Phonograph needle?

3/13/2006 3:06:09 PMPeter

Hi Guys,

With the help of your experts I was able to start my phonograph inside my old Motorola Console #75F31 from 1952. I played a record and it sounds weak. An the needle slides, so I flipped it, slidding stopped, but it it still doesn't sound great. I'd like to replace the needle. Any thoughts to where I can get one. The schematic doesn't indicate anything about the turntable at all. The origin appears to be Great Britan from what I can read on the platter. Can anyone help?

Peter

3/13/2006 3:37:17 PMThomas Dermody

Your problem is most likely the cartridge, not the needle. The cartridge could be deteriorating. Many of the cartridges from this era are made using a salt crystal. The salt crystal deteriorates easily when exposed to moisture. If the sound isn't crunchy and distorted sounding--what a broken crystal usually sounds like, you may have amplifier issues instead. In order for your amplifier to work properly, all resistors must be on value (+/- 10%). All condensers must have ABSOLUTELY NO leakage. Tubes must be in fairly good condition, though weak ones will work well occasionally. It is best to start with strong tubes if you aren't sure what your problem is. Then try out the weaker ones later, once you have solved your problem. Don't go replacing tubes until you have checked your condensers and resistors first. If your problem is indeed the cartridge, www.west-techservices.com can rebuild the cartridge for you.

If you are playing a 33 or 45, using the 78 rpm needle will cause sliding. The 78 rpm needle is 3 mil. in diameter (could this be thousandths of an inch???). The LP needle is about 1 or 2 mil. The 3 mil needle won't ride down in the 1 mil groove of an LP properly, and so it'll skate across the record. This doesn't mean that it's bad. You should never use the LP needle on 78s, either, because it'll dig through the bottom of the groove, and since it doesn't fit properly, it won't ride on the sides of the groove where the music is--the music will be quiet and distorted. On the other hand, if you use a 3 mil needle on an LP, you'll lack treble response because it won't fit into the small treble waves of the groove. It'll also tend to spread the groove--making it wider. .....And of course it'll skate across the record as I mentioned earlier.

You should check both of the jewels under a microscope or stylus examiner. They should be cone shaped with a nice ball-round tip. The tip should in no way be chipped or have flat edges. If there are chips or wear spots, or rapid record wear is evident, you must replace the offending needle. www.west-techservices will have replacement needles for you. If you want to play 78 rpm records, you must use the finest 3 mil needle you can obtain. Never use a smaller needle or an "all-speed" needle. These are bogus needles, and will ruin your records. A diamond needle is best for 78s because it won't chip from bits of steel from those records which were originally played with a steel needle. With the right needle and cartridge, good 78s can sound velvety smooth, and can last a long time (you should also never clean your 78s with any cleaner containing alcohol, as 78s are made of shellac....shellac is soluble in alcohol...terrible surface noise will occur after cleaning 78s with alcohol). You may wonder whether using a 3 mil needle will cut frequency response in 78s as it does with LPs. 78s spin faster, though, and so the treble waves are more spread out...they will be reproduced properly with a 3 mil needle, which fits the 3 mil groove. I am in no way an expert on 78 rpm records and playing methods. I have a lot of experience with them, though, and know how to get fine, noiseless results from them. If you want to play them, with experience you should be able to secure fine results from every record, too.

If you intend to play LPs, you must also use a fine LP needle. LPs are not so critical of their needles, though a good needle and cartridge must be used, since LPs are just as easily damaged as 78s.

3/13/2006 5:47:53 PMBill VA

Hi Peter,
I was looking for the SAMS on your 75F31 because lots time the SAMS will list needle and suggested replacements. The SAMS I came up with is Set 29 Folder 18...it a 1947 set. Didn't list the needle. I looked up your model to changer and the changer could be Mototola B24RC, B25RC, B27RC, B28RC. So I'm not much help here. Sometimes skipping can be corrected by cleaning the needle and straighting. But I'm sure Thomas has you on the right track. If you can verify you record changer number by markings on it that will help some of the vendors locate the right needle. When I get my old Magnavox going, I'm going to get Thomas to revisit this topic about the 78's and the 3 mil. I have some brand new 78's and want to keep them in good shape.

Bill VA
:
:
:Hi Guys,
:
:With the help of your experts I was able to start my phonograph inside my old Motorola Console #75F31 from 1952. I played a record and it sounds weak. An the needle slides, so I flipped it, slidding stopped, but it it still doesn't sound great. I'd like to replace the needle. Any thoughts to where I can get one. The schematic doesn't indicate anything about the turntable at all. The origin appears to be Great Britan from what I can read on the platter. Can anyone help?
:
:Peter

3/18/2006 7:00:27 PMDoug Criner

Peter, I've never had any luck trying to find needles by searching against the radio set model number. The radio manufacturers usually outsourced their record changers, and the record changer people typically outsourced their cartridges/needles.

Here are two sources for needles that have photos of each needle. If you can find one that matches, physically, there's a reasonable chance that it will work:

http://www.jukn55.com/other-items-cartridgesandneedles.html

http://www.needledoctor.com/

I don't know about the NeedleDoctor, but Chuck at Junkn55 probably would be happy for you to mail him your old needle and let him paw through his stash for a replacement. You could check with him.

Chuck had the needle for an English BSR turntable that was in a 1950s Grundig-Majestic (German) console. I bought several to have a lifetime supply. It was one of the flipper-types that have two needles, LP and 78.