I ordered 5 bluetooth boards from PCBWAY on Monday and they arrived on Friday of the same week( I live in Iowa, USA). The quality of the boards is impressive. I'm bummed that I didn't order 10.
Thank you , this is a good blue tooth receiver. I have made it and installed on 4 German radios . With a mirco switch for the power on . Would like to improve this using the magic eye voltage .
very good explanation and straightforward approach to explain possible problems. I had two times problems with interference between Bluetooth module type M18 and the preamp 4558, the solution was to put the module about 10cm away from this pcb!
I'm keeping everything crossed that I can use the forthcoming switch module with your v2 Bluetooth board of which I have several already built up. It'll solve a problem as the Saba Freudenstadt 9 I've just done has no spare contacts for supply switching on the PU switch and I don't want to do a hardware modification to add a microswitch as I want to keep this radio as original as possible. Thanks for sharing these projects. 🙏
Done a similar thing to an old Phillips AM radio. However, I went with a 5v relay that is powered from the heater voltage, which then switched a 5v phone charger that made the isolated power for the Bluetooth module. Didn't want to switch 220vac and the audio on the same tumbler. I was worried about both crosstalk and safety of the radio in case I shorted something. No opamp used as it was a ECH-81 superhet (was redone to more modern tubes) and the output level was enough for loud speaker sound. Actually a great rework since it got signals from north Africa with just a wire. Video is on my channel.
In my tube radio project I have sacrificed the "local/distant station" option and use its switch to supply 5 v to the Bluetooth module, while in transistor radio use a pair of contacts of the fm switch to the antenna socket. Just surgery.
You can use an opto-coupler or a hall effect sensor instead of the relay. Opto-coupler, if there‘s a switchable voltage, hall effect sensor, if not. The latter solution ist a mechanical one using a magnet.
I wonder if someone could take a vintage tube TV/radio and add a daughter board and a duplicate audio section with an extra speaker and decode and play stereo audio. You'd have to capture the audio signal, decode the channels it and send one channel to the existing audio circuit and the other channel to the extra audio circuit and speaker.
@@electronicsoldandnew with newer mobile phones you can have two or more bluetooth devices, so all you need is the two Sabas. Small matter! Now two Freiburgs, that would be something...
@@electronicsoldandnew Not too long ago, these could be had for peanuts. Then came the internet "cult" craze for Saba drivers and now even gutted Freiburgs cost an arm and a leg.
Great made. What if the fillament is not connected to ground? There is a way to use a DC to DC converter that has 2x9V but I think it is overkill. Keep up the great videos.
Hi, nice video, well done as always. Just wondering since you've gone to the trouble (correctly) of the DC/DC converter why have you left the chassis ground of the split rail power supply as is ? Surely there is room for a ground loop between the audio ground and that ground ? Options could have been a single rail op amp(s) or a DC to split rail DC converter ? Just saying..
The ground of the opamp supply is effectively provided by the ground connection of the audio connection to the radio. This was the quietest solution I was able to find after numerous attempts. I needed a split supply and did not want to use a doubler to get a higher DC voltage to use a single supply opamp configuration, so I ended up with this solution.
its been a while since i used PCB Way, but there should be a way to select cheaper shipping options at checkout. Otherwise I would download the gerbers and use JLC PCB. Should be able to get 5 boards for $2 plus $1.50 shipping for the cheapest/slowest option.
I ordered several boards and paid $10.55 for shipping to New York. Before you hit the purchase button there are shipping options. The least expensive is USPS. It is a bit slow, one week or so, but it works.
