Ticket #495 (new defect)

Opened 19 months ago

TellStickNet RF performance

Reported by: juha juha <oh2nlt@…> Owned by:
Priority: major Milestone:
Component: other Version:
Keywords: Cc:
Blocked By: Blocking:
Platform: Windows Sensitive: no
Verified by Telldus: no

Description

I recently bought TellStickNet (Batch code 14409, Model TSNET). In my application I needed all available RF performance. I noticed that 433.92 nominal TX frequency is about 80kHz high (434.0MHz). This is so much that it already decrease receiver sensitivity. Deepper investigation revealed that either TX chip XTAL load capacitors do not match with the XTAL spec. Without knowing the XTAL spec I experimentally set the load capacitors. 33pF each gave exact 433.92 RF output.

Also noticed that output level is only about +4dBm measured directly from the antenna connector.

Attachments

IMG_5277.JPG Download (234.9 KB) - added by juha juha <oh2nlt@…> 19 months ago.
Original freq, spectra & power
IMG_5277_small.jpg Download (79.2 KB) - added by juha juha <oh2nlt@…> 19 months ago.
Original freq, spectra & power
IMG_5279.JPG Download (241.2 KB) - added by juha juha <oh2nlt@…> 19 months ago.
after XTAL cap adjustment, no modulation
IMG_5278.JPG Download (220.7 KB) - added by juha juha <oh2nlt@…> 19 months ago.

Change History

Changed 19 months ago by juha juha <oh2nlt@…>

Original freq, spectra & power

Changed 19 months ago by juha juha <oh2nlt@…>

Original freq, spectra & power

Changed 19 months ago by juha juha <oh2nlt@…>

after XTAL cap adjustment, no modulation

Changed 19 months ago by juha juha <oh2nlt@…>

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