thanks,
Wade
If the mixer is where things go haywire, maybe the oscilator isn't running?
Doug
:I need a schematic for an rca 5c581 clock radio. I've got the clock running, but no audio from the radio. Chasis number is RC 1148a. I've been able to inject signals into a few places, and I just can't seem to get anything through the oscillator. I'd like to have a diagram before I proceed. I'll gladly answer any questions you may have.
:
:thanks,
:
:Wade
There is a schematic for the RCA RC-1148A on the TechPreservation site at:
http://techpreservation.dyndns.org/schematics/RCA.htm
The file is in Lizard Tech djvu format so you will need the djvu browser dropin or the djvu standalone program to view and print. The program(s) can be found on that site.
Radiodoc
**************
:I need a schematic for an rca 5c581 clock radio. I've got the clock running, but no audio from the radio. Chasis number is RC 1148a. I've been able to inject signals into a few places, and I just can't seem to get anything through the oscillator. I'd like to have a diagram before I proceed. I'll gladly answer any questions you may have.
:
:thanks,
:
:Wade
it's and aa5. Tube lineup is as follows:
50c5,35w4, 12av6, 12ba6, 12be6.
Thanks for the link, Doc. I have recapped this feller already, and just neglected to remember I still had to tackle a couplate component. I guess since I didn't know its contents, it was very much 'out of sight out of mind'. Now seeing it on the schematic, it is obvious that all reception would be cut out by a failure one of these, while audio could still be injected. I have some breadboard here, so I'll make up a replacement and let you folks know how that pans out...
thanks,
Wade
:Wade,
:
:There is a schematic for the RCA RC-1148A on the TechPreservation site at:
:
:http://techpreservation.dyndns.org/schematics/RCA.htm
:
:The file is in Lizard Tech djvu format so you will need the djvu browser dropin or the djvu standalone program to view and print. The program(s) can be found on that site.
:
:Radiodoc
:**************
:
:
::I need a schematic for an rca 5c581 clock radio. I've got the clock running, but no audio from the radio. Chasis number is RC 1148a. I've been able to inject signals into a few places, and I just can't seem to get anything through the oscillator. I'd like to have a diagram before I proceed. I'll gladly answer any questions you may have.
::
::thanks,
::
::Wade
thanks,
Wade
:
:thanks,
:Wade
Wade:
Try the old "second radio oscillator" check. Get an known working radio, and tune it to a "dead" spot at the high end of the dial, say above 1000 kHz. Place the RCA nearby, and tune it across the low end of the band. If the oscillator is working, you should hear a sound as you tune the RCA 455 kHz. below the frequency the good radio is tuned.
Lewis
::
::thanks,
::Wade
If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
Lewis
:
:
:Wade:
:Try the old "second radio oscillator" check. Get an known working radio, and tune it to a "dead" spot at the high end of the dial, say above 1000 kHz. Place the RCA nearby, and tune it across the low end of the band. If the oscillator is working, you should hear a sound as you tune the RCA 455 kHz. below the frequency the good radio is tuned.
:Lewis
:If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
:Lewis
::
:
Lewis
:D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
:
::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
::Lewis
:::
::
:Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
:Lewis
:
:
::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
::
:::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
:::Lewis
::::
:::
Lewis
Well, just got your message and checked out the ferrite-solid as far as I can tell, no breaks, wobbles or cracks so it looks perfectly healthy to me. I hooked up another cheapo loop antenna from another AA5 radio and it picks up 3 strong stations (about what most of my other simple radios pick up. However, I hear next to no static when tuning across the band-it is more or less silent until I hit on a station.
:
::Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
::Lewis
::
::
:::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
:::
::::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
::::Lewis
:::::
::::
Wade
There is a trimmer screw across the large plates of the tuning capacitor. With the original antenna in place, try adjusting that screw when tuned to whatever station you can find. See what happens.
:Lewis
:
:
:
:
:
:Well, just got your message and checked out the ferrite-solid as far as I can tell, no breaks, wobbles or cracks so it looks perfectly healthy to me. I hooked up another cheapo loop antenna from another AA5 radio and it picks up 3 strong stations (about what most of my other simple radios pick up. However, I hear next to no static when tuning across the band-it is more or less silent until I hit on a station.
::
:::Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
:::Lewis
:::
:::
::::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
::::
:::::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
:::::Lewis
::::::
:::::
:
:Wade
:
:There is a trimmer screw across the large plates of the tuning capacitor. With the original antenna in place, try adjusting that screw when tuned to whatever station you can find. See what happens.
