Does anyone have any information on this radio, schematic?
Thank you,
Mitch
:
:Does anyone have any information on this radio, schematic?
:
:Thank you,
:
:Mitch
:
http://www.radiomuseum.org/r/rca_superheterodyne_ar812.html
::
::Does anyone have any information on this radio, schematic?
::
::Thank you,
::
::Mitch
::
:http://www.radiomuseum.org/r/rca_superheterodyne_ar812.html
:
This is what i have come up with thus far, it does use #99 tubes, comments welcome.
http://i1178.photobucket.com/albums/x379/wandzel/RCA_AR812_Simplified_Diagram_1926_RN_Superhet_Book.jpg>
Mitch
:::
:::Does anyone have any information on this radio, schematic?
:::
:::Thank you,
:::
:::Mitch
:::
::http://www.radiomuseum.org/r/rca_superheterodyne_ar812.html
::
:
:
:This is what i have come up with thus far, it does use #99 tubes, comments welcome.
:
:
:
:Mitch
:
Richard
:
Richard
I know that the schematic i posted is for this radio, i would appreciate any other information from the forum on it.
Mitch
::
:
:Richard
:
:I know that the schematic i posted is for this radio, i would appreciate any other information from the forum on it.
:
:Mitch
:
Look these sites:
http://www.cfp-radio.com/restaurations/AR812/ar812-01.html
http://www.duanesradios.info/html/rca__ar812_superheterodyne.html
Jules
I have an AR 812.The unit runs on batteries and uses the tubes you mentioned. The fun part about restoring this unit is:
1. The tubes are hard to find and/or very costly
2. The wired portion of this receiver is encased in a tar block
Other than that its a cinch (Ha Ha). Just having fun with you because I have to yet restore MINE.
Lou
I picked up one last year but have yet to really do any research or look it up.
::
:
:Richard
:
:I know that the schematic i posted is for this radio, i would appreciate any other information from the forum on it.
:
:Mitch
:
:
:I have an AR 812.The unit runs on batteries and uses the tubes you mentioned. The fun part about restoring this unit is:
:
:1. The tubes are hard to find and/or very costly
:
:2. The wired portion of this receiver is encased in a tar block
:
:Other than that its a cinch (Ha Ha). Just having fun with you because I have to yet restore MINE.
:
:Lou
:
:I picked up one last year but have yet to really do any research or look it up.
:::
::
::Richard
::
::I know that the schematic i posted is for this radio, i would appreciate any other information from the forum on it.
::
::Mitch
::
:
:
Hello everyone,
Seems that i have read now that the model AR-812 uses the exact catacomb as the model's 24, 26 and the Super VIII Super Heterodynes.
The catacomb in incased in a wax epoxy, it will be much eaiser to clean out than the tar PS's i did on a AK radio.
I am posting another schematic and will follow with the RAC service notes (9 pages) when i get it in a better format.
Responses welcome,
Thank you,
Mitch
There is some good information here:
http://antiqueradios.com/forums/viewtopic.php?f=1&t=170405
Which includes a link to this schematic PDF that looks to be most helpful:
http://radioremembered.org/images/AR812/RCACatacombSch.pdf
Richard
:
:There is some good information here:
:
:http://antiqueradios.com/forums/viewtopic.php?f=1&t=170405
:
:Which includes a link to this schematic PDF that looks to be most helpful:
:
:http://radioremembered.org/images/AR812/RCACatacombSch.pdf
:
:Richard
:
Thank you Richard, that is great information.
Hello again everyone,
I am begining the work on this giant portable radio that weighs at least 60 lbs without batteries, portable.
I have the six tubes that came with this radio, they are UV-199's. The short pins with the locking side pin. I have measured the filament resistances and they range from 4.5 ohms to 7 ohms. My tube tester cannot test these tubes (no socket for them). I could apply a 3 volt battery to the filaments to check the filaments to see if they light up.
Does anyone have any ideas on how to test the grids and plates outside of the radio?
Thank you,
Mitch
:Does anyone have any ideas on how to test the grids and plates outside of the radio?
= = = = =
You should be able to find a data sheet for this tube type. That will give you its transfer function. From that point it's just a matter of making a "test bed" which will allow you to apply the necessary heater and plate voltages, and vary the grid voltages while monitoring plate current. This will give you a general idea as to how functional the tubes are. The "fly in the ointment" is that a given tube can deviate quite a bit from the published transfer function and still be usable. If the tube roughly tracks the transfer function, it will probably work in your radio.
::Does anyone have any ideas on how to test the grids and plates outside of the radio?
