What are "Dale 100 09 29"  "Dale R27 09 46" ? - Page 1
Forum section: electronics / beginners

author: awallin
author_rank: Frequent Contributor
timestamp: January 15, 2016, 08:18:55 pm
content: I opened up an amplifier and found yellow square SMD parts with the texts:"Dale 100 09 29"and"Dale R27 09 46"at first I thought they were tantalum caps, but at least the first one can't reasonably be a cap because it seems to be in series with the power-supply feed, so some kind of inductor, filter, ferrite?The second one with R27 is in series with the RF signal output path.thanks!

author: helius
author_rank: Super Contributor
timestamp: January 15, 2016, 08:22:23 pm
content: Resistor networks. Used for signal termination.

author: awallin
author_rank: Frequent Contributor
timestamp: January 15, 2016, 09:14:40 pm
content: Hm, ok, why would one use a resistor network instead of a single SMD resistor?It looks like they are connected only to two pads, so if there is a 2x or 3x network inside they are all in parallel.I couldn't find a part-number or datasheet based on the text on the partsOn VCC it looks like two RC-filters in series. First the Dale100-part and a cap, then a 10R0 resistor and two caps.On the output the R27 device isn't the output-impedance, because there is a separate 51R1 resistor for that.I also find the (very small?) capacitor to ground on the output a bit strange.

author: helius
author_rank: Super Contributor
timestamp: January 15, 2016, 11:09:11 pm
content: Maybe I spoke hastily: I am familiar with Dale resistor packs, haven't seen the devices you showed. They look like they could be resistors, ferrites or RC networks. The last four digits are a date code, so the only useful info is "100" vs "R27": probably an indication of 100 ohms and 0.27 ohms.The Dale brand is not used for chip capacitors, but does include some capacitor networks.

author: awallin
author_rank: Frequent Contributor
timestamp: January 16, 2016, 02:14:55 pm
content: FWIW some more pictures that shows the context:https://www.dropbox.com/sh/3vxyu87ax5cqjyf/AACQWDG3lN5lpnvTAqRXKW9ia?dl=0

author: helius
author_rank: Super Contributor
timestamp: January 19, 2016, 03:53:24 am
content: I had a spare minute so I looked in the mouser catalog to see what uses the Dale brand. It covers DC-DC converters (!), crystals, thermistors, resistors and networks, inductors, ferrites, and those plasma displays that you find on 1990s pinball machines.Out of all the components, only inductors are sold in values of .27 and 10 (microhenries). The marking matches your part:http://www.mouser.com/ds/2/427/imc1210-239765.pdfhttp://www.mouser.com/ds/2/427/isc1210-239905.pdf

author: awallin
author_rank: Frequent Contributor
timestamp: January 19, 2016, 07:04:41 am
content: Quote from: helius on January 19, 2016, 03:53:24 amGreat work! ThanksOn the output I actually measured a higher Vpp voltage after the inductor (.27) than before, so maybe the output-filter is designed to be (mildly) resonant at maybe 5- 10 MHz and then kill off high frequencies (the LMH6609 op-amps on the output have a bandwidth of 280MHz at Av = +2)

author: Shock
author_rank: Super Contributor
timestamp: January 19, 2016, 09:02:53 am
content: The Vishay Dale inductors seem to be labelled where the last digit is the tens, hundreds, thousands (etc) multiplier:100=10uH101=100uH102=1mH220=22uH