Hi Manuel, did you use C0G caps for the decoupling capacitors? Just wondering as I currently have only X7R 104’s in stock and I’m concerned about the piezoelectric effect
interesting you don't seem to have a connection between the isolated 0V and Aground. I can't find a description of the chip only the module, but doing this could cause the chip problems as the digital side of the chip's ground is isolated from the analogue ground side. so it's a bit like trying to pass a signal between a source and an amplifier with only one wire. Normally you would sort out this issue with a star ground so the digital and analogue grounds are separated right up to the last minute. so currents flowing in the digital ground are not superimposed on the analogue ground. they same way that you do with A2D's Ref-grounds, they need to be connected to work but you connected them in away to reduce or eliminate digital ground noise. i suppose the other way is to use a 1:1 isolation transformer on the audio but they are not as cheap. Anyway thanks for giving me something to think about on a Sunday morning. I'm looking for a nice Bluetooth module to go the other way. which is much harder to do as a standalone module. I want to take an audio source and connected it to a Bluetooth headset, but how you get the headset to connect to a module without handshaking controlled by the user?
The isolated 0V is connected internally to the AGND at the module output. Internally it has the separation of the analogue and digital grounds, so the ground reference is achieved with no noise. I tried numerous grounding schemes before this one and they simply did not work. The noise was a constant issue until this version finally resulted in noise-free audio.
@@electronicsoldandnew you might get less noise if you cut the connection between the Aground and 0V on the module and reconnect them at the point where you connect the ground to the radio. this will give the best noise performance you could expect. Moving the star ground right up to the last point possible. if the module was done correctly they would have separated them on the PC and told the user how to connect them correctly. the way they have done it only breaks the paths the last inch or so. not much point in that if the ground from the board to 6" or more long.
These modules come with zero info 😊 Fortunately the noise is not at all audible as it is right now. The noise pickup on FM is there regardless of whether the module is connected to the radio or not. I experimented with an externally powered module (not at all connected to the radio) and got the same result.
@@electronicsoldandnew in all my years of integrating audio systems into aircraft, ground loops and noise were a real pain. trying to find a ground for your audio that was not going up and down due to currents flowing from other high power controls was like looking for unicorn poo. Made even worse as controls moved away from hydraulically powered to electrically powered. Now there are vast amounts of current flowing in the airframe, which makes it hard to find a stable ground. We started to use fibre optics to stop radiated signals from our systems, but it also meant that we had local grounds that were isolated. so no ground currents causing us more noise issues. Now i just sit back and play TH-cam much less stress. 🙂
I can imagine the headaches trying to find loops in a plane. Not exactly something you can ignore and hope for the best 😊 You’re right: TH-cam is a lot simpler 😊 For me, it serves as a platform to learn constantly. I remember our Dean saying on the first day of university, that we’d leave that institution knowing quite little, but being experts at learning. Nearly 40 years later, experience has taught me that he really got that right 😊
Very good, like the use of the Recom for isolation (been using them for years). My daughter's got one of these in his bedroom (24:09), great to see a channel supporting all gender types.
BTW Mr Caldeira is the main reason why I ve gone back to this hobby after 45 years messing around with digital and software. Thanks !
I ordered 5 bluetooth boards from PCBWAY on Monday and they arrived on Friday of the same week( I live in Iowa, USA). The quality of the boards is impressive. I'm bummed that I didn't order 10.
👍
Thank you , this is a good blue tooth receiver. I have made it and installed on 4 German radios . With a mirco switch for the power on . Would like to improve this using the magic eye voltage .
👍
very good explanation and straightforward approach to explain possible problems. I had two times problems with interference between Bluetooth module type M18 and the preamp 4558, the solution was to put the module about 10cm away from this pcb!
I went through all those issues 😊 this solution works for me. I’ve used it in over 20 radios.
I'm keeping everything crossed that I can use the forthcoming switch module with your v2 Bluetooth board of which I have several already built up. It'll solve a problem as the Saba Freudenstadt 9 I've just done has no spare contacts for supply switching on the PU switch and I don't want to do a hardware modification to add a microswitch as I want to keep this radio as original as possible. Thanks for sharing these projects. 🙏
The add-on PCB will simply act on the incoming 6.3VAC so the previous boards should work just fine.
Done a similar thing to an old Phillips AM radio. However, I went with a 5v relay that is powered from the heater voltage, which then switched a 5v phone charger that made the isolated power for the Bluetooth module. Didn't want to switch 220vac and the audio on the same tumbler. I was worried about both crosstalk and safety of the radio in case I shorted something. No opamp used as it was a ECH-81 superhet (was redone to more modern tubes) and the output level was enough for loud speaker sound. Actually a great rework since it got signals from north Africa with just a wire.
Video is on my channel.
👍 will look at the video
Wow great episode. That board came out beautiful !!! Love those isolated power modules. I have used them myself. Great for lots of things...
Indeed 👍
In my tube radio project I have sacrificed the "local/distant station" option and use its switch to supply 5 v to the Bluetooth module, while in transistor radio use a pair of contacts of the fm switch to the antenna socket. Just surgery.
👍
You can use an opto-coupler or a hall effect sensor instead of the relay. Opto-coupler, if there‘s a switchable voltage, hall effect sensor, if not. The latter solution ist a mechanical one using a magnet.
Tried a few options, even a trial. The issue is switching AC voltage.
I wonder if someone could take a vintage tube TV/radio and add a daughter board and a duplicate audio section with an extra speaker and decode and play stereo audio. You'd have to capture the audio signal, decode the channels it and send one channel to the existing audio circuit and the other channel to the extra audio circuit and speaker.
You can get two identical Sabas and using these modules you can make a great stereophonic system!
Well, one can dream!
😊 one can
@@electronicsoldandnew with newer mobile phones you can have two or more bluetooth devices, so all you need is the two Sabas. Small matter!
Now two Freiburgs, that would be something...
Two Freiburgs … I’m dreaming already 😊
@@electronicsoldandnew Not too long ago, these could be had for peanuts. Then came the internet "cult" craze for Saba drivers and now even gutted Freiburgs cost an arm and a leg.
True. They’re being gutted for the speakers.
Great made. What if the fillament is not connected to ground? There is a way to use a DC to DC converter that has 2x9V but I think it is overkill. Keep up the great videos.
I’ll be doing a video soon to cover those situations. Should be a small adjustment.
Newbie here is there circuit for ac/dc radio? That's what we have in the States mostly, great educational videos!
I think I’ll make a video soon specifically for the ac/dc radios. Won’t take too much adaptation as the boards will probably work.
Hi, nice video, well done as always. Just wondering since you've gone to the trouble (correctly) of the DC/DC converter why have you left the chassis ground of the split rail power supply as is ? Surely there is room for a ground loop between the audio ground and that ground ? Options could have been a single rail op amp(s) or a DC to split rail DC converter ? Just saying..
The ground of the opamp supply is effectively provided by the ground connection of the audio connection to the radio. This was the quietest solution I was able to find after numerous attempts. I needed a split supply and did not want to use a doubler to get a higher DC voltage to use a single supply opamp configuration, so I ended up with this solution.
@@electronicsoldandnew anything that works is good enough for me. keep up the good work
👍
Any chance you could walk us through the ordering process to get the circuit boards? I can't seem to get it to work.
Thanks
There’s a link in the video description that says “PCBWay share”. Just click on that and you’ll get to the PCBWay page where you just add to cart.
Love the board. But $26 shipping for 5 boards in the US is nuts!
its been a while since i used PCB Way, but there should be a way to select cheaper shipping options at checkout. Otherwise I would download the gerbers and use JLC PCB. Should be able to get 5 boards for $2 plus $1.50 shipping for the cheapest/slowest option.
There are various shipping options. I normally use the fastest, but that’s my personal choice.
I ordered several boards and paid $10.55 for shipping to New York. Before you hit the purchase button there are shipping options. The least expensive is USPS. It is a bit slow, one week or so, but it works.
Thank you.
Pleasure
Hi Manuel, did you use C0G caps for the decoupling capacitors? Just wondering as I currently have only X7R 104’s in stock and I’m concerned about the piezoelectric effect
No, I used normal ceramics.
interesting you don't seem to have a connection between the isolated 0V and Aground. I can't find a description of the chip only the module, but doing this could cause the chip problems as the digital side of the chip's ground is isolated from the analogue ground side. so it's a bit like trying to pass a signal between a source and an amplifier with only one wire.
Normally you would sort out this issue with a star ground so the digital and analogue grounds are separated right up to the last minute. so currents flowing in the digital ground are not superimposed on the analogue ground. they same way that you do with A2D's Ref-grounds, they need to be connected to work but you connected them in away to reduce or eliminate digital ground noise.
i suppose the other way is to use a 1:1 isolation transformer on the audio but they are not as cheap.
Anyway thanks for giving me something to think about on a Sunday morning.
I'm looking for a nice Bluetooth module to go the other way. which is much harder to do as a standalone module. I want to take an audio source and connected it to a Bluetooth headset, but how you get the headset to connect to a module without handshaking controlled by the user?
The isolated 0V is connected internally to the AGND at the module output. Internally it has the separation of the analogue and digital grounds, so the ground reference is achieved with no noise. I tried numerous grounding schemes before this one and they simply did not work. The noise was a constant issue until this version finally resulted in noise-free audio.
@@electronicsoldandnew you might get less noise if you cut the connection between the Aground and 0V on the module and reconnect them at the point where you connect the ground to the radio. this will give the best noise performance you could expect. Moving the star ground right up to the last point possible.
if the module was done correctly they would have separated them on the PC and told the user how to connect them correctly. the way they have done it only breaks the paths the last inch or so. not much point in that if the ground from the board to 6" or more long.
These modules come with zero info 😊
Fortunately the noise is not at all audible as it is right now. The noise pickup on FM is there regardless of whether the module is connected to the radio or not. I experimented with an externally powered module (not at all connected to the radio) and got the same result.
@@electronicsoldandnew in all my years of integrating audio systems into aircraft, ground loops and noise were a real pain. trying to find a ground for your audio that was not going up and down due to currents flowing from other high power controls was like looking for unicorn poo. Made even worse as controls moved away from hydraulically powered to electrically powered. Now there are vast amounts of current flowing in the airframe, which makes it hard to find a stable ground. We started to use fibre optics to stop radiated signals from our systems, but it also meant that we had local grounds that were isolated. so no ground currents causing us more noise issues.
Now i just sit back and play TH-cam much less stress. 🙂
I can imagine the headaches trying to find loops in a plane. Not exactly something you can ignore and hope for the best 😊 You’re right: TH-cam is a lot simpler 😊 For me, it serves as a platform to learn constantly. I remember our Dean saying on the first day of university, that we’d leave that institution knowing quite little, but being experts at learning. Nearly 40 years later, experience has taught me that he really got that right 😊
Hi there. Do you have a “parts” list for the completion of this mod for the noobs? Thanks
Nope. The video explains it all and the schematic can be downloaded. See the video description
Thanks ❤
Pleasure
Nice 👍🏾
👍
What do you do if you have 6.3 volts AC that it not connect to ground?
Use an external independent supply.
I use a Finder 40.31.8.230.0000 relay Have not had any problems with it so far
A single relay is the way to go, but I wanted to prevent loading of the B+ at the magic eye.
Very good, like the use of the Recom for isolation (been using them for years). My daughter's got one of these in his bedroom (24:09), great to see a channel supporting all gender types.
The channel does, but I’m afraid you heard wrong 😊 possibly an accent issue 😊
I'm wondering whether the 0V 'out' of the B0505 is connected to AGND. It does not say in the schematic, or am I missing something?
It gets connected through the BT module itself.
@@electronicsoldandnew Just to make sure I understand. The 0V Out of the B0505 is connected to the GND terminal on the Bluetooth module?
Internally, yes.
how do i contact you robert
My email is in the “about” page of the channel.
👍
well though out
Thanks
Very good .
Thank you