:
:= = = = =
:
:You should be able to find a data sheet for this tube type. That will give you its transfer function. From that point it's just a matter of making a "test bed" which will allow you to apply the necessary heater and plate voltages, and vary the grid voltages while monitoring plate current. This will give you a general idea as to how functional the tubes are. The "fly in the ointment" is that a given tube can deviate quite a bit from the published transfer function and still be usable. If the tube roughly tracks the transfer function, it will probably work in your radio.
:
Hello everyone,
I did melt out the electronics of the radio from the resin/wax. I baked it in an oven in my shed for 1.5 hours at 200 degrees. It came out very clean, but i think that the baking contributed to some broken wires on the coils. There were eight broken wires from the coils that had to be reconnected/soldered.
At this point all of the coils measure correct according to the schematics and the diagrams.
It appears that C1 is 185 pf to the first grid, any comments on this value?
It is time to put the electronics unit back into the metal housing, do i need to refill it with wax, can it just go in with a insulated lining of some sort?
I think i have posted the photos properly.
Mitch
::
::I have an AR 812.The unit runs on batteries and uses the tubes you mentioned. The fun part about restoring this unit is:
::
::1. The tubes are hard to find and/or very costly
::
::2. The wired portion of this receiver is encased in a tar block
::
::Other than that its a cinch (Ha Ha). Just having fun with you because I have to yet restore MINE.
::
::Lou
::
::I picked up one last year but have yet to really do any research or look it up.
::::
:::
:::Richard
:::
:::I know that the schematic i posted is for this radio, i would appreciate any other information from the forum on it.
:::
:::Mitch
:::
::
::
:Hello everyone,
:
:Seems that i have read now that the model AR-812 uses the exact catacomb as the model's 24, 26 and the Super VIII Super Heterodynes.
:
:The catacomb in incased in a wax epoxy, it will be much eaiser to clean out than the tar PS's i did on a AK radio.
:
:I am posting another schematic and will follow with the RAC service notes (9 pages) when i get it in a better format.
:
:Responses welcome,
:
:Thank you,
:
:Mitch
:
:
:
Hello everyone,
In final testing of the chassis i find that coil L2, 1st IF, is open. It was 30 ohms. Looking at the schematic the coil has a tickler that goes to a dead end, no connection. It measures 25 ohms. My thought is to use the tickler portion of the coil across C4 in place of the open 30 ohm coil. I will lose the tickler portion.
Does anyone have any comments on this solution, should it work for the radio?
The schematic is posted on this thread.
Mitch
:::
:::I have an AR 812.The unit runs on batteries and uses the tubes you mentioned. The fun part about restoring this unit is:
:::
:::1. The tubes are hard to find and/or very costly
:::
:::2. The wired portion of this receiver is encased in a tar block
:::
:::Other than that its a cinch (Ha Ha). Just having fun with you because I have to yet restore MINE.
:::
:::Lou
:::
:::I picked up one last year but have yet to really do any research or look it up.
:::::
::::
::::Richard
::::
::::I know that the schematic i posted is for this radio, i would appreciate any other information from the forum on it.
::::
::::Mitch
::::
:::
:::
::Hello everyone,
::
::Seems that i have read now that the model AR-812 uses the exact catacomb as the model's 24, 26 and the Super VIII Super Heterodynes.
::
::The catacomb in incased in a wax epoxy, it will be much eaiser to clean out than the tar PS's i did on a AK radio.
::
::I am posting another schematic and will follow with the RAC service notes (9 pages) when i get it in a better format.
::
::Responses welcome,
::
::Thank you,
::
::Mitch
::
::
::
:
:Hello everyone,
:
:In final testing of the chassis i find that coil L2, 1st IF, is open. It was 30 ohms. Looking at the schematic the coil has a tickler that goes to a dead end, no connection. It measures 25 ohms. My thought is to use the tickler portion of the coil across C4 in place of the open 30 ohm coil. I will lose the tickler portion.
:
:Does anyone have any comments on this solution, should it work for the radio?
:
:The schematic is posted on this thread.
:
:Mitch
:
Hello everyone,
I have completed the restoration on this radio and have been listening to it for several nights now.
This RCA model was the first commercially available Super Heterodyne radio sold in the US, it was designed by Anderson/RCA/Westinghouse.
Through your help here and various information from ARF and the Web i have accumulated a treasure of information on the servicing and repair of this radio. I also have a copy of the original RCA service notes for the radio. If anyone is interested in this information i can email it to you.
Baking the wax and removing the chassis was the easiest part of the restoration, the most difficult was soldering the tiny broken wisker wires from the coils. Some capacitors had also seperated and had to be repaired. Coil L2 was a concern but the tickler coil worked just fine as the first IF coil.
If you follow this thread you will see the efforts and understand some of my comments.
The radio is being powered by my ARBE III.
I am posting some final photos, comments/questions welcome and i will share my information with anyone who desires copies of it.
Thank you,
Mitch
