Search found 12 matches

by NoisyBoy
Wed Oct 21, 2020 7:24 am
Forum: DM41X
Topic: Precision of DM42 vs. DM41X
Replies: 4
Views: 639

Re: Precision of DM42 vs. DM41X

Hi Thomas and Thomas, Thank you so much for the excellent explanation, that makes perfect sense. I love both machines, what a great combo, one high fidelity, the other high optimization/precision. They make great addition to my HP collection, I am just thankful for SwissMicros and all the developers...
by NoisyBoy
Tue Oct 20, 2020 6:48 am
Forum: DM41X
Topic: Precision of DM42 vs. DM41X
Replies: 4
Views: 639

Precision of DM42 vs. DM41X

I did some searches on the forum but I could not find any reference to the accuracy of DM42 vs. DM41X. I am aware of the precision in the DM42, and the SHOW function allows me to see the glory of all the digits. But I have not been able to come across anything similar in the DM41X, can anyone shed s...
by NoisyBoy
Wed Oct 14, 2020 7:47 am
Forum: Hardware issues
Topic: Upgraded keypad
Replies: 31
Views: 3884

Re: Upgraded keypad

Got my 42 a couple months ago, and the 41X just arrived today. First impression is it is slightly easier to press, and with a more audible click. However, I feel the 42 is actually closer to the 41CX when it comes to the keyboard because it is almost silent. I think if you have a late built 42, the ...
by NoisyBoy
Fri Sep 25, 2020 5:16 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 99
Views: 32535

Re: DM42- clock losing time

After over a month, I have to declare that once you dial in the proper correction value, the clock is highly accurate and consistent. After 34 days, the delta is under 1 sec. Which represents an accuracy better than 0.34 ppm.
by NoisyBoy
Fri Aug 28, 2020 8:03 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 99
Views: 32535

Re: DM42- clock losing time

I have been tweaking with the correction factor and finally settled on a correction factor C=-22. After daily checking for a week, there is no detectable drift from the reference clock in my lab. I will keep it running for another month and see what happens. But so far, it appears that despite the c...
by NoisyBoy
Wed Aug 26, 2020 6:27 am
Forum: Software Library
Topic: Polynomial Roots Finder
Replies: 13
Views: 1757

Re: Polynomial Roots Finder

Very interesting, as the TI59 was my primary calculator in college as well.

Have you consider running the test against both the Prime and Prime G2?
by NoisyBoy
Sun Aug 09, 2020 7:08 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 99
Views: 32535

Re: DM42- clock losing time

Some discoveries to share: • bobhwasatch is absolutely right. Sign-wise for the compensation variable C, a -ve value slows down the clock, and vice versa. • Starting from C=-14 (from the crystal frequency deviation measurement), after a couple tries, I found a value of C=-16 gives my calculator almo...
by NoisyBoy
Thu Aug 06, 2020 9:32 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 99
Views: 32535

Re: DM42- clock losing time

Hi Werner, No, it does not seem to work. The instruction is very vague, I am reversing the sign and will check in a couple days, I am currently gaining around 2 seconds after 24 hours. The following from the manual: "Note that to apply RTC correction you have to know (measure and calculate) ppm...
by NoisyBoy
Wed Aug 05, 2020 9:41 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 99
Views: 32535

Re: DM42- clock losing time

Good catch, Werner. I meant C=+14 I set the time with my lab master reference clock, that clock is accurate to <1 ps error. Unfortunately, I had to set it by hand as I don’t know a way to do a programmatic sync. My guess is RTC correction value is intended to compensate crystal error to 0.5 ppm - un...
by NoisyBoy
Wed Aug 05, 2020 12:35 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 99
Views: 32535

Re: DM42- clock losing time

Just perform a measurement on the crystal on board the DM42, the spec frequency is 32.768 kHz. I tested its output on my counter, the crystal is stable to the 1Hz, but digit below the decimal point is not stable. I had the counter collect 100 samples at full resolution, the average is 32,767.548954 ...