Roger,
Thanks for the idea. I already tried sending them an email a while ago for that exact request ! The phone is still ringing, nobody answered yet at the other end ;( But I should throw the fishing stick once again using my email address from the office, that would look more serious... I'll let you know.
In the meantime, I've conducted one more test tonight, with interesting but a little disappointing results. arrrrgg, I'm missing the knowledge and there may be something obvious I don't get. Maybe someone has the right batteries to fit my torch !
I've cut on end of a 36" long RG316. I soldered it to the PCB. I reinstalled the pcb in its case and made the cable going through a hole on the underside. Straight out the box I wrapped the cable 3 times around a Fair-Rite 61 material that has a 0.9" inside diameter. I connected this to another 12" premade cable then to the VNA just to give me some length. That is for sure, I took the time to calibrate OSL right before mounting all that. BTW the load has been done a 50 Ohm 0603 chip resistor at 0.1% accuracy spec (at 3$ a piece !!).
Picture 1 : Test setup (the same as all my other tests)
Picture 2 : Measurement in this condition (no matching network, only a 0 ohm resitor to pass through)
Picture 3 : Data from the VNA plotted in SimSmith,
Picture 4 : Expected reading (or close) after putting a 10nH in series.
Picture 5 : Actual reading I got after installing the inductor.
Every time I tried to correct/match the antenna it gave me horrible results like that. There must be something obvious I don't see.
At the end, I do not expect to achieve the 1.5 VSWR flat as in the datasheet. It is a personal project after all. But if I could at least match it down to 2, I would be more than happy. This module will be installed in my backyard and the receiver will be at less than 50 feet. It is more a matter of learning new things. The one thing I want to avoid though, is to make it work by pure luck without knowing why.
I'm searching for a needle in the haystack, can someone lend me a metal detector please !!
Nico
