Well, this is the time when I get out of my lazy zone and finished one job planned for an unknown future. I knew I was gonna do it but, didn’t have time and, more importantly, I was focusing on the other things rather than complete this modification.
My Sony XDR-F1HD was working fine with 230V/120V step-down converter, but after only a few hours (with added cooling fan) the top cover was getting really warm. As I mentioned in my previous post 12V external PSU was needed to reduce unnecessary heat generated by the main transformer.
I was off from work today and I get motivated to complete the entire job. It’s a fairly easy job to do if you know what you are doing. My missus was at work so I had plenty of time in the morning.
First step was to cut out and solder 12V PSU socked as well as the adapter jack. I used an old Canon 12V 1.5A (rated) adapter that I salvaged from, long gone, flatbed scanner. The adapter is still working good, so why not to recycle? A 15 minutes later chop-chop job is done!
This sucker has two ferrite cores near the plug and these need to stay. I could get rid of those but I would lose about 20 cm of lead so I would rather keep those together with lead. Also, I need to drill a hole for the 12V PSU socket. That’s not a big deal. There is plenty of space on the back panel of the Sony XDR.
I had (almost) all the parts that need I for this job. The only part that I was still waiting for are thermal shrink tubes, but I found some old ones and I decided to use it. For this simple modification, I decided to use adjustable LM2596S based regulators. I purchased these on eBay for £1.99 each. These are rated (for maximum current) at 3.0 A and can be pushed slightly more with an additional heat sink provided. I need two of these, one for 5.2V line and another one for the 10.5V line. These simple regulators are adjustable between 1.25V to 35V.
I decided to attach the regulators to a small aluminium sheet plate that cut out from an old radio. I drilled the holes and attach mounting screws. Aluminium plate will be placed on the same spot where the original transformer was. There are two mounting brackets that have holes for screws. I also used the same screws from the transformer bracket to attach the aluminium plate to the casing.
At this point, I decided to try to use XDR without a cooling fan (at least for a time) to see how warm the tuner will be. Original 120V transformer running of the 50Hz stepdown converter was a source of additional heat in the radio. DSP tuner in this radio gets really hot when running so a cooling fan was necessary. Also, the ability to use the radio without a step-down converter is a great bonus.
The job has been completed! The regulators working great. The radio became lighter without its original power supply. I decided to mount rubber feet to lift the radio from the desk and improve stability. I used double sided duck tape to attach the rubber feet to the radio. Rubber feet are 2 cm high so I have plenty of space between the radio and the desk. Lots of space for airflow!
The radio now can be powered from 12V external PSU. I got it running today for about 5 hours receiving various stations and the radio doesn’t get really warm without a cooling fan. It’s warm to the point when you place your hand on the top cover but this warmth is very much acceptable. When on standby the XDR is now dead cold.>
One job done and onto the another. You pretty much know what it will be… The saga with SONY XDR-F1HD will continue!