Archive for the ‘Uncategorized’ Category

Download Of George Augspurger’s Transmission Line Design Program.

Sunday, June 28th, 2020

George Augspurger has graciously allowed me to publish a download of his Transmission line speaker modelling program.

It is published here for download for the benefit of loudspeaker building enthusiasts and designers. Unzip this file and then run the TLwrx3.2.exe program directly. No installer is required.

I have personally designed built and measured five TL designs using George Augspurger’s model and that the designs measure as predicted.

I am very much indebted to George Augspurger for allowing publication of this TL design model for the benefit of all.

1958 John Deere 420 Tractor Steering Valve Endcap Redesign.

Tuesday, May 31st, 2016

I hove owned this JD 420 Dubuque tractor for 18 years.  It has been a wonderful tractor for mowing, spraying, and moving boats and trailers about.

There is however a serious problem with these late Dubuque tractors with power steering.  This concerns severe leaks developing around the input and output shafts of the steering valve.

The problem is that the endcaps have no bushings and the seals are just 0-rings and not spring seals.  Whilst there is a 3:1 reduction in pressure to this valve, this in not an adequate design.  In addition there is no bracket holding this valve on the 420s, although I believe there is on the 430s.  The valve is just held by the pressure lines and input and output shafts.  This results in a continuous shifting of the valve increasing the wear on the endcaps by the shafts.

When this problem became serious I changed the seals.  Improvement was temporary.  So I changed the seals again and fashioned brackets.

This worked fairly well for one summer season.  I also obtained another valve and used the best two endcaps, but both had significant wear.  I was told by experts that there were no good endcaps to be had.  It was clear there had to be a redesign of these endcaps or the tractor would have to be parted out, as it was now useless.

So I had International Seals of Texas make me some small hydraulic spring seals with a large pressure margin.  I wanted these seals over designed.  I had Randi Torvinen of Torvinen Machine in Menahga MN machine the endcaps to take a bushing and the spring seals.


This has been a 100% successful solution to this very serious and troublesome problem with these steering valves.  The hydraulics have never worked better on this tractor since I have owned it.

There are zero leaks and the pressure stays up no matter how long the tractor sits.  As soon as you start the tractor, the hydraulics are instantly available.  There are no delays.  It lifts the mowing deck even on the lowest idle instantly.

For those of you having this problem with the valve, which I understand is common, this is a complete and certain solution.

I should state that any of these tractors I have seen in recent years have been leaking from this valve worse than mine ever has.

I’m proud to present this solution to a problem that has led, and will lead to more of these fine tractors being parted out.

Chrysler DeSoto 1930 to 1931 S-CF flat head “8” Ignition adjustments.

Wednesday, July 10th, 2013

1930 DeSoto ?8? Ignition adjustments.

The distributor, which is of the four lobe cam and double breaker arm type with condenser on the outside of the base, is accessibly mounted on the cylinder head and driven through a vertical shaft from the camshaft. The ignition coil is mounted on the dash.
Firing order is 1-6-2-5-8-3-7-4

Spark Advance
For all ordinary road and driving the spark control button should be in the advanced position, which is pushed ?in? to the instrument panel. When cranking the engine by hand, the spark control button should be pulled all the way out. The automatic advance will take care of all other conditions.
To Adjust the Point Opening
Two sets of breaker points are actuated by a four lobe cam which causes one pair of breaker points to open at a time. One set of breakers controls the spark to one set of four cylinders (1-2-8-7) and the other set of breaker points to the other four cylinders (6-5-3-4); therefore, the opening of both sets of breaker points must be equal or the spark timing will be different in the two sets of four cylinders. The points open alternately.
The rotor should be removed and the engine turned by means of the hand crank until one breaker point rests on the high point of the cam. The gap between the breaker points that have opened should be 0.022?. If necessary to correct the adjustment of the gap, the breaker point lock screw should be loosened and the gap increased or decreased, as required, with a 0.022? feeler gauge on the gap, by means of the breaker point adjustment screw.
The engine should then be turned until the other breaker point is resting on the high point of the cam, and the gap adjusted as for the previous breaker set.

To Set Ignition Timing
The spark control button should be checked for full advance and retard. The breaker points should be adjusted to 0.022? opening and the manual spark control placed in the fully advanced position. The 1/8? pipe plug should be removed from the cylinder head above Number 8 piston and a gauge rod placed through the hole and in contact with piston head. The crankshaft should be rotated until No. 8 piston is coming up on exhaust stroke and stopped when the piston is 0.037? before top dead center. The screw which clamps the distributor should be loosened and the distributor rotated in an anti-clockwise rotation, as viewed from above, until No. 1 piston cam begins to separate the breaker points. Before doing this, the distributor should be pressed against the direction of rotation to be certain that all backlash is removed. The clamp screw should then be tightened and the distributor cap reinstalled as well as the spark plug cables connected to the proper spark plugs and terminals of the distributor cap.
Firing Order
The firing order of the cylinders is 1-6-2-5-8-3-7-4. No. 1 cylinder is nearest the radiator.
The breaker points will in time change their synchronization slightly because of wearing or burning off unequally. Ordinarily when the points are cleaned and readjusted to the proper opening synchronization is automatically corrected. If after the breaker points have been cleaned and adjusted the engine seems rough in its operation, especially so when idling and accelerating, then synchronization should be checked.
Spark Plugs
The spark plug gaps should be set to 0.027? to 0.030?. Care should be taken to set all sparking plug gaps uniformly.

Tektron doodle

Monday, September 17th, 2012



Eminence Delta 10 A 16 ohm X 2 vented

Could my Car Friend me on Facebook?

Thursday, December 9th, 2010

I finally weakened and let Detroit have some of my hard earned cash.  Six days ago I collected my first new vehicle since 1981.

A very nice Chevy equinox LTZ. I picked it up with 11 miles on it. The nice young lady at OnStar even gave the vehicle a telephone number. When I got back to Benedict I found my trusty 1994 Chrysler LHS had already sold in the space of a couple of hours. We had already said our goodbyes after nearly 100,000 miles and nearly eight years faithful service.

On checking my Email, I found my car had already Emailed me as soon as I had taken delivery.   The Email informed me that health status was good with all engine, transmission, stability codes and tire pressures listed.

I got up Tuesday and it was cold day at the lake, now covered in ice and a blanket of snow.   I had to make my way to Eagan for an AES meeting at MPR studios yesterday.  The electric heat was rippled out, so I went down to the fire which was still in, and built up a roaring fire.  I then went over to my laptop to check the mornings offerings.  Right there another Email from the Chevy.  It informed me the tire pressures were low.  It happens in cold weather.

It took me aback though. You can’t be Emailed from a inanimate chunk of metal.  Can you?  I thought not.  The old Sage of Donnebrog Nebraska, Roger Welsch must have been right all along.  Machines do have souls after all!

So she must have a name.  Whenever my father got a call from the office, the secretary was always Flossie.   So these messages had to be from Flossie.  So Flossie she is!

So after packing up I went to the shop and switched on the air compressor.  Since Flossie had sent me such a nice message, and was so concerned for my safety, I could not possibly disobey.  So all tires where set at just a hare over 35 lb/ in case it got colder.  Flossie told me via her message center she was relieved and satisfied.

As I moved off, Flossie flashed a message to be careful of ice.  We had a good journey down, and I held her below 68 mph, with no harsh acceleration or braking.   I frequently let the power off to make sure Flossie’s rings seal well, all part of the bonding process.

Coming in on I94 about six miles from the Lowry tunnel, Flossie suddenly turns down the radio and gently says, “slow moving traffic six miles ahead 6/10 of a mile long.”  As I turn onto Crosstown MN 62 Flossie says “stop and go traffic 7/10 of a mile long.”  In both instances Flossie was right and knew before I did.

This morning in addition to ice, Flossie flashed a weather update to warn of snow.

Flossie guides me with a moving map. If I should get lost, all I have to do is tell Flossie my destination and she will guide me to it.  What a friend in need.

When I back up Flossie shows me a good rear view on her sat nav. screen and car length grid.  As I was backing out of a parking space at Trader Joe’s this morning I had a clear view to rear on screen and visually.  As I looked to my front so as not to scrape the vehicle behind me, Flossie sounds a mighty alarm.  I look to the screen and a pedestrian is right behind Flossie seemingly having appeared from nowhere.   Lucky for me and especially the pedestrian Flossie is ever vigilant!

This has all got me thinking about the bonding of men and machine.  I think women also bond, but perhaps not in the way men do but I could be wrong about that, may be they don’t own up to it as often.  Then there is Thomas and Friends with very human faces on the engines, that in the stories have a will of their own.   Herbie the Lovebug very much comes to mind.

In my career I have certainly had farmer patients who have had strong emotional bonds to their machinery, especially old tractors.  Sailors have long been known to develop very strong emotional bonds with their vessels, especially after difficult passages. I certainly don’t mind admitting I bond with my machinery.  Not a bad thing really, it all helps needed maintenance become a pleasure rather than a chore.  Dues are then being freely granted to an old friend.

So now the machinery can talk to you and send you messages through the Ether, how will this affect the depth and incidence of bonding?  My guess is that human machine bonding will occur quicker and deeper than before.  I can tell you in less than a week Flossie and I are fast friends. I’m just waiting for a Facebook request from my new friend.

Vifa_TC14WG-49-08_optimum box

Friday, February 13th, 2009

In my view this box gives the best compromise between f3 and linearity of response.  I consider this the optimal box.

Dons problem.

Wednesday, February 11th, 2009

Don (Moron) posted on the Audioholics forum about adding a sub woofer to his speakers.

His speaker system was a reflex loaded MTM system, using dual Focal 7W4411 woofers and Focal axiom TLR tweeter in MTM configuration.  Don had built the speakers which had been professionally designed and the crossovers supplied by the designer.

Don put this post on the Audioholics Subwoofer forum on 12/19/2008.  Don’s main complaint about his speakers was severe lack of bass.  However in further correspondence via Email, it became there were other issues.  Don complained, that the sound was generally poor and that he did not listen to music much anymore.  Speech clarity was so poor, and he had had to resort to using an old cheap RCA speaker as center channel to make speech intelligible.

Obviously with drivers of that quality something had to be seriously amiss.  Attention was paid to the bass tuning.  On information supplied by Don it seemed that the bass alignment was optimal.  The F3 was an excellent 41 Hz, so the speakers should not be bass shy.  Don did however volunteer that all internal surfaces were covered with 1″ Black Hole sound absorbing material.  I advised him to reduce coverage to 50% of the internal surface, but to make sure the rear wall remained covered.

From Don’s plans it seemed the enclosure was well designed and braced.  Don reassured me about the constructional integrity of the speakers.

So suspicion naturally turned to the crossovers.  These were Don?s crossovers.  They are fourth order Linkwitz/Riley crossing over at 2.4 kHz  There is a frequency response chasm from 200 Hz to 4 kHz, centered on 1.5 kHz.  It is easy to see why Don was unhappy with his speakers.  The major part of the dip is across the speech discrimination band from 400 Hz to 2 kHz.  So it is easy to understand how speech intelligibility was compromised.  The tweeter level is two high, so the speaker is poorly balanced, leading to the perception of lack of bass.

So new crossovers were designed.  A second order impedance compensated crossover was designed crossing over at 3 kHz.  The response in the crossover region is +/- 2db.  when combined with the driver roll offs, this constructs a composite fourth order crossover.  The tweeter is 90 degrees ahead of the woofers at crossover, so tweeter polarity is not reversed.  The crossover is impedance compensated, with impedance of 4 to 5 ohms except for a rise to 16 ohm at crossover.

The crossovers were constructed, and Don had a friend help with installation.

Don has been very pleased with the result.  We have confirmed Fb  is very close to 35 Hz. With Dons Radio Shack spl meter, the speakers would apear to be 4 Hz down at 40 Hz.  There is useful audible output to 30 Hz.

Since this modification Don has used his speaker more, and the old RCA center channel speaker is gone.  Speech clarity is reported as excellent, with a good stable center image.  Don now finds the bass adequate and no longer feels a need for a sub.

This is Don’s impression of his “new speakers,” in his own words.

“I can barely believe the sound of my “new” stereo system. The crossovers you designed and made, and your suggestion of removing about half of the insulation, has turned a rinky-dink system into a concert of beautiful music. I can now easily understand voices – which I couldn’t before – and the music is beautiful, AND, you saved me hundreds of dollars, because the bass is so much deeper and clearer that I don’t feel the need of a subwoofer. I use the stereo soley for music and TV.

I paid a considerable amount of money to have a “professional” chief engineer of an audio company design the cabinets and crossovers for my componts, and the sound was pretty lousy: Couldn’t understand voices and pretty much a jumble of music. Seemed like the tweeters and woofers were in conflict.

As I admitted, I’m a moron regarding the topic of stereos, so I have no idea what the terms you used mean, or why your crossovers have made such a difference, but the sound that my speakers now reproduce is stunning. I had no idea a home stereo system could produce such beautiful music.”

Don’s post is interesting and shows that things are not always what they seem.  If Don were so inclined his system would now likely have improved performance with a sub, were as previously a sub would have provided little benefit.

It is gratifying when a long range call for help can have such as satisfying outcome.

Crossover Circuit

Tuesday, June 24th, 2008

Here is a circuit for you to look at.  NFM-1 crossover circuit

Here is the crossover and service manual for the JBL PRO III AW ts.pdfb

Barack Obama’s Speech on Race

Tuesday, March 18th, 2008

Here is a link to Barack Obama’s speech on race in America today:

John Edwards . . . This is what I’m talking about . . .

Sunday, February 17th, 2008

I mean, you just knew this was the kind of thing this guy was into: