Wow guys I have done it successfully . It's not expensive . All I did was purchase a bluetooth reciever from Jaycar (21 bucks) and rechargeable batteries plus cable, lugs and a 3.5 mm mono plug. It's connected to the phonograph posts in the back and hey presto it works. Now a way of playing your collection of old radio serials with not to much trouble. I did check for high tension on the posts as advised and no worries.

Well that's something I did not think of. For some it may be useful and a good experiment.

The only thing with it is that it is still lower volume than the radio section so I am considering a small preamp to adjust this with but it certainly is good volume and very listenable. I am quite pleasantly surprised with the fidelity. Its very nice indeed.

The small yellow transformer at Jaycar (small speaker transformer) is a 1:1 turns ratio former that couples well to photo inputs, unless the whole idea was to be mobile at the source end.

ps.
I just sacrificed one in the name of Science, and on second thought,
they aren’t the greatest electrical isolator if something went wrong.
There’s absolutely no dielectric between the primary and secondary other than the enamel on the copper wire.
It’s also possible the primary and secondary are wound together turn for turn (hard to tell when you’re just looking at wire), which would explain why it makes a great AC coupling capacitor at MW frequencies when just one leg of each turn is used!

Yeah I want the tablet end mobile so if a fault develops the tablet will be fine. I have seen a small preamplifier kit at Jaycar or would the said transformer work with the Bluetooth.

Unless there's a typo, Art seems to be talking about a transformer with a winding ratio of 1:1 -- in other words voltage in equals voltage out. No step up there. Purely a device to decouple (DC isolate) inputs and outputs.

The transformer wouldn’t help if the RCA outs are too low, it would slightly attenuate signal if anything.
I’ve only used them between the earphone socket on smartphones where the preamp is behind the socket,
and the phono inputs on valve stuff.

Yeah I realise that in retro a bit tired after a 20 hour day

There can be some serious oversights here: I have a Philips here that is back biased and the pickup head floats and is low impedance.

That means that there is a matching circuit & blocking caps to stop it wiping out the backbias.
Some sets require low impedance some high.

Then there is Stereo often going into a Mono radio.

Often missed is isolation, that goes back to backbias and the fact that some Solid State power supplies go crazy if negative, or positive are grounded back to supply in any way.

You may have to step up with a coupling transformer/s, to get the voltage swing for a grid, albeit some feed to the cathode for matching.

Not all Beer & Skittles ...... You may end up with damage & distortion.... look before you leap.

Marc

Point taken.