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Re: Noise Burst
#bitx40
Thanks Nick.
I will try that fix for the audio amp noise burst by muting the LM386 via pin7. Seems that there are two problems here. One is the audio noise burst which your fix addresses. The other is a burst of RF noise as charging capacitors in the microphone amp unbalance the balanced mixer at the start of a transmission. I have looked through the Wiki and there are lots of discussions about curing the audio burst, there is not much about fixing the RF noise burst. I have been thinking about putting a FET in the line from the mic amp to the balanced mixer to act as an isolating switch while the mic amp settles down. Use an RC time constant on the gate to delay turn on. Use some steering diodes so that the fet is on via the Rx line during receive, goes off when the Rx/Tx changeover occurs and comes on after a delay via the Tx line when in transmit. -Cheers- John VK6JAH |
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Re: W8TEE Power/SWR Sketch for Nano
Kees, i'm in the middle of a similar project.? 2 x AD8307's. The bridge uses a balun core. PCB is 50x50mm.?? No Nano etc.
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There is a neat SWR meter here using the AD8307's but with a Teensy. A very interesting SWR meter is here. It auto computes SWR using an LM555. I use this in my shack and it works well. Glenn vk3pe On Mon, Jun 25, 2018 at 06:57 pm, Kees T wrote:
OK, so |
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Re: W8TEE Power/SWR Sketch for Nano
Kees,
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Also, both your implementation and my implementation use the single ADC in the Arduino to read?the forward and reverse channels one at a time There will be a significant delay between readings. That delay will likely be too large for accurate SWR readings during SSB phone use, as per Dr Bill's objection of a month or two ago. However, those SWR readings should be accurate when transmitting CW. On Mon, Jun 25, 2018 at 09:54 pm, Jerry Gaffke wrote:
Regarding code for your Tandem Match SWR meter, |
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Re: KD8CEC - Nextion Display - IAN questions
Hello
i tried hexuploader and it does not work with nano arduino while it works with arduino uno. he puts as a message: avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_ReceiveMessage (): timeout . . .avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_ReceiveMessage (): timeout avrdude: stk500v2_getsync (): timeout communicating with program It does not matter, I will wait to have the source files. Thank you Michel |
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Re: W8TEE Power/SWR Sketch for Nano
Regarding code for your Tandem Match SWR meter,
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below is where my code was parked a couple months ago. It may or may not be stuff you can use. I haven't made time yet to fully implement it, though I'm pretty sure it's very close to good. I'm not planning to talk to anything like the OLED, will use the Raduino's LCD I am planning to just read Diz's diode detectors (with a slight dc bias current through the diodes) using the Nano's 10 bit ADC's.?? The code that converts the AD8307 log response to volts is unused and has been commented out. That 32 bit fixed point code works, but you are probably better of just using a floating point library as you won't be pressed for flash space. Jerry, KE7ER ########################### void lcd_printline(char n, char* s) { // n=0 for top, n=1 for bottom
? ? lcd.setCursor(0,n);
? ? lcd.print(s);
? ? for (n=strlen(s); n<16; n++)? lcd.print(" ");
}
?
// Print val as d digits with r digits after the decimal point
// Will print any leading zeros, if r==0 then no decimal point
void pnum(uint32_t val, uint8_t d, uint8_t r) {
? uint32_t? div=1;
? uint8_t? ?n;?
? for (n=1; n<d; n++)? div*=10;
? while (div>0) {
? ? if (d--==r)? ?lcd.print('.');
? ? lcd.print(val/div);
? ? val = val%div;
? ? div = div/10;
? }
? lcd.print(" ");
}
?
?
//? // Accurately transform AD8307 readings to RF voltage per post 48570
//? int32_t adcSlope32 = 5922023;? // 0x7FFFFFFF * (0.025/2.50 * (20*m.log10(32.0/31)) );? ?5922023.090616257
//? int32_t adcSlope2048 = 91056;? // 0x7FFFFFFF * (0.025/2.50 * (20*m.log10(2049.0/2048))) 91055.92544695384
//? uint32_t? adcRFmax = 100UL<<24;? ? ? ? ?// Calibrated Volts*2**24 rms of RF when adcRead at 0xFFFF
//? uint32_t findVoltsRF(uint16_t adcRead)? {? ? ? ? ? ? ? ?// adcRead is 16 bit ADC read of AD8307's output
//? ? uint32_t voltsRF = adcRFmax;? ? ? ? ? ? ? ? ? ? ? ? ? // At adcRead max of 0xFFFF, voltsRF is adcRFmax
//? ? int32_t? voltsADC = 0x7FFFFFFF - (adcRead<<15);? ? ? ?// Will subtract adcSlope from this till goes negative
//??
//? ? // The RF voltage falls by 1/32 for each drop in voltsADC by adcSlope32
//? ? while (voltsADC > 0)? {? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?// while (voltsADC > adcRead<<16)
//? ? ? voltsRF = voltsRF - (voltsRF>>5);? ? ? ? ? ?// voltsRF *= (31.0/32)
//? ? ? voltsADC = voltsADC - adcSlope32;
//? ? }
//? ? while (voltsADC < 0) {
//? ? ? voltsRF = voltsRF + (voltsRF>>11);
//? ? ? voltsADC = voltsADC + adcSlope32/65-52;
//? ? }
//? ? return(voltsRF);
//? }
// Read TandemMatch's 2 detectors, display forward and reverse power, swr
#define PSCALE? (1023L*1023/(25*10)) // ADC max of 1023 is 25 Watts, display Watts*10
void? show_swr() {? // SWR = (1+1.0*vr/vf)/(1-1.0*vr/vf);
? uint32_t vr, vf, swr; // Voltage squared proportional to power
? vf = analogRead(RF_FWD); // Peak RF volts from forward detector
? vr = analogRead(RF_REV); // Peak RF volts from reverse detector
? if (vr>=vf) swr=0; // If vr,vf illegal, force SWR to zero
? else {
? ? swr = (vr*1024)/vf; // Voltage ratio, 10 fractional bits
? ? swr = (1000*(1024+swr))/(1024-swr); // 1000*swr, nearly 10 fractional bits
? ? swr = (swr+50)/100; // 10*swr, rounded to nearest tenth
? ? if (swr>99) swr=99;? // Display a max SWR of 9.9
? }
? lcd.setCursor(0, 1); // Fill bottom LCD line, example:
? lcd.print('f'); pnum(vf*vf/PSCALE,3,1); // "f12.4 r03.1 s1.7"
? lcd.print('r'); pnum(vr*vf/PSCALE,3,1); // with fwd,rev power in watts
? lcd.print('s'); pnum(swr,2,1); // and swr to max of 9.9
}
?
On Mon, Jun 25, 2018 at 06:57 pm, Kees T wrote:
all I need now is some code...... |
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Re: W8TEE Power/SWR Sketch for Nano
Kees, I'm very interested in this too!
Please share more if you care too. I have a Kits an parts bridge and am incorporating that + Arduino + 2x8 LCD and a Pi tuner into a portable box for my ubitx...? I would love to use the?AD8307s? instead of diode detectors...? I am basing mine on:??and? Cheers. |
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Noise Burst
#bitx40
Any simple cure for the noise burst when you key the mic? There is a burst of noise from the speaker as well as a transmitted noise burst.
I see some suggest that the audio preamp? Q16 stays active after change-over to transmit due to residual charge in the supply line filter capacitor. Maybe there needs to be some sequencing of the Tx/Rx change over relays so the audio and antenna relay switches before the Tx/Rx power supply relay. Any suggestions? -- John VK6JAH |
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Re: Schematic . . . What Schematic . . mine?
Vince Vielhaber
I do the same thing. Mainly because I figure I won't remember it tomorrow!
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Vince. On 06/25/2018 11:00 PM, Ashhar Farhan wrote:
I always work with a lab notebook. Each time something is finished (as a --
Michigan VHF Corp. |
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Re: Schematic . . . What Schematic . . mine?
I always work with a lab notebook. Each time something is finished (as a module or rig), i pull out the notebook, draw out the circuit and note the readings and the performance. Then, move on. It is a habit worth cultivating. In six month time you will forget what you built and why. Building without a log book is filling a leaky bucket. - f On Tue, Jun 26, 2018 at 8:14 AM, <russkg0bk@...> wrote: Ty Jon. That's about what I was saying. |
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Re: Schematic . . . What Schematic . . mine?
Ty Jon. That's about what I was saying.
I'm I retired Broadcast Engineer an never kept a notepad (except hidden) Job security I guess. hi hi Just wanted those that were making mods to know. When some quits working. . . how do i get through this rats net to fond it. AGN TY 73 |
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Re: Bitx40 75KHz Spurious, How to solve it.
#bitx40
It shows scanning from 7.029Mhz to 7.049Mhz. That's only a 20khz
scan, not 50khz. And certainly not 50khz per division on the screen. The funny thing is that those unknowns are *increasing* in amplitude as you move away from the carrier instead of decreasing. I'm not sure what would generate this. Could these be products from overdriving the spectrum analyzer? tim ab0wr On Tue, 26 Jun 2018 04:30:56 +0530 "Raj vu2zap" <rajendrakumargg@...> wrote: Allard, |
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Re: Bitx40 75KHz Spurious, How to solve it.
#bitx40
Your carrier is at 7.029Mhz. Did you have your mode set to CW?
If so, you aren't seeing "spurious" mixer products at 75khz, 150khz, and 225khz. They are something else. Since their appear on both sides of the carrier I would have called them some kind of IMD products but I've never seen IMD go up as you move away from the carrier. If you were in CW mode, the mixers aren't used to generate the carrier frequency so you wouldn't see any spurious mixer products. There is something else going on here. Since harmonics are based on the carrier frequency the closest one you would have would be at 14.058Mhz. It wouldn't show up on your scan. It's very obvious that you are picking up something that is harmonically related at multiples on both sides of the carrier. I have to admit I'm not sure what your screen is telling me. It appears it is scanning from 7.029Mhz to 7.049Mhz. That's only 20khz total from screen-edge to screen-edge, not the 500khz that would be required to put your unknown 75khz away from the carrier. If your total scan is 20khz then your unknowns are at 3khz, 5khz, and 8khz. They wouldn't even be harmonically related. Are you sure your "50.0KHZ/" on the screen isn't the video bandwidth or something? tim ab0wr On Mon, 25 Jun 2018 00:09:11 -0700 jj1epe@... wrote: Hi! |
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Re: Understanding Spurious Emissions
Allison, What is the exact math of the spur? We can swap the two local oscillators around in software. That is,? the local oscillator can be injected on the other side. Would that help? - f On Tue, 26 Jun 2018, 03:09 ajparent1/KB1GMX, <kb1gmx@...> wrote: On Fri, Jun 22, 2018 at 10:38 pm, Ashhar Farhan wrote: |
Nick VK4PP
Don, ND6T
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