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Showing content with the highest reputation on 05/03/2021 in all areas

  1. Brisket was much more tender than it looks.
    7 points
  2. Several years ago I changed all LEDs (only three per channel compared to 25 in the original DIY T2) in my modified T2 to LM336 2.5V, a voltage reference device in TO-92 case (I also changed resistor values to keep desired current of the CCS). Pros LED/BJT see Lefferts_LED_Used_as_Voltage_Reference_ED_Feb_15_1975.pdf. Pros LM336/BLT see Sources_101_P1.pdf and Sources_101_P2.pdf. Overall, at least in theory, I think LM336/BJT wins. My version of LM336 have operational temperature up to +70 degrees Celsius and I don’t think I exceed that.
    2 points
  3. I'm stuck inside working all day but at least I was able to arrange for the Chairman of the Board to come by and play a set.
    2 points
  4. Looks like the chips did not impact my order. Mine will be here in two weeks, about a month and a half earlier than I expected.
    1 point
  5. GR78xx and gr79xx are surface mount versions of the golden reference LV without the input or output smoothing capacitors. In general the golden reference LV come in dual (both positive and negative supplies on one pcb) or separate plus and minus pcbs. The gerbers can be found at: https://drive.google.com/drive/folders/0B_iJFfZStuVhSE5nOHBVdTByR1k the latest dual golden reference that I know about is goldenreference6D.zip this is marked on the pcb as version 0.45: the dual output board has provision for 25mm diameter input smoothing cap and optional output on led. https://drive.google.com/file/d/0B6JqIzEX9jZ0LTQ4ZG9HTDE2U0k/view?usp=sharing the individual rail pcbs are goldenreference6minus.zip and goldenreference6plus.zip: https://drive.google.com/file/d/0B6JqIzEX9jZ0ejFrM2lQZnFMa0U/view?usp=sharing https://drive.google.com/file/d/0B6JqIzEX9jZ0R1NpaDNuSzl4NHM/view?usp=sharing there is a goldenreference7plus.zip and minus but the pcb markings for them say 0.43 and do not have an option for a led showing the output is on, however the board allows for a larger diameter input smoothing cap at ~35mm diameter. https://drive.google.com/file/d/0B6JqIzEX9jZ0UFRaQzJSd1UwOTQ/view?usp=sharing and https://drive.google.com/file/d/0B6JqIzEX9jZ0YksyazZ0QXZ5djg/view?usp=sharing
    1 point
  6. Deck Dessert ( Lemon Mousse ) and proper Tea. Apropos from a friend who doesn't relate
    1 point
  7. Longish term modern DIY T2 reliability. I estimate its been used around 8+ hours (and more often than not 12 hours) a day almost every day since I built it. yesterday I took it apart for cleaning. I noticed all four 140K resistor strings connected to the voltage reference in the virtual batteries where somewhat discoloured.... hmmm... on further testing I found the D24 led on both channels did not light up at all not even dimly. :-(. but the amp seemed to work and sounded good. (on the left is a brand new resistor from the same pack as the 140Ks I removed from the virtual batteries.) I checked also psu voltages - good. I measured the voltage across the D24 led- about 1.4V. When the amp was originally built these leds definitely glowed as strongly as the others. All the leds where tested before soldering in and were from the same bag I even hand matched them just for overkill. The D24 leds are part of the circuit that provides base voltage and current to transistors that provide feed into the virtual batteries. I checked the virtual batteries - all were 741V on startup and the adjustment pots could adjust the output. So the batteries look good despite the slightly cooked resistors. I removed the voltage references and tested them in a glden reference LV - all good. The discoloured resistors can be explained by the fact they have about 0.423W flowing through them excluding base current draw from the 2 transistors and are on the underside of the board with little airflow - maybe1W would be better or some airflow holes in the pcb, or mount them to the topside of the pcb. So I decided to de-solder the 140K resistors for measuring and the 140K resistors have drifted slightly but all measure within 141.5K. So a little cooked but probably not the case of the problem. But why are the leds not lighting.... Looking at the circuit diagram the D24 leds should get about 0.5mA current excluding any draw from the bases of the transistors. (560V / (560K *2 resistor string to ground). I used the exact SAME leds for the other positions and it also looks like those leds get about 0.5mA excluding base transistor draw and they glow nice and bright. I de-soldered the leds and tested the D24 resistor string to ground. They spot on resistance and have not been damaged or drifted and so should provide 0.5mA current draw through the led. However the desoldered D24 leds would not glow at all with diode check on my brymen BM869s multimeter but do pass current and are not open or shorted. I tried my keithley 2015 in diode check mode (it has adjustable test current) and got absolutely no glow at 10 or 100micro amp but did get strong glow at 1mA - same situation on both D24 leds. I tested my remaining leds from the same bag and they glow on the brymen admittedly fairly dimly, and glow on the keithley at 100 micro amp again dimly but visibly. (I did test all of them on the brymen before soldering into the amp). So the leds in D24 have degraded over time . I used the same leds in the other places in the amp and they are all fine. This would explain why the batteries are working but the leds are off.... So the plan is to do some more testing on the leds and replace them with another model. But what's causing the leds to degrade in brightness on the -560V rail when the others have not? any ideas? regards and and I apologise for the long winded post James Update: I replaced the D24 leds... they now light brightly with a voltage drop across them of about 1.7V. I replaced the resistor strings with the same resistors but now placed on the top of the pcb, raised from the pcb by about 1cm. After a ten minutes with no lid on the amp the resistors reach 65C on the top and 71C on the sides. So its easy to see how on the underside of the pcb with the lid on they could reach temperatures which could cause discolouration.
    1 point
  8. Run the Jewels - RTJ2 Today requires some full-rage hip hop.
    1 point
  9. Is Jeff gonna get one of those 3d printers?
    1 point
  10. Greg gifted us a beautiful, original, one of a kind knife for BBQ and other meat related duties. These pics don't do it justice but I'll try again in the daylight. Thank you for your thoughtless and kudos on your artistry! The Meat Machete Rulez!
    1 point
  11. Franklin BBQ method. Two hours rubbed and naked at 275 then about the same spritzed, sauced and wrapped. Turned out well -- the family killed two racks and asked if there was any more.
    1 point
  12. Have had a 10 lb rib roast in the smoker at 150 for 5-1/2 hours so far. Will pull at 125-ish, rest a 1/2 hour then nuke in the big gas grill for a few minutes at 750+ to get a nice crust.
    1 point
  13. Did a bone-in turkey breast on the Traeger today because life required more turkey. I cooked it just a little long (was not at home when the temp probe fired) and it was still moist and juicy on the inside.
    1 point
  14. I'm sorry, what is that in Freedom Units please?
    1 point
  15. All of those delicious posts from Nate and Stretch have made me jealous so I took a 2.5 kilo brisket and did a quick 8.5 hour roast. We shall see if it is tender yet. At least the Booker wine is setting the stage for something epic.
    1 point
  16. Ho. Lee. Shit. I'm hella jealous of your pending gyro. Not that my dinner was lacking.
    1 point
  17. Rotisserie leg of lamb. Going to chop up and eat in pitas with tzatziki and Greek salad.
    1 point
  18. Fun story. Any racing post pandemic has been such a treat. I did not appreciate how much I needed it until the first pass... HD
    1 point
  19. R.I.P. 3 time Indy 500 winner Bobby Unser... he was 87...
    0 points
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