posted 15 January 2000 12:33 AM         

Bob Lee's "Pedal Steel Guitar
String Gauge Guide" at the URL:
http://www.b0b.com/infoedu/gauges.htm

makes no mention of the string length of the instrument.

For example, my Fender 1000 has a 24 1/2" string length while the Fender PS 210 has a 23 1/2" string length.

I would expect that a given tuning on either instrument would use slightly different gauged strings?

I looked over a string gauge chart that I obtained years ago from the Ernie Ball Company and the reported guages are very similar to those reported on Bob Lee's chart. I believe that Ball's chart was developed for a 24 1/2" string length pedal steel guitar.

On the packaging for a .011" (.28mm) D'Addario Guitar Strings, it says:

Tension at Pitch:

"B" note = 11.1 Lbs
"D" note = 15.9 Lbs
"E" note = 19.9 Lbs
"F" note = 21.2 Lbs

25 1/2" scale length used for tension measurements.

They must supply this information for a practical reason and I'm wondering if we can make use of it in gauging our pedal steel guitars?

I'm also wondering if there's a mathmatical formula that would compute the "tension" (in pounds) on a string for a given pitch, a given string guage, a given string length and a given type of string (type of metal, and plain or wound string)?

With such a formula, you should be able to first determine what "tension(s)" (in pounds) you want on your guitar. Should the target be to have "all" the strings at the same tension?

I look forward to your comments on this subject as I suspect that it's been discussed before.

Regards,
Al Gershen
Grants Pass, Oregon
aldg@mail.rvi.net & aldg@webtv.net;
and thru ICQ # 12342782

posted 16 January 2000 08:31 PM         

http://nightshift.net/tech.htm

posted 16 January 2000 11:23 PM         

I want to thank Terry Downs for providing a fine article on his website (see his "link" above in his posting) about how to compute the string guages for instruments such as the steel guitar and the lead guitar. I hope that Buck OBrian finds Terry's aritcle as informative as I have.

I was able to transfer his formula to my programmable HP 48GX calculator and test it against the computations that D'Addario came up with on the packaging for their .011 guitar strings.

I'll next write out my tuning pedal co-pedent for my Fender PS 210 and compute the string guages.

Does anyone have a suggestion for the "string tension" (in pounds) that I should use on the 23 1/2" string length Fender PS 210 pedal steel guitar? I suspect somewhere between 15 and 20 pounds would be adequate.

Marty Pollard's comment about having equal string tension on each string seems to make sense but there may be other factors to consider.

Ultimately the real test is to string up the instrument at the computed string guages and see how it feels and sounds. For example, do the pedals and knee levers operate at comfortable pressure levels?

Most instruments allow for linkage adjustments that affect pedal/knee lever travel distance and pressure. With all these "variables, it should be possible to get your instrument "tweaked" just the way you want it.

I'll report on a future Subject Thread my results with my Fender PS 210. It should be an interesting learning experience.

Finally to Al Marcus, thank you for your nice comment.

posted 18 January 2000 05:40 PM         

There is no real rule and people like different sounds from different gauges. The means of course that you don't exceed the yield strength of the steel and get into a breakage problem.

Regards,

posted 20 January 2000 11:15 PM         

I enjoyed reading the comments of Terry Downs, Jim Palenscal and Jim Smith but I would still like an answer to the question:

Does anyone have a suggestion for the "string tension" (in pounds) that I should use on my 23 1/2" string length Fender PS 210 pedal steel guitar or for that matter, any pedal steel guitar, regardless of the string length?

A pedal steel guitar is probably a "stronger" built instrument than other acoustic instruments such as a guitar or mandolin, as Terry Downs mentions in his above posting. As such, it should be able to handle stronger string tensions than these other instruments without the usual side effects (neck warpage, etc.).

But isn't "cabinet drop" an unwanted result, especially when string tensions are too high on a pedal steel guitar?

So it seems to me that there is probably some optimum string tension level that yields:

1. Comfortable pressure levels for the floor pedals and knee levers; and

2. Minimal cabinet drop tuning problems.

I look forward to more of your comments on this subject.

posted 21 January 2000 07:08 AM         

Hello to Johnny "Mack" Brown.

Unfortunately, what you ask does not have a yes or no answer, ..the tensions for the strings vary with the neck length, the string diameter, and the string material for starters.

This is further complicated by taste, ..you may want a "sharp thin" tone so you would use "light" gauge strings and the tension for a given open string note would be lower than if you wanted a deeper "warm" tone in which case you would use "medium", or "heavy" gauge strings with the attendant greater tension (pounds pull).

I think of "cabinet drop" in the same terms as the bending (string to fret distance) found on the "Spanish" guitars caused by bending vs. tension; tension being greater for heavier gauge strings. Remember how you can pull on the neck of the Spanish guitar and change the pitch of the open string? You can do this on the lap steel and the pedal steel to the extent that the body is flimsy or the mechanisms not well fixed in place. The pedals and levers tend to do this to the PSG and do it more when changing more strings at a time.

To see the stability of the body (cabinet), put a tuner on a string, then put your weight (some of it) on the center of the body and see how much the pitch changes.

There is also the "axel" problem on the PSG, ..this is often referred to as cabinet drop also. The axel is the rod through the finger mechanism. If it is too small, of a flexible material, or poorly supported, activating certain changes will cause the adjacent (usually the more center strings) to change in pitch as it flexes. The heavier the activated change, the greater the flexing.

The limits of tension on different string materials is different; when the "elastic limit" is exceeded "plastic deformation" will set in and the string will not return to pitch after stretching, ..it will very soon break after this begins to happen.

If the string makes a sharp bend over the bridge or nut it will take less tension to reach the plastic deformation point than if it makes a shallow bend. Thin unwound strings like the G# are most succeptable to this problem as are small gauge strings on long neck instruments.

Another factor is the way the string is terminated. Any sharp edges are tough on small gauge strings. The edges of the hole on the "keyed" tuners, and the edges of the screws and angle of string departure from said screws on the "keyless/gearless" units.

All of these things can effect the max tension that will work best mechanically on any given instrument. What is the max (statisticallly stated) tension value used on the 25.5 inch neck with 1n 11.5 gauge string (G# stretched to A)?, ..something under 35 pounds per inch, depending on what you plug in for string density, modulus of elasticity, shear strength, etc for the particular string material. Smaller diameter strings or shorter necks will tune to the same pitch with less tension.

Remember how you used to break wire (baling or barb) by bending it rapidly back and forth (you could feel it heat up), ..that is what the PSG does the the music wire (string)only slower.

Summation, ..stay under 35 PSI, and choose the string gauge for the tone that you like; this may not be "equal tensioned" strings.