Thanks Harold, i'll focus on the PU now.

I think the first thing to achieve first is to make sure the radio doesn't have a dangerous fault in it. Radios stop working for a number of reasons. It could be a popped valve, a capacitor, a broken wire. These are simple fixes. Even at this stage of the game where a set of valves can be more than 60 years old, it's rare for a valve to go on its own.

It's also unwise to leave valve radios playing whilst no-one is nearby supervising them because if a more serious fault develops, things can get problematic, heatwise. Most valve radios have voltages higher than the mains running through the circuit, so the radios should be operating in as good repair as possible at all times. This shouldn't be construed as a scare tactic - just as a reminder that these machines are quite old and need to be micro-managed.

Once it can be satisfied that nothing else can be done to make the radio safer, then it will be time to install modern addons. There are many examples of where MP3, Bluetooth and audio inputs have been installed so sources such as digital radios or Internet record libraries like Spotify can be played through the radio however the radio itself has to be in good working order first.

Here's a video showing how to go about one of these modifications. This sort of work does require some knowledge of ancient electronics though, and again, working safely is paramount.

https://www.youtube.com/watch?v=RySHQeoWn1Q

Thanks for the advice Brad and duly noted.

Because all old parts have been replaced it is now "safer" than previously, this unit is now hitting nearly 90 years old, but extra caution is being taken, only switching on for small periods of time and always attended to.

Thanks for the link, would the use of the PU make a simpler connection?

Thanks for the link, would the use of the PU make a simpler connection?

It can, yes, as you won't need to find the correct parts of the circuit to connect an auxiliary input to. Bear in mind that the amplification may be higher from the pickup terminals though, to allow for the smaller signals coming from the stylus (on the turntable, if that were connected), so you won't need the volume from the source to be up as high.

I've actually proceeded with the mod from the video you provided, all a success!
Thank you

Does this mean a Bluetooth receiver plugged into the 3.5mm pork will work?
Just want to check before I purchase.

Whilst I was doing this mod I noticed on the inside of the PU port it was very minimum, I could see only one soldered link, nothing else, no metal sleeve, like the external speakers connection, very basic, so i'm wondering if to was even functional?

Well one week with this forum, fixed my rotary phone and now my radio all in that time, thats good going!

I am not up to speed on how Bluetooth receivers work but others here may have worked with them. I am glad to see that the radio is indeed a goer, even if only with the amplifier section of it. Down the track when you are not busy with other things, I reckon it would still be worthwhile getting that working, assuming you haven't already done that.

Sydney is still lucky to have a few AM stations left - 2UE (now 100 years old) for music and 2GB for talkback are the ones I generally go to when testing a radio.

Most definitely I will be pursuing getting this all totally working, as I learn more and more bit by bit.

As far as Bluetooth I have connected an Alexa to the 3.5mm port, and works perfectly, so it is now all voice controlled, and can now play Old Time Radio on YouTube and much more.

At this very moment, as this is a 1939 unit I’m listening to the Declaration of War and other broadcasts that were broadcast in 1939, all I can is I am amazed how well it has all turned out.
Thanks for the guidance

I have available the control panels for that model. Take a look at this.

https://www.ebay.com.au/itm/226544957118

Brad, re the modification for the MP3 pick-up, I would have thought that interrupting the shielded feed to the volume control using unshielded cable, could cause feedback problems when listening to the radio, since after all it is necessary to shield the phono pickup lead to prevent feedback.

If this did happen, then couldn't the couldn't the connection be made at the phono pickup, switching the MP3 in and out there. Then the long unshielded runs across the chassis would not be needed.

Or am I missing something here - maybe the phono pickup arrangement doesn't suit for some reason - can't see it in the video.

I suppose it is possible, but as I have not delved into doing this for myself I can't say for certain. It's funny, the cabling inside the radio is shielded, and earthed at each end and the cabling from phonographs is usually shielded to, though the binding posts are not and pretty much can't conveniently be shielded.

It works in this case and that is what matters.

Now using an app called Radio Garden, I can literally listen to any station in the world and play through this unit, AM and FM, also there are other apps for SW which I am using.

I have available the control panels for that model. Take a look at this.

https://www.ebay.com.au/itm/226544957118

Yes, I’ve communicated with you regarding this, I asked if it had adhesive, which you replied to
Did they have this originally?
Or is it a modern add on?

On my unit there was an untouched part that was the shape of that panel

HMV used these plastic panels on quite a few of their receivers, both consoles and table models. One or two other brands used them to a lesser extent.

These lock in place with the locating slots which slip into the shafts on the control pots. The originals go yellow with age and end up falling apart.

One thing to be aware of is the way an "add on" is actually added on to a tube radio: Relative to the DC paths.

Sets to be wary of are back biased and being careful that the "add on" does not destroy the bias of a tube as can occur with a magnetic PU not properly wired. Some devices that output to headphones are in the collector or source of a transistor.

It all comes back to know your gear: "Caveat Actor" applies.