After getting the amp and speaker in the old Telefunken Bajazzo shell to work (last post here) it was time for some extra features, to make it the perfect „Festival Companion“.
Firstly it is always a good idea to make the power supply rock solid. As I had access to some 1 Farad / 5 Volt double-layer capacitors I quickly put together a pack of them (about 2 F for 10 V).
The picture above already shows another add-on: As In-Car Chargers usually are step-down converters it is no problem to supply 9V (actually 4,8…9,6 V depending on the discharge of the six D-cells) instead of 14.4 V. So I cracked one open and placed it where the old DIN connector was.
As I had left two switches in place below that aperture, one can now enable the charging port. That way you can easily charge the smartphone playing the music to the speaker from the enormous capacity of the alkaline primary „Flashlight Batteries“. Or any other USB-chargeable device.
No silly „powerbank“ needed.
The proper „Bajazzo CR1000“ illuminated the frequencies and my daughter started to randomly push the buttons – so I built an indicator to see if the amp was running.
As open air festivals can be quite hot I wanted some fan. Not necessarily a Huge Metal Fan, but something you can store away for transport. And fortunately two standard 60 mm fans have about the same size as an old MC. The second switch on the side now turns these two on or off. If you need them you can clip them on top with the handle. 🙂
The next thing you need is some light. And as I wasn’t sure where to direct it I kept it flexible. The seven 10 mm LEDs fit into an old „diffractor lens“ from a garden solar lamp. I tried to keep the current down a bit, so they don’t get too hot (and live long enough).
On the back of the radio was the connector for an external speaker. Now you can connect the light via (extendable) cable and e.g. clip the lamp onto the top just like the fans at daytime. The „afc“ button switches the lamp.
As you can see above I tried to wrap up the speaker a bit with acoustic insulation for PC cases I had left.
The prices for solar panels (and additional recahrgeable batteries) are still quite high, so I don’t think I will go that way in the near future. Expensive stuff is not safe in a tent.
An idea I did not implement (by now) is adding a second (or third) battery compartment to be able to use e.g. AA-cells if no D-cells are available. It would fit into the space previously taken up by the telescopic antenna.