Nagra ivl recorder power supply.
 

Hopefully there remain a few mature age folk who know about Nagra recorders.

I have a Nagra IVL which I bought used for a film documentary project back when film was still around.

From go, the power supply adaptor from mains power did not work. The recorder powers up but there is a dreadful hum in the audio which suggests either something is seriously wrong in the power supply or there is needed another box of tricks to be connected in series, a rectifier perhaps. My money is on diodes or capacitors having failed.

If anyone has any advice it will be muchly appreciated.

The unit is very similar to this one except that the mains voltage selector is not fitted but a cover plate is in its place.

Re: Nagra ivl recorder power supply.
 

Hi Bob,

Been a while since I've seen you around here.

My guess is that the electrolytic capacitors in that power supply have gone phut and need replacing though if the values are unreadable it may be a bit of uphill task without a schematic.

However, this line of attack looks positive if you're a dab hand with a soldering iron and associated weapons.


Sounds great in the video.

Good luck!

Regards,


CS

Re: Nagra ivl recorder power supply.
 

A P.S. to the above...............

You could try plugging the Nagra power supply into the mains, connected to the tape deck, for a week or four and see if that sorts the problem, power on both, of course.

I built myself a dinky digital clock in 1974 based on the AY 51224A chip which later, because of travel/ moves/ life etc didn't get powered up for nearly 25 years and went nuts when it eventually was. I left it running for a few weeks while I decided whether I dare try to open the unopenable box I had built for it but lo and behold, a few weeks under power and the electrolytics obviously reformed their capacitive coatings and its been functioning perfectly ever since!

Yes folks, that's 50 years!

It's a cheap fix if it works.


CS

PS: Courtesy of the UK Vintage Radio Repair & Restoration site, the external power supply apparently only contains a transformer, diode bridge and smoothing caps, with further regulation being done within the deck itself. A doddle to rebuild if necessary (says they). As there are obviously caps used in the Nagra internal regulator itself I've revised my suggestion above accordingly.

Re: Nagra ivl recorder power supply.
 

I used this heavy thing back in the 90s and the reason it was so heavy was that it was full of D-cell batteries. But at least it was portable.

Would it be worth putting some batteries in your unit and see if it makes any difference? You'd be able to tell if it is the external power supply or not.

Andrew

PS. If you can't source some D-cells, you can always do some MacGyver-ing with C-cells (which are the same length), and this has worked with other devices.

Re: Nagra ivl recorder power supply.
 

Anyone heard from Bob recently? Wonder if he got this sorted.


CS

Re: Nagra ivl recorder power supply.
 

Bob has posted this problem a few times over the years, one reply was to try the old Nagra site.
Cheers.

Re: Nagra ivl recorder power supply.
 

I try to be cautious when reforming caps. I plug the supply into a Variac, start for several days at 25% rated voltage, then up to 50%, then 75%, and after a week or so I finally get up to full voltage. I've seen a few electrolytics explode, and it's something I'd rather avoid.

I would *not* do this with the recorder connected. No telling how it would react to a substantially low voltage like that. Just bring it up slowly w/ no load.