::Lewis
::
::
::
::
::
::Well, just got your message and checked out the ferrite-solid as far as I can tell, no breaks, wobbles or cracks so it looks perfectly healthy to me. I hooked up another cheapo loop antenna from another AA5 radio and it picks up 3 strong stations (about what most of my other simple radios pick up. However, I hear next to no static when tuning across the band-it is more or less silent until I hit on a station.
:::
::::Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
::::Lewis
::::
::::
:::::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
:::::
::::::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
::::::Lewis
:::::::
::::::
:
:Wade
:
:There is a trimmer screw across the large plates of the tuning capacitor. With the original antenna in place, try adjusting that screw when tuned to whatever station you can find. See what happens.
::Lewis
::
::
::
::
::
::Well, just got your message and checked out the ferrite-solid as far as I can tell, no breaks, wobbles or cracks so it looks perfectly healthy to me. I hooked up another cheapo loop antenna from another AA5 radio and it picks up 3 strong stations (about what most of my other simple radios pick up. However, I hear next to no static when tuning across the band-it is more or less silent until I hit on a station.
:::
::::Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
::::Lewis
::::
::::
:::::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
:::::
::::::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
::::::Lewis
:::::::
::::::
Let's see if I am in the right ballpark: Does the radio work fine with one antenna, but not with the original? Maybe we're into some really weird stuff like shorted turns in the original ferrite loop, or something really goofy like that.
Lewis
:You mean the antenna trimmer? I did fiddle with that a bit. Turning it fully in and out just caused the signal to fade dramatically, peak signal only being reached from where it was set during the alignment.
::
::Wade
::
::There is a trimmer screw across the large plates of the tuning capacitor. With the original antenna in place, try adjusting that screw when tuned to whatever station you can find. See what happens.
:::Lewis
:::
:::
:::
:::
:::
:::Well, just got your message and checked out the ferrite-solid as far as I can tell, no breaks, wobbles or cracks so it looks perfectly healthy to me. I hooked up another cheapo loop antenna from another AA5 radio and it picks up 3 strong stations (about what most of my other simple radios pick up. However, I hear next to no static when tuning across the band-it is more or less silent until I hit on a station.
::::
:::::Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
:::::Lewis
:::::
:::::
::::::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
::::::
:::::::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
:::::::Lewis
::::::::
:::::::
I'm apt to agree with you on the shorted turns. I've hooked up a number of antennas to it, and all perform much better than the original. I'd happily replace the ferrite unit, but I just don't have anything that would come close to fitting in the tiny cabinet. I do have some magnet wire. Would it be possible to rewind the antenna? Oh, and just to cover everything, I am aware of the fact that these bar antennas have a null zone where you'll pick up nothing until you rotate it in proper line with the transmitting station.
wade
:Wade:
:Let's see if I am in the right ballpark: Does the radio work fine with one antenna, but not with the original? Maybe we're into some really weird stuff like shorted turns in the original ferrite loop, or something really goofy like that.
:Lewis
:
:
:
:
:
:
::You mean the antenna trimmer? I did fiddle with that a bit. Turning it fully in and out just caused the signal to fade dramatically, peak signal only being reached from where it was set during the alignment.
:::
:::Wade
:::
:::There is a trimmer screw across the large plates of the tuning capacitor. With the original antenna in place, try adjusting that screw when tuned to whatever station you can find. See what happens.
::::Lewis
::::
::::
::::
::::
::::
::::Well, just got your message and checked out the ferrite-solid as far as I can tell, no breaks, wobbles or cracks so it looks perfectly healthy to me. I hooked up another cheapo loop antenna from another AA5 radio and it picks up 3 strong stations (about what most of my other simple radios pick up. However, I hear next to no static when tuning across the band-it is more or less silent until I hit on a station.
:::::
::::::Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
::::::Lewis
::::::
::::::
:::::::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
:::::::
::::::::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
::::::::Lewis
:::::::::
::::::::
http://scitoys.com/
They have some loops here that might fit your radio for two bucks.
Lewis
:Lewis,
:
: I'm apt to agree with you on the shorted turns. I've hooked up a number of antennas to it, and all perform much better than the original. I'd happily replace the ferrite unit, but I just don't have anything that would come close to fitting in the tiny cabinet. I do have some magnet wire. Would it be possible to rewind the antenna? Oh, and just to cover everything, I am aware of the fact that these bar antennas have a null zone where you'll pick up nothing until you rotate it in proper line with the transmitting station.
:wade
:
::Wade:
::Let's see if I am in the right ballpark: Does the radio work fine with one antenna, but not with the original? Maybe we're into some really weird stuff like shorted turns in the original ferrite loop, or something really goofy like that.
::Lewis
::
::
::
::
::
::
:::You mean the antenna trimmer? I did fiddle with that a bit. Turning it fully in and out just caused the signal to fade dramatically, peak signal only being reached from where it was set during the alignment.
::::
::::Wade
::::
::::There is a trimmer screw across the large plates of the tuning capacitor. With the original antenna in place, try adjusting that screw when tuned to whatever station you can find. See what happens.
:::::Lewis
:::::
:::::
:::::
:::::
:::::
:::::Well, just got your message and checked out the ferrite-solid as far as I can tell, no breaks, wobbles or cracks so it looks perfectly healthy to me. I hooked up another cheapo loop antenna from another AA5 radio and it picks up 3 strong stations (about what most of my other simple radios pick up. However, I hear next to no static when tuning across the band-it is more or less silent until I hit on a station.
::::::
:::::::Your last post tells me the oscillator is OK (whew) not, it looks like you have antenna troubles. Ferrite loops can break inside the coil, and still look good to an Ohmmeter (been there, done that). Injecting a signal with your finger makes the radio work (hmmmmm, thinking again). OK, see if you can pull the ferrite apart by pulling gently on the ends, and let me know.
:::::::Lewis
:::::::
:::::::
::::::::D'oh lewis, looks like you're right on that one...I have aligned the set, and still could not get any reception...until I put my hand on the antenna-bingo! Perfect reception accurately tracking across the band. I hooked up a loop antenna and got decent reception as well. But the darn original antenna picks up nearly nothing-just one station weakly-a high powered station just a few miles from here. The antenna is a ferrite rod with wire wound around it. Can these go bad? It checks for continuity, so the wire is in one piece...
::::::::
:::::::::If you have audio, the couplate is good. It connects the first and second audio stages, and has nothing to do with the RF.
:::::::::Lewis
::::::::::
:::::::::
If that ferrite rod unit is not working up to spec, don’t hesitate to look into its further evaluation.
Typical units will be using the ~ 7 inch length of rod, but if you are lucky, you might have snagged onto one of the ~10 in long units.
I seem to never have seen any of those units that are not outperforming the common wire wound loop that one finds mounted onto the back cover of a receiver.
The first thing that needs to be checked out is the form that the ant coil is wound upon and just HOW firmly anchored down that coil form is. Typically it is just using a bit of added sealing wax melted onto one end of the form. The logic, being the fact that the final tuning step on AM alignment on the high end of the AM band was the use of the trimmer capacitor on the antenna section of the tuning condenser to peak to optimum reception at ~1600Khz and then the ferrite rods coil form was …ever so slightly..slid up and down the rod length until the RF of a received at ~1400 was peaked up, with that inductive adjustment having then been made, they then sealed that setting.
Now in getting back to the freeing of the coil form from the rod, such that sliding adjustments can be made, I have had some units so tight that heat from a hair dryer was needed, while continually sliding the coil from side to side during cool down was needed, or additionally, the scraping away of excess wax from the rod.
Recently, with the scarcity of finding some of those large rods I have even successfully used some of the shorter 3-4 inch rectangular rod units that are basically oriented in their inductive design value to be used with a solid state receiver. Additionally there is a second few turns winding that is oriented towards the coupling into and low Z-matching into transistor circuitry. That winding was of no concern, and was not used. There was no problem on matching up the proper inductive value with the main / larger winding, since the value/turns on the coil is higher than needed, with the end result being the hooking up of a units coil into circuit and then the slow skirling off-of turns until the unit starts peaking onto a received station in the ~1600-1700 Khz range.
Summation:
Confirm that there is but one winding on the coil, and that is usually in the order of 40-65 turns, in accordance to diameter of the coil form and the characteristics of the ferrite rod.
Initially have the coil wired into the antenna circuit and initially just tune the radio to the high end of the dial and pick up a radio station there, then see if the added capacitance of gripping the coil between a thumb and index / middle finger of a hand either enhances or dampens the reception of that station. If so, the effective inductance of that coil needs shifting. If your thumb nail and your middle fingers nail will span the distance of each end of the coil and be able to grip it, and then slide the coil both directions to see if reception enhancement occurs.(This spaces your fingers from adding stray circuitry capacitance) If improvement occurs when moving the coil towards the center of the rod occurs, it is suggesting that your coil needs more inductance. If improvement occurs when moving the coil form towards the end of the rod or completely off from the rod, it is suggesting the existent coil has too much inductance.
Try out your unit and see what can be determined….and yes, you can totally rewind the coil IF required. As of lately, I have been using insulated wire wrap wire, as I have a large spool of it and a coil usually only takes about 5-6 ft of wire.
Ferrite Rod Antenna:
73's de Edd
