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Tantalum Capacitors
I'm sure we've all repaired some equipment where a tantalum capacitor has shorted. I lived for 30 years in San Jose, and collected lots of parts, including a lifelong supply of teardrop tantalum
By Gary Appel · #148734 ·
Re: VNA Resonance Methodology
Thanks. It's a long time since I wrote that software program but (to compute Q) I think the program uses a map based on empirical measurements made decades ago by Butterworth and Medhurst some time
By jmr · #148733 ·
Re: VNA Resonance Methodology
Thanks. It is a bit hard to see the blue arc in the image so I've thickened up the blue trace width and plotted it again without the markers. The top of the blue arc corresponds with the start
By jmr · #148732 ·
Re: HP 6114A - looking for R8A, 15.82K 0.1% 1ppm resistor
Maybe because I also wrote them?... The ones I ordered before - bulk foil Z201 - are not smd, though, and I wonder if that has to do with them coming up with an MOQ (the VSMP1206, which is what I
By Radu Bogdan Dicher · #148731 ·
Re: VNA Resonance Methodology
Thanks very much, jmr, for going to the trouble of running the numbers through Genesys. You've provided a valuable cross-check of my cheese formulas, which give L = 64uH, Q = 190, and srf = 16MHz. The
By Tom Lee · #148730 ·
Re: VNA Resonance Methodology
Richard, It is a short blue arc at the right edge of the chart.? Pretty hard to see unless you save the image and enlarge it. --John Gord
By John Gord · #148729 ·
Re: VNA Resonance Methodology
I see zilch on the chart. Did something get left out? -- Richard Knoppow Los Angeles WB6KBL SKCC 19998
By Richard Knoppow · #148728 ·
Re: VNA Resonance Methodology
Here's what you should see on a smith chart with a start frequency of 1 MHz and a stop frequency of 2 MHz when resonated at 1.45 MHz with a 187pF cap and with a series 50R resistor inline.
By jmr · #148727 ·
Re: VNA Resonance Methodology
If it helps add some confidence to this stuff, I used the air cored solenoid model in Genesys to predict the inductance and Q vs frequency for your coil. 49 turns 31mm diameter length 22mm wire
By jmr · #148726 ·
Re: HP 6114A - looking for R8A, 15.82K 0.1% 1ppm resistor
I asked for the 1206 size as I only needed 1/8W and the price was less. Here's the part https://webdirect.texascomponents.com/ProductDetails.asp?ProductCode=VSMP%5F1206%5FCUSTOM%5F0%2E01 Looks like I
By Dave Schmidt · #148725 ·
Re: VNA Resonance Methodology
If I go with what you posted earlier I can assume that your current tank coil has 49 turns on a 31mm OD former using 0.4mm diameter wire (close wound) I can punch these numbers into the software
By jmr · #148724 ·
Re: HP 6114A - looking for R8A, 15.82K 0.1% 1ppm resistor
That's surprising to me - I hope they're not changing their business model. I've been able to order single parts at my exactly specified value to two decimals before, on the Z201 variety. Is this what
By Radu Bogdan Dicher · #148723 ·
Re: HP 6114A - looking for R8A, 15.82K 0.1% 1ppm resistor
I contacted TTC and the reality is less exciting than what their website suggests.? T heir reply was "The MOQ for the series is 5 pc. since is a very peculiar R value." Not sure why my 'any custom
By Dave Schmidt · #148722 ·
Re: VNA Resonance Methodology
Hi jmr, Well, it's an interesting methodology for sure. I do have a Nanovna which I bought purely for evaluation purposes, but I have two proper lab-grade HP VNAs as well. Can't recall the model
By Jinxie · #148721 ·
Re: VNA Resonance Methodology
Thanks, Froggie. By all means PM me when you have access to all your test equipment again.
By Jinxie · #148720 ·
Re: Sticky ink of schematics
Personally, I have found that the laser printer at home doesn't do this while the ones at work and in the print shop I use do --- the difference may be that the one at home is black+white only and is
By David Slipper · #148719 ·
Re: HP 8341B 1992 firmware version
That is correct, the firmware is the same for both. I have used exactly this firmware to update my 8341B without issues.
By saevar · #148718 ·
Re: HP 8594E PSU repair/debug safety checklist
Hi Group check the power switch they tend to fail on those. if the PSU is faulty contact me on OZ11LPR@... I have alot of parts for those units. It is a pain to work on that powersupply type.
By Peter Hansen · #148717 ·
Re: Sticky ink of schematics
Like Chuck said, laser printed items tend to stick to other stuff over time. I haven't seen it too bad from one paper sheet to another, but definitely from paper to plastics, or (toner sides) face to
By ed breya · #148716 ·
Re: HP 8341B 1992 firmware version
There is no differences in CPU board and firmware between 8340B and 8341B. Calibration constants 79 and 98 must 2 for 8340B and 5 for 8341B, according to service manual.
By §¥§Þ§Ú§ä§â§Ú§Û §À§â§î§Ö§Ó · #148715 ·