Very frustrating. The V2 boards have arrived in Melbourne but are "on hold" presumably for Covid19 reasons.
Glenn <vk3pe>


Regarding V2 PCB's and the TG, awesome!
73,
Robert, WA2T

After being on hold, my new "V2" panels have arrived.? These are slightly modified V1.0 versions to provide for a tracking generator option once software is fully developed for it.

Glenn
vk3pe

The V2.0 panels have been loaded and tested in the Tracking Gen mode. Very promising.? Note no shielding was fitted anywhere in this test. (with some small mods for chip selects, V1.0 panels should work too.)

Comparison with my Rigole on testing a junk box High Pass Filter look promising.?? The roll-off at the high end maybe due to the Si4342 module LPF filters which can be bypassed. Will look at that later but the concept is proven.? It uses 1 x control board (top of the panel and two x RF boards, so two panels are needed.

Many thanks to M0WID, WA2FZW & G3ZQC for software.

Glenn

Is the tracking generator able to also ( with appropriate firmware) be a useful stand-alone rf signal generator?

I had asked a question on the Homebrew (I think) group if any enterprising designer was interested in a Tinysa- type signal generator to complete the stable of this fantastic set of affordable gear. The tracking generator seems to be already half the device ( including an attenuator to adjust the output signal).

I do not think my design skills ( not to mention programming ability) ate up to it, even with a “starter for 10 board potentially available.

Steve L. G7PSZ

The tinySA I designed is able to act as a signal generator.
See here for the specs:?
--
HBTE Files section:?/g/HBTE/files
Erik, PD0EK

Yes, should be possible.? Note this is for a homebrew version based on ESP32 processor, not the tinySA developed by Erik/Hugen.

The firmware already allows use of the main SA RF connection as a signal generator.? The frequency range will depend on the low pass filter components installed, typically up to 200/250MHz but it should be possible to design for higher cut off, say up to 350MHz, we have not tested that yet.? Output level can be adjusted using the attenuator and varying drive strengths from the SI4432.

The tracking generator based on two SI4432 should be capable of the same performance, and indeed adding a signal generator facility for the TG is already on the ToDo list.? Note that the frequency resolution of the SI4432 tranceiver module limits the resolution of the output frequency.? With a nominal 434MHz IF, the resolution is 156Hz below 46MHz output and 312Hz above that.? Not sure if that is good enough for your needs.? The oscillator in the SI4432 modules can also drift badly - not so bad given the resolution available, but could be a problem in certain cases.

Also currently there are no modulation options programmed in the firmware, though again this is planned.? AM is likely to be fairly crude!

There are options to improve performance - a TCXO could be used for example, different tranceiver modules such as SI4468 are available with finer frequency resolution (14.3Hz), or a suitable low phase noise clock generator ic could be selected.

Dave M0WID

What kind of dynamic range are you seeing with the tracking generator add-on module?? One of the advantages of using the HP856x series spectrum analyzers with a HP8444 tracking generator was the LO tracking allowed a much greater dynamic range than a similar stepped sweep using a CW generator.

? A plot of a bandpass filter with 70dB or better skirts would be appreciated.

- Herb??

Here's a plot a 20M BPF I had in my junque box.?? Comparing "simpleSA" with a Rigole SA-TG. Same span (15MHz.)

The simple SA is not quite as good, but its pretty close for a cheap instrument.

EDIT:- the simpleSA top of screen is actual "0dB" point in this case for tracking.?? So you can compare BPF losses.

glenn
vk3pe

What kind of dynamic range are you seeing with the tracking generator add-on module?? One of the advantages of using the HP856x series spectrum analyzers with a HP8444 tracking generator was the LO tracking allowed a much greater dynamic range than a similar stepped sweep using a CW generator.
? A plot of a bandpass filter with 70dB or better skirts would be appreciated.
- Herb?

On Sun, Aug 30, 2020 at 07:22 PM, Glenn wrote:

Here's a plot a 20M BPF I had in my junque box.?? Comparing "simpleSA" with a Rigole SA-TG. Same span (15MHz.)

The simple SA is not quite as good, but its pretty close for a cheap instrument.

Glen,
? ?Thanks for the reply.? Considering the cost difference between the Rigol and the simpleSA, I think your hardware build is well worth the effort.? I am especially impressed by how smooth and noise free the tracking waveform is.

? ?I own Erik's tinySA and was looking into a similar tracking set-up with it.? Erik has suggested investing in an external amplifier and attenuator at the LO output to increase the dynamic range for tracking generator applications.? I wanted to see what you were achieving before investing in the additional components.

- Herb

开云体育

Thats a winner...