer all the time removes the hazard vis-vis external grounds, if you try you can still get a nasty shock by getting across the secondary wires of the isolation transformer. Hope this explains the "hot chassis" and alerts you to the dangers that a moment of inadvertance can cause. PL

:Jessie, to answer your question about the "hot chassis" you were told about. Earlier (OLD) radios were made to play on AC/DC as thats what was available in the early days of electrification in this country. If you wanted to sell radios, you made them AC/DC so anywhere in the US they could be pluged in. As a short aside, this is why you will find that the filament voltages add up to approximately 110V (50XX4, 35BB2, and 3 6YY7s). The power cord had one side grounded to the chassis and the other side to the circuit wiring. Plugs were not polarized so depending on how it was plugged in the chassis could be your hot wire relative to ground. If you touched the chssis and, say, your steam radiator you lit up! Under Writers Lab was in it's infancy and since the sets were in wood cases usually with closures to prevent the user from getting at the chassis all was we. How about the hapless repairman? He's got this out of the wood case and on his work bench and if he's not careful he gets hit with 110 Volts. If you use an Isolation transformer regardless of what wire goes to the chassis there is no reference to ground (outlet grd, radiator, water pipe, even earth) The flow of electricity only occures between the two wires of the secondary winding of the transformer. What Bill was saying is if your not knowledgable of the above dangers, you could kill yourself playing around with the radio. Even experienced servicemen and electricians make mistakes that can be fatal. While there are other methods to minimize or even totally remove it, the use of the isolation transformer all the time removes the hazard vis-vis external grounds, if you try you can still get a nasty shock by getting across the secondary wires of the isolation transformer. Hope this explains the "hot chassis" and alerts you to the dangers that a moment of inadvertance can cause. PL

:Jesse, I'm sure radiodaze is selling you an isolation transformer if they said so. As I told you in my email SAMS 492-13 is "similiar", sufficient to work on a Model A9B. If the set you have is not almost entirely like the schematic then it's not for you to use. I really don't understand what you mean by different. You had some symptom of problem before you removed the tubes and board? I would think at the least the filter cap needs replacement. Don't you do any work on this radio with it turn on. Until you get a better understanding of the purpose of isolation transformers don't attempt to use it. Most of the time these types of radios can be fixed with replacement of parts. The radio does not need to be on. And if it needs alignment...well to me they aren't worth the trouble.
:Bill VA
: Bill,
The radio in the schematic is a battery operated unit.
It also has the metal chassis with all the caps and such underneath. My radio has a printed circuit board and all caps and such are mounted on the board. Mine has a volume knob, and tuning and thats it. Again thanks for your kind words, I feel as though once I get this one going, I will learn more and more through doing. I had the same feeling about the Isolation transformer. I dont see the purpose in one. Thank you for clearing it up. I would be happy if we could speak off board about this unit. Would love to send you some pics of the board and such so you could see to what I am refering. Thanks again, let me know about what you think from here. Jesse
:
:::Jesse, I sent you the schematic according to SAMS, Set 492 folder 13.
:::
:::Bill VA
:::
:::
::Bill,
:: Thanks, I guess you can see Im a little green at this so far. But like I said the set up of the schematic is nothing like my radio. Im wondering why I cannot find a schematic on my radio. Mine looks totally different. But can someone clear another issue up? I went to radiodaze.com and found what someone told me I need to work on this unit with, a isolation transformer, which I hope I ordered the correct one, where you plug the radio into it, and plug the transformer in the wall? I was told my radio was a all american 5 tube with a hot chassis, can someone please clear this up?

Hi Jesse,
First let me make something very clear about my use of isolation transformers...I use them. There's definitely a purpose for one and that's safety. Planigan has explained that. When it has been determined what parts need replacement you should not have the radio plugged into ANYTHING while you make the changes.

Rick and Richard's help was an attempt to locate a schematic for your radio. Tho it didn't pan out their help is appreciated. That's what this hobby is about. It's a dead issue about the schematic for the 5A9B being different and wrong. Incidentally the 5A9B is actually a 3-power, AC/DC/Battery.

I know of your radio. It is like a trillion others. Well maybe not that many. There is not always an individual schematic for every model. I now have sent you all of SAMS Set 492 Folder 13. As you will see it covers the circuit board, parts layout, parts list, etc. There may be some minor differences. But believe me your radio is in there.

As for as going off the forum you would be the loser in doing that. There's a tremendous group of folks here to help get your radio fixed. I may not be as responsive since I got fishing to do plus getting some good excuses together about why I can't go shopping for Christmas. But there's always someone here who can fill the gap, certainly for me. But here's some things you should do. Post pictures on one of the free host sites. Plenty out there. Since we don't really have input from you on what your radio does or doesn't do, put your tubes in the correct sockets, plug in your isolation transformer, plug the radio into the isolation transformer, turn the radio on. I'm very doubtful you will have a disaster happen to you radio. Pay attention to what it does, e. g., plays with hum, plays with static, no playing, tubes don't light, smokes, sizzling sound, anything. Of course unplug once you feel endangered. The last note from me tonight: These early '60 circuit boards get real brittle with the heat from the tubes. If handled too rough inserting and pulling the tubes or removing to replace parts you can add to your problems. Now come back with your report and let's get this thing fixed. You can learn by doing but hit the books too. Don't be in a rush.

Bill VA

::Jesse, I'm sure radiodaze is selling you an isolation transformer if they said so. As I told you in my email SAMS 492-13 is "similiar", sufficient to work on a Model A9B. If the set you have is not almost entirely like the schematic then it's not for you to use. I really don't understand what you mean by different. You had some symptom of problem before you removed the tubes and board? I would think at the least the filter cap needs replacement. Don't you do any work on this radio with it turn on. Until you get a better understanding of the purpose of isolation transformers don't attempt to use it. Most of the time these types of radios can be fixed with replacement of parts. The radio does not need to be on. And if it needs alignment...well to me they aren't worth the trouble.
::Bill VA
:: Bill,
:The radio in the schematic is a battery operated unit.
:It also has the metal chassis with all the caps and such underneath. My radio has a printed circuit board and all caps and such are mounted on the board. Mine has a volume knob, and tuning and thats it. Again thanks for your kind words, I feel as though once I get this one going, I will learn more and more through doing. I had the same feeling about the Isolation transformer. I dont see the purpose in one. Thank you for clearing it up. I would be happy if we could speak off board about this unit. Would love to send you some pics of the board and such so you could see to what I am refering. Thanks again, let me know about what you think from here. Jesse
::
::::Jesse, I sent you the schematic according to SAMS, Set 492 folder 13.
::::
::::Bill VA
::::
::::
:::Bill,
::: Thanks, I guess you can see Im a little green at this so far. But like I said the set up of the schematic is nothing like my radio. Im wondering why I cannot find a schematic on my radio. Mine looks totally different. But can someone clear another issue up? I went to radiodaze.com and found what someone told me I need to work on this unit with, a isolation transformer, which I hope I ordered the correct one, where you plug the radio into it, and plug the transformer in the wall? I was told my radio was a all american 5 tube with a hot chassis, can someone please clear this up?

:Hi Jesse,
:First let me make something very clear about my use of isolation transformers...I use them. There's definitely a purpose for one and that's safety. Planigan has explained that. When it has been determined what parts need replacement you should not have the radio plugged into ANYTHING while you make the changes.
:
:Rick and Richard's help was an attempt to locate a schematic for your radio. Tho it didn't pan out their help is appreciated. That's what this hobby is about. It's a dead issue about the schematic for the 5A9B being different and wrong. Incidentally the 5A9B is actually a 3-power, AC/DC/Battery.
:
:I know of your radio. It is like a trillion others. Well maybe not that many. There is not always an individual schematic for every model. I now have sent you all of SAMS Set 492 Folder 13. As you will see it covers the circuit board, parts layout, parts list, etc. There may be some minor differences. But believe me your radio is in there.
:
:As for as going off the forum you would be the loser in doing that. There's a tremendous group of folks here to help get your radio fixed. I may not be as responsive since I got fishing to do plus getting some good excuses together about why I can't go shopping for Christmas. But there's always someone here who can fill the gap, certainly for me. But here's some things you should do. Post pictures on one of the free host sites. Plenty out there. Since we don't really have input from you on what your radio does or doesn't do, put your tubes in the correct sockets, plug in your isolation transformer, plug the radio into the isolation transformer, turn the radio on. I'm very doubtful you will have a disaster happen to you radio. Pay attention to what it does, e. g., plays with hum, plays with static, no playing, tubes don't light, smokes, sizzling sound, anything. Of course unplug once you feel endangered. The last note from me tonight: These early '60 circuit boards get real brittle with the heat from the tubes. If handled too rough inserting and pulling the tubes or removing to replace parts you can add to your problems. Now come back with your report and let's get this thing fixed. You can learn by doing but hit the books too. Don't be in a rush.

Bill,
First of all thanks. I also thank everyone who has tried to help on this radio. I have been hitting books, websites, and e.t.c. about this new hobby I have found. I have gotton this in by blood honestly, My uncle owned a TV, Radio repair shop in the late 50s
thru the 70s. God , If I only had access to all the tubes,capacitors, e.t.c. that was trashed when he passed in 76. I will post some pics in some free sites soon.Thanks for the schematic and I will read it,as soon as I can. Now for the fun part, I have pulled some parts from the circuit board, replaced all the capacitors, since from day one 15 years ago this radio never worked. I had to order a 50C5 since this tube was missing, and I am currently looking for the Electrolytic capacitor because Mine is the tin can type with two in one. 50mfd@150 ,30@150. I know I will probably have to use another type. I just have to figure out which is postive and negative on the board,
then put in. I also know that the exact values wont be found, but in anycase I know exactly where all the parts re connect to. I have no paper caps in this radio unlike the one my wife gave to me as a early xmas gift, Zenith 508W. This is a neat looking radio with a metal chassis, looks like a more stable radio,
with the metal chassis. It played with very low volume
I replaced the 50c5 tube in it, the volume is great now, but has a hum, havent recapped it yet, havent had time, but Im not playing it either. Just tinkering.
Thank you all, and bill's correct, lets get my motorola playing.. see yall. Jesse in Lilburn.