# Why is HP Pro module transmit power so low?

**URL:** <https://forums.digi.com/t/why-is-hp-pro-module-transmit-power-so-low/15060>\
**Category:** XBee - 802.15.4\
**Tags:** xbp9b-dpst-021-modul\
**Created:** [July 2, 2015, 8:45am UTC](https://forums.digi.com/t/why-is-hp-pro-module-transmit-power-so-low/15060 "2015-07-02T08:45:59Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![KJM](https://avatars.discourse-cdn.com/v4/letter/k/d26b3c/32.png) [@KJM](https://forums.digi.com/u/KJM)\
**Post date:** [July 2, 2015, 8:45am UTC](https://forums.digi.com/t/why-is-hp-pro-module-transmit-power-so-low/15060/1 "2015-07-02T08:45:59Z")

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So these XBP9B-DPST-021 modules are supposed to transmit 24dBm(0.25w) on power level 4 but when I do a range test between 2 modules (1m apart on the bench with 3dB antennas) using the XCTU software it reports -40dbm. Even with a 22dB fade margin ([http://www.digi.com/technology/rf-articles/frequency-comparison](http://www.digi.com/technology/rf-articles/frequency-comparison)) that corresponds to a transmit power of only 8dbm?

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**Author:** ![mvut](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.digi.com/mvut/32/31_2.png) [@mvut](https://forums.digi.com/u/mvut)\
**Post date:** [September 3, 2015, 3:58pm UTC](https://forums.digi.com/t/why-is-hp-pro-module-transmit-power-so-low/15060/2 "2015-09-03T15:58:26Z")

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How are you measuring this? Are you connecting a Spectrum analyzer to the radio and measuring the output power?