Easy Bluetooth to vintage radio.

[Goldieoldie]

Hi Lloyd,
I have used the Bluetooth module used with the early bose speakers ( plugs into the multi pin iPhone plug )
They are easy to break open and have used them successfully in a car radio ( old mw/LW radiomobile )
It does play a short tune when fired up but no speech !
Auto pairing etc
No data noise
About a fiver on eBay
Cheers Pete

[John10b]

I have been reading about Spitfire MW TX. It seems you feed this from Bluetooth device and you can tune into it on the MW band.
No modifications etc are required to the receiver just tune in.
I wonder has any member tried this out, and is it legal?
Cheers
John

[kalee20]

Originally Posted by crackle

Apparently adding bluetooth facility to your vintage radio can increase its value by up to 1000%

What's actually needed, is a Bluetooth receiver module that takes 30mA or so at 5V, and has a logic output that flags when a device is paired and active with it.

Then, we can power the module from the output valve cathode (with a 5.1V Zener diode in parallel to shunt the surplus current), reducing the remaining cathode resistance to still give the correct bias.

The logic output drives a sensitive relay to automatically switch the Bluetooth module output to the volume control, while disconnecting the AM detector from it.

The whole caboodle can be fitted inside the cabinet; there are no wires to come out, so it's applicable for live-chassis radios.

Doing all this, the modification is easily reversible. Radios are preserved, don't end up in landfill or butchered for a couple of parts.

Does such a module exist, or can a cheapo one be modified suitably?

[Stuart R]

The module I mentioned doesn't come with a user manual, but a downloadable data sheet mentions a pin marked "EN" (I forgot about this!)

EN pin is "Bluetooth connection indicator" 3.3V connected, 0V disconnet. Not tested, but that's what the book says.

I've dug out the multimeter and had a measure.

At first power-up, it draws around 27mA. This is running off 3 AAA batteries in series.

Whilst waiting to pair, it pulses between 8 and 15mA.

When paired, current draw rises to 20mA but then settles down to 12mA - but there's a couple of mA flutter indicated on the needle.

When playing tunes into my Hacker Herald - the draw is back at 27mA.

Could be just the thingy you need.

(No connection with the company)

Regards,

SR.

[Lloyd 1985]

I’m liking the sound of this module, I’ll get a couple ordered to play with! I’ll also have a look for one of the ones mentioned by Pete.

I do have one that has its own internal battery, which works very well, only thing is it requires pressing of buttons, and you can’t charge it and use it at the same time, when the charger is connected it shuts off! It’s still being useful plugged into my Sony FH-7 in the workshop

Regards
Lloyd

[Goldieoldie]

Hi Lloyd
It's a while since I designed the circuit but I think I used the drive to the on board led
To switch the radio from AM to the output of the Bluetooth
It flashes slowly when not paired to steady when paired .
I think I used a simple 555 circuit to switch a relay
As usual did not make a sketch of the circuit at the time !
Cheers Pete