FYI...

---------- Forwarded message --------- From: Rich Gopstein rich@ourowndomain.com Date: Sun, Feb 28, 2021, 5:04 PM Subject: Re: ax5043 RSSI calibration To: Burns Fisher (AMSAT) wb1fj@fisher.cc, Zach Metzinger < zmetzing@pobox.com>, Eric Skoog eric.n.skoog@gmail.com

And I just double checked the secondary ax5043 again - and it varied in the -97 to -90 range with a dummy load, but didn't go any lower than that.

Note that on my board, I don't have mmcx connectors, only coax soldered to the board with SMA connectors on the other end, so maybe that's the problem?

Rich

On Sun, Feb 28, 2021 at 4:51 PM Rich Gopstein rich@ourowndomain.com wrote:

Sorry - you're right - I just checked my notes again, and one of my two ax5043's did go down to -115 with a dummy load. The other only went down to -90 or so.

Rich

On Sun, Feb 28, 2021 at 4:50 PM Burns Fisher (AMSAT) wb1fj@fisher.cc wrote:

...

Hmm. Odd. With no signal being sent at all, I'm at -114 or so. Do you get that kind of value with no signal in the air?

Good to know it is pretty good though. And on the other end, we are unlikely to get a signal as strong as -27!

Thanks for checking!

73,

Burns Fisher, WB1FJ *AMSAT(R) Flight Software*

On Sun, Feb 28, 2021 at 4:44 PM Rich Gopstein rich@ourowndomain.com wrote:

...

Using the new "get rssi" command, I checked the calibration of the RSSI when driven with my HP signal generator tuned to the input frequency.

The reported values closely (within 2-3 dBm) matched the generated power between -90 dBm and -30 dBm. -27 dBm was the largest RSSI value reported by the ax5043 even with increasing input power.

One of the two ax5043s was able to go down to -97 dBm, the other one only went down to -90 dBm (more or less).

Rich