Can someone please tell what the wattage of the resistor (SMB) that are in the Ultra Probe and Demodulator amp are because when I go to Mouser or Digikey they appear to not have all the values you want with the same wattage and as it doesn’t appear to have the wattage in the parts list, I just wondered what most people have selected?
Pete
Hi, if you have all documentation at your disposal and read the parts list (for the probe head unit as well as the base/demodulation/amp. unit you can easily see that MCL has clearly mentioned all resistors are 1206 (SMD style) so… I don’t know shat you mean by “SMB” you probably meant SMD (Surface Mount Device).
So, talking about wattage for those resistors here is what i can say:
Standard 1206 (3216 metric) SMD resistors, the nominal power rating is for instance:
Standard thick-film 1206 resistor: 0.25 W (¼ W) at 70°C ambient
Standard thin-film resistor 0.125-0.25W (but manufacturer dependent)
High-power thick-film 0.5-0.75W (it does not apply to the ultra-probe design)
Further on I can assure you that Mouser and Digikey do have all values (not likely for them not to have those) as the values are standard values so…nothing specialized as such (to make it hard to find). You see the problem lots of people have with them sites is that there is a little learning curve until you can master the navigation and obviously tons of patience.
TIP: beware of filters and how to work with them (when to apply them and when to reset them) also make sure you always tick off the IN STOCK box cos otherwise the search results could be highly deceiving.
As a general idea the Ultra-Probe is not a power device as it operates on batteries it has been conceived with power economy in mind so 0.25W for all resistors (I would say) should be plenty.
Good luck
PS: you might want to search for an assortment pack of resistors. Something that is generically called a Sample Book. You can find Those sometimes on Amazon, eBay, or those well-known Chinese websites just do a search for 1206 Sample book that contains resistors made by a known company called (YAGEO) with 1% to 5% accuracy and you-ll get all standard values as from zero ohms all the way to 10 sometimes even 20 M Ohms. That book usually has 14-16 pages and you’ll get pretty much all standard values in it.
You can also find them on Mouser or DigiKey . Here is a list of a list of sample books advertised for sale by Mouser:
https://www.mouser.com/catalog/specsheets/YAGEO_04-15-2026_Resistor_Kits.pdf
Pick and choose whichever one you might think will suite you best. 🙂