Hello everyone,
A question on possible Bluetooth input for this model. I do have the companion 2nd channel Box and I am curious about the aux. input as it is a single RCA jack.
Is it possible to get stereo out put using this jack from a bluetooth adapter, or is Mono even a hope? There is a back panel selector switch on the chassis. I am assuming it is expecting a mono audio feed. I am also assuming that the MPX processing will not apply to a line input, but you never know what might be out there to fool this old radio into bluetooth playback in stereo.
thanks for any insight on this!
A question on possible Bluetooth input for this model. I do have the companion 2nd channel Box and I am curious about the aux. input as it is a single RCA jack.
Is it possible to get stereo out put using this jack from a bluetooth adapter, or is Mono even a hope? There is a back panel selector switch on the chassis. I am assuming it is expecting a mono audio feed. I am also assuming that the MPX processing will not apply to a line input, but you never know what might be out there to fool this old radio into bluetooth playback in stereo.
thanks for any insight on this!
Attachments
A Bluetooth adapter would not turn the mono signal into a stereo signal.
What you would need would be a Stereo decoder and then tap off at the appropriate spot in the radio.
The Stereo decoders are available but rare, so you will need to do some digging (typically they are a small solid-state board).
I gave away a Mono tuner and a decoder board that I found online a few years ago, so hopefully you can find one available.
I just searched for "FM Stereo Devoder" on ebay and a few popped up
What you would need would be a Stereo decoder and then tap off at the appropriate spot in the radio.
The Stereo decoders are available but rare, so you will need to do some digging (typically they are a small solid-state board).
I gave away a Mono tuner and a decoder board that I found online a few years ago, so hopefully you can find one available.
I just searched for "FM Stereo Devoder" on ebay and a few popped up
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Thanks HarrY,
I'm still confused. The radio has an mpx stereo option built in, so it does decode FM from the airwaves. what I think i'm looking for is a stereo to mpx encoder. But i don't know yet if the single rca input is even routed through the mpx circuit on the chassis. I doubt it, so maybe I need to find out how and where tap into the circuit and see if I can get the Volume, tone and balance controls to function if I add a dual channel aux RCA input.
i'm looking for a manual / schematic for this model online tonight. Perhaps at that time, i can state my problem a little more intelligently?
I'm still confused. The radio has an mpx stereo option built in, so it does decode FM from the airwaves. what I think i'm looking for is a stereo to mpx encoder. But i don't know yet if the single rca input is even routed through the mpx circuit on the chassis. I doubt it, so maybe I need to find out how and where tap into the circuit and see if I can get the Volume, tone and balance controls to function if I add a dual channel aux RCA input.
i'm looking for a manual / schematic for this model online tonight. Perhaps at that time, i can state my problem a little more intelligently?
The usual situation for jacks labeled "mplx" or "mpx" is that they're a wideband output from the detector, intended to be fed to a separate multiplex adaptor, once the FCC had settled on one of the proposed formats. At the time, public demand for stereo was rabid, but competing potential formats delayed the choice. "Format wars" were not possible because only one could be adopted.
Also, if your radio only has one speaker it just can't play in stereo. No biggie, Back to Mono! You can, however, simply "Y" the stereo outputs of your BlueTooth box into a mono input jack, and it'll work just fine.
All good fortune,
Chris
Also, if your radio only has one speaker it just can't play in stereo. No biggie, Back to Mono! You can, however, simply "Y" the stereo outputs of your BlueTooth box into a mono input jack, and it'll work just fine.
All good fortune,
Chris
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Thanks Chris and again to HarryY,,
To clarify, this unit does indeed have the companion 2nd channel add on. So I see the easy path to mono aux. input, For the sake of illustration let's call it the left channel input for now. But i'm looking to tap into the circuit (please see attached diagram). my question....is the MX output jack something I could splice into via toggle switch to capture the remaining right channel. It doesn't appear to me to be doable.
Alternately is there an fm stereo encoder circuit or box that would broadcast that rca input on a preset frequency. Much like the old portable CD to car radio adapters of yeaster year?
I might have answered my own question with that last ponderance?!?!
To clarify, this unit does indeed have the companion 2nd channel add on. So I see the easy path to mono aux. input, For the sake of illustration let's call it the left channel input for now. But i'm looking to tap into the circuit (please see attached diagram). my question....is the MX output jack something I could splice into via toggle switch to capture the remaining right channel. It doesn't appear to me to be doable.
Alternately is there an fm stereo encoder circuit or box that would broadcast that rca input on a preset frequency. Much like the old portable CD to car radio adapters of yeaster year?
I might have answered my own question with that last ponderance?!?!
Attachments
Can't see the jacks, but looks like the companion contains a multiplex decoder and another channel of audio amp plus speaker. If so, you would feed from mplx output on the radio to a mplx in on the companion, then send one decoded channel back to the radio's aux input. Separate volume controls for each channel.
All good fortune,
Chris
All good fortune,
Chris
Chris,
Thanks again for your time and input. I do not have these units in house at the moment, they are in route. But as soon as they get here, Ill have a better idea on the channel hookup and more clarity on the input output options. Attached are 2 views of just the Tuner unit. That's all I have until it arrives here.
Im still "Bird-doging" documentation on the complete set.
Thanks again for your time and input. I do not have these units in house at the moment, they are in route. But as soon as they get here, Ill have a better idea on the channel hookup and more clarity on the input output options. Attached are 2 views of just the Tuner unit. That's all I have until it arrives here.
Im still "Bird-doging" documentation on the complete set.
Attachments
I have the schematics, email tbavis(at)rochester(dot)rr(dot)com. A Bluetooth receiver could be installed in the FM multiplex adapter unit, since both channels are there, but a switch would be needed before the dual volume control. The AUX input on the main unit is mono only, and the separated channels are only present in the stereo adapter.
Thanks Tom,
That would be fantastic! I'll get an email out to you right away with the subject Heathkit Schematic. This looks to hold promise of a more elegant solution! I love doing minimal mods to vintage audio gear. Long lasting irreversible hacks are not my go to style.
_mike
That would be fantastic! I'll get an email out to you right away with the subject Heathkit Schematic. This looks to hold promise of a more elegant solution! I love doing minimal mods to vintage audio gear. Long lasting irreversible hacks are not my go to style.
_mike