Extending TX range

[Stephen DeVience]

Hi,

I'm using my RS-HFIQ with a 2m transverter, and using an input from 28-30 MHz I can get 144-146 MHz out. The transverter can go up to 148 MHz if I can extend the input to 32 MHz. Is there an easy way to change the firmware to allow that? From what I can tell, it looks like it would not be a problem for the physical filters, and that it's just a matter of software.

Thanks,

Stephen

N8URE

[all...@gmail.com]

Stephen

I am running HDSDR with my RS-HFIQ and also using 6, 2 and 70 cm transverters. I have no problem running the HDSDR from 28 - 32 MHz. I did this sometime ago and I honestly don't remember if I changed the firmware but, if I did, it was something really obvious in the source code. In any event, it works great!

WA8TOD

[Stephen DeVience]

Thanks, it's good to know it's possible. Right now, if I set it above 30 MHz there's no output. I can probably find it in the arduino code somewhere but I thought maybe someone knows offhand.

-Stephen

N8URE

[all...@gmail.com]

Stephen

I had a look at the source code. In version 3.2 there is this routine that sets the limits for the LO. Remember the LO operates at 4x actual frequency. So its range normally is 12,000,000 to 120,000,000 Hz for an operating range of 2 - 30 MHz. To extend the upper limit I think all I did was change 120,000,000 to 128,000,000. In my source code this was lines 87 - 94.

  // The LO frequency is also stored in EEPROM. We'll restore it and of the value isn't

  // between 12 000 000 and 120 000 000 then we'll reset it to 40 000 000. 

  // (4 times the operating frequency)

  LO_freq = readLong(5);

  if (LO_freq < 12000000 || LO_freq > 120000000) {

    LO_freq = 40000000;

    writeLong(5, LO_freq);

  }

WA8TOD

[WA2EUJ]

You are going to need to recompile the sketch. So you'll need the Arduino IDE installed on your computer and the RS-HFIQ sketch and associated libraries. 

Then change:

if (LO_freq > 11999999 && LO_freq < 120000001)

to:

if (LO_freq > 11999999 && LO_freq < 128000001)

But it seems like the SI5351 had something wonky at 120MHz but I think that the new libraries handles it no problem.

Jim.

[Stephen DeVience]

Thanks, I changed that and it looks to be working up to 32 MHz now.

-Stephen

N8URE