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Re: 10 turn pot question
That means the ground pin is not connected to the 10T pot. One end of the pot may be internally damaged.
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This happens when you connect the center and one end to the supply and ground. As you come towards ZERO the pot just burns out. Please note the pin connections are different - the center pin of a normal pot is the back most pin in the Bourne. I would recommend a new pot and careful of the connections. 73 Raj At 18-02-2017, you wrote:
My 40 with stock 10k pot works and I have several Q's. I get about 200 KHz tuning. |
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Re: Rarduino WAY off Freq ... there is more
Finally got some time to work on this. Checked ripple coming in, between 10-20 mV on the 12 V line coming in. Measured 5.08 V and 3.28 V on 5 and 3.3 rails, ac coupled on the scope seems clean. There is a traffic on SDA line whenever pot is moved. It stops when pot is moved to any of the ends and reading gets to the limit (6.99 or 7.50), or sometimes when . Wasn't able to scope 25 MHz crystal. Loaded Nano with the following code, from etherkit github readme page, slightly modified, see highlighted comments: /*--------------------------*/ #include <EEPROM.h> #include <Wire.h> #include <si5351.h> Si5351 si5351; /*-----------------------------*/ void setup() { ? // put your setup code here, to run once: ? Serial.begin(9600); ? si5351.init(SI5351_CRYSTAL_LOAD_8PF,25000000l,0); ? Serial.println("*Initiliazed Si5351\n"); ? si5351.set_freq(1000000000ULL, SI5351_CLK2); // 10 MHz on clock 2 ? si5351.set_freq(500000000ULL, SI5351_CLK1); ?// ?5 MHz on clock 1 ? si5351.set_freq(100000000ULL, SI5351_CLK0); ?// ?1 MHz on clock 0 ? delay(10); } /*-----------------------------*/ void loop() { ? // put your main code here, to run repeatedly: ? si5351.update_status(); ? Serial.print("SYS_INIT: "); ? Serial.print(si5351.dev_status.SYS_INIT); ? Serial.print(" ?LOL_A: "); ? Serial.print(si5351.dev_status.LOL_A); ? Serial.print(" ?LOL_B: "); ? Serial.print(si5351.dev_status.LOL_B); ? Serial.print(" ?LOS: "); ? Serial.print(si5351.dev_status.LOS); ? Serial.print(" ?REVID: "); ? Serial.println(si5351.dev_status.REVID); } /*----------------------*/ What I'm measuring is: 2.110 MHz on CLK2, 1.055 on CLK1, 211 kHz on CLK0. All three outputs are about 4.74 times lower than set in the sketch. And the same 740 us pauses every 38 ms, on all three outputs (almost) perfectly lined up with each other (couple of cycles difference). Then, I unsoldered Nano ( so, no returning to hfsigs, I guess, but I want to thank Ashhar for all the work he's doing :) and had a spare Arduino. Wired 3.3, GND, A4, and A5 from Arduino to the Raduino board (now without Nano) and got it going with the sketch above - results were the same as above. So, definitelly not a Nano problem. I'll be getting one of those Adafruit breakout boards with Si5351, but before that I'm going to try Adafruit library, hoping that it may resolve the issue. But, that will happen tomorrow ... Goran VE6GPO |
Mark
Raj vu2zap
Goran VE6GPO
Don, ND6T