Recently obtained a Norelco (Phillips) CarryCorder 150 (model 3300) which was the first Compact Cassette recorder ever made. Unfortunately it suffers from a slow motor speed as well as a noisy playback. The 3300 didn't have a motor control board so I presume either a capacitor has gone bad (which might account for the noise) or a resistor is out of true. Anyone know anything about bringing these up to speed?
Norelco CarryCorder 150 (EL-3300) running slowel-3300
Posted 03 July 2014 - 04:02 AM
Yes, there's an audio section HERE and plenty of members all over the world who are willing to offer support. There's a lot of love for these early machines.
In fact, the first thread you come to in the tape section today is about this very machine!
Regarding the noise, if it's a hissing type of sound then it's quite likely to be a resistor or an a/f driver going soft, the audio is all Germanium on these and that driver (0C81D probably, though it's not a fussy circuit) is cheap and easily available.
An original machine of that age would almost certainly benefit from a change of any Hunts caps, wax caps and electrolytics, especially if the electrolytics are Plessey ones in the red and black PVC cases. In a Philips machine you would also be likely to find pitch caps which can go off but aren't as unreliable as waxed ones. Bad caps in a/f stages tend to cause distortion and/or random hash rather than the hiss you'd get with resistors that had gone awry.
Posted 04 July 2014 - 12:27 AM
Just about everything you typed went over my head as I'm not very good with electronics other than basic soldering. Here's a video of my EL-3300 and EL-3301 playing the CarryCorder demonstration tape intro song.
Posted 04 July 2014 - 04:33 AM
All the more reason to check it out at the address I put up in the link then. Just make it known in your post that you're new at this and we'll start with the basics.
That said, if you want to start with putting your soldering skills to the test, light your iron and give the machine a blanket reflow. Don't know an audio amp from a sack of turnips? No obstacle there, just reflow every single joint. Dry joints aren't unheard of and this way, you get to eliminate a possible source of that hash at no cost beyond a small amount of 60/40 (only needed if you lift the old solder with braid and need to replace it, this is rarely essential) and some butane for your iron (unless you use an electric one).
Posted 04 July 2014 - 12:29 PM
Early motors were controlled with mechanical centrifugal governors. Two rotating masses suspended from the rotating rotor controls the speed by regulating the current to the rotor brushes.
Mostly, these can be accessed only by opening the motor. By adjusting the contact break gaps on the governor, speed can be adjusted. It is a straight forward work with some patience.
Posted 04 July 2014 - 06:54 PM
I have checked out the link. Only 'fix' I came away with after some wading through postings was maybe altering the pulley ratio. I've been inside a governor motor. Not fun especially if any lubricant gets in the works. Was Phillips still loading these with governor motors as late as the first week of 1965 (when this unit was made)?
More important. Is there a minimal number resistor or capacitor I can change out that'll get this at the proper speed? I wanted to keep this as original as possible - to the point where I don't even plan to enable the record-protect feature with the spares I have on hand - I've had several of these in various state of in/operational condition.
Posted 05 July 2014 - 04:41 AM
Governor motors were in use even in the 70's. My 1977 National MAC-5 stereo has one such motor.
You can easily trace the power supply route to the motor. Many have only a leaf switch between the Power supply and the motor.
Posted 05 July 2014 - 07:43 AM
After a bit of practice on some old spares I was able to get the motor apart for a look-see...
DSC00005.JPG 82.18K 30 downloads
It's a 'govern-ator'.
A few minutes later...
Unfortunately the set screws were pretty close to their limit but hope was not lost. Read a suggestion on another thread to build up the pulley diameter so I trimmed a bit of that blue painters tape to fit.
Works well enough to play Herbie Hancock's 'Rockit'.
Looking over one of the motors I'd disassembled for practice and I found I'd been looking at the wrong set of grub scews. The ones I'd wanted to adjust were obscured by black paint/gunk. Lesson for the next one of these I might come across.
Now if I can tamp down some of the speaker noise. Probably a duff filter cap or something like that. That I will need help with.
Posted 05 July 2014 - 12:38 PM
Easy to test whether it's a filter cap. Try it on battery and if it still makes the noise, then that wasn't the cause of it. Be aware that if you replace filter caps, you must use class X2 or Y2 replacements, a good source for these is old computer PSUs.
But if the noise you're meaning is that hash that we hear in the vid, it's an audio issue rather than a supply one. Another possible source and just as easy to change as a capacitor is the "lockfit" style transistors on the a/f amp board. They can get randomly noisy with no apparent reason and bizarrely, can then be quiet when swapped to a different location with a device of the same